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Sample records for joaquin basin california

  1. Cenozoic evolution of San Joaquin basin, California

    SciTech Connect

    Bartow, J.A.

    1988-03-01

    The Neogene San Joaquin basin in the southern part of the 700-km long Great Valley of California is a successor to a late Mesozoic and earliest Tertiary forearc basin. The transition from forearc basin to the more restricted Neogene marine basin occurred principally during the Paleogene as the plate tectonic setting changed from oblique convergence to normal convergence, and finally to the initiation of tangential (transform) movement near the end of the Oligocene. Regional-scale tectonic events that affected the basin include: (1) clockwise rotation of the southernmost Sierra Nevada, and large-scale en echelon folding in the southern Diablo Range, both perhaps related to Late Cretaceous and early Tertiary right slip on the proto-San-Andreas fault; (2) regional uplift of southern California in the Oligocene that resulted from the subduction of the Pacific-Farallon spreading ridge: (3) extensional tectonism in the Basin and Range province, particularly in the Miocene; (4) wrench tectonism adjacent to the San Andreas fault in the Neogene; (5) northeastward emplacement of a wedge of the Franciscan complex at the west side of the Sierran block, with associated deep-seated thrusting in the late Cenozoic; and (6) the accelerated uplift of the Sierra Nevada beginning in the late Miocene. Neogene basin history was controlled principally by the tectonic effects of the northwestward migration of the Mendocino triple junction along the California continental margin and by the subsequent wrench tectonism associated with the San Andreas fault system. East-west compression in the basin, resulting from extension in the Basin and Range province was an important contributing factor to crustal shortening at the west side of the valley. Analysis of the sedimentary history of the basin, which was controlled to some extent by eustatic sea level change, enables reconstruction of the basin paleogeography through the Cenozoic.

  2. Paleohydrogeology of the San Joaquin basin, California

    USGS Publications Warehouse

    Wilson, A.M.; Garven, G.; Boles, J.R.

    1999-01-01

    Mass transport can have a significant effect on chemical diagenetic processes in sedimentary basins. This paper presents results from the first part of a study that was designed to explore the role of an evolving hydrodynamic system in driving mass transport and chemical diagenesis, using the San Joaquin basin of California as a field area. We use coupled hydrogeologic models to establish the paleohydrogeology, thermal history, and behavior of nonreactive solutes in the basin. These models rely on extensive geological information and account for variable-density fluid flow, heat transport, solute transport, tectonic uplift, sediment compaction, and clay dehydration. In our numerical simulations, tectonic uplift and ocean regression led to large-scale changes in fluid flow and composition by strengthening topography-driven fluid flow and allowing deep influx of fresh ground water in the San Joaquin basin. Sediment compaction due to rapid deposition created moderate overpressures, leading to upward flow from depth. The unusual distribution of salinity in the basin reflects influx of fresh ground water to depths of as much as 2 km and dilution of saline fluids by dehydration reactions at depths greater than ???2.5 km. Simulations projecting the future salinity of the basin show marine salinities persisting for more than 10 m.y. after ocean regression. Results also show a change from topography-to compaction-driven flow in the Stevens Sandstone at ca. 5 Ma that coincides with an observed change in the diagenetic sequence. Results of this investigation provide a framework for future hydrologic research exploring the link between fluid flow and diagenesis.

  3. Paleohydrogeology of the San Joaquin basin, California

    SciTech Connect

    Wilson, A.M.; Garven, G.; Boles, J.R.

    1999-03-01

    Mass transport can have a significant effect on chemical diagenetic processes in sedimentary basins. This paper presents results from the first part of a study that was designed to explore the role of an evolving hydrodynamic system in driving mass transport and chemical diagenesis, using the San Joaquin basin of California as a field area. The authors use coupled hydrogeologic models to establish the paleohydrogeology, thermal history, and behavior of nonreactive solutes in the basin. These models rely on extensive geological information and account for variable-density fluid flow, heat transport, solute transport, tectonic uplift, sediment compaction, and clay dehydration. In the numerical simulations, tectonic uplift and ocean regression led to large-scale changes in fluid flow and composition by strengthening topography-driven fluid flow and allowing deep influx of fresh ground water in the San Joaquin basin. Sediment compaction due to rapid deposition created moderate overpressures, leading to upward flow from depth. The unusual distribution of salinity in the basin reflects influx of fresh ground water to depths of as much as 2 km and dilution of saline fluids by dehydration reactions at depths greater than {approximately}2.5 km. Simulations projecting the future salinity of the basin show marine salinities persisting for more than 10 m.y. after ocean regression. Results also show a change from topography- to compaction-driven flow in the Stevens Sandstone at ca. 5 Ma that coincides with an observed change in the diagenetic sequence. Results of this investigation provide a framework for future hydrologic research exploring the link between fluid flow and diagenesis.

  4. Environmental setting of the San Joaquin-Tulare basins, California

    USGS Publications Warehouse

    Gronberg, JoAnn A.; Dubrovsky, Neil M.; Kratzer, Charles R.; Domagalski, Joseph L.; Brown, Larry R.; Burow, Karen R.

    1998-01-01

    The National Water-Quality Assessment Program for the San Joaquin- Tulare Basins began in 1991 to study the effects of natural and anthropogenic influences on the quality of ground water, surface water, biology, and ecology. The San Joaquin-Tulare Basins study unit, which covers approximately 31,200 square miles in central California, is made up of the San Joaquin Valley, the eastern slope of the Coast Ranges to the west, and the western slope of the Sierra Nevada to the east. The sediments of the San Joaquin Valley can be divided into alluvial fans and basin deposits. The San Joaquin River receives water from tributaries draining the Sierra Nevada and Coast Ranges, and except for streams discharging directly to the Sacramento-San Joaquin Delta, is the only surface- water outlet from the study unit. The surface-water hydrology of the San Joaquin-Tulare Basins study unit has been significantly modified by development of water resources. Almost every major river entering the valley from the Sierra Nevada has one or more reservoirs. Almost every tributary and drainage into the San Joaquin River has been altered by a network of canals, drains, and wasteways. The Sierra Nevada is predominantly forested, and the Coast Ranges and the foothills of the Sierra Nevada are predominately rangeland. The San Joaquin Valley is dominated by agriculture, which utilized approximately 14.7 million acre-feet of water and 597 million pounds active ingredient of nitrogen and phosphorus fertilizers in 1990, and 88 million pounds active ingredient of pesticides in 1991. In addition, the livestock industry contributed 318 million pounds active ingredient of nitrogen and phosphorus from manure in 1987. This report provides the background information to assess the influence of these and other factors on water quality and to provide the foundation for the design and interpretation of all spatial data. These characterizations provide a basis for comparing the influences of human activities

  5. Transport of diazinon in the San Joaquin River Basin, California

    USGS Publications Warehouse

    Kratzer, C.R.

    1999-01-01

    Most of the application of the organophosphate insecticide diazinon in the San Joaquin River Basin occurs in winter to control wood-boring insects in dormant almond orchards. A federal-state collaborative study found that diazinon accounted for most of the observed toxicity of San Joaquin River water in February 1993. Previous studies focused mainly on west-side inputs to the San Joaquin River. In this 1994 study, the three major east-side tributaries to the San Joaquin River - the Merced, Tuolumne, and Stanislaus rivers - and a downstream site on the San Joaquin River were sampled throughout the hydrographs of a late January and an early February storm. In both storms, the Tuolumne River had the highest concentrations of diazinon and transported the largest load of the three tributaries. The Stanislaus River was a small source in both storms. On the basis of previous storm sampling and estimated travel times, ephemeral west-side creeks probably were the main diazinon source early in the storms, whereas the Tuolumne and Merced rivers and east-side drainages directly to the San Joaquin River were the main sources later. Although 74 percent of diazinon transport in the San Joaquin River during 1991-1993 occurred in January and February, transport during each of the two 1994 storms was only 0.05 percent of the amount applied during preceding dry periods. Nevertheless, some of the diazinon concentrations in the San Joaquin River during the January storm exceeded 0.35 ??g/L, a concentration shown to be acutely toxic to water fleas. On the basis of this study and previous studies, diazinon concentrations and streamflow are highly variable during January and February storms, and frequent sampling is required to evaluate transport in the San Joaquin River Basin.

  6. Transport of diazinon in the San Joaquin River basin, California

    USGS Publications Warehouse

    Kratzer, Charles R.

    1997-01-01

    Most of the application of the organophosphate insecticide diazinon in the San Joaquin River Basin occurs in winter to control wood boring insects in dormant almond orchards. A federal-state collaborative study found that diazinon accounted for most of the observed toxicity of San Joaquin River water to water fleas in February 1993. Previous studies focussed mainly on west-side inputs to the San Joaquin River. In this 1994 study, the three major east-side tributaries to the San Joaquin River, the Merced, Tuolumne, and Stanislaus Rivers, and a downstream site on the San Joaquin River were sampled throughout the hydrographs of a late January and an early February storm. In both storms, the Tuolumne River had the highest concentrations of diazinon and transported the largest load of the three tributaries. The Stanislaus River was a small source in both storms. On the basis of previous storm sampling and estimated traveltimes, ephemeral west-side creeks were probably the main diazinon source early in the storms, while the Tuolumne and Merced Rivers and east-side drainage directly to the San Joaquin River were the main sources later. Although 74 percent of diazinon transport in the San Joaquin River during 199193 occurred in January and February, transport during each of the two 1994 storms was only 0.05 percent of the amount applied during preceeding dry periods. Nevertheless, some of the diazinon concentrations in the San Joaquin River during the January storm exceeded 0.35 micrograms per liter, a concentration shown to be acutely toxic to water fleas. Diazinon concentrations were highly variable during the storms and frequent sampling was required to adequately describe the concentration curves and to estimate loads.

  7. Miocene temblor formation and related basin evolution, southwestern San Joaquin Basin, California

    SciTech Connect

    Gillespie, B.W.

    1988-01-01

    The southwestern San Joaquin basin is an area of great importance for the energy industry and academic basin analysts. Understanding basin evolution is a key concern for explorationists in this essentially pristine province. Temblor Formatio is exposed in an east-west-trending belt that comprises the north flank of the San Emigdio Mountains. Field and subsurface evidence were used to elucidate the geology, depositional environments, and age of the Temblor Formation. The formation represents sand-rich borderland sedimentation in a predominantly deep-marine setting. Deposition of Temblor clastics reflects deformation due to the impingement of the Farallon Pacific ridge with the California-North American plate margin during the middle Oliocene. As a result, severe uplift along the margins of the southern San Joaquin basin, reinforced by a lowstand of global seal level, caused large volumes of coarse, immature clastics to be shed into the rapidly subsiding deep-marine depocenter. Deposition of the Temblor was thus concurrent with the transformation from a convergent margin tectonic regime to one of dextral strike-slip. This transformation was marked by an episode of transform-extension indicated by volcanism, rapid subsidence, and marine transgression during the early Miocene. The Maricopa trough or oceanic connection from the San Joaquin basin to the Pacific Ocean is inferred to have existed between Recruit Pass and Maricopa. The age of the Temblor Formation is late Oligocene to early Miocene. Petroleum production is limited to the upper member in small oil fields flanking the northern Sam Emigdio Mountains.

  8. Early Eocene uplift of southernmost San Joaquin basin, California

    SciTech Connect

    Reid, S.A.; Cox, B.F.

    1989-04-01

    Stratigraphic studies in the southern San Joaquin basin and in the El Paso Mountains of the southwestern Great Basin corroborate a hypothesized early Eocene regional uplift event. Eocene uplift and erosion of the southernmost San Joaquin basin south of Bakersfield were recently proposed because an early Paleogene fluviodeltaic sequence in the El Paso Mountains (Goler Formation) apparently had no seaward counterpart to the southwest. New microfossil data (coccoliths) indicate that marine deposits near the top of the Goler Formation are uppermost Paleocene (nannofossil zone CP8) rather than lower Eocene, as reported previously. These data (1) confirm that the oldest known Tertiary strata south of Bakersfield (Eocene Tejon Formation) are younger than the uppermost Goler Formation and (2) seem to restrict uplift to the earliest Eocene. The authors propose that the uppermost Cretaceous and Paleocene deposits were eroded and the Mushrush trough was cut and filled mainly in response to earliest Eocene uplift. The uplift was transverse to the northwest-trending forearc basin. Thus, it was distinct from late early Eocene (pre-Comengine Formation) regional tilting and uplift, which produced northwest-trending structures. Early Eocene uplift probably played only a minor role in the southward termination of pre-Maastrichtian parts of the forearc basin, which they instead attribute to massive uplift of the southernmost Sierra Nevada during the early(.) Late Cretaceous.

  9. Biofacies zonation of middle Miocene benthic foraminifera, southeastern San Joaquin basin, California

    SciTech Connect

    Olson, H.C.

    1987-05-01

    The quantitative distribution of benthic foraminifera across the middle Miocene margin of the southeastern San Joaquin basin constitutes a useful tool in applying benthic biofacies zonation to the interpretation of marine paleoenvironments. A middle Miocene transect (near the Luisian/Relizian boundary) was completed across the margin of the southeastern San Joaquin basin near Bakersfild, California. Surface and subsurface fauna encompass strandline through bathyal environments. Quantitative analyses of these fauna result in a useful biofacies zonation for the middle Miocene which can be applied to the interpretation of middle Miocene paleobathymetric and paleogeographic reconstructions, basin analysis, and subsidence histories of the San Joaquin basin. In addition, these data suggest that vertical faunal migration of continental slope fauna has occurred between the middle Miocene and Recent. During the early and middle Miocene, marine temperatures were warmer than today and lower latitudinal gradients prevailed. Stepwise climatic cooling since the middle Miocene has been accompanied by the latitudinal adjustment of surface isotherms, strengthening of the permanent thermocline, and the associated migration of temperature-sensitive planktonic and benthic biofacies. Sedimentologic and seismic evidence in the southeastern San Joaquin basin suggests that present-day lower bathyal biofacies may have been at shallower depths during the middle Miocene. Such migrations would have a significant impact on paleoenvironmental interpretations. Middle Miocene faunal transects from the southeastern San Joaquin basin are compared with equivalent Holocene transects from the eastern Pacific, and differences are discussed in light of this proposal.

  10. Diazinon and chlorpyrifos loads in the San Joaquin River basin, California, January and February 2000

    USGS Publications Warehouse

    Kratzer, Charles R.; Zamora, Celia; Knifong, Donna L.

    2002-01-01

    The application of diazinon and chlorpyrifos on dormant orchards in 2000 in the San Joaquin River Basin was less than 21 percent of application in 1993 and 1994. A total of 13 sites were sampled weekly during nonstorm periods and more frequently during two storm periods. The sites included five major river and eight minor tributary sites. The highest concentrations of diazinon and chlorpyrifos occurred during the storm periods. Four samples from major river sites (Tuolumne River and two San Joaquin River sites) had diazinon concentrations greater than 0.08 microgram per liter, the concentration being considered by the state of California as its criterion maximum concentration for the protection of aquatic habitat. One sample from a major river site (San Joaquin River) exceeded the equivalent State guideline of 0.02 microgram per liter for chlorpyrifos. At the eight minor tributary sites, 24 samples exceeded the diazinon guideline and four samples exceeded the chlorpyrifos guideline. The total diazinon load in the San Joaquin River near Vernalis during January and February 2000 was 19.6 pounds active ingredient; of this, 8.17 pounds active ingredient was transported during two storms. In 1994, 27.4 pounds active ingredient was transported during two storms. The total chlorpyrifos load in the San Joaquin River near Vernalis during January and February 2000 was 5.68 pounds active ingredient; of this, 2.17 pounds active ingredient was transported during the two storms. During the frequently sampled February 2000 storm, the main sources of diazinon in the San Joaquin River Basin were the San Joaquin River near Stevinson Basin (25 percent), Tuolumne River Basin (14 percent), and the Stanislaus River Basin (10 percent). The main sources of chlorpyrifos in the San Joaquin River Basin were the San Joaquin River near Stevinson Basin (17 percent), Tuolumne River Basin (13 percent), and the Merced River Basin (11 percent). The total January and February diazinon load in the

  11. Middle Cenozoic depositional, tectonic, and sea level history of southern San Joaquin basin, California

    SciTech Connect

    Decelles, P.G.

    1988-11-01

    As a prolific producer of hydrocarbons, the San Joaquin basin in south-central California has been the subject of geological research since the late nineteenth century. Much of this research has focused on the subsurface Eocene to lower Miocene succession because of its attractive reservoir potential. Although seismic and well-log data are available in profuse quantities, the complex sedimentary architecture of the basin fill, the application of local and inconsistent stratigraphic nomenclature, and the inherent limitations of subsurface data have led to much confusion concerning the middle Cenozoic history of the basin. This paper presents a sedimentological analysis of the depositional systems in the Eocene to lower Miocene strata of the San Emigdio and Tehachapi Mountains. The various depositional systems are considered within the contexts of encompassing depositional sequences to reconstruct the middle Cenozoic depositional, tectonic, and sea level history of the southern San Joaquin basin. 14 figures, 1 table.

  12. Reservoir geology of Landslide field, southern San Joaquin basin, California

    SciTech Connect

    Carr, T.R.; Tucker, R.D.; Singleton, M.T. )

    1991-02-01

    The Landslide field, which is located on the southern margin of the San Joaquin basin, was discovered in 1985 and consists of 13 producers and six injectors. Cumulative production as of mid-1990 was approximately 10 million bbl of oil with an average daily production of 4700 BOPD. Production is from a series of late Miocene turbidite sands (Stevens Sand) that were deposited as a small constructional submarine fan (less than 2 mi in diameter). Based on interpretation of wireline logs and engineering data, deposition of the fan and of individual lobes within the fan was strongly influenced by preexisting paleotopography and small syndepositional slump features. Based on mapping of individual depositional units and stratigraphic dipmeter analysis, transport direction of the sand was to the north-north across these paleotopographic breaks in slope. Dipmeter data and pressure data from individual sands are especially useful for recognition and mapping of individual flow units between well bores. Detailed engineering, geophysical and geological studies have increased our understanding of the dimensions, continuity, geometry, and inherent reservoir properties of the individual flow units within the reservoir. Based on the results of these studies a series of water isolation workovers and extension wells were proposed and successfully undertaken. This work has increased recoverable reserves and arrested the rapid production decline.

  13. Assessment of remaining recoverable oil in selected major oil fields of the San Joaquin Basin, California

    USGS Publications Warehouse

    Tennyson, Marilyn E.; Cook, Troy A.; Charpentier, Ronald R.; Gautier, Donald L.; Klett, Timothy R.; Verma, Mahendra K.; Ryder, Robert T.; Attanasi, E.D.; Freeman, P.A.; Le, Phoung A.

    2012-01-01

    The U.S. Geological Survey (USGS) recently completed an estimate of volumes of technically recoverable, conventional oil that could eventually be added to reserves in nine selected major oil fields in the San Joaquin Basin in central California. The mean total volume of potential oil reserves that might be added in the nine fields using improved oil-recovery technologies was estimated to be about 6.5 billion barrels of oil.

  14. California: San Joaquin Valley

    Atmospheric Science Data Center

    2014-05-15

    article title:  Fog and Haze in California's San Joaquin Valley   ... is noted for its hazy overcasts and a low, thick ground fog known as the Tule. Owing to the effects of the atmosphere on reflected ... as the angle of view changes. An area of thick, white fog in the San Joaquin Valley is visible in all three of the images. However, ...

  15. Assessing the Carbon Sequestration Potential within the San Joaquin Basin, California

    NASA Astrophysics Data System (ADS)

    Drake, R. M.; Brennan, S.

    2012-12-01

    The United States Geological Survey (USGS) was directed by the 2007 Energy Independence and Security Act (Public Law 110-140) to assess the potential geologic storage resources for carbon dioxide (CO2) within the United States. Utilizing its probabilistic methodology for a national CO2 sequestration assessment, the USGS has assessed the storage potential of Cretaceous and Tertiary formations within the San Joaquin Basin, California. The basic unit of assessment for the USGS methodology is the Storage Assessment Unit (SAU), which consists of a storage formation and an overlying regional seal formation. The SAUs are defined by geologic criteria that include rock properties, formation depth, and regional extents of the storage and seal formations. The methodology requires that the storage formation be at depths from 3,000-13,000 ft below ground surface. This minimum required depth ensures that CO2 will be in a supercritical phase. Within the San Joaquin Basin a significant portion of the Cretaceous to Tertiary section (such as the Tertiary Temblor Sandstone) fits within this depth interval. However, where rock properties indicate that CO2 could be stored at depths greater than 13,000 ft, a separate deep SAU is assessed. The areal extent of the storage formation and overlying seal are required to be continuous and regional in extent. Within the San Joaquin Basin, there are thick, laterally extensive, marine shales, (Kreyenhagen and Monterey Shales) which could inhibit CO2 flow to superjacent strata. In some cases, the stratigraphy includes the potential for multiple or stacked seals. During this assessment the seal was evaluated for leakage potential and a minimum seal thickness of about 75 ft was defined. This minimum seal thickness must exist over the extent of the storage formation that is to be included in the SAU. A final consideration is the salinity of the water within the pore space of the storage formation. Based on available salinity data and geologic models

  16. Sequence stratigraphy of a Pliocene delta complex deposited in an active margin setting, Etchegoin and San Joaquin gas sands, San Joaquin basin, California

    SciTech Connect

    Steward, D.C.

    1996-12-31

    Prolific gas sands of the Pliocene Etchegoin and San Joaquin formations of the southern San Joaquin basin, California, are part of a 1300-m thick succession of deltaic sediments that record the final regression of the Pacific Ocean from a tectonically active, restricted basin associated with the California transform margin. Individual field studies, lacking a regional framework and based primarily on electric log data, correlate these gas sands to the extent that individual sands maintain the same stratigraphic level within the succession. However, a high-resolution sequence stratigraphic framework, constructed from recent 3D-seismic data and detailed well log correlations on the Bakersfield Arch area of the basin, indicates that the Pliocene succession is part of a south/southwest prograding delta complex. Therefore, sands climb up-section in the landward direction and grade laterally from deep-water to shallow-water facies. Because lithofacies boundaries cross chronostratigraphic surfaces, previous interpretations of the reservoir architecture are inaccurate. This model increases predictability of reservoir facies by constraining lithofacies mapping and enables interpretation of the effects on deposition of the integrated and inter-related controls of tectonics, eustatic sea-level change, and sediment supply. With this understanding, a well-defined model of the stratal architecture of the Pliocene succession of the southern San Joaquin basin is now possible.

  17. Sequence stratigraphy of a Pliocene delta complex deposited in an active margin setting, Etchegoin and San Joaquin gas sands, San Joaquin basin, California

    SciTech Connect

    Steward, D.C. )

    1996-01-01

    Prolific gas sands of the Pliocene Etchegoin and San Joaquin formations of the southern San Joaquin basin, California, are part of a 1300-m thick succession of deltaic sediments that record the final regression of the Pacific Ocean from a tectonically active, restricted basin associated with the California transform margin. Individual field studies, lacking a regional framework and based primarily on electric log data, correlate these gas sands to the extent that individual sands maintain the same stratigraphic level within the succession. However, a high-resolution sequence stratigraphic framework, constructed from recent 3D-seismic data and detailed well log correlations on the Bakersfield Arch area of the basin, indicates that the Pliocene succession is part of a south/southwest prograding delta complex. Therefore, sands climb up-section in the landward direction and grade laterally from deep-water to shallow-water facies. Because lithofacies boundaries cross chronostratigraphic surfaces, previous interpretations of the reservoir architecture are inaccurate. This model increases predictability of reservoir facies by constraining lithofacies mapping and enables interpretation of the effects on deposition of the integrated and inter-related controls of tectonics, eustatic sea-level change, and sediment supply. With this understanding, a well-defined model of the stratal architecture of the Pliocene succession of the southern San Joaquin basin is now possible.

  18. Real-time management of water quality in the San Joaquin River Basin, California.

    SciTech Connect

    Quinn, N.W.T.; Karkoski, J.

    1997-09-01

    In the San Joaquin River Basin, California, a realtime water quality forecasting model was developed to help improve the management of saline agricultural and wetland drainage to meet water quality objectives. Predicted salt loads from the water quality forecasting model, SJRIODAY, were consistently within +- 11 percent of actual, within +- 14 percent for seven-day forecasts, and with in +- 26 percent for 14-day forecasts for the 16-month trial period. When the 48 days dominated by rainfall/runoff events were eliminated from the data set, the error bar decreased to +- 9 percent for the model and +- 11 percent and +- 17 percent for the seven-day and 14-day forecasts, respectively. Constraints on the use of the model for salinity management on the San Joaquin River include the number of entities that control or influence water quality and the lack of a centralized authority to direct their activities. The lack of real-time monitoring sensors for other primary constituents of concern, such as selenium and boron, limits the application of the model to salinity at the present time. A case study describes wetland drainage releases scheduled to coincide with high river flows and significant river assimilative capacity for salt loads.

  19. Evolution of the Southern San Joaquin Basin and mid-Tertiary "transitional" tectonics, central California

    NASA Astrophysics Data System (ADS)

    Goodman, Emery D.; Malin, Peter E.

    1992-06-01

    A Cenozoic tectonic and sedimentary history is proposed for the Southern San Joaquin Basin (SSJB) and Tehachapi Mountains that evolved adjacent to the plate margin off central California. Seismic reflection, borehole, field, biostratigraphic, and paleomagnetic data are integrated into geologic and fault structure maps, cross sections, and geohistory plots and are analyzed with previous work in the region to develop a model relating the sequence, timing, and distribution of complex, tectonically linked events. The largely buried structures and strata in the SSJB preserve an unusually complete record of the mid-Tertiary transition from convergent to transform plate boundary as well as the regional transition to contraction during the Pliocene. Significant structural relief, existing across both extensional and contractile features, is preserved in the subsurface and an active fold-thrust belt propagates basinward along the margin of the U-shaped Tejon embayment The Cenozoic evolution of the SSJB reflects the regional deformation of central California as different tectonic events followed each other along the adjacent North American plate margin. Five Oligocene-Miocene basin phases are identified in the SSJB: (1) late Oligocene/early Miocene extensional subsidence, with high- and low-angle normal faulting, accompanied by volcanism and deposition of coarse syntectonic conglomerates; (2) middle Miocene uplift; (3) later mid-Miocene transtensional subsidence to lower bathyal depths; (4) alternating subsidence and uplift until the late Miocene; and (5) flexural subsidence due to Pliocene to Recent contraction. Reconstructions of mid-Tertiary California place the southern San Joaquin/Tehachapi extensional terrane as a paleotectonic block located between the Western Mojave terrane (then to the east) and the Western California terrane (then to the south and west). Regional extension occurred during a long transition period between convergent and transform boundaries along

  20. Occurrence and distribution of dissolved pesticides in the San Joaquin River basin, California

    USGS Publications Warehouse

    Panshin, Sandra Yvonne; Dubrovsky, Neil M.; Gronberg, JoAnn M.; Domagalski, Joseph L.

    1998-01-01

    The effects of pesticide application, hydrology, and chemical and physical properties on the occurrence of pesticides in surface water in the San Joaquin River Basin, California, were examined. The study of pesticide occurrence in the highly agricultural San Joaquin?Tulare Basins is part of the National Water-Quality Assessment Program of the U.S. Geological Survey. One hundred forty-three water samples were collected throughout 1993 from sites on the San Joaquin River and three of its tributaries: Orestimba Creek, Salt Slough, and the Merced River. Of the 83 pesticides selected for analysis in this study, 49 different compounds were detected in samples from the four sites and ranged in concentration from less than the detection limit to 20 micrograms per liter. All but one sample contained at least one pesticide, and more than 50 percent of the samples contained seven or more pesticides. Six compounds were detected in more than 50 percent of the samples: four herbicides (dacthal, EPTC, metolachlor, and simazine) and two insecticides (chlorpyrifos and diazinon). None of the measured concentrations exceeded U.S. Environmental Protection Agency drinking water criteria, and many of the measured concentrations were very low. The concentrations of seven pesticides exceeded criteria for the protection of freshwater aquatic life: azinphos-methyl, carbaryl, chlorpyrifos, diazinon, diuron, malathion, and trifluralin. Overall, some criteria for protection of aquatic life were exceeded in a total of 97 samples. Factors affecting the spatial patterns of occurrence of the pesticides in the different subbasins included the pattern of application and hydrology. Seventy percent of pesticides with known application were detected. Overall, 40 different pesticides were detected in Orestimba Creek, 33 in Salt Slough, and 26 in the Merced River. Samples from the Merced River had a relatively low number of detections, despite the high number (35) of pesticides applied, owing to the

  1. Late Cretaceous and Paleogene sedimentation along east side of San Joaquin basin, California

    SciTech Connect

    Reid, S.A.

    1986-04-01

    Depositional systems of the Late Cretaceous contrast with those of the Paleogene in the subsurface along the east side of the San Joaquin basin between Bakersfield and Fresno, California. Upper Cretaceous deposits include thick fan-delta and submarine fan facies of the Moreno and Panoche Formations, whereas the paleogene contains extensive nearshore, shelf, slope, and submarine fan deposits of the Lodo, Domengine, and Kreyenhagen Formations. These sediments were deposited on a basement surface having several west-trending ridges and valleys. West-flowing streams draining an ancestral Sierra Nevada of moderate relief formed prograding fan deltas that filled the valleys with thick wedges of nonmarine channel deposits, creating a bajada along the shoreline. Detrital material moved rapidly from the shoreline through a narrow shelf, into a complex of submarine fans in the subduction trough. During the early Eocene, a low sea level stand plus an end of Sierra Nevada uplift resulted in the erosion of the range to a peneplain. Stream-fed fan deltas were replaced by a major river system, which flowed west on about the present course of the Kern River. Following a rapid sea level increase, sand from the river system was deposited on the now broad shelf along a wide belt roughly coincident with California Highway 99. The river was also the point source for sand in a submarine fan northwest of Bakersfield. Both Upper Cretaceous and Paleogene depositional systems probably continue north along the east edge of the Great Valley. This proposed scenario for the east side of the San Joaquin is analogous to forearc deposits in the San Diego area, including the Cretaceous Rosario fan-delta and submarine fan system and the Eocene La Jolla and Poway nearshore, shelf, and submarine fan systems.

  2. California GAMA Program: Ground-Water Quality Data in the Northern San Joaquin Basin Study Unit, 2005

    USGS Publications Warehouse

    Bennett, George L.; Belitz, Kenneth; Milby Dawson, Barbara J.

    2006-01-01

    Growing concern over the closure of public-supply wells because of ground-water contamination has led the State Water Board to establish the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. With the aid of the U.S. Geological Survey (USGS) and Lawrence Livermore National Laboratory, the program goals are to enhance understanding and provide a current assessment of ground-water quality in areas where ground water is an important source of drinking water. The Northern San Joaquin Basin GAMA study unit covers an area of approximately 2,079 square miles (mi2) across four hydrologic study areas in the San Joaquin Valley. The four study areas are the California Department of Water Resources (CADWR) defined Tracy subbasin, the CADWR-defined Eastern San Joaquin subbasin, the CADWR-defined Cosumnes subbasin, and the sedimentologically distinct USGS-defined Uplands study area, which includes portions of both the Cosumnes and Eastern San Joaquin subbasins. Seventy ground-water samples were collected from 64 public-supply, irrigation, domestic, and monitoring wells within the Northern San Joaquin Basin GAMA study unit. Thirty-two of these samples were collected in the Eastern San Joaquin Basin study area, 17 in the Tracy Basin study area, 10 in the Cosumnes Basin study area, and 11 in the Uplands Basin study area. Of the 32 samples collected in the Eastern San Joaquin Basin, 6 were collected using a depth-dependent sampling pump. This pump allows for the collection of samples from discrete depths within the pumping well. Two wells were chosen for depth-dependent sampling and three samples were collected at varying depths within each well. Over 350 water-quality field parameters, chemical constituents, and microbial constituents were analyzed and are reported as concentrations and as detection frequencies, by compound classification as well as for individual constituents, for the Northern San Joaquin Basin study unit as a whole and for each individual study area

  3. A brief history of oil and gas exploration in the southern San Joaquin Valley of California: Chapter 3 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Takahashi, Kenneth I.; Gautier, Donald L.

    2007-01-01

    The Golden State got its nickname from the Sierra Nevada gold that lured so many miners and settlers to the West, but California has earned much more wealth from so-called “black gold” than from metallic gold. The San Joaquin Valley has been the principal source for most of the petroleum produced in the State during the past 145 years. In attempting to assess future additions to petroleum reserves in a mature province such as the San Joaquin Basin, it helps to be mindful of the history of resource development. In this chapter we present a brief overview of the long and colorful history of petroleum exploration and development in the San Joaquin Valley. This chapter relies heavily upon the work of William Rintoul, who wrote extensively on the history of oil and gas exploration in California and especially in the San Joaquin Valley. No report on the history of oil and gas exploration in the San Joaquin Valley would be possible without heavily referencing his publications. We also made use of publications by Susan Hodgson and a U.S. Geological Survey Web site, Natural Oil and Gas Seeps in California (http://seeps.wr.usgs.gov/seeps/index.html), for much of the material describing the use of petroleum by Native Americans in the San Joaquin Valley. Finally, we wish to acknowledge the contribution of Don Arnot, who manages the photograph collection at the West Kern Oil Museum in Taft, California. The collection consists of more than 10,000 photographs that have been scanned and preserved in digital form on CD-ROM. Many of the historical photographs used in this paper are from that collection. Finally, to clarify our terminology, we use the term “San Joaquin Valley” when we refer to the geographical or topographical feature and the term “San Joaquin Basin” when we refer to geological province and the rocks therein.

  4. Chinese mitten crab surveys of San Joaquin River basin and Suisun Marsh, California, 2000

    USGS Publications Warehouse

    May, Jason T.; Brown, Larry R.

    2001-01-01

    Juvenile Chinese mitten crabs (Eriocheir sinensis) are known to use both brackish and freshwater habitats as rearing areas. The objectives of this study were to examine the habitat use and potential effects of mitten crabs in the freshwater habitats of the San Joaquin River drainage up-stream of the Sacramento-San Joaquin Delta. After several unsuccessful attempts to catch or observe mitten crabs by trapping, electrofishing, and visual observations, the study was redirected to determine the presence of crabs in the San Joaquin River (in the vicinity of Mossdale) and Suisun Marsh. Monthly surveys using baited traps in the San Joaquin River were done from June through November 2000 and in the Suisun Marsh from August through October 2000. No mitten crabs were caught in the San Joaquin River Basin and only one mitten crab was caught in Suisun Marsh. Surveys were conducted at 92 locations in the San Joaquin River Basin by deploying 352 traps for 10,752 hours of trapping effort; in Suisun Marsh, 34 locations were investigated by deploying 150 traps for 3,600 hours of trapping effort. The baited traps captured a variety of organisms, including catfishes (Ictularidae), yellowfin gobies (Acantho-gobius flavimanus), and crayfish (Decapoda). It is unclear whether the failure to capture mitten crabs in the San Joaquin River Basin and Suisun Marsh was due to ineffective trapping methods, or repre-sents a general downward trend in populations of juvenile mitten crabs in these potential rearing areas or a temporary decline related to year-class strength. Available data (since 1998) on the number of mitten crabs entrained at federal and state fish salvage facilities indicate a downward trend in the number of crabs, which may indicate a declining trend in use of the San Joaquin River Basin by juvenile mitten crabs. Continued monitoring for juvenile Chinese mitten crabs in brackish and freshwater portions of the Sacramento-San Joaquin River Basins is needed to better assess the

  5. Executive Summary -- assessment of undiscovered oil and gas resources of the San Joaquin Basin Province of California, 2003: Chapter 1 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Gautier, Donald L.; Scheirer, Allegra Hosford; Tennyson, Marilyn E.; Peters, Kenneth E.; Magoon, Leslie B.; Lillis, Paul G.; Charpentier, Ronald R.; Cook, Troy A.; French, Christopher D.; Klett, Timothy R.; Pollastro, Richard M.; Schenk, Christopher J.

    2007-01-01

    In 2003, the U.S. Geological Survey (USGS) completed an assessment of the oil and gas resource potential of the San Joaquin Basin Province of California (fig. 1.1). The assessment is based on the geologic elements of each Total Petroleum System defined in the province, including hydrocarbon source rocks (source-rock type and maturation and hydrocarbon generation and migration), reservoir rocks (sequence stratigraphy and petrophysical properties), and hydrocarbon traps (trap formation and timing). Using this geologic framework, the USGS defined five total petroleum systems and ten assessment units within these systems. Undiscovered oil and gas resources were quantitatively estimated for the ten assessment units (table 1.1). In addition, the potential was estimated for further growth of reserves in existing oil fields of the San Joaquin Basin.

  6. Aquatic biology of the San Joaquin-Tulare basins, California; analysis of available data through 1992

    USGS Publications Warehouse

    Brown, Larry R.

    1996-01-01

    Available data through 1992 on aquatic biota in the San Joaquin-Tulare Basins study unit of the National Water-Quality Assessment Program were analyzed to provide a conceptual framework to guide study design. The analysis included information on the biology of fish, aquatic macroinvertebrates, aquatic algae, and concentrations of trace elements and organic pesticides in aquatic biota.

  7. Age, distribution, and stratigraphic relationship of rock units in the San Joaquin Basin Province, California: Chapter 5 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Hosford Scheirer, Allegra; Magoon, Leslie B.

    2008-01-01

    The San Joaquin Basin is a major petroleum province that forms the southern half of California’s Great Valley, a 700-km-long, asymmetrical basin that originated between a subduction zone to the west and the Sierra Nevada to the east. Sedimentary fill and tectonic structures of the San Joaquin Basin record the Mesozoic through Cenozoic geologic history of North America’s western margin. More than 25,000 feet (>7,500 meters) of sedimentary rocks overlie the basement surface and provide a nearly continuous record of sedimentation over the past ~100 m.y. Further, depositional geometries and fault structures document the tectonic evolution of the region from forearc setting to strike-slip basin to transpressional margin. Sedimentary architecture in the San Joaquin Basin is complicated because of these tectonic regimes and because of lateral changes in depositional environment and temporal changes in relative sea level. Few formations are widespread across the basin. Consequently, a careful analysis of sedimentary facies is required to unravel the basin’s depositional history on a regional scale. At least three high-quality organic source rocks formed in the San Joaquin Basin during periods of sea level transgression and anoxia. Generated on the basin’s west side, hydrocarbons migrated into nearly every facies type in the basin, from shelf and submarine fan sands to diatomite and shale to nonmarine coarse-grained rocks to schist. In 2003, the U.S. Geological Survey (USGS) completed a geologic assessment of undiscovered oil and gas resources and future additions to reserves in the San Joaquin Valley of California (USGS San Joaquin Basin Province Assessment Team, this volume, chapter 1). Several research aims supported this assessment: identifying and mapping the petroleum systems, modeling the generation, migration, and accumulation of hydrocarbons, and defining the volumes of rock to be analyzed for additional resources. To better understand the three dimensional

  8. Petroleum systems of the San Joaquin Basin Province, California -- geochemical characteristics of oil types: Chapter 9 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Lillis, Paul G.; Magoon, Leslie B.

    2007-01-01

    New analyses of 120 oil samples combined with 139 previously published oil analyses were used to characterize and map the distribution of oil types in the San Joaquin Basin, California. The results show that there are at least four oil types designated MM, ET, EK, and CM. Most of the oil from the basin has low to moderate sulfur content (less than 1 weight percent sulfur), although a few unaltered MM oils have as much as 1.2 weight percent sulfur. Reevaluation of source rock data from the literature indicate that the EK oil type is derived from the Eocene Kreyenhagen Formation, and the MM oil type is derived, in part, from the Miocene to Pliocene Monterey Formation and its equivalent units. The ET oil type is tentatively correlated to the Eocene Tumey formation of Atwill (1935). Previous studies suggest that the CM oil type is derived from the Late Cretaceous to Paleocene Moreno Formation. Maps of the distribution of the oil types show that the MM oil type is restricted to the southern third of the San Joaquin Basin Province. The composition of MM oils along the southern and eastern margins of the basin reflects the increased contribution of terrigenous organic matter to the marine basin near the Miocene paleoshoreline. EK oils are widely distributed along the western half of the basin, and ET oils are present in the central and west-central areas of the basin. The CM oil type has only been found in the Coalinga area in southwestern Fresno County. The oil type maps provide the basis for petroleum system maps that incorporate source rock distribution and burial history, migration pathways, and geologic relationships between hydrocarbon source and reservoir rocks. These petroleum system maps were used for the 2003 U.S. Geological Survey resource assessment of the San Joaquin Basin Province.

  9. Porosity evolution in reservoir sandstones in the West-Central San Joaquin basin, California

    SciTech Connect

    Horton, R.A. Jr.; McCullough, P.T.; Houghton, B.D.; Pennell, D.A.; Dunwoody, J.A. III; Menzie, R.J. Jr.

    1995-04-01

    Miocene reservoir sands (feldspathic and lithic arenites) in central San Joaquin basin oil fields show similar trends in porosity development despite differences in depositional environment, pore-fluid chemistry, and burial history. Burial and tectonic compaction caused grain rotation, deformation of altered lithics, and extensive fracturing of brittle grains, thereby eliminating most primary porosity. Diagenetic fluids, infiltrating along fractures in grains, reacted with freshly exposed mineral surfaces causing extensive leaching of framework components. All major grain types were affected but preferential removal of feldspars and lithics resulted in changes in QFL ratios. With continued compaction angular remnants of partially disolved grains were rotated and rearranged while secondary intergranular and moldic porosity collapsed to form secondary intergranular porosity. This resulted in reservoir sands that are less well sorted, more angular, and mineralogically more mature than they were at deposition. Such changes appear to widespread in the San Joaquin basin and may be more important than is generally acknowledged.

  10. Middle Tertiary stratigraphic sequences of the San Joaquin Basin, California: Chapter 6 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Johnson, Cari L.; Graham, Stephan A.

    2007-01-01

    An integrated database of outcrop studies, borehole logs, and seismic-reflection profiles is used to divide Eocene through Miocene strata of the central and southern San Joaquin Basin, California, into a framework of nine stratigraphic sequences. These third- and higher-order sequences (<3 m.y. duration) comprise the principal intervals for petroleum assessment for the basin, including key reservoir and source rock intervals. Important characteristics of each sequence are discussed, including distribution and stratigraphic relationships, sedimentary facies, regional correlation, and age relations. This higher-order stratigraphic packaging represents relatively short-term fluctuations in various forcing factors including climatic effects, changes in sediment supply, local and regional tectonism, and fluctuations in global eustatic sea level. These stratigraphic packages occur within the context of second-order stratigraphic megasequences, which mainly reflect long-term tectonic basin evolution. Despite more than a century of petroleum exploration in the San Joaquin Basin, many uncertainties remain regarding the age, correlation, and origin of the third- and higher-order sequences. Nevertheless, a sequence stratigraphic approach allows definition of key intervals based on genetic affinity rather than purely lithostratigraphic relationships, and thus is useful for reconstructing the multiphase history of this basin, as well as understanding its petroleum systems.

  11. Water quality assessment of the San Joaquin--Tulare basins, California; analysis of available data on nutrients and suspended sediment in surface water, 1972-1990

    USGS Publications Warehouse

    Kratzer, Charles R.; Shelton, Jennifer L.

    1998-01-01

    Nutrients and suspended sediment in surface water of the San Joaquin-Tulare basins in California were assessed using 1972-1990 data from the U.S. Geological Survey's National Water Information System and the U.S. Environmental Protection Agency's STOrage and RETrieval database. Loads of nutrients and suspended sediment were calculated at several sites and the contributions from point and nonpoint sources were estimated. Trends in nutrient and suspended-sediment concentrations were evaluated at several sites, especially at the basin outlet on the San Joaquin River. Comparisons of nutrient and suspended sediment concentrations were made among three environmental settings: the San Joaquin Valley--west side, the San Joaquin Valley--east side, and the Sierra Nevada.

  12. Provenance and diagenesis of Oligocene sandstones, southern San Joaquin basin, California

    SciTech Connect

    Hayes, M.J.

    1988-03-01

    Oligocene Vedder sandstones and correlatives from the southern San Joaquin basin provide an opportunity to compare diagenesis resulting from variable provenance, depositional environment, and burial or tectonic history. Sandstones were examined from 15 cores in this basin-wide petrographic survey. Oligocene sandstones typically are fine to medium grained, moderately sorted, subangular, and quartzofeldspathic, although sandstones from the western and east-central basin are enriched in potassium feldspar and intermediate volcanic rock fragments, respectively. Detrital compositions are transitional between uplifted continental block and undissected to dissected magmatic arc on provenance diagrams. Sediment provenance included the granodioritic Sierra Nevada-Tehachapi Mountain magmatic arc complex and perhaps granitic terranes to the west. Volcanic detritus was shed from southern and eastern sources. Diagenesis varies within the basin, partly reflecting local pore-fluid evolution and detrital composition. The effects of variable geothermal gradients, sedimentation rate, and tectonism on diagenesis await evaluation. In the composite basin-wide paragenetic sequence, calcite, dolomite, siderite, and chlorite-smectite are earliest authigenic phases. Variable cement and compaction relationships indicate nonuniform depth and timing of cementation. Early cements inhibited subsequent diagenesis and compaction. With deeper burial, plagioclase, potassium feldspar, and carbonates dissolved, pore-filling kaolinite precipitated, plagioclase was albitized and zeolitized, and late-stage carbonates crystallized. Further geochemical analyses will better define composition and origin of authigenic phases and document reaction progress. Cement zones and sources may be identified and spatially and temporally linked in an attempt to constrain scales and rates of mass transfer of calcium basin wide.

  13. Status and Understanding of Groundwater Quality in the Central-Eastside San Joaquin Basin, 2006: California GAMA Priority Basin Project

    USGS Publications Warehouse

    Landon, Matthew K.; Belitz, Kenneth; Jurgens, Bryant C.; Justin T. Kulongoski, Justin T.; Johnson, Tyler D.

    2010-01-01

    Groundwater quality in the approximately 1,695-square-mile Central Eastside San Joaquin Basin (Central Eastside) study unit was investigated as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001, and is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The GAMA Central Eastside study unit was designed to provide a spatially unbiased assessment of untreated-groundwater quality, as well as a statistically consistent basis for comparing water quality throughout California. During March through June 2006, samples were collected from 78 wells in Stanislaus and Merced Counties, 58 of which were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and 20 of which were sampled to evaluate changes in water chemistry along groundwater-flow paths (understanding wells). Water-quality data from the California Department of Public Health (CDPH) database also were used for the assessment. An assessment of the current status of the groundwater quality included collecting samples from wells for analysis of anthropogenic constituents such as volatile organic compounds (VOCs) and pesticides, as well as naturally occurring constituents such as major ions and trace elements. The assessment of status is intended to characterize the quality of untreated-groundwater resources within the primary aquifer system, not the treated drinking water delivered to consumers by water purveyors. The primary aquifer system (hereinafter, primary aquifer) is defined as that part of the aquifer corresponding to the perforation interval of wells listed in the CDPH database for the Central Eastside study unit. The quality of groundwater in shallower or

  14. Reevaluation of Stevens sand potential - Maricopa depocenter, southern San Joaquin basin, California

    SciTech Connect

    Kolb, M.M.; Parks, S.L. )

    1991-02-01

    During the upper Miocene in the Southern San Joaquin basin surrounding highlands contributed coarse material to a deep marine basin dominated by fine grained silicious bioclastic deposition. these coarse deposits became reservoirs isolated within the silicious Antelope Shale Member of the Monterey Formation. In the southern Maricopa depocenter these Stevens sands are productive at Yowlumne, Landslide, Aqueduct, Rio Viejo, San Emidio Nose, Paloma, and Midway-Sunset fields, and are major exploration targets in surrounding areas. In the ARCO Fee lands area of the southern Maricopa depocenter, Stevens sands occur as rapidly thickening lens-shaped bodies that formed as channel, levee, and lobe deposits of deep-marine fan systems. These fans were fed from a southerly source, with apparent transport in a north-northwesterly direction. Sands deflect gently around present-day structural highs indicating that growth of structures influenced depositional patterns. Correlations reveal two major fan depositional intervals bounded by regional N, O, and P chert markers. Each interval contains numerous individual fan deposits, with many lobes and channels recognizable on three-dimensional seismic data. In addition to these basinal sand plays presently being evaluated, ARCO is pursuing a relatively new trend on Fee lands along the southern basin margin, where correlation to mountain data reveals Stevens sands trend into the steeply dipping beds of the mountain front. This area, the upturned Stevens,' has large reserve potential and producing analogies at Metson, Leutholtz, Los Lobos, and Pleito Ranch fields.

  15. Chemometric differentiation of crude oil families in the San Joaquin Basin, California

    USGS Publications Warehouse

    Peters, Kenneth E.; Coutrot, Delphine; Nouvelle, Xavier; Ramos, L. Scott; Rohrback, Brian G.; Magoon, Leslie B.; Zumberge, John E.

    2013-01-01

    Chemometric analyses of geochemical data for 165 crude oil samples from the San Joaquin Basin identify genetically distinct oil families and their inferred source rocks and provide insight into migration pathways, reservoir compartments, and filling histories. In the first part of the study, 17 source-related biomarker and stable carbon-isotope ratios were evaluated using a chemometric decision tree (CDT) to identify families. In the second part, ascendant hierarchical clustering was applied to terpane mass chromatograms for the samples to compare with the CDT results. The results from the two methods are remarkably similar despite differing data input and assumptions. Recognized source rocks for the oil families include the (1) Eocene Kreyenhagen Formation, (2) Eocene Tumey Formation, (3–4) upper and lower parts of the Miocene Monterey Formation (Buttonwillow depocenter), and (5–6) upper and lower parts of the Miocene Monterey Formation (Tejon depocenter). Ascendant hierarchical clustering identifies 22 oil families in the basin as corroborated by independent data, such as carbon-isotope ratios, sample location, reservoir unit, and thermal maturity maps from a three-dimensional basin and petroleum system model. Five families originated from the Eocene Kreyenhagen Formation source rock, and three families came from the overlying Eocene Tumey Formation. Fourteen families migrated from the upper and lower parts of the Miocene Monterey Formation source rocks within the Buttonwillow and Tejon depocenters north and south of the Bakersfield arch. The Eocene and Miocene families show little cross-stratigraphic migration because of seals within and between the source rocks. The data do not exclude the possibility that some families described as originating from the Monterey Formation actually came from source rock in the Temblor Formation.

  16. 77 FR 70707 - Approval of Air Quality Implementation Plans; California; San Joaquin Valley and South Coast...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-27

    ... AGENCY 40 CFR Part 52 Approval of Air Quality Implementation Plans; California; San Joaquin Valley and... Ambient Air Quality Standards in the San Joaquin Valley and the South Coast Air Basin. These technical...) in the San Joaquin Valley and South Coast (Los Angeles) Air Basin and included provisions of...

  17. Trends in nutrient concentrations, loads, and yields in streams in the Sacramento, San Joaquin, and Santa Ana Basins, California, 1975-2004

    USGS Publications Warehouse

    Kratzer, Charles R.; Kent, Robert; Seleh, Dina K.; Knifong, Donna L.; Dileanis, Peter D.; Orlando, James L.

    2011-01-01

    A comprehensive database was assembled for the Sacramento, San Joaquin, and Santa Ana Basins in California on nutrient concentrations, flows, and point and nonpoint sources of nutrients for 1975-2004. Most of the data on nutrient concentrations (nitrate, ammonia, total nitrogen, orthophosphate, and total phosphorus) were from the U.S. Geological Survey's National Water Information System database (35.2 percent), the California Department of Water Resources (21.9 percent), the University of California at Davis (21.6 percent), and the U.S. Environmental Protection Agency's STOrage and RETrieval database (20.0 percent). Point-source discharges accounted for less than 1 percent of river flows in the Sacramento and San Joaquin Rivers, but accounted for close to 80 percent of the nonstorm flow in the Santa Ana River. Point sources accounted for 4 and 7 percent of the total nitrogen and total phosphorus loads, respectively, in the Sacramento River at Freeport for 1985-2004. Point sources accounted for 8 and 17 percent of the total nitrogen and total phosphorus loads, respectively, in the San Joaquin River near Vernalis for 1985-2004. The volume of wastewater discharged into the Santa Ana River increased almost three-fold over the study period. However, due to improvements in wastewater treatment, the total nitrogen load to the Santa Ana River from point sources in 2004 was approximately the same as in 1975 and the total phosphorus load in 2004 was less than in 1975. Nonpoint sources of nutrients estimated in this study included atmospheric deposition, fertilizer application, manure production, and tile drainage. The estimated dry deposition of nitrogen exceeded wet deposition in the Sacramento and San Joaquin Valleys and in the basin area of the Santa Ana Basin, with ratios of dry to wet deposition of 1.7, 2.8, and 9.8, respectively. Fertilizer application increased appreciably from 1987 to 2004 in all three California basins, although manure production increased in the

  18. Dissolved pesticide concentrations detected in storm-water runoff at selected sites in the San Joaquin River basin, California, 2000-2001

    USGS Publications Warehouse

    Orlando, James L.; Kuivila, Kathryn M.; Whitehead, Andrew

    2003-01-01

    As part of a collaborative study involving the United States Geological Survey Toxics Substances Hydrology Project (Toxics Project) and the University of California, Davis, Bodega Marine Laboratory (BML), water samples were collected at three sites within the San Joaquin River Basin of California and analyzed for dissolved pesticides. Samples were collected during, and immediately after, the first significant rainfall (greater than 0.5 inch per day) following the local application of dormant spray, organophosphate insecticides during the winters of 2000 and 2001. All samples were collected in conjunction with fish-caging experiments conducted by BML researchers. Sites included two locations potentially affected by runoff of agricultural chemicals (San Joaquin River near Vernalis, California, and Orestimba Creek at River Road near Crows Landing, California, and one control site located upstream of pesticide input (Orestimba Creek at Orestimba Creek Road near Newman, California). During these experiments, fish were placed in cages and exposed to storm runoff for up to ten days. Following exposure, the fish were examined for acetylcholinesterase concentrations and overall genetic damage. Water samples were collected throughout the rising limb of the stream hydrograph at each site for later pesticide analysis. Concentrations of selected pesticides were measured in filtered water samples using solid-phase extraction (SPE) and gas chromatography-mass spectrometry (GC/MS) at the U.S. Geological Survey organic chemistry laboratory in Sacramento, California. Results of these analyses are presented.

  19. Paleogeographic and paleoecologic model as a predictive tool for Late Miocene accumulation of biosiliceous sediments in the Monterey Formation of the San Joaquin basin, California

    SciTech Connect

    Bulter, T.H. ); Dumont, M.P. )

    1991-03-01

    The marine ecology of diatoms in the Pacific Ocean can be invoked to explain late Miocene diatom population trends. The impact of seafloor physiography on diatom productivity in the modern ocean was compared with mappable biosiliceous trends in the Monterey Formation of the San Joaquin basin, California. A depositional model is proposed to explain the significance of paleogeography on variations in the biosiliceous content of the Monterey Formation. Diatoms thrive where nutrient-rich bottom waters flow upslope to replace the surface waters moved basinward by atmospherically induced circulation. Organic-rich siliceous material settles through the water column beneath the upwelling region. Oxidation of organic matter within the water column below the areas of intense upwelling creates an oxygen-depleted layer and limits bioturbation at the sediment-water interface. The resultant sedimentary rocks are laminated siliceous shales characteristic of the Monterey Formation. Forty-two Monterey well penetrations form a variety of locations in the San Joaquin basin were analyzed for biosiliceous content. Biosiliceous facies trends were established by relating the quantity of siliceous material to depositional environment and paleobathymetry. Lithofacies trends were then modeled using the paleogeography of the San Joaquin basin during the late Miocene. According to the model, the rocks with the highest content of biogenic silica are expected in a slope setting. This model also suggests that slop angle controls the intensity of upwelling and subsequent diatom productivity.

  20. A four-dimensional petroleum systems model for the San Joaquin Basin Province, California: Chapter 12 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Peters, Kenneth E.; Magoon, Leslie B.; Lampe, Carolyn; Scheirer, Allegra Hosford; Lillis, Paul G.; Gautier, Donald L.

    2008-01-01

    A calibrated numerical model depicts the geometry and three-dimensional (3-D) evolution of petroleum systems through time (4-D) in a 249 x 309 km (155 x 192 mi) area covering all of the San Joaquin Basin Province of California. Model input includes 3-D structural and stratigraphic data for key horizons and maps of unit thickness, lithology, paleobathymetry, heat flow, original total organic carbon, and original Rock-Eval pyrolysis hydrogen index for each source rock. The four principal petroleum source rocks in the basin are the Miocene Antelope shale of Graham and Williams (1985; hereafter referred to as Antelope shale), the Eocene Kreyenhagen Formation, the Eocene Tumey formation of Atwill (1935; hereafter referred to as Tumey formation), and the Cretaceous to Paleocene Moreno Formation. Due to limited Rock-Eval/total organic carbon data, the Tumey formation was modeled using constant values of original total organic carbon and original hydrogen index. Maps of original total organic carbon and original hydrogen index were created for the other three source rocks. The Antelope shale was modeled using Type IIS kerogen kinetics, whereas Type II kinetics were used for the other source rocks. Four-dimensional modeling and geologic field evidence indicate that maximum burial of the three principal Cenozoic source rocks occurred in latest Pliocene to Holocene time. For example, a 1-D extraction of burial history from the 4-D model in the Tejon depocenter shows that the bottom of the Antelope shale source rock began expulsion (10 percent transformation ratio) about 4.6 Ma and reached peak expulsion (50 percent transformation ratio) about 3.6 Ma. Except on the west flank of the basin, where steep dips in outcrop and seismic data indicate substantial uplift, little or no section has been eroded. Most petroleum migration occurred during late Cenozoic time in distinct stratigraphic intervals along east-west pathways from pods of active petroleum source rock in the Tejon and

  1. SAN JOAQUIN ROADLESS AREA, CALIFORNIA.

    USGS Publications Warehouse

    McKee, Edwin H.; Capstick, Donald O.

    1984-01-01

    The San Joaquin Roadless Area is composed of three noncontiguous areas on the eastern side of the Sierra Nevada in Madera County, California. The results of geologic, geochemical, and mining-activity and production surveys in the central part of the area indicate little promise for the occurrence of metallic-mineral or energy resources in the area. Sand, gravel, and pumice exist in the area but occurrences are small and isolated and farther from major markets than similar deposits outside the roadless area. Rocks in the area are exhibited in exposures of unaltered and nonmineralized granitic and metavolcanic rock along the steep western wall of the glacially carved valley of the Middle Fork of the San Joaquin River. Drainage in the area consists of seeps along fractures in the cliff or small cascading streams, a hydraulic setting not favorable for the development of placer deposits. No mines or prospect workings were found in the roadless area. Alteration zones within the granitic and metamorphic rock that crop out within the area are small, isolated, and consist only of limonitic staining and bleached quartzose rock.

  2. Pliocene facies trends and controls on deposition of lower gusher shallow gas reservoirs, North Coles Levee Field, San Joaquin Basin, California

    SciTech Connect

    Steward, D.C.; Gillespie, J.M. )

    1994-04-01

    Net sand isochore maps of three Pliocene-age Lower Gusher sands in the Etchegoin Formation at North Coles Levee field, southern San Joaquin basin, California display geometries suggestive of deposition in delta front settings. The north-south depositional strike of these sands approximately parallels the orientation of the paleoshoreline. The sands thicken and display greater lateral continuity near distributary channel sands, which are oriented east-northeast approximately perpendicular to the shoreline. A comparison of the isochore maps of each of the three sand bodies show that they are stacked vertically above each other, indicating that the position of the shoreline remained stationary during deposition of the Gusher interval. This apparent stillstand of the shoreline is superimposed on an overall regression of the sea from the San Joaquin basin during the Pliocene. Therefore, we believe that the Lower Gusher sands were deposited during a period of relatively rapid basin subsidence, which negated the effects of the marine regression and caused vertical aggradation of shoreline facies in the North Coles Levee area. The Lower Gusher interval at North and South Coles Levee contains the most prolific shallow gas reservoirs on the Bakersfield Arch. A thorough knowledge of depositional trends in the Lower Gusher interval increases the probability of encountering reservoir-quality facies in exploration programs focusing on Pliocene gas.

  3. Groundwater quality in the southeast San Joaquin Valley, California

    USGS Publications Warehouse

    Burton, Carmen A.; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The subbasins in the southeast portion of the San Joaquin Valley constitute one of the study units being evaluated.

  4. Landslide oil field, San Joaquin Valley, California

    SciTech Connect

    Collins, B.P.; March, K.A.; Caballero, J.S.; Stolle, J.M.

    1988-03-01

    The Landslide field, located at the southern margin of the San Joaquin basin, was discovered in 1985 by a partnership headed by Channel Exploration Company, on a farm out from Tenneco Oil Company. Initial production from the Tenneco San Emidio 63X-30 was 2064 BOPD, making landslide one of the largest onshore discoveries in California during the past decade. Current production is 7100 BOPD from a sandstone reservoir at 12,500 ft. Fifteen wells have been drilled in the field, six of which are water injectors. Production from the Landslide field occurs from a series of upper Miocene Stevens turbidite sandstones that lie obliquely across an east-plunging structural nose. These turbidite sandstones were deposited as channel-fill sequences within a narrowly bounded levied channel complex. Both the Landslide field and the larger Yowlumne field, located 3 mi to the northwest, comprise a single channel-fan depositional system that developed in the restricted deep-water portion of the San Joaquin basin. Information from the open-hole logs, three-dimensional surveys, vertical seismic profiles, repeat formation tester data, cores, and pressure buildup tests allowed continuous drilling from the initial discovery to the final waterflood injector, without a single dry hole. In addition, the successful application of three-dimensional seismic data in the Landslide development program has helped correctly image channel-fan anomalies in the southern Maricopa basin, where data quality and severe velocity problems have hampered previous efforts. New exploration targets are currently being evaluated on the acreage surrounding the Landslide discovery and should lead to an interesting new round of drilling activity in the Maricopa basin.

  5. Source-rock geochemistry of the San Joaquin Basin Province, California: Chapter 11 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Peters, Kenneth E.; Magoon, Leslie B.; Valin, Zenon C.; Lillis, Paul G.

    2007-01-01

    Source-rock thickness and organic richness are important input parameters required for numerical modeling of the geohistory of petroleum systems. Present-day depth and thickness maps for the upper Miocene Monterey Formation, Eocene Tumey formation of Atwill (1935), Eocene Kreyenhagen Formation, and Cretaceous-Paleocene Moreno Formation source rocks in the San Joaquin Basin were determined using formation tops data from 266 wells. Rock-Eval pyrolysis and total organic carbon data (Rock-Eval/TOC) were collected for 1,505 rock samples from these source rocks in 70 wells. Averages of these data for each well penetration were used to construct contour plots of original total organic carbon (TOCo) and original hydrogen index (HIo) in the source rock prior to thermal maturation resulting from burial. Sufficient data were available to construct plots of TOCo and HIo for all source-rock units except the Tumey formation of Atwill (1935). Thick, organic-rich, oil-prone shales of the upper Miocene Monterey Formation occur in the Tejon depocenter in the southern part of the basin with somewhat less favorable occurrence in the Southern Buttonwillow depocenter to the north. Shales of the upper Miocene Monterey Formation generated most of the petroleum in the San Joaquin Basin. Thick, organic-rich, oil-prone Kreyenhagen Formation source rock occurs in the Buttonwillow depocenters, but it is thin or absent in the Tejon depocenter. Moreno Formation source rock is absent from the Tejon and Southern Buttonwillow depocenters, but thick, organic-rich, oil-prone Moreno Formation source rock occurs northwest of the Northern Buttonwillow depocenter adjacent to the southern edge of Coalinga field.

  6. Periphyton and Macroinvertebrate Communities at Five Sites in the San Joaquin River Basin, California, during June and September, 2001

    USGS Publications Warehouse

    Brown, Larry R.; May, Jason T.

    2004-01-01

    The effects of agriculture, particularly from the use of pesticides, on aquatic ecosystems in the San Joaquin River Basin concern many aquatic resource managers, water quality managers, and water users. A total of five sites were sampled once in June 2001 and once in September 2001 to document the periphyton (attached algae) community, the benthic macroinvertebrate (insects and non-insects) community, and stream habitat conditions. The purposes of the study were to document existing conditions and, to the extent possible, relate the periphyton and macroinvertebrate community condition to environmental conditions. A total of 161 taxa of algae were collected during the study. Samples from the richest targeted habitat, woody debris, included 109 taxa. In both the June and September samples, greater than 95 percent of the taxa collected were diatoms. Cluster analysis and detrended correspondence analysis of sample data showed that Orestimba Creek had a very different periphyton community than the Merced and Tuolumne Rivers. Salt Slough and the San Joaquin River had community compositions that were intermediate between the two extremes. A total of 126 taxa of macroinvertebrates were collected during the study. Samples from woody debris included 59 taxa. The samples included a variety of both insect and non-insect taxa. Cluster analysis and detrended correspondence analysis of sample data showed that Orestimba Creek was very different from the Merced River and Tuolumne River, similar to the results for periphyton. Orestimba Creek was dominated by non-insects, while the Merced and Tuolumne Rivers were dominated by insects. Salt Slough was more similar to Orestimba Creek because of the abundance of non-insects. The San Joaquin River was more similar to the Merced and Tuolumne Rivers. There was no evidence of major differences between June and September samples for either the periphyton or macroinvertebrate communities. Specific conductance (a surrogate for salinity) and

  7. Sequence stratigraphy, tectonics and hydrocarbon trap geometries of Middle Tertiary strata in the southern San Joaquin Basin, California

    SciTech Connect

    Phillips, S.; Hewlett, J.S.; Bazeley, W.J.M.

    1996-12-31

    Tectonic evolution of the southern San Joaquin basin exerted a fundamental control on Cenozoic sequence boundary development, reservoir, source and seal facies distribution, and hydrocarbon trap development. Spatial and temporal variations in Tertiary sequence architecture across the basin reflect differences in eastside versus westside basin-margin geometries and deformation histories. Deposition of Tertiary sequences initiated in a forearc basin setting, bounded on the east by a ramp-margin adjacent to the eroded Sierran arc complex and on the west by the imbricated accretionary wedge of the Coast Ranges thrust. The major stages of Cenozoic basin evolution are: (1) Episodic compressional folding and thrusting associated with oblique convergence of the Farallon and North American plates (Late Cretaceous to Oligocene), (2) localized folding and onset of basin subsidence related to Pacific Plate reorganization, microplate formation and rotation (Oligocene to Early Miocene), (3) transtensional faulting, folding basin subsidence associated with initiation of the San Andreas transform and continued microplate rotation (Micocene to Pliocene), and (4) compressional folding, extensional and strike- slip faulting related to evolution of the Pacific-North American transform boundary (Plio- Pleistocene). Complex stratigraphic relationships within Eocene to Middle Miocene rocks provide examples of tectonic influences on sequence architecture. These include development of: (1) Tectonically enhanced sequence boundaries (Early Eocene base Domengine unconformity) and local mid-sequence angular unconformities, (2) westside-derived syntectonic {open_quotes}lowstand{close_quotes} systems (Yokut/Turitella Silt wedge and Leda Sand/Cymric/Salt Creek wedge), (3) regional seals associated with subsidence-related transgressions (Round Mountain Silt), and (4) combination traps formed by structural inversion of distal lowstand delta reservoirs (e.g. Coalinga East Extension field).

  8. Sequence stratigraphy, tectonics and hydrocarbon trap geometries of Middle Tertiary strata in the southern San Joaquin Basin, California

    SciTech Connect

    Phillips, S.; Hewlett, J.S. ); Bazeley, W.J.M.

    1996-01-01

    Tectonic evolution of the southern San Joaquin basin exerted a fundamental control on Cenozoic sequence boundary development, reservoir, source and seal facies distribution, and hydrocarbon trap development. Spatial and temporal variations in Tertiary sequence architecture across the basin reflect differences in eastside versus westside basin-margin geometries and deformation histories. Deposition of Tertiary sequences initiated in a forearc basin setting, bounded on the east by a ramp-margin adjacent to the eroded Sierran arc complex and on the west by the imbricated accretionary wedge of the Coast Ranges thrust. The major stages of Cenozoic basin evolution are: (1) Episodic compressional folding and thrusting associated with oblique convergence of the Farallon and North American plates (Late Cretaceous to Oligocene), (2) localized folding and onset of basin subsidence related to Pacific Plate reorganization, microplate formation and rotation (Oligocene to Early Miocene), (3) transtensional faulting, folding basin subsidence associated with initiation of the San Andreas transform and continued microplate rotation (Micocene to Pliocene), and (4) compressional folding, extensional and strike- slip faulting related to evolution of the Pacific-North American transform boundary (Plio- Pleistocene). Complex stratigraphic relationships within Eocene to Middle Miocene rocks provide examples of tectonic influences on sequence architecture. These include development of: (1) Tectonically enhanced sequence boundaries (Early Eocene base Domengine unconformity) and local mid-sequence angular unconformities, (2) westside-derived syntectonic [open quotes]lowstand[close quotes] systems (Yokut/Turitella Silt wedge and Leda Sand/Cymric/Salt Creek wedge), (3) regional seals associated with subsidence-related transgressions (Round Mountain Silt), and (4) combination traps formed by structural inversion of distal lowstand delta reservoirs (e.g. Coalinga East Extension field).

  9. Pesticides in Surface and Ground Water of the San Joaquin-Tulare Basins, California: Analysis of Available Data, 1966 Through 1992

    USGS Publications Warehouse

    Domagalski, Joseph L.

    1997-01-01

    Available pesticide data (1966-92) for surface and ground water were analyzed for the San Joaquin-Tulare Basins, California, one of 60 large hydrologic systems being studied as part of the National Water-Quality Assessment Program of the U.S. Geological Survey. Most of the pesticide data were for the San Joaquin Valley, one of the most intensively farmed and irrigated areas of the United States. Data were obtained from the Storage and Retrieval data base of the U.S. Environmental Protection Agency, the water-quality data base of the U.S. Geological Survey, and from data files of State agencies. Pesticides detected in surface water include organochlorine pesticides, organophosphate pesticides, carbamate pesticides, and triazine herbicides. Pesticides detected in ground water include triazine and other organonitrogen herbicides and soil fumi gants. Surface-water data indicate seasonal patterns for the detection of organophosphate and carbamate pesticides, which are attributed to their use on almond orchards and alfafa fields. Organochlorine pesticides were detected primarily in river-bed sediments. Concentrations detected in bed sediments of the San Joaquin River near Vernalis are among the highest of any major river system in the United States. Patterns and timing of pesticide use indicate that pesticides might be present in surface-water systems during most months of a year. The most commonly detected pesticide in ground water is the soil fumigant, dibromochloropropane. Dibromochloropropane, used primarily on vineyards and orchards, was detected in ground water near the city of Fresno. Triazine and other organonitrogen herbicides were detected near vineyards and orchards in the same general locations as the detections of dibromochloropropane. Pesticides were detected in ground water of the east side of the valley floor, where the soils are sandy or coarsegrained, and water-soluble pesticides with long environmental half-lives were used. In contrast, fewer

  10. Petroleum systems of the San Joaquin Basin Province -- geochemical characteristics of gas types: Chapter 10 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Lillis, Paul G.; Warden, Augusta; Claypool, George E.; Magoon, Leslie B.

    2008-01-01

    The San Joaquin Basin Province is a petroliferous basin filled with predominantly Late Cretaceous to Pliocene-aged sediments, with organic-rich marine rocks of Late Cretaceous, Eocene, and Miocene age providing the source of most of the oil and gas. Previous geochemical studies have focused on the origin of the oil in the province, but the origin of the natural gas has received little attention. To identify and characterize natural gas types in the San Joaquin Basin, 66 gas samples were analyzed and combined with analyses of 15 gas samples from previous studies. For the purpose of this resource assessment, each gas type was assigned to the most likely petroleum system. Three general gas types are identified on the basis of bulk and stable carbon isotopic composition—thermogenic dry (TD), thermogenic wet (TW) and biogenic (B). The thermogenic gas types are further subdivided on the basis of the δ13C values of methane and ethane and nitrogen content into TD-1, TD-2, TD-Mixed, TW-1, TW-2, and TW-Mixed. Gas types TD-1 and TD-Mixed, a mixture of biogenic and TD-1 gases, are produced from gas fields in the northern San Joaquin Basin. Type TD-1 gas most likely originated from the Late Cretaceous to Paleocene Moreno Formation, a gas-prone source rock. The biogenic component of the TD-Mixed gas existed in the trap prior to the influx of thermogenic gas. For the assessment, these gas types were assigned to the Winters- Domengine Total Petroleum System, but subsequent to the assessment were reclassified as part of the Moreno-Nortonville gas system. Dry thermogenic gas produced from oil fields in the southern San Joaquin Basin (TD-2 gas) most likely originated from the oil-prone source rock of Miocene age. These samples have low wetness values due to migration fractionation or biodegradation. The thermogenic wet gas types (TW-1, TW-2, TW-Mixed) are predominantly associated gas produced from oil fields in the southern and central San Joaquin Basin. Type TW-1 gas most likely

  11. Status and understanding of groundwater quality in the two southern San Joaquin Valley study units, 2005-2006 - California GAMA Priority Basin Project

    USGS Publications Warehouse

    Burton, Carmen A.; Shelton, Jennifer L.; Belitz, Kenneth

    2012-01-01

    Groundwater quality in the southern San Joaquin Valley was investigated from October 2005 through March 2006 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project is conducted by the U.S. Geological Survey (USGS) in collaboration with the California State Water Resources Control Board and the Lawrence Livermore National Laboratory. There are two study units located in the southern San Joaquin Valley: the Southeast San Joaquin Valley (SESJ) study unit and the Kern County Subbasin (KERN) study unit. The GAMA Priority Basin Project in the SESJ and KERN study units was designed to provide a statistically unbiased, spatially distributed assessment of untreated groundwater quality within the primary aquifers. The status assessment is based on water-quality and ancillary data collected in 2005 and 2006 by the USGS from 130 wells on a spatially distributed grid, and water-quality data from the California Department of Public Health (CDPH) database. Data was collected from an additional 19 wells for the understanding assessment. The aquifer systems (hereinafter referred to as primary aquifers) were defined as that part of the aquifer corresponding to the perforation interval of wells listed in the CDPH database for the SESJ and KERN study units. The status assessment of groundwater quality used data from samples analyzed for anthropogenic constituents such as volatile organic compounds (VOCs) and pesticides, as well as naturally occurring inorganic constituents such as major ions and trace elements. The status assessment is intended to characterize the quality of untreated groundwater resources within the primary aquifers in the SESJ and KERN study units, not the quality of drinking water delivered to consumers. Although the status assessment applies to untreated groundwater, Federal and California regulatory and non-regulatory water-quality benchmarks that apply to drinking water are used

  12. Regional skew for California, and flood frequency for selected sites in the Sacramento-San Joaquin River Basin, based on data through water year 2006

    USGS Publications Warehouse

    Parrett, Charles; Veilleux, Andrea; Stedinger, J.R.; Barth, N.A.; Knifong, Donna L.; Ferris, J.C.

    2011-01-01

    Improved flood-frequency information is important throughout California in general and in the Sacramento-San Joaquin River Basin in particular, because of an extensive network of flood-control levees and the risk of catastrophic flooding. A key first step in updating flood-frequency information is determining regional skew. A Bayesian generalized least squares (GLS) regression method was used to derive a regional-skew model based on annual peak-discharge data for 158 long-term (30 or more years of record) stations throughout most of California. The desert areas in southeastern California had too few long-term stations to reliably determine regional skew for that hydrologically distinct region; therefore, the desert areas were excluded from the regional skew analysis for California. Of the 158 long-term stations used to determine regional skew, 145 have minimally regulated annual-peak discharges, and 13 stations are dam sites for which unregulated peak discharges were estimated from unregulated daily maximum discharge data furnished by the U.S. Army Corp of Engineers. Station skew was determined by using an expected moments algorithm (EMA) program for fitting the Pearson Type 3 flood-frequency distribution to the logarithms of annual peak-discharge data. The Bayesian GLS regression method previously developed was modified because of the large cross correlations among concurrent recorded peak discharges in California and the use of censored data and historical flood information with the new expected moments algorithm. In particular, to properly account for these cross-correlation problems and develop a suitable regression model and regression diagnostics, a combination of Bayesian weighted least squares and generalized least squares regression was adopted. This new methodology identified a nonlinear function relating regional skew to mean basin elevation. The regional skew values ranged from -0.62 for a mean basin elevation of zero to 0.61 for a mean basin elevation

  13. Data on dissolved pesticides and volatile organic compounds in surface and ground waters in the San Joaquin-Tulare basins, California, water years 1992-1995

    USGS Publications Warehouse

    Kinsey, Willie B.; Johnson, Mark V.; Gronberg, JoAnn M.

    2005-01-01

    This report contains pesticide, volatile organic compound, major ion, nutrient, tritium, stable isotope, organic carbon, and trace-metal data collected from 149 ground-water wells, and pesticide data collected from 39 surface-water stream sites in the San Joaquin Valley of California. Included with the ground-water data are field measurements of pH, specific conductance, alkalinity, temperature, and dissolved oxygen. This report describes data collection procedures, analytical methods, quality assurance, and quality controls used by the National Water-Quality Assessment Program to ensure data reliability. Data contained in this report were collected during a four year period by the San Joaquin?Tulare Basins Study Unit of the United States Geological Survey's National Water-Quality Assessment Program. Surface-water-quality data collection began in April 1992, with sampling done three times a week at three sites as part of a pilot study conducted to provide background information for the surface-water-study design. Monthly samples were collected at 10 sites for major ions and nutrients from January 1993 to March 1995. Additional samples were collected at four of these sites, from January to December 1993, to study spatial and temporal variability in dissolved pesticide concentrations. Samples for several synoptic studies were collected from 1993 to 1995. Ground-water-quality data collection was restricted to the eastern alluvial fans subarea of the San Joaquin Valley. Data collection began in 1993 with the sampling of 21 wells in vineyard land-use settings. In 1994, 29 wells were sampled in almond land-use settings and 9 in vineyard land-use settings; an additional 11 wells were sampled along a flow path in the eastern Fresno County vineyard land-use area. Among the 79 wells sampled in 1995, 30 wells were in the corn, alfalfa, and vegetable land-use setting, and 1 well was in the vineyard land-use setting; an additional 20 were flow-path wells. Also sampled in 1995

  14. Estimating Aquifer Properties in the San Joaquin Basin, California, through the Analysis of InSAR Data

    NASA Astrophysics Data System (ADS)

    Smith, R. G.; Knight, R. J.; Zebker, H. A.; Farr, T. G.; Liu, Z.; Chen, J.; Crews, J.; Reeves, J.

    2015-12-01

    Increased groundwater withdrawal in the San Joaquin Valley, California, due to recent droughts has over-stressed many parts of the aquifer system, resulting in widespread aquifer compaction and land subsidence. Using Interferometric Synthetic Aperture Radar, or InSAR, we measure the magnitude of land subsidence to be as much as 20 cm/year for the period from 2007-2011. By comparing the observed subsidence with current and historic groundwater levels, we estimate that 90% of the observed subsidence is inelastic, or not recoverable. Due to delayed drainage in thick aquitards, we find that the majority (>95%) of compaction is caused by thin clay lenses within the upper and lower aquifers, which agrees with previous studies in the area. We use representative skeletal storage coefficients from previous studies in conjunction with observed subsidence and groundwater levels in a 1-dimensional vertical diffusion model to estimate the effective vertical hydraulic conductivity of the aquifer, and determine it is on the order of 1×10-6 cm/second.

  15. Determination of traveltimes in the lower San Joaquin River basin, California, from dye-tracer studies during 1994-1995

    USGS Publications Warehouse

    Kratzer, Charles R.; Biagtan, Rhoda N.

    1997-01-01

    Dye-tracer studies were done in the lower San Joaquin River Basin in February 1994, June 1994, and February 1995. Dye releases were made in the Merced River (February 1994), Salt Slough (June 1994), Tuolumne River (February 1995), and Dry Creek (February 1995). The traveltimes determined in the studies aided the interpretation of pesticide data collected during storm sampling and guided sample collection during a Lagrangian pesticide study. All three studies used rhodamine WT 20-percent dye solution, which was released as a slug in midstream. The mean traveltime determined in the dye studies were compared to estimates based on regression equations of mean stream velocity as a function of streamflow. Dye recovery, the ratio of the calculated dye load at downstream sites to the initial amount of dye released, was determined for the 1994 studies and a dye-dosage formula was evaluated for all studies. In the February 1994 study, mean traveltime from the Merced River at River Road to the San Joaquin River near Vernalis (46.8 river miles) was 38.5 hours, and to the Delta-Mendota Canal at Tracy pumps (84.3 river miles) was 90.4 hours. In the June 1994 study, mean traveltime from Salt Slough at Highway 165 to Vernalis (64.0 river miles) was 80.1 hours. In the February 1995 study, the mean traveltime from the Tuolumne River at Roberts Ferry to Vernalis (51.5 river miles) was 35.8 hours. For the 1994 studies, the regression equations provided suitable estimates of travel-time, with ratios of estimated traveltime to mean dye traveltime of 0.94 to 1.08. However, for the 1995 dye studies, the equations considerably underestimated traveltime, with ratios of 0.49 to 0.73.In the February 1994 study, 70 percent of the dye released was recovered at Vernalis and 35percent was recovered at the Delta-Mendota Canal at Tracy pumps. In the June 1994 study, recovery was 61 percent at Patterson, 43 percent just upstream of the Tuolumne River confluence, and 37 percent at Vernalis. The dye

  16. Miocene Total Petroleum System -- Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province: Chapter 13 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Gautier, Donald L.; Hosford Scheirer, Allegra

    2008-01-01

    The confirmed stratigraphic and structural-stratigraphic Southeast Stable Shelf Assessment Unit (AU) of the Miocene Total Petroleum System (San Joaquin Basin Province) comprises all hydrocarbon accumulations within the geographic limits of the AU. Traps typically display low dip angles, gentle folds, and normal faults. Reservoirs, which range in age from fractured Mesozoic basement rocks to Holocene nonmarine rocks, are mainly Oligocene to Miocene sandstones from the uppermost slope and adjacent shelf of the San Joaquin Basin, shallow marine shelf sandstones mainly of Miocene age, and nonmarine sandstones and conglomerates mostly of Pliocene- Pleistocene age. Faults have relatively small vertical displacements. Map boundaries of the assessment unit are shown in figures 13.1 and 13.2; this assessment unit replaces the Southeast Stable Shelf play 1002 considered by the U.S. Geological Survey (USGS) in its 1995 National Assessment (Beyer, 1996). Stratigraphically, the AU extends from the uppermost crystalline basement to the topographic surface (fig. 13.3). The AU is bounded on the west by the approximate location of the shelfslope break of the San Joaquin Basin in late Miocene time, thus excluding reservoirs in the deep-water Stevens sand of Eckis (1940). The eastern boundary of the AU is the edge of onlap of Neogene sedimentary sequences on crystalline basement rocks of the Sierra Nevada. The northern AU boundary is placed at the approximate northern extent of oils in shelf-facies reservoirs known to be sourced by the Miocene Total Petroleum System. This northern boundary explicitly excludes the Deer Creek and Jasmin fields, which were included in the corresponding earlier (1995) USGS play (Beyer, 1996), but which are now known to contain oil generated from Eocene source rocks. The White Wolf Fault bounds the AU on the south.

  17. Miocene Total Petroleum System -- Lower Bakersfield Arch Assessment Unit of the San Joaquin Basin Province: Chapter 14 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Gautier, Donald L.; Hosford Scheirer, Allegra

    2008-01-01

    The Lower Bakersfield Arch Assessment Unit (AU) of the Miocene Total Petroleum System (San Joaquin Basin Province) is primarily defined by the distribution of hydrocarbons generated from biosiliceous shale of the Monterey Formation and by the distribution of basinal-facies sandstones of the Stevens sand of Eckis (1940; hereafter referred to as Stevens sand). Traps are principally stratigraphic and structural/stratigraphic, with most discovered accumulations occurring in deep-sea channel, fan, and braided submarine channel deposits of the late Miocene Stevens sand. Smaller and fewer accumulations are found in older sandstones such as the Vedder and Jewett Sands of Oligocene to Miocene age. Compared to the west side of the basin, the AU is largely unstructured, except for localized down-to-the-basin normal faults. Map boundaries of the assessment unit are shown in figures 14.1 and 14.2; this assessment unit supersedes the Lower Bakersfield Arch play 1003 considered by the U.S. Geological Survey (USGS) in the 1995 National Assessment (Beyer, 1996). Stratigraphically, the AU extends from the uppermost crystalline basement to the topographic surface (fig. 14.3). The AU is bounded on the east and north by the limit of basinal- facies sandstones of the Stevens sand; this eastern boundary corresponds to the approximate location of the shelf-slope break of the San Joaquin Basin in late Miocene time. The western boundary of the AU is the approximate eastern limit of structural deformation on the basin’s west side. The White Wolf Fault bounds the AU on the south.

  18. Winters-Domengine Total Petroleum System—Northern Nonassociated Gas Assessment Unit of the San Joaquin Basin Province: Chapter 21 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Hosford Scheirer, Allegra; Magoon, Leslie B.

    2008-01-01

    The Northern Nonassociated Gas Assessment Unit (AU) of the Winters-Domengine Total Petroleum System of the San Joaquin Basin Province consists of all nonassociated gas accumulations in Cretaceous, Eocene, and Miocene sandstones located north of township 15 South in the San Joaquin Valley. The northern San Joaquin Valley forms a northwest-southeast trending asymmetrical trough. It is filled with an alternating sequence of Cretaceous-aged sands and shales deposited on Franciscan Complex, ophiolitic, and Sierran basement. Eocene-aged strata unconformably overlie the thick Cretaceous section, and in turn are overlain unconformably by nonmarine Pliocene-Miocene sediments. Nonassociated gas accumulations have been discovered in the sands of the Panoche, Moreno, Kreyenhagen, andDomengine Formations and in the nonmarine Zilch formation of Loken (1959) (hereafter referred to as Zilch formation). Most hydrocarbon accumulations occur in low-relief, northwest-southeast trending anticlines formed chiefly by differential compaction of sediment and by northeast southwest directed compression during the Paleogene (Bartow, 1991) and in stratigraphic traps formed by pinch out of submarine fan sands against slope shales. To date, 176 billion cubic feet (BCF) of nonassociated recoverable gas has been found in fields within the assessment unit (table 21.1). A small amount of biogenic gas forms near the surface of the AU. Map boundaries of the assessment unit are shown in figures 21.1 and 21.2; in plan view, this assessment unit is identical to the Northern Area Nonassociated Gas play 1007 considered by the U.S. Geological Survey (USGS) in its 1995 National Assessment (Beyer, 1996). The AU is bounded on the east by the mapped limits of Cretaceous sandstone reservoir rocks and on the west by the east flank of the Diablo Range. The southern limit of the AU is the southernmost occurrence of nonassociated thermogenic-gas accumulations. The northern limit of the AU corresponds to the

  19. Diazinon and chlorpyrifos loads in precipitation and urban and agricultural storm runoff during January and February 2001 in the San Joaquin River basin, California

    USGS Publications Warehouse

    Zamora, Celia; Kratzer, Charles R.; Majewski, Michael S.; Knifong, Donna L.

    2003-01-01

    The application of diazinon and chlorpyrifos on dormant orchards in 2001 in the San Joaquin River Basin was 24 percent less and 3.2 times more than applications in 2000, respectively. A total of 16 sites were sampled during January and February 2001 storm events: 7 river sites, 8 precipitation sites, and 1 urban storm drain. The seven river sites were sampled weekly during nonstorm periods and more frequently during storm runoff from a total of four storms. The monitoring of storm runoff at a city storm drain in Modesto, California, occurred simultaneously with the collection of precipitation samples from eight sites during a January 2001 storm event. The highest concentrations of diazinon occurred during the storm periods for all 16 sites, and the highest concentrations of chlorpyrifos occurred during weekly nonstorm sampling for the river sites and during the January storm period for the urban storm drain and precipitation sites. A total of 60 samples (41 from river sites, 10 from precipitation sites, and 9 from the storm drain site) had diazinon concentrations greater than 0.08 ?g/L, the concentration being considered by the California Department of Fish and Game as its criterion maximum concentration for the protection of aquatic habitats. A total of 18 samples (2 from river sites, 9 from precipitation sites, and 7 from the storm drain site) exceeded the equivalent California Department of Fish and Game guideline of 0.02 ?g/L for chlorpyrifos. The total diazinon load in the San Joaquin River near Vernalis during January and February 2001 was 23.8 pounds active ingredient; of this amount, 16.9 pounds active ingredient were transported by four storms, 1.06 pounds active ingredient were transported by nonstorm events, and 5.82 pounds active ingredient were considered to be baseline loads. The total chlorpyrifos load in the San Joaquin River near Vernalis during January and February 2001 was 2.17 pounds active ingredient; of this amount, 0.702 pound active

  20. Fine-scale simulation of ammonium and nitrate over the South Coast Air Basin and San Joaquin Valley of California during CalNex-2010

    NASA Astrophysics Data System (ADS)

    Kelly, James T.; Baker, Kirk R.; Nowak, John B.; Murphy, Jennifer G.; Markovic, Milos Z.; VandenBoer, Trevor C.; Ellis, Raluca A.; Neuman, J. Andrew; Weber, Rodney J.; Roberts, James M.; Veres, Patrick R.; Gouw, Joost A.; Beaver, Melinda R.; Newman, Sally; Misenis, Chris

    2014-03-01

    National ambient air quality standards (NAAQS) have been set for PM2.5 due to its association with adverse health effects. PM2.5 design values in the South Coast Air Basin (SoCAB) and San Joaquin Valley of California exceed NAAQS levels, and NH4+ and NO3- make up the largest fraction of total PM2.5 mass on polluted days. Here we evaluate fine-scale simulations of PM2.5 NH4+ and NO3- with the Community Multiscale Air Quality model using measurements from routine networks and the California Research at the Nexus of Air Quality and Climate Change 2010 campaign. The model correctly simulates broad spatial patterns of NH4+ and NO3- including the elevated concentrations in eastern SoCAB. However, areas for model improvement have been identified. NH3 emissions from livestock and dairy facilities appear to be too low, while those related to waste disposal in western SoCAB may be too high. Analyses using measurements from flights over SoCAB suggest that problems with NH3 predictions can influence NO3- predictions there. Offline ISORROPIA II calculations suggest that overpredictions of NHx in Pasadena cause excessive partitioning of total nitrate to the particle phase overnight, while underpredictions of Na+ cause too much partitioning to the gas phase during the day. Also, the model seems to underestimate mixing during the evening boundary layer transition leading to excessive nitrate formation on some nights. Overall, the analyses demonstrate fine-scale variations in model performance within and across the air basins. Improvements in inventories and spatial allocations of NH3 emissions and in parameterizations of sea spray emissions, evening mixing processes, and heterogeneous ClNO2 chemistry could improve model performance.

  1. Neogene Gas Total Petroleum System -- Neogene Nonassociated Gas Assessment Unit of the San Joaquin Basin Province: Chapter 22 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Hosford Scheirer, Allegra; Magoon, Leslie B.

    2009-01-01

    The Neogene Nonassociated Gas Assessment Unit (AU) of the Neogene Total Petroleum System consists of nonassociated gas accumulations in Pliocene marine and brackish-water sandstone located in the south and central San Joaquin Basin Province (Rudkin, 1968). Traps consist mainly of stratigraphic lenses in low-relief, elongate domes that trend northwest-southeast. Reservoir rocks typically occur as sands that pinch out at shallow depths (1,000 to 7,500 feet) within the Etchegoin and San Joaquin Formations. Map boundaries of the assessment unit are shown in figures 22.1 and 22.2; this assessment unit replaces the Pliocene Nonassociated Gas play 1001 (shown by purple line in fig. 22.1) considered by the U.S. Geological Survey (USGS) in its 1995 National Assessment (Beyer, 1996). The AU is drawn to include all existing fields containing nonassociated gas accumulations in the Pliocene to Pleistocene section, as was done in the 1995 assessment, but it was greatly expanded to include adjacent areas believed to contain similar source and reservoir rock relationships. Stratigraphically, the AU extends from the topographic surface to the base of the Etchegoin Formation (figs. 22.3 and 22.4). The boundaries of the AU explicitly exclude gas accumulations in Neogene rocks on the severely deformed west side of the basin and gas accumulations in underlying Miocene rocks; these resources, which primarily consist of a mixture of mostly thermogenic and some biogenic gas, are included in two other assessment units. Lillis and others (this volume, chapter 10) discuss the geochemical characteristics of biogenic gas in the San Joaquin Basin Province. Primary fields in the assessment unit are defined as those containing hydrocarbon resources greater than the USGS minimum threshold for assessment—3 billion cubic feet (BCF) of gas; secondary fields contain smaller volumes of gas but constitute a significant show of hydrocarbons. Although 12 fields meet the 3 BCF criterion for inclusion in

  2. Using Coupled Subsurface-Atmospheric Simulations to Investigate the Impact of Irrigation on Atmospheric Response in the San Joaquin River Basin, California

    NASA Astrophysics Data System (ADS)

    Gilbert, J. M.; Maxwell, R. M.; Gochis, D. J.; Maples, S.; Markovich, K. H.

    2015-12-01

    Observational and modeling studies are continually improving our understanding of terrestrial and atmospheric process interactions over natural and managed systems. Recent studies have implicated irrigation as a strong factor in perturbing land-atmosphere coupling, although the details of this interaction are not fully characterized. Therefore, in this study we seek to better understand the role of subsurface flow under conditions of groundwater extraction and irrigation on resulting atmospheric states. We use an ensemble of coupled ParFlow-WRF simulations over the San Joaquin River Basin in California to identify the type and character of land-atmosphere interactions for a set of irrigation scenarios. Ensemble members include selected boundary layer schemes, land surface model configurations, and initial and boundary condition perturbations. Variability in atmospheric response, particularly in boundary layer height and precipitation patterns, under high water table (characteristic of predevelopment conditions) and lowered water table (resulting from historic groundwater extraction) conditions are evaluated in the context of the uncertainty resulting from choice of model physics and atmospheric perturbations. Hydrologic alterations associated with lowered water table elevation appear linked to the atmosphere via changes in boundary layer height.

  3. Identifying sources of dissolved organic carbon in agriculturally dominated rivers using radiocarbon age dating: Sacramento-San Joaquin River Basin, California

    USGS Publications Warehouse

    Sickman, James O.; DiGiorgio, Carol L.; Davisson, M. Lee; Lucero, Delores M.; Bergamaschi, Brian A.

    2010-01-01

    We used radiocarbon measurements of dissolved organic carbon (DOC) to resolve sources of riverine carbon within agriculturally dominated landscapes in California. During 2003 and 2004, average Δ14C for DOC was -254‰ in agricultural drains in the Sacramento-San Joaquin Delta, -218‰ in the San Joaquin River, -175‰ in the California State Water Project and -152‰ in the Sacramento River. The age of bulk DOC transiting the rivers of California's Central Valley is the oldest reported for large rivers and suggests wide-spread loss of soil organic matter caused by agriculture and urbanization. Using DAX 8 adsorbent, we isolated and measured 14C concentrations in hydrophobic acid fractions (HPOA); river samples showed evidence of bomb-pulse carbon with average Δ14C of 91 and 76‰ for the San Joaquin and Sacramento Rivers, respectively, with older HPOA, -204‰, observed in agricultural drains. An operationally defined non-HPOA fraction of DOC was observed in the San Joaquin River with seasonally computed Δ14C values of between -275 and -687‰; the source of this aged material was hypothesized to be physically protected organic-matter in high clay-content soils and agrochemicals (i.e., radiocarbon-dead material) applied to farmlands. Mixing models suggest that the Sacramento River contributes about 50% of the DOC load in the California State Water Project, and agricultural drains contribute approximately one-third of the load. In contrast to studies showing stabilization of soil carbon pools within one or two decades following land conversion, sustained loss of soil organic matter, occurring many decades after the initial agricultural-land conversion, was observed in California's Central Valley.

  4. Ground-Water Quality Data in the Central Eastside San Joaquin Basin 2006: Results from the California GAMA Program

    USGS Publications Warehouse

    Landon, Matthew K.; Belitz, Kenneth

    2008-01-01

    Ground-water quality in the approximately 1,695-square-mile Central Eastside study unit (CESJO) was investigated from March through June 2006 as part of the Statewide Basin Assessment Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Statewide Basin Assessment project was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the California State Water Resources Control Board (SWRCB) in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory (LLNL). The study was designed to provide a spatially unbiased assessment of raw ground-water quality within CESJO, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 78 wells in Merced and Stanislaus Counties. Fifty-eight of the 78 wells were selected using a randomized grid-based method to provide statistical representation of the study unit (grid wells). Twenty of the wells were selected to evaluate changes in water chemistry along selected lateral or vertical ground-water flow paths in the aquifer (flow-path wells). The ground-water samples were analyzed for a large number of synthetic organic constituents [volatile organic compounds (VOCs), gasoline oxygenates and their degradates, pesticides and pesticide degradates], constituents of special interest [perchlorate, N-nitrosodimethylamine (NDMA), and 1,2,3-trichloropropane (1,2,3-TCP)], inorganic constituents that can occur naturally [nutrients, major and minor ions, and trace elements], radioactive constituents, and microbial indicators. Naturally occurring isotopes [tritium, carbon-14, and uranium isotopes and stable isotopes of hydrogen, oxygen, nitrogen, sulfur, and carbon], and dissolved noble and other gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, samples for matrix spikes) were collected

  5. Petroleum systems used to determine the assessment units in the San Joaquin Basin Province, California: Chapter 8 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Magoon, Leslie B.; Lillis, Paul G.; Peters, Kenneth E.

    2009-01-01

    The figures and tables for each petroleum system and TPS are as follows: (1) the San Joaquin(?) petroleum system or the Neogene Nonassociated Gas TPS is a natural gas system in the southeast part of the province (figs. 8.3 through 8.8; table 8.5; this volume, chapter 22); (2) the Miocene TPS (this volume, chapters 13, 14, 15, 16, and 17) includes the McLure-Tulare(!) petroleum system north of the Bakersfield Arch (figs. 8.9 through 8.13; table 8.6), and the Antelope-Stevens(!) petroleum system south of the arch (figs. 8.14 through 8.18; table 8.7), and is summarized in figure 8.19; (3) the Eocene TPS (this volume, chapters 18 and 19) combines two petroleum systems, the Tumey-Temblor(.) covering much of the province (figs. 8.20 through 8.24; table 8.8) and the underlying Kreyenhagen-Temblor(!) (figs. 8.25 through 8.29: table 8.9), and is summarized in figure 8.30; (4) the Eocene-Miocene Composite TPS, formed by combining the Miocene and Eocene TPS (this volume, chapter 20); and (5) the Moreno-Nortonville(.) is both a petroleum system and a TPS consisting mainly of natural gas in the northern part of the province (figs. 8.31 through 8.36: table 8.10; this volume, chapter 21). Oil samples with geochemistry from surface seeps and wells used to map these petroleum systems are listed in table 8.11. Finally, the volume of oil and gas expelled by each pod of active source rock was calculated and compared with the discovered hydrocarbons in each petroleum system (figs. 8.37 through 8.39; tables 8.12 and 8.13).

  6. Status and understanding of groundwater quality in the two southern San Joaquin Valley study units, 2005-2006 - California GAMA Priority Basin Project

    USGS Publications Warehouse

    Burton, Carmen A.; Shelton, Jennifer L.; Belitz, Kenneth

    2012-01-01

    Groundwater quality in the southern San Joaquin Valley was investigated from October 2005 through March 2006 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project is conducted by the U.S. Geological Survey (USGS) in collaboration with the California State Water Resources Control Board and the Lawrence Livermore National Laboratory. There are two study units located in the southern San Joaquin Valley: the Southeast San Joaquin Valley (SESJ) study unit and the Kern County Subbasin (KERN) study unit. The GAMA Priority Basin Project in the SESJ and KERN study units was designed to provide a statistically unbiased, spatially distributed assessment of untreated groundwater quality within the primary aquifers. The status assessment is based on water-quality and ancillary data collected in 2005 and 2006 by the USGS from 130 wells on a spatially distributed grid, and water-quality data from the California Department of Public Health (CDPH) database. Data was collected from an additional 19 wells for the understanding assessment. The aquifer systems (hereinafter referred to as primary aquifers) were defined as that part of the aquifer corresponding to the perforation interval of wells listed in the CDPH database for the SESJ and KERN study units. The status assessment of groundwater quality used data from samples analyzed for anthropogenic constituents such as volatile organic compounds (VOCs) and pesticides, as well as naturally occurring inorganic constituents such as major ions and trace elements. The status assessment is intended to characterize the quality of untreated groundwater resources within the primary aquifers in the SESJ and KERN study units, not the quality of drinking water delivered to consumers. Although the status assessment applies to untreated groundwater, Federal and California regulatory and non-regulatory water-quality benchmarks that apply to drinking water are used

  7. Core description and analysis using X-radiography and cat-scanning: examples from Sacramento and San Joaquin basins, California

    SciTech Connect

    Fischer, P.J.; Setiawan, J.; Cherven, V.B.

    1986-04-01

    X-radiographs of cores from Forbes deep basin sands, the tar-saturated paralic sands of the Temblor and the Tulare fluvial sands and silts, as well as fractured siliceous units (the Monterey Formation and equivalents) reveal geologic features that are either not visible or barely discernible to the naked eye. These features include changes in grain size, grading, ripple lamination to cross-bedding, cyclic couplets in tidal sequences, bioturbation and burrowing, and fracture patterns and filling. Forbes core x-radiography from the northern Sacramento basin clearly shows a sequence of thinly bedded sand and mudstones that are microripple cross-laminated. Partial Bouma sequences (Ta-b or Tb with Ta-c) are characteristic of the thickly bedded sands below the ripple-laminated units. Cyclic sequences of mud-turbidites and finely laminated, very fine-grained sands to coarse silts characterize a sand-poor sequence that overlies a massive to indistinctly thin-bedded sand. Most of these features described above are barely discernible without x-radiography, yet all provide major input to the interpretation of the depositional environment of the Forbes Formation, as well as information regarding reservoir continuity. Tar or heavy-oil saturation of cores can be a severe problem when cores are examined. In a Tulare Formation core sequence that was x-radiographed, essentially no bedding was visible, even using UV photography. However, extensive fluvial cross-bedding throughout the core was revealed by the x-radiography. A similar, heavy oil masking problem in a Temblor Formation core near East Coalinga was also resolved by the x-ray technique. The reservoir is divided into multiple, thin, tidal couplets (4-6 in.) of oil-saturated sand separated by 1 to 3 in. thick mudstones.

  8. The Cenozoic evolution of the San Joaquin Valley, California

    USGS Publications Warehouse

    Bartow, J. Alan

    1991-01-01

    The San Joaquin Valley, which is the southern part of the 700-km-long Great Valley of California, is an asymmetric structural trough that is filled with a prism of upper Mesozoic and Cenozoic sediments up to 9 km thick; these sediments rest on crystalline basement rocks of the southwestward-tilted Sierran block. The San Joaquin sedimentary basin is separated from the Sacramento basin to the north by the buried Stockton arch and associated Stockton fault. The buried Bakersfield arch near the south end of the valley separates the small Maricopa-Tejon subbasin at the south end of the San Joaquin basin from the remainder of the basin. Cenozoic strata in the San Joaquin basin thicken southeastward from about 800 m in the north to over 9,000 m in the south. The San Joaquin Valley can be subdivided into five regions on the basis of differing structural style. They are the northern Sierran block, the southern Sierran block, the northern Diablo homocline, the westside fold belt, and the combined Maricopa-Tejon subbasin and southmargin deformed belt. Considerable facies variation existed within the sedimentary basin, particularly in the Neogene when a thick section of marine sediment accumulated in the southern part of the basin, while a relatively thin and entirely nonmarine section was deposited in the northern part. The northern Sierran block, the stable east limb of the valley syncline between the Stockton fault and the San Joaquin River, is the least deformed region of the valley. Deformation consists mostly of a southwest tilt and only minor late Cenozoic normal faulting. The southern Sierran block, the stable east limb of the valley syncline between the San Joaquin River and the Bakersfield arch, is similar in style to the northern part of the block, but it has a higher degree of deformation. Miocene or older normal faults trend mostly north to northwest and have a net down-to-the-west displacement with individual offsets of as much as 600 m. The northern Diablo

  9. Albitization of plagioclase crystals in the Stevens sandstone (Miocene), San Joaquin Basin, California, and the Frio Formation (Oligocene), Gulf Coast, Texas. A TEM/AEM study

    SciTech Connect

    Hirt, W.G. ); Wenk, H.R. ); Boles, J.R. )

    1993-06-01

    Conventional Transmission Electron Microscopy (CTEM) and Analytical Electron Microscopy (AEM) studies of partially albitized plagioclase crystals taken from drill cores from the Stevens sandstone (Miocene), San Joaquin, California, and the Frio Formation (Oligocene), Gulf Coast, Texas, reveal that replacement of Ca-rich plagioclase cores by nearly pure albite (Ab[sub 96]-Ab[sub 100]) occurs along submicroscopic ([minus]15 nm wide) en echelon (001) and (110) cleavages. The cleavages are the result of changes in the localized stress regime created by dissolution of adjacent phases. Photomicrographs show albite-lined brittle cleavage crosscutting albitized semibrittle fractures. Such crosscutting relationships can be explained by a reduction in effective stress associated with the albitization process. On a macroscopic scale, this reduction in effective stress implies that the transition from hydrostatic to lithostatic pressure is discontinuous. 30 refs., 7 figs.

  10. Effects of smectite on the oil-expulsion efficiency of the Kreyenhagen Shale, San Joaquin Basin, California, based on hydrous-pyrolysis experiments

    USGS Publications Warehouse

    Lewan, Michael D.; Dolan, Michael P.; Curtis, John B.

    2014-01-01

    The amount of oil that maturing source rocks expel is expressed as their expulsion efficiency, which is usually stated in milligrams of expelled oil per gram of original total organic carbon (TOCO). Oil-expulsion efficiency can be determined by heating thermally immature source rocks in the presence of liquid water (i.e., hydrous pyrolysis) at temperatures between 350°C and 365°C for 72 hr. This pyrolysis method generates oil that is compositionally similar to natural crude oil and expels it by processes operative in the subsurface. Consequently, hydrous pyrolysis provides a means to determine oil-expulsion efficiencies and the rock properties that influence them. Smectite in source rocks has previously been considered to promote oil generation and expulsion and is the focus of this hydrous-pyrolysis study involving a representative sample of smectite-rich source rock from the Eocene Kreyenhagen Shale in the San Joaquin Basin of California. Smectite is the major clay mineral (31 wt. %) in this thermally immature sample, which contains 9.4 wt. % total organic carbon (TOC) comprised of type II kerogen. Compared to other immature source rocks that lack smectite as their major clay mineral, the expulsion efficiency of the Kreyenhagen Shale was significantly lower. The expulsion efficiency of the Kreyenhagen whole rock was reduced 88% compared to that of its isolated kerogen. This significant reduction is attributed to bitumen impregnating the smectite interlayers in addition to the rock matrix. Within the interlayers, much of the bitumen is converted to pyrobitumen through crosslinking instead of oil through thermal cracking. As a result, smectite does not promote oil generation but inhibits it. Bitumen impregnation of the rock matrix and smectite interlayers results in the rock pore system changing from water wet to bitumen wet. This change prevents potassium ion (K+) transfer and dissolution and precipitation reactions needed for the conversion of smectite to

  11. Floods of 1952 in California. Flood of January 1952 in the south San Francisco Bay region; Snowmelt flood of 1952 in Kern River, Tulare Lake, and San Joaquin River basins

    USGS Publications Warehouse

    Rantz, S.E.; Stafford, H.M.

    1956-01-01

    Two major floods occurred in California in 1952. The first was the flood of January 11-13 in the south San Francisco Bay region that resulted from heavy rains which began on the morning of January 11 and ended about noon January 13. This flood was notable for the magnitude of the peak discharges, although these discharges were reduced by the controlling effect of reservoirs for conservation and flood-control purposes. The flood damage was thereby reduced, and no lives were lost; damage, nevertheless, amounted to about $1.400.000. The second flood was due, not to the immediate runoff of heavy rain, but to the melting of one of the largest snow packs ever recorded in the Sierra Nevada range. In the spring and summer of 1952, flood runoff occurred on all the major streams draining the Sierra Nevada. In the northern half of the Central Valley basin?the Sacramento River basin?flood volumes and maximum daily discharges were not exceptional. and flood damage was not appreciable. However, in the southern half, which is formed by the Kern River, Tulare Lake, and San Joaquin River basins, new records for snowmelt runoff were established for some streams; but for below-normal temperatures and shorter, less warm hot spells, record flood discharges would have occurred on many others. In the three basins an area of 200,000 acres. largely cropland. was inundated, and damage was estimated at $11,800,000.

  12. Water supply issues of the San Joaquin Valley in California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The San Joaquin Valley of California is undoubtedly one of the most productive agricultural regions of the United States, and of the world. The valley was a Miocene epicontinental sea bounded by the Sierra Nevada igneous arc in the east and the Coast Range accretionary terrane in the west. It is now...

  13. Occurrence, Distribution, Instantaneous Loads, and Yields of Dissolved Pesticides in the San Joaquin River Basin, California, During Summer Conditions, 1994 and 2001

    USGS Publications Warehouse

    Brown, Larry R.; Panshin, Sandra Y.; Kratzer, Charles R.; Zamora, Celia; Gronberg, JoAnn M.

    2004-01-01

    Water samples were collected from 22 drainage basins for analysis of 48 dissolved pesticides during summer flow conditions in 1994 and 2001. Of the 48 pesticides, 31 were reported applied in the basin in the 28 days preceding the June 1994 sampling, 25 in the 28 days preceding the June 2001 sampling, and 24 in the 28 days preceding the August 2001 sampling. The number of dissolved pesticides detected was similar among sampling periods: 26 were detected in June 1994, 28 in June 2001, and 27 in August 2001. Concentrations of chlorpyrifos exceeded the California criterion for the protection of aquatic life from acute exposure at six sites in June 1994 and at five sites in June 2001. There was a single exceedance of the criterion for diazinon in June 1994. The number of pesticides applied in tributary basins was highly correlated with basin area during each sampling period (Spearman's r = 0.85, 0.70, and 0.84 in June 1994, June 2001, and August 2001, respectively, and p < 0.01 in all cases). Larger areas likely include a wider variety of crops, resulting in more varied pesticide use. Jaccard's similarities, cluster analysis, principal components analysis, and instantaneous load calculations generally indicate that west-side tributary basins were different from east-side tributary basins. In general, west-side basins had higher concentrations, instantaneous loads, and instantaneous yields of dissolved pesticides than east-side basins, although there were a number of exceptions. These differences may be related to a number of factors, including differences in basin size, soil texture, land use, irrigation practices, and stream discharge.

  14. California Cenozoic Biostratigraphy -- Paleogene: Chapter 4 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    McDougall, Kristin

    2008-01-01

    The time transgressive nature of the California benthic foraminiferal stages is in most cases the result of poor taxonomy, use of local species ranges, and a lack of understanding about the type sections. Correcting these problems allows the stages to be consistently applied and enhances their ability to identify coeval strata. Each stage is identified by the first and last appearances of selected cosmopolitan benthic foraminiferal species and of reliable local species. Although further study is needed, the stages correlate with the international time scale. The revised age interpretation of the stages suggests that the Cheneyian Stage is coeval with planktic zone P1 through P3, the Ynezian Stage is coeval with planktic zone P4, the Bulitian Stage is missing in most section but when present is coeval with zones P5 and P6a, the Penutian Stage is coeval with planktic zones P6b through early P9 (no younger than the overlap between P9 and CP11), the Ulatisian Stage is coeval with P9 (younger than CP11) through P11, the Narizian Stage is coeval with zones P12 through P15, and the Refugian Stage is coeval with zones P16 and P17.

  15. Bottom-up, decision support system development : a wetlandsalinity management application in California's San Joaquin Valley

    SciTech Connect

    Quinn, Nigel W.T.

    2006-05-10

    Seasonally managed wetlands in the Grasslands Basin ofCalifornia's San Joaquin Valley provide food and shelter for migratorywildfowl during winter months and sport for waterfowl hunters during theannual duck season. Surface water supply to these wetland contain saltwhich, when drained to the San Joaquin River during the annual drawdownperiod, negatively impacts downstream agricultural riparian waterdiverters. Recent environmental regulation, limiting discharges salinityto the San Joaquin River and primarily targeting agricultural non-pointsources, now addresses return flows from seasonally managed wetlands.Real-time water quality management has been advocated as a means ofmatching wetland return flows to the assimilative capacity of the SanJoaquin River. Past attempts to build environmental monitoring anddecision support systems to implement this concept have failed forreasons that are discussed in this paper. These reasons are discussed inthe context of more general challenges facing the successfulimplementation of environmental monitoring, modelling and decisionsupport systems. The paper then provides details of a current researchand development project which will ultimately provide wetland managerswith the means of matching salt exports with the available assimilativecapacity of the San Joaquin River, when fully implemented. Manipulationof the traditional wetland drawdown comes at a potential cost to thesustainability of optimal wetland moist soil plant habitat in thesewetlands - hence the project provides appropriate data and a feedback andresponse mechanism for wetland managers to balance improvements to SanJoaquin River quality with internally-generated information on the healthof the wetland resource. The author concludes the paper by arguing thatthe architecture of the current project decision support system, whencoupled with recent advances in environmental data acquisition, dataprocessing and information dissemination technology, holds significantpromise

  16. A delta-fed submarine ramp alternative to the canyon-fed depositional model of the Stevens submarine fan system, southeastern San Joaquin basin, Kern County, California

    SciTech Connect

    Harrison, C.P.

    1996-12-31

    Deep-marine sands of the Upper Miocene Stevens Sandstone, one of the most important hydrocarbon-producing units in the United States, were deposited by sediment-gravity flows in the Bakersfield Arch area of the southern San Joaquin basin. The Stevens Sandstone has historically been considered to be a thick turbidite succession shed off the southern Sierra Nevada as four fans in a long-lived submarine fan system fed by several large submarine canyons. Access to previously unavailable proprietary 2-D and 3-D seismic data sets, carefully calibrated by well-log and core data, permits a more complete understanding of the depositional architecture of this highly petroliferous, deep-marine depositional system. This study concludes that these units were deposited in a delta-fed, line- sourced deep-sea system, whose distribution was structurally-controlled. Seismic lines examined in this study show evidence for a large fault-controlled slump feature in the area that has been referred to as {open_quotes}Rosedale Canyon,{close_quotes} and no evidence supports the existence of submarine canyons feeding the system. The highly progradational Stevens interval consists of thick siliciclastic units separated by thin, intervening biosiliceous shales. Seismically, the upper bounding surfaces of these biosiliceous shales represent major downlap surfaces. As sands were deposited by high-density turbidity currents, the area of the present Bakersfield Arch developed into a deep-sea braid plain. Smaller-scale linear features detected on horizon slices through the 3-D seismic data cube have been interpreted in this study as braided channelform features deposited on the deep-sea braid plain. Hydrocarbon production along these linear trends may be associated with porosity and permeability variations resulting from channelized versus non-channelized sedimentation.

  17. A delta-fed submarine ramp alternative to the canyon-fed depositional model of the Stevens submarine fan system, southeastern San Joaquin basin, Kern County, California

    SciTech Connect

    Harrison, C.P. )

    1996-01-01

    Deep-marine sands of the Upper Miocene Stevens Sandstone, one of the most important hydrocarbon-producing units in the United States, were deposited by sediment-gravity flows in the Bakersfield Arch area of the southern San Joaquin basin. The Stevens Sandstone has historically been considered to be a thick turbidite succession shed off the southern Sierra Nevada as four fans in a long-lived submarine fan system fed by several large submarine canyons. Access to previously unavailable proprietary 2-D and 3-D seismic data sets, carefully calibrated by well-log and core data, permits a more complete understanding of the depositional architecture of this highly petroliferous, deep-marine depositional system. This study concludes that these units were deposited in a delta-fed, line- sourced deep-sea system, whose distribution was structurally-controlled. Seismic lines examined in this study show evidence for a large fault-controlled slump feature in the area that has been referred to as [open quotes]Rosedale Canyon,[close quotes] and no evidence supports the existence of submarine canyons feeding the system. The highly progradational Stevens interval consists of thick siliciclastic units separated by thin, intervening biosiliceous shales. Seismically, the upper bounding surfaces of these biosiliceous shales represent major downlap surfaces. As sands were deposited by high-density turbidity currents, the area of the present Bakersfield Arch developed into a deep-sea braid plain. Smaller-scale linear features detected on horizon slices through the 3-D seismic data cube have been interpreted in this study as braided channelform features deposited on the deep-sea braid plain. Hydrocarbon production along these linear trends may be associated with porosity and permeability variations resulting from channelized versus non-channelized sedimentation.

  18. Geological literature on the San Joaquin Valley of California

    USGS Publications Warehouse

    Maher, J.C.; Trollman, W.M.; Denman, J.M.

    1973-01-01

    The following list of references includes most of the geological literature on the San Joaquin Valley and vicinity in central California (see figure 1) published prior to January 1, 1973. The San Joaquin Valley comprises all or parts of 11 counties -- Alameda, Calaveras, Contra Costa, Fresno, Kern, Kings, Madera, Merced, San Joaquin, Stanislaus, and Tulare (figure 2). As a matter of convenient geographical classification the boundaries of the report area have been drawn along county lines, and to include San Benito and Santa Clara Counties on the west and Mariposa and Tuolumne Counties on the east. Therefore, this list of geological literature includes some publications on the Diablo and Temblor Ranges on the west, the Tehachapi Mountains and Mojave Desert on the south, and the Sierra Nevada Foothills and Mountains on the east.

  19. 75 FR 2079 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-14

    ... facilities. Also, please see our response to CPF comment 3. B. San Joaquin Valley Air Pollution Control...) San Joaquin Valley Unified Air Pollution Control District. (1) Rule 4570, ``Confined Animal Facilities... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, San Joaquin Valley...

  20. 78 FR 53038 - Interim Final Determination to Stay and Defer Sanctions; California; San Joaquin Valley

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ..., 2011 (76 FR 69896), we published a partial approval and partial disapproval of the San Joaquin Valley... AGENCY 40 CFR Part 52 Interim Final Determination to Stay and Defer Sanctions; California; San Joaquin... imposition of highway sanctions based on a proposed approval of revisions to the San Joaquin Valley...

  1. The three-dimensional geologic model used for the 2003 National Oil and Gas Assessment of the San Joaquin Basin Province, California: Chapter 7 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Hosford Scheirer, Allegra

    2013-01-01

    We present a three-dimensional geologic model of the San Joaquin Basin (SJB) that may be the first compilation of subsurface data spanning the entire basin. The model volume spans 200 × 90 miles, oriented along the basin axis, and extends to ~11 miles depth, for a total of more than 1 million grid nodes. This model supported the 2003 U.S. Geological Survey assessment of future additions to reserves of oil and gas in the SJB. Data sources include well-top picks from more than 3,200 wildcat and production wells, published cross sections, regional seismic grids, and fault maps. The model consists of 15 chronostratigraphic horizons ranging from the Mesozoic crystalline basement to the topographic surface. Many of the model units are hydrocarbon reservoir rocks and three—the Cretaceous Moreno Formation, the Eocene Kreyenhagen Formation, and the Miocene Monterey Formation—are hydrocarbon source rocks. The White Wolf Fault near the southern end of the basin divides the map volume into 2 separate fault blocks. The construction of a three-dimensional model of the entire SJB encountered many challenges, including complex and inconsistent stratigraphic nomenclature, significant facies changes across and along the basin axis, time-transgressive formation tops, uncertain correlation of outcrops with their subsurface equivalents, and contradictory formation top data. Although some areas of the model are better resolved than others, the model facilitated the 2003 resource assessment in several ways, including forming the basis of a petroleum system model and allowing a precise definition of assessment unit volumes.

  2. Areal distribution of selected trace elements, salinity, and major ions in shallow ground water, Tulare Basin, Southern San Joaquin Valley, California

    USGS Publications Warehouse

    Fujii, Roger; Swain, W.C.

    1995-01-01

    The distribution of salinity and selected trace elements in shallow ground water in the Tulare Basin, California, was assessed to evaluate potential problems related to disposal in evaporation ponds of irrigation drain water containing elevated concentrations of selenium and other trace elements. The constituents of primary concern were selenium, arsenic, and salinity; uranium, boron, and molybdenum also were evaluated. Samples from 117 shallow wells were analyzed, and the results for samples from 110 of the wells were interpreted in relation to surficial geology, sediment depositional environment, soil characteristics, and hydrologic processes to determine the geochemical and hydrologic factors affecting the distribution of these constituents in ground water. In general, shallow ground water in areas where concentrations of salinity and most trace elements are elevated is influenced primarily by sediments derived from marine sedimentary rocks originating in the Coast Range, San Emigdio Mountains, and Tehachapi Mountains, and probably by unusual exposures of similar marine formations in the Sierra Nevada. Ground water in areas where concentrations of salinity and trace elements are significantly lower generally is influenced by igneous and metamorphic rocks exposed in the Sierra Nevada. In addition to sources of sediments, evaporation of shallow ground water, as indicated by isotopic enrichment of oxygen-18 and deuterium, increases salinity and concentrations of conservative trace elements such as selenium (under oxidizing conditions) and boron. Redox conditions affect the oxidation state of all trace elements of concern, except boron, and were found to be a major influence on trace-element solubility. Under oxidized conditions, selenate predominates and behaves conservatively, and arsenate predominates and is affected by sorption reactions that can limit arsenic solubility. Under reduced conditions, selenium is reduced to insoluble elemental selenium and arsenite

  3. Late Cenozoic Basins of northern California

    NASA Astrophysics Data System (ADS)

    Nilsen, Tor H.; Clarke, Samuel H.

    1989-12-01

    The late Cenozoic basins of northern California developed in response to both convergent tectonics associated with subduction of the Farallon plate (and its modern representatives, the Juan de Fuca and Gorda plates) and transform tectonics associated with northward migration of the Mendocino triple junction and formation of the San Andreas fault system. The modern Eel River basin north of the Mendocino triple junction is an active forearc basin located between the Cascade magmatic arc to the east and the trench at the foot of the continental slope of northern California and Oregon to the west. Five different types of late Cenozoic basins or fragments of basins are preserved in onshore northern California south of the Mendocino triple junction: (1) remnants of a formerly more extensive Neogene forearc basin preserved locally in downdropped blocks within the San Andreas fault system; (2) remnants of slightly older trench-slope basins that generally developed west of but which may locally structurally underlie the younger forearc basin; (3) younger strike-slip-related structural basins that have developed along active right-lateral faults of the San Andreas fault system; (4) broad shallow embayments, perhaps similar to the modern San Francisco Bay, that were connected to the deeper Pacific Ocean to the west; and (5) structurally emplaced remnants of oceanic crust and its overlying sedimentary cover (the King Range terrane). Our preliminary stratigraphic and sedimentologic studies suggest that much of northern California was covered during the Neogene by a forearc basin that may have extended as far south as the San Francisco Bay region and into the southern San Joaquin Valley. As the Mendocino triple junction migrated northward during the late Cenozoic, the southern margin of the forearc basin was uplifted, basin deposits were stripped off by erosion, and the locus of forearc sedimentation shifted progressively northward through time. Preserved but isolated fragments

  4. Eocene Total Petroleum System -- North and East of the Eocene West Side Fold Belt Assessment Unit of the San Joaquin Basin Province: Chapter 19 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Gautier, Donald L.; Hosford Scheirer, Allegra

    2009-01-01

    The North and East of Eocene West Side Fold Belt Assessment Unit (AU) of the Eocene Total Petroleum System of the San Joaquin Basin Province comprises all hydrocarbon accumulations within the geographic and stratigraphic limits of this confirmed AU. Oil and associated gas accumulations occur in Paleocene through early middle Miocene marine to nonmarine sandstones found on the comparatively stable northeast shelf of the basin. The assessment unit is located north and east of the thickest accumulation of Neogene sediments and the west side fold belt. The area enclosed by the AU has been affected by only mild deformation since Eocene time. Traps containing known accumulations are mostly low-relief domes, anticlines, and up-dip basin margin traps with faulting and stratigraphic components. Map boundaries of the assessment unit are shown in figures 19.1 and 19.2; this assessment unit replaces the Northeast Shelf of Neogene Basin play 1006, the East Central Basin and Slope North of Bakersfield Arch play 1010, and part of the West Side Fold Belt Sourced by Pre-middle Miocene Rocks play 1005 considered by the U.S. Geological Survey (USGS) in their 1995 National Assessment (Beyer, 1996). Stratigraphically, the AU includes rocks from the uppermost crystalline basement to the topographic surface. In the region of overlap with the Central Basin Monterey Diagenetic Traps Assessment Unit, the North and East of Eocene West Side Fold Belt AU extends from basement rocks to the top of the Temblor Formation (figs. 19.3 and 19.4). In map view, the northern boundary of the assessment unit corresponds to the northernmost extent of Eocene-age Kreyenhagen Formation. The northeast boundary is the eastern limit of possible oil reservoir rocks near the eastern edge of the basin. The southeast boundary corresponds to the pinch-out of Stevens sand of Eckis (1940) to the south, which approximately coincides with the northern flank of the Bakersfield Arch (fig. 19.1). The AU is bounded on the

  5. 76 FR 68103 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... Rulemaking For the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

  6. 77 FR 7536 - Revisions to the California State Implementation Plan, Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-13

    ... is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control District... 40 CFR Part 52 Environmental protection, Air pollution control, Incorporation by reference, Reporting... AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, Joaquin Valley Unified...

  7. SRTM Perspective View with Landsat Overlay: San Joaquin Valley, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    San Joaquin, the name given to the southern portion of California's vast Central Valley, has been called the world's richest agricultural valley. In this perspective view generated using data from the Shuttle Radar Topography Mission and an enhanced Landsat image, we are looking toward the southwest over a checkerboard pattern of agricultural fields. Mt. Pinos, a popular location for stargazing at 2,692 meters (8,831 feet) looms above the valley floor and is visible on the left side of the image. The productive southern San Joaquin is in reality a desert, averaging less than 12.7 cm (5 inches) of rain per year. Through canals and irrigation, the region nurtures some two hundred crops including grapes, figs, apricots, oranges, and more than 4,047 square-km (1,000,000 acres) of cotton. The California Aqueduct, transporting water from the Sacramento River Delta through the San Joaquin, runs along the base of the low-lying Wheeler Ridge on the left side of the image. The valley is not all agriculture though. Kern County, near the valley's southern end, is the United States' number one oil producing county, and actually produces more crude oil than Oklahoma. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors, from Landsat data, approximate natural color.

    The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U

  8. Sustainability of irrigated agriculture in the San Joaquin Valley, California.

    PubMed

    Schoups, Gerrit; Hopmans, Jan W; Young, Chuck A; Vrugt, Jasper A; Wallender, Wesley W; Tanji, Ken K; Panday, Sorab

    2005-10-25

    The sustainability of irrigated agriculture in many arid and semiarid areas of the world is at risk because of a combination of several interrelated factors, including lack of fresh water, lack of drainage, the presence of high water tables, and salinization of soil and groundwater resources. Nowhere in the United States are these issues more apparent than in the San Joaquin Valley of California. A solid understanding of salinization processes at regional spatial and decadal time scales is required to evaluate the sustainability of irrigated agriculture. A hydro-salinity model was developed to integrate subsurface hydrology with reactive salt transport for a 1,400-km(2) study area in the San Joaquin Valley. The model was used to reconstruct historical changes in salt storage by irrigated agriculture over the past 60 years. We show that patterns in soil and groundwater salinity were caused by spatial variations in soil hydrology, the change from local groundwater to snowmelt water as the main irrigation water supply, and by occasional droughts. Gypsum dissolution was a critical component of the regional salt balance. Although results show that the total salt input and output were about equal for the past 20 years, the model also predicts salinization of the deeper aquifers, thereby questioning the sustainability of irrigated agriculture.

  9. Pesticide transport in the San Joaquin River Basin

    USGS Publications Warehouse

    Dubrovsky, N.M.; Kratzer, C.R.; Panshin, S.Y.; Gronberg, J.A.M.; Kuivila, K.M.

    2000-01-01

    Pesticide occurrence and concentrations were evaluated in the San Joaquin River Basin to determine potential sources and mode of transport. Land use in the basin is mainly agricultural. Spatial variations in pesticide occurrence were evaluated in relation to pesticide application and cropping patterns in three contrasting subbasins and at the mouth of the basin. Temporal variability in pesticide occurrence was evaluated by fixed interval sampling and by sampling across the Hydrograph during winter storms. Four herbicides (simazine, metolachlor, dacthal, and EPTC) and two insecticides (diazinon and chlorpyrifos) were detected in more than 50 percent of the samples. Temporal, and to a lesser extent spatial, variation in pesticide occurrence is usually consistent with pesticide application and cropping patterns. Diazinon concentrations changed rapidly during winter storms, and both eastern and western tributaries contributed diazinon to the San Joaquin River at concentrations toxic to the water flea Ceriodaphnia dubia at different times during the hydrograph. During these storms, toxic concentrations resulted from the transport of only a very small portion of the applied diazinon.

  10. Thermal history determined by fission-track dating for three sedimentary basins in California and Wyoming

    USGS Publications Warehouse

    Naeser, Nancy D.

    1984-01-01

    The use of fission-tracks is demonstrated in studies of time-temperature relationships in three sedimentary basins in the western United States; in the Tejon Oil Field area of the southern San Joaquin Valley, California; in the northeastern Green River basin, Wyoming, and in drill holes in the southern Powder River Basin, Wyoming.

  11. Foraminifera and paleoenvironments in the Etchegoin and lower San Joaquin Formations, west-central San Joaquin valley, California

    SciTech Connect

    Lagoe, M.B.; Tenison, J.A.; Buehring, R. )

    1991-02-01

    The Etchegoin and San Joaquin formations preserve a rich stratigraphic record of paleoenvironments, deposition, and tectonics during the late Miocene-Pliocene development of the San Joaquin basin. The distribution of foraminifera within these formations can help constrain this record, which includes final filling of the basin, facies responses to sea level changes, and active movement on the San Andreas fault system. The distribution of foraminifera in core samples is analyzed from seven wells along the west-central San joaquin basin - four from Buena Vista oil field, one from western Elk Hills oil field, and two from an area just south of South Belridge oil field. A model of modern, shallow- to marginal-marine foraminiferal biofacies is used to interpret the Etchegoin-San Joaquin faunal distributions. This modern model distinguishes marsh, tidal channel, intertidal, lagoonal, littoral, and shallow sublittoral environments. Ongoing work calibrating this foraminiferal record to the lithologic and macrofossil records in addition to interpreted depositional systems within these formations will further define relationships between paleoenvironments, relative sea level, and tectonics.

  12. Geothermal resources of California sedimentary basins

    USGS Publications Warehouse

    Williams, C.F.; Grubb, F.V.; Galanis, S.P.

    2004-01-01

    The 2004 Department of Energy (DOE) Strategic Plan for geothermal energy calls for expanding the geothermal resource base of the United States to 40,000 MW of electric power generating potential. This will require advances in technologies for exploiting unconventional geothermal resources, including Enhanced Geothermal Systems (EGS) and geopressured geothermal. An investigation of thermal conditions in California sedimentary basins through new temperature and heat flow measurements reveals significant geothermal potential in some areas. In many of the basins, the combined cooling effects of recent tectonic and sedimentary processes result in relatively low (<60 mW/m2) heat flow and geothermal gradients. For example, temperatures in the upper 3 km of San Joaquin, Sacramento and Ventura basins are typically less than 125??C and do not reach 200??c by 5 km. By contrast, in the Cuyama, Santa Maria and western Los Angeles basins, heat flow exceeds 80 mW/m2 and temperatures near or above 200??C occur at 4 to 5 km depth, which represents thermal conditions equivalent to or hotter than those encountered at the Soultz EGS geothermal site in Europe. Although the extractable geothermal energy contained in these basins is not large relative to the major California producing geothermal fields at The Geysers or Salton Sea, the collocation in the Los Angeles basin of a substantial petroleum extraction infrastructure and a major metropolitan area may make it attractive for eventual geothermal development as EGS technology matures.

  13. Status and understanding of groundwater quality in the northern San Joaquin Basin, 2005

    USGS Publications Warehouse

    Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth; Jurgens, Bryant C.

    2010-01-01

    Groundwater quality in the 2,079 square mile Northern San Joaquin Basin (Northern San Joaquin) study unit was investigated from December 2004 through February 2005 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project was developed in response to the Groundwater Quality Monitoring Act of 2001 that was passed by the State of California and is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The Northern San Joaquin study unit was the third study unit to be designed and sampled as part of the Priority Basin Project. Results of the study provide a spatially unbiased assessment of the quality of raw (untreated) groundwater, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 61 wells in parts of Alameda, Amador, Calaveras, Contra Costa, San Joaquin, and Stanislaus Counties; 51 of the wells were selected using a spatially distributed, randomized grid-based approach to provide statistical representation of the study area (grid wells), and 10 of the wells were sampled to increase spatial density and provide additional information for the evaluation of water chemistry in the study unit (understanding/flowpath wells). The primary aquifer systems (hereinafter, primary aquifers) assessed in this study are defined by the depth intervals of the wells in the California Department of Public Health database for each study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from quality of groundwater in the primary aquifers; shallow groundwater may be more vulnerable to contamination from the surface. Two types of assessments were made: (1) status, assessment of the current quality of the groundwater resource; and (2) understanding, identification of the natural and human factors

  14. Estimating Natural Flows into the California's Sacramento - San Joaquin Delta

    NASA Astrophysics Data System (ADS)

    Huang, G.; Kadir, T.; Chung, F. I.

    2014-12-01

    Natural flows into the California's Sacramento - San Joaquin Delta under predevelopment vegetative conditions, if and when reconstructed, can serve as a useful guide to establish minimum stream flows, restoration targets, and a basis for assessing impacts of global warming in the Bay-Delta System. Daily simulations of natural Delta flows for the period 1922-2009 were obtained using precipitation-snowmelt-runoff models for the upper watersheds that are tributaries to the California's Central Valley, and then routing the water through the Central Valley floor area using a modified version of the California Central Valley Groundwater-Surface Water Simulation Model (C2VSIM) for water years 1922 through 2009. Daily stream inflows from all major upper watersheds were simulated using 23 Soil Water Assessment Tool (SWAT) models. Historical precipitation and reference evapotranspiration data were extracted from the SIMETAW2 with the 4km gridded meteorological data. The Historical natural and riparian vegetation distributions were compiled from several pre-1900 historical vegetation maps of the Central Valley. Wetlands were dynamically simulated using interconnected lakes. Flows overtopping natural levees were simulated using flow rating curves. New estimates of potential evapotranspiration from different vegetative classes under natural conditions were also used. Sensitivity simulations demonstrate that evapotranspiration estimates, native vegetation distribution, surface-groundwater interaction parameters, extinction depth for groundwater uptake, and other physical processes play a key role in the magnitude and timing of upstream flows arriving at the Delta. Findings contradict a common misconception that the magnitude of inflows to the Delta under natural vegetative conditions is greater than those under the historical agricultural and urban land use development. The developed models also enable to study the impacts of global warming by modifying meteorological and

  15. Geologic maps of the Sacramento-San Joaquin Delta, California

    USGS Publications Warehouse

    Atwater, Brian F.

    1982-01-01

    The Sacramento-San Joaquin Delta, the arm of the San Francisco Bay estuary that reaches into the Central Valley of California, differs from typical coastal-plain deltas in three important respects.  First, rather than meeting the ocean individually and directly, all major waterways of this delta discharge via a single constricted outlet into a chain of estuarine bays and straits.  Second, in the most common vertical sequence of deposits, peat and mud deposited in tidal marshes and swamps (tidal wetlands) directly overlie alluvium or eolian sand, a sequence recording a landward spread of tidal environments rather than the seaward migration of fluvial environments that is typical of coastal-plain deltas (Cosby, 1941, p. 43; Thompson, 1957, p. 12; Shlemon and Begg, 1975, p. 259; Atwater and Belknap, 1980).  Finally, intensive human use has led to a peculiar set of conflicts involving rights to water and responsibilities for flood-control levees (Kockelman and other, 1982).

  16. Groundwater quality in the Madera and Chowchilla subbasins of the San Joaquin Valley, California

    USGS Publications Warehouse

    Shelton, Jennifer L.; Fram, Miranda S.; Belitz, Kenneth

    2013-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s untreated groundwater quality and increases public access to groundwater-quality information. The Madera and Chowchilla subbasins of the San Joaquin Valley constitute one of the study units being evaluated. The Madera-Chowchilla study unit is about 860 square miles and consists of the Madera and Chowchilla groundwater subbasins of the San Joaquin Valley Basin (California Department of Water Resources, 2003; Shelton and others, 2009). The study unit has hot, dry summers and cool, moist winters. Average annual rainfall ranges from 11 to 15 inches, most of which occurs between November and February. The main surface-water features in the study unit are the San Joaquin, Fresno, and Chowchilla Rivers, and the Madera and Chowchilla canals. Land use in the study unit is about 69 percent (%) agricultural, 28% natural (mainly grasslands), and 3% urban. The primary crops are orchards and vineyards. The largest urban area is the city of Madera. The primary aquifer system is defined as those parts of the aquifer corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. In the Madera-Chowchilla study unit, these wells typically are drilled to depths between 200 and 800 feet, consist of a solid casing from land surface to a depth of about 140 to 400 feet, and are perforated below the solid casing. Water quality in the primary aquifer system may differ from that in the shallower and deeper parts of the aquifer system. The primary aquifer system in the study unit consists of Quaternary-age alluvial-fan and fluvial deposits that were formed by the rivers draining the Sierra Nevada. Sediments consist of gravels, sands

  17. Groundwater Quality in the Central Eastside San Joaquin Valley, California

    USGS Publications Warehouse

    Belitz, Kenneth; Landon, Matthew K.

    2010-01-01

    The Central Eastside study unit is located in California's San Joaquin Valley. The 1,695 square mile study unit includes three groundwater subbasins: Modesto, Turlock, and Merced (California Department of Water Resources, 2003). The primary water-bearing units consist of discontinuous lenses of gravel, sand, silt, and clay, which are derived largely from the Sierra Nevada Mountains to the east. Public-supply wells provide most of the drinking water supply in the Central Eastside. Consequently, the primary aquifer in the Central Eastside study unit is defined as that part of the aquifer corresponding to the perforated interval of wells listed in the California Department of Public Health database. Public-supply wells are typically drilled to depths of 200 to 350 feet, consist of solid casing from the land surface to a depth of about 100 to 200 feet, and they are perforated below the solid casing. Water quality in the shallower and deeper parts of the aquifer system may differ from that in the primary aquifer. The Central Eastside study unit has hot and dry summers and cool, moist, winters. Average annual rainfall ranges from 11 to 15 inches. The Stanislaus, Tuolumne, and Merced Rivers, with headwaters in the Sierra Nevada Mountains, are the primary streams traversing the study unit. Land use in the study unit is approximately 59 percent (%) agricultural, 34% natural (primarily grassland), and 7% urban. The primary crops are almonds, walnuts, peaches, grapes, grain, corn, and alfalfa. The largest urban areas (2003 population in parentheses) are the cities of Modesto (206,872), Turlock (63,467), and Merced (69,512). Municipal water use accounts for about 5% of the total water use in the Central Eastside study unit, with the remainder used for irrigated agriculture. Groundwater accounts for about 75% of the municipal supply, and surface water accounts for about 25%. Recharge to the groundwater flow system is primarily from percolation of irrigation return

  18. Subsidence due to Excessive Groundwater Withdrawal in the San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Corbett, F.; Harter, T.; Sneed, M.

    2011-12-01

    Francis Corbett1, Thomas Harter1 and Michelle Sneed2 1Department of Land Air and Water Resources, University of California, Davis. 2U.S. Geological Survey Western Remote Sensing and Visualization Center, Sacramento. Abstract: Groundwater development within the Central Valley of California began approximately a century ago. Water was needed to supplement limited surface water supplies for the burgeoning population and agricultural industries, especially within the arid but fertile San Joaquin Valley. Groundwater levels have recovered only partially during wet years from drought-induced lows creating long-term groundwater storage overdraft. Surface water deliveries from Federal and State sources led to a partial alleviation of these pressure head declines from the late 1960s. However, in recent decades, surface water deliveries have declined owing to increasing environmental pressures, whilst water demands have remained steady. Today, a large portion of the San Joaquin Valley population, and especially agriculture, rely upon groundwater. Groundwater levels are again rapidly declining except in wet years. There is significant concern that subsidence due to groundwater withdrawal, first observed at a large scale in the middle 20th century, will resume as groundwater resources continue to be depleted. Previous subsidence has led to problems such as infrastructure damage and flooding. To provide a support tool for groundwater management on a naval air station in the southern San Joaquin Valley (Tulare Lake Basin), a one-dimensional MODFLOW subsidence model covering the period 1925 to 2010 was developed incorporating extensive reconstruction of historical subsidence and water level data from various sources. The stratigraphy used for model input was interpreted from geophysical logs and well completion reports. Gaining good quality data proved problematic, and often values needed to be estimated. In part, this was due to the historical lack of awareness/understanding of

  19. Geologic logs of geotechnical cores from the subsurface Sacramento-San Joaquin Delta, California

    USGS Publications Warehouse

    Maier, Katherine L.; Ponti, Daniel J.; Tinsley, John C.; Gatti, Emma; Pagenkopp, Mark

    2014-01-01

    This report presents and summarizes descriptive geologic logs of geotechnical cores collected from 2009–12 in the Sacramento–San Joaquin Delta, California, by the California Department of Water Resources. Graphic logs are presented for 1,785.7 ft of retained cores from 56 borehole sites throughout the Sacramento-San Joaquin Delta. Most core sections are from a depth of ~100–200 feet. Cores primarily contain mud, silt, and sand lithologies. Tephra (volcanic ash and pumice), paleosols, and gravels are also documented in some core sections. Geologic observations contained in the core logs in this report provide stratigraphic context for subsequent sampling and data for future chronostratigraphic subsurface correlations.

  20. Ground-water conditions and storage capacity in the San Joaquin Valley, California

    USGS Publications Warehouse

    Davis, G.H.; Green, J.H.; Olmsted, F.H.; Brown, D.W.

    1959-01-01

    The San Joaquin Valley includes roughly the southern two-thirds of the Great Central Valley of California. It is a broad structural trough surrounded by mountains. The northern part of the valley drains through the San Joaquin River northward to San Francisco Bay ; the southern part of the valley normally is a basin of interior drainage tributary to evaporation sumps in the trough of the valley, chiefly Tulare and Buena Vista Lake beds. In years of normal discharge most of the streamflow in the southern part of the valley not diverted for irrigation finds its way to Tulare and Buena Vista Lake beds. In the historic past, however, during years of heavy floods the low divide between Buena Vista and Tulare Lakes and the low divide between Tulare Lake and the San Joaquin River were overtopped and through-flowing drainage occurred over the full length of the valley. Because the Tulare Lake bed is the lowest point and also the largest sump, this whole basin of interior drainage is commonly referred to as the Tulare Lake drainage basin. Average annual precipitation ranges from more than 15 inches in the north- eastern part of the valley to less than 4 inches in the southwestern part. The precipitation decreases from north to south and from east to west across the valley. Streamflow, the critical quantity in the water supply, depends almost wholly on the amount and distribution of precipitation in the Sierra Nevada to the east. Much of this precipitation falls as snow, and the snowpack acts as a natural reservoir retaining much of the annual runoff until late spring and early summer. The mean seasonal runoff to the San Joaquin Valley is nearly 10 million acre- feet, of which about two-thirds is tributary to the San Joaquin River; the remaining third is tributary to Tulare Lake drainage basin. In 1952 about 8.5 million acre-feet of surface water was diverted for irrigation. Withdrawals of ground water for irrigation in 1952 approximated 7.5 million acre-feet. The surface of

  1. Organic Carbon Trends, Loads, and Yields to the Sacramento-San Joaquin Delta, California, Water Years 1980 to 2000

    USGS Publications Warehouse

    Saleh, Dina K.; Domagalski, Joseph L.; Kratzer, Charles R.; Knifong, Donna L.

    2003-01-01

    Organic carbon, nutrient, and suspended sediment concentration data were analyzed for the Sacramento and San Joaquin River Basins for the period 1980-2000. The data were retrieved from three sources: the U.S. Geological Survey's National Water Information System, the U.S. Environmental Protection Agency's Storage and Retrieval System, and the California Interagency Ecological Program's relational database. Twenty sites were selected, all of which had complete records of daily streamflow data. These data met the minimal requirements of the statistical programs used to estimate trends, loads, and yields. The seasonal Kendall program was used to estimate trends in organic carbon, nutrient, and suspended sediment. At all 20 sites, analyses showed that in the 145 analyses for the seven constituents, 95 percent of the analyses had no significant trend. Dissolved organic carbon (DOC) concentrations were significant only for four sites: the American River at Sacramento, the Sacramento River sites near Freeport, Orestimba Creek at River Roads near Crows Landing, and the San Joaquin River near Vernalis. Loads were calculated using two programs, ESTIMATOR and LOADEST2. The 1998 water year was selected to describe loads in the Sacramento River Basin. Organic carbon, nutrient, and suspended sediment loads at the Sacramento River sites near Freeport included transported loads from two main upstream sites: the Sacramento River at Verona and the American River at Sacramento. Loads in the Sacramento River Basin were affected by the amount of water diverted to the Yolo Bypass (the amount varies annually, depending on the precipitation and streamflow). Loads at the Sacramento River sites near Freeport were analyzed for two hydrologic seasons: the irrigation season (April to September) and the nonirrigation season (October to March). DOC loads are lower during the irrigation season then they are during the nonirrigation season. During the irrigation season, water with low

  2. 76 FR 298 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-04

    ... Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation......... 12/17/92 08/24/07 On September 17, 2007, the submittal for San Joaquin Valley Unified Air Pollution... require that fixed covers be equipped with a 95% efficient Air Pollution Control (APC) device. c....

  3. 76 FR 39777 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollutions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... Air Pollutions Control District (SJVUAPCD) AGENCY: Environmental Protection Agency (EPA). ACTION... San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State... Rule 344 D.2.b.2 require that fixed covers be equipped with a 95% efficient Air Pollution Control...

  4. 77 FR 745 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) Correction In rule document 2011-33660 appearing on...

  5. 77 FR 58078 - Withdrawal of Approval of Air Quality Implementation Plans; California; San Joaquin Valley; 1...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-19

    ... San Joaquin Valley (SJV) extreme ozone nonattainment area. 75 FR 10420. The California Air Resources... the 1-hour ozone NAAQS effective May 17, 2004. 69 FR 20550 (April 16, 2004).\\1\\ The SIP revisions that...-hour ozone standard in the SJV area. See 75 FR 10420, 10421 (March 8, 2010). \\1\\ EPA established a...

  6. 78 FR 58266 - Designation of Areas for Air Quality Planning Purposes; California; San Joaquin Valley, South...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-23

    ... AGENCY 40 CFR Part 81 Designation of Areas for Air Quality Planning Purposes; California; San Joaquin... standard. DATES: The proposed rule published on August 27, 2009 (74 FR 43654) is withdrawn with respect to...-4102, israels.ken@epa.gov . SUPPLEMENTARY INFORMATION: On August 27, 2009 (74 FR 43654), EPA...

  7. Distribution and movements of female northern pintails radiotagged in San Joaquin Valley, California

    USGS Publications Warehouse

    Fleskes, Joseph P.; Jarvis, Robert L.; Gilmer, David S.

    2002-01-01

    To improve understanding of northern pintail (Anas acuta) distribution in central California (CCA), we radiotagged 191 Hatch-Year (HY) and 228 After-Hatch-Year (AHY) female northern pintails during late August-early October, 1991-1993, in the San Joaquin Valley (SJV) and studied their movements through March each year. Nearly all (94.3%) wintered in CCA, but 5.7% went to southern California, Mexico, or unknown areas; all that went south left before hunting season. Of the 395 radiotagged pintails that wintered in CCA, 83% flew from the SJV north to other CCA areas (i.e., Sacramento Valley [SACV], Sacramento-San Joaquin River Delta [Delta], Suisun Marsh, San Francisco Bay) during September-January; most went during December. Movements coincid- ed with start of hunting seasons and were related to pintail age, mass, capture location, study year, and weather. Among pintails with less than average mass, AHY individuals tended to leave the SJV earlier than HY individuals. Weekly distribution was similar among capture locations and years but a greater percentage of pintails radiotagged in Tulare Basin (south part of SJV) were known to have (10.3% vs. 0.9%) or probably (13.8% vs. 4.6%) wintered south of CCA than pintails radiotagged in northern SJV areas (i.e., Grassland Ecological Area [EA] and Mendota Wildlife Area [WA]). Also, a greater percentage of SJV pintails went to other CCA areas before hunting season in the drought year of 1991-1992 than later years (10% vs. 3-5%). The percent of radiotagged pintails from Grass- land EA known to have gone south of CCA also was greater during 1991-1992 than later years (2% vs. 0%), but both the known (19% vs. 4%) and probable (23% vs. 12%) percent from Tulare Basin that went south was greatest during 1993-1994, when availability of flooded fields there was lowest. The probability of pintails leaving the SJV was 57% (95% CI = 8-127%) greater on days with than without rain, and more movements per bird out of SJV occurred in years

  8. Transport of sediment-bound organochlorine pesticides to the San Joaquin River, California

    USGS Publications Warehouse

    Kratzer, Charles R.

    1998-01-01

    Most of the application of the organophosphate insecticide diazinon in the San Joaquin River Basin occurs in winter to control wood boring insects in dormant almond orchards. A federal-state collaborative study found that diazinon accounted for most of the observed toxicity of San Joaquin River water to water fleas in February 1993. Previous studies focused mainly on west-side inputs to the San Joaquin River. In this 1994 study, the three major east-side tributaries to the San Joaquin River, the Merced, Tuolumne, and Stanislaus Rivers, and a downstream site on the San Joaquin River were sampled throughout the hydrographs of a late January and an early February storm. In both storms, the Tuolumne River had the highest concentrations of diazinon and transported the largest load of the three tributaries. The Stanislaus River was a small source in both storms. On the basis of previous storm sampling and estimated traveltimes, ephemeral west-side creeks probably were the main diazinon source early in the storms, whereas the Tuolumne and Merced Rivers and east-side drainages directly to the San Joaquin River were the main sources later. Although 74 percent of diazinon transport in the San Joaquin River during 1991-1993 occurred in January and February, transport during each of the two 1994 storms was only 0.05 percent of the amount applied during preceding dry periods. Nevertheless, some of the diazinon concentrations in the San Joaquin River during the January storm exceeded 0.35 micrograms per liter, a concentration shown to be acutely toxic to water fleas. Diazinon concentrations were highly variable during the storms and frequent sampling was required to adequately describe the concentration curves and to estimate loads.

  9. Water-Quality Assessment of the San Joaquin-Tulare Basins--Entering a New Decade

    USGS Publications Warehouse

    Gronberg, Jo Ann M.; Kratzer, Charles R.; Burow, Karen R.; Domagalski, Joseph L.; Phillips, Steven P.

    2004-01-01

    In 1991, the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey began to address the need for consistent and scientifically sound information for managing the Nation's water resources. The long-term goals of this program are to assess the status of the quality of freshwater streams and aquifers, to describe trends or changes in water quality over time, and to provide a sound understanding of the natural and human factors that affect the quality of these resources (Hirsch and others, 1988). Investigations are being conducted within major river basins and aquifer systems, or 'study units,' throughout the Nation to provide a framework for national and regional water-quality assessments. In 2001, the NAWQA Program began its second decade of intensive water-quality assessments. Forty-two of the original 59 study units (reduced by elimination or combination) are being revisited (Gilliom and others, 2001). The San Joaquin-Tulare Basins study unit (fig. 1), located in central California, was a part of the first decadal cycle of the Program investigations and remains in the second cycle.

  10. 3D Geologic Modeling of the Southern San Joaquin Basin for the Westcarb Kimberlina Demonstration Project- A Status Report

    SciTech Connect

    Wagoner, J

    2009-02-23

    The objective of the Westcarb Kimberlina pilot project is to safely inject 250,000 t CO{sub 2}/yr for four years into the deep subsurface at the Clean Energy Systems (CES) Kimberlina power plant in southern San Joaquin Valley, California. In support of this effort, we have constructed a regional 3D geologic model of the southern San Joaquin basin. The model is centered on the Kimberlina power plant and spans the UTM range E 260000-343829 m and N 3887700-4000309 m; the depth of the model ranges from the topographic surface to >9000 m below sea level. The mapped geologic units are Quaternary basin fill, Tertiary marine and continental deposits, and pre-Tertiary basement rocks. Detailed geologic data, including surface maps, borehole data, and geophysical surveys, were used to define the geologic framework. Fifteen time-stratigraphic formations were mapped, as well as >140 faults. The free surface is based on a 10 m lateral resolution DEM. We use Earthvision (Dynamic Graphics, Inc.) to integrate the geologic and geophysical information into a 3D model of x,y,z,p nodes, where p is a unique integer index value representing the geologic unit. This grid represents a realistic model of the subsurface geology and provides input into subsequent flow simulations.

  11. 3D Geologic Modeling of the Southern San Joaquin Basin for the Westcarb Kimberlina Demonstration Project- A Status Report

    SciTech Connect

    Wagoner, J

    2009-04-24

    The objective of the Westcarb Kimberlina pilot project is to safely inject 250,000 t CO{sub 2}/yr for four years into the deep subsurface at the Clean Energy Systems (CES) Kimberlina power plant in southern San Joaquin Valley, California. In support of this effort, we have constructed a regional 3D geologic model of the southern San Joaquin basin. The model is centered on the Kimberlina power plant and spans the UTM range E 260000-343829 m and N 3887700-4000309 m; the depth of the model ranges from the topographic surface to >9000 m below sea level. The mapped geologic units are Quaternary basin fill, Tertiary marine and continental deposits, and pre-Tertiary basement rocks. Detailed geologic data, including surface maps, borehole data, and geophysical surveys, were used to define the geologic framework. Fifteen time-stratigraphic formations were mapped, as well as >140 faults. The free surface is based on a 10 m lateral resolution DEM. We use Earthvision (Dynamic Graphics, Inc.) to integrate the geologic and geophysical information into a 3D model of x,y,z,p nodes, where p is a unique integer index value representing the geologic unit. This grid represents a realistic model of the subsurface geology and provides input into subsequent flow simulations.

  12. Comparison of Oxygenate Mixing Ratios Observed in the San Joaquin Valley, California, as a Consequence of Dairy Farming

    NASA Astrophysics Data System (ADS)

    Yang, M. M.; Blake, D. R.

    2009-12-01

    The San Joaquin Valley Air Basin in Central California is plagued with air quality problems, and is classified by the U.S. Environmental Protection Agency (EPA) as a serious non-attainment area for health-based eight-hour federal ozone (smog) standard (1). One of the main sources of Volatile Organic Compounds (VOCs), and indirect sources of ozone in the Valley, has been identified as dairy farming (2). Among these compounds, we have found that several OVOCs such as ethanol, methanol, acetone and acetaldehyde are produced in major quantities throughout the San Joaquin valley as by-products of yeast fermentation of silage and photochemical oxidation. These oxygenates, especially ethanol, play an important role in ozone (O3) formation within the valley. Since 2008, several different types of sampling protocols have been employed by our group in order to determine the degree of enhancement of the four oxygenates in the valley air shed, as well as to determine their sources, emission profiles and emission rates (2). In 2008 and 2009, samples were in early summer, allowing us to compare the difference in concentration levels between both years.The photochemical production of ozone was calculated for each of the four oxygenates and approximately one hundred other quantified VOCs. Based on the Maximum Incremental Reactivity (MIR) scale and concentrations of each oxygenate in the atmosphere, for both 2008 and 2009, as much as 15% of O3 production in the valley is from ethanol and its photochemical by-product acetaldehyde. Our findings suggest that the data observed in 2008 is consistent with that observed in 2009, with a slight decrease in concentrations overall for 2009. 1. Lindberg, J. Analysis of the San Joaquin Valley 2007 Ozone Plan. State of California Air Resources Board. Final Draft Staff Report. 5/30/2007. 2. M. Yang, S. Meinardi, C. Krauter, D.R. Blake. Characterization of VOC Emissions from Various Components of Dairy Farming and their effect on San Joaquin

  13. Conjunctive management of groundwater and surface water resources in the San Joaquin Valley of California

    SciTech Connect

    Quinn, N.W.T.

    1992-01-01

    The San Joaquin-Tulare Conjunctive Use Model (SANTUCM) was developed to evaluate possible long-term scenarios for long term management of drainage and drainage related problems in the western San Joaquin Valley of California. The unique aspect of the conjunctive use model is its coupling of a surface water delivery operations model with a regional groundwater model. A salinity model has been added to utilize surface water model output and allow assessment of compliance with State Water Resources Control Board water quality objectives for the San Joaquin River. The results of scenario runs, performed to data, using the SANTUCM model show table lowering and consequent drainage reduction can be achieved through a combination of source control, land retirement and regional groundwater pumping. The model also shows that water transfers within the existing distribution system are technically feasible and might allow additional releases to be made from Friant Dam for water quality maintenance in the San Joaquin River. However, upstream of Mendota Pool, considerable stream losses to the aquifer are anticipated, amounting to as much as 70% of in-stream flow.

  14. Trace elements in bed sediments of the San Joaquin River and its tributary streams, California, 1985

    SciTech Connect

    Clifton, D.G.; Gilliom, R.J.

    1989-01-01

    Bed sediments were sampled at 24 sites on the San Joaquin River, California and its tributaries in October 1985 to assess the distribution of trace elements and factors affecting their concentrations. The proportion of less than 62-micrometer sediment was significantly (alpha = 0.05) correlated with organic-carbon concentrations. Bed sediments from tributaries originating in the Sierra Nevada were much coarser than sediments in streams draining the Coast Range and western valley. Selenium concentrations in water have been measured. Interrelations among trace elements were examined using principal component analysis. 57% of the variance was accounted for in the first two principal components, which together show a distinct separation between sites dominated by Coast Range sediments and sites dominated by Sierra Nevada sediments. The third and fourth components accounted for 21% of the variance and distinguished the mixed-source sediments of the intermittent upper San Joaquin River from other parts of the river system. Generally, elements in bed sediments of the San Joaquin River and its tributaries were similar in concentration to elements in San Joaquin Valley soils, and concentrations were far below hazardous waste criteria. Concentrations were lower than in sediments from some polluted urban rivers and water more comparable to other rural agricultural rivers. 35 refs., 3 figs., 14 tabs.

  15. Adaptive Management Methods to Protect the California Sacramento-San Joaquin Delta Water Resource

    NASA Technical Reports Server (NTRS)

    Bubenheim, David

    2016-01-01

    The California Sacramento-San Joaquin River Delta is the hub for California's water supply, conveying water from Northern to Southern California agriculture and communities while supporting important ecosystem services, agriculture, and communities in the Delta. Changes in climate, long-term drought, water quality changes, and expansion of invasive aquatic plants threatens ecosystems, impedes ecosystem restoration, and is economically, environmentally, and sociologically detrimental to the San Francisco Bay/California Delta complex. NASA Ames Research Center and the USDA-ARS partnered with the State of California and local governments to develop science-based, adaptive-management strategies for the Sacramento-San Joaquin Delta. The project combines science, operations, and economics related to integrated management scenarios for aquatic weeds to help land and waterway managers make science-informed decisions regarding management and outcomes. The team provides a comprehensive understanding of agricultural and urban land use in the Delta and the major water sheds (San Joaquin/Sacramento) supplying the Delta and interaction with drought and climate impacts on the environment, water quality, and weed growth. The team recommends conservation and modified land-use practices and aids local Delta stakeholders in developing management strategies. New remote sensing tools have been developed to enhance ability to assess conditions, inform decision support tools, and monitor management practices. Science gaps in understanding how native and invasive plants respond to altered environmental conditions are being filled and provide critical biological response parameters for Delta-SWAT simulation modeling. Operational agencies such as the California Department of Boating and Waterways provide testing and act as initial adopter of decision support tools. Methods developed by the project can become routine land and water management tools in complex river delta systems.

  16. Distribution and mobility of selenium and other trace elements in shallow ground water of the western San Joaquin Valley, California

    USGS Publications Warehouse

    Deverel, S.J.; Millard, S.P.

    1986-01-01

    Samples of shallow groundwater that underlies much of the irrigated area in the western San Joaquin Valley of California were analyzed for various major ions and trace elements, including selenium. Concentrations of the major ions generally were similar for groundwater collected in the two primary geologic zones--the alluvial fan and basin trough. Soils in the alluvial fan zone are derived from Coast Range rocks and soils in the basin-trough zone are from a mixture of Sierra Nevada and Coast Range sources. Most of the variance in concentrations of major ions, as determined by principal components analysis, was associated with groundwater salinity and the dominant ions--magnesium, sodium, sulfate, and chloride. Most of the variance in trace elements was associated with concentrations of boron, molybdenum, selenium, and vanadium, which are present as mobile oxyanions. The concentrations of oxyanions trace elements were significantly correlated (a=0.05) with groundwater salinity , but the correlations between selenium and salinity and molybdenum and salinity were significantly different (a=0.05) in the alluvial fan geologic zone compared with the basin-trough geologic zone. In addition, selenium concentrations are significantly (a=0.05) higher in the groundwater of the alluvial fan zone than in the basin-trough zone. The evidence suggests that the main factors influencing selenium concentrations in the shallow groundwater are the degree of groundwater salinity and geologic source of the alluvial soil material. (Author 's abstract)

  17. Environmental Setting of the Lower Merced River Basin, California

    USGS Publications Warehouse

    Gronberg, Jo Ann M.; Kratzer, Charles R.

    2006-01-01

    In 1991, the U.S. Geological Survey began to study the effects of natural and anthropogenic influences on the quality of ground water, surface water, biology, and ecology as part of the National Water-Quality Assessment (NAWQA) Program. As part of this program, the San Joaquin-Tulare Basins study unit is assessing parts of the lower Merced River Basin, California. This report provides descriptions of natural and anthropogenic features of this basin as background information to assess the influence of these and other factors on water quality. The lower Merced River Basin, which encompasses the Mustang Creek Subbasin, gently slopes from the northeast to the southwest toward the San Joaquin River. The arid to semiarid climate is characterized by hot summers (highs of mid 90 degrees Fahrenheit) and mild winters (lows of mid 30 degrees Fahrenheit). Annual precipitation is highly variable, with long periods of drought and above normal precipitation. Population is estimated at about 39,230 for 2000. The watershed is predominately agricultural on the valley floor. Approximately 2.2 million pounds active ingredient of pesticides and an estimated 17.6 million pounds active ingredient of nitrogen and phosphorus fertilizer is applied annually to the agricultural land.

  18. Organochlorine pesticide residues in bed sediments of the San Joaquin River and its tributary streams, California

    USGS Publications Warehouse

    Gilliom, R.J.; Clifton, D.G.

    1987-01-01

    The distribution and concentrations of organochlorine pesticide residues in bed sediments were assessed from samples collected at 24 sites in the San Joaquin River and its tributaries in the San Joaquin Valley, California. Sampling was designed to collect the finest grained bed sediments present in the vicinity of each site. One or more of the 14 pesticides analyzed were detected at every site. Pesticides detected at one or more sites were chlordane, DDD, DDE, DDT, dieldrin, endosulfan, mirex, and toxaphene. Pesticides not detected were endrin, heptachlor, heptachlor epoxide, lindane, methoxychlor, and perthane. The most frequently detected pesticides were DDD (83% of sites), DDE (all sites), DDT (33% of sites), and dieldrin (58% of sites). Maximum concentrations of these pesticides, which were correlated with each other and with the amount of organic carbon in the sample, were DDD, 260 micrograms/kg; DDE, 430 micrograms/kg; DDT, 420 micrograms/kg; and dieldrin, 8.9 micrograms/kg. Six small tributary streams that drain agricultural areas west of the San Joaquin River had the highest concentrations. Water concentrations and loads were estimated for each pesticide from its concentration in bed sediments, the concentration of suspended sediment, and streamflow. Estimated loadings of DDD, DDE, DDT, and dieldrin from tributaries to the San Joaquin River indicate that most of the loading to the river at the time of the study was probably from the westside tributaries. Estimated water concentrations exceeded the aquatic life criterion for the sum of DDD, DDE, and DDt of 0.001 microgram/L at nine of the 24 sites sampled. Five of the nine sites are westside tributaries and one is the San Joaquin River near Vernalis. (Author 's abstract)

  19. Inputs of the Dormant-Spray Pesticide, Diazinon, to the San Joaquin River, California, February 1993

    USGS Publications Warehouse

    Domagalski, Joseph L.; Dubrovsky, Neil M.; Kratzer, Charles R.

    1995-01-01

    INTRODUCTION The objective of the National Water Quality Assessment (NAWQA) Program of the U.S. Geological Survey is to describe the status and trends of the Nation's water quality with respect to natural features of the environment and human activities or land-use. Pesticides are a major water-quality issue in the San Joaquin Valley of California (fig. 1), and pesticide residues may be transported to rivers and streams in agricultural runoff following winter storms. Three sites in the western San Joaquin Valley were monitored during and after two February 1993 storms. The storms occurred after extensive spraying of organophosphate insecticides, mostly diazinon, on almond and other stone-fruit orchards.

  20. Cotton yield losses and ambient ozone concentrations in California's San Joaquin Valley

    SciTech Connect

    Olszyk, D.; Bytnerowicz, A.; Kats, G.; Reagan, C.; Hake, S.

    1993-01-01

    Based on controlled experiments and simulation modeling, ozone air pollution has been estimated to cause significant yield losses to cotton. The study reported here was conducted to verify losses for Acala cotton (Gossypium hirsutum SJ2) along a gradient of ambient ozone (O3) concentrations across the San Joaquin Valley in California. Cotton was grown in nonfiltered (NF) and charcoal-filtered (CF) open-top chambers at four sites during the 1988-1989 summer growing seasons. Cotton yields were reduced in NF compared to CF air in general proportion to O3 concentrations across all sites and years. Greatest cotton yield losses were at Dinuba on the east side of the San Joaquin Valley and lowest were on the west side of the valley. Ozone injury symptoms on cotton were most noticeable in areas with greatest yield losses.

  1. Emissions of organic carbon and methane from petroleum and dairy operations in California's San Joaquin Valley

    NASA Astrophysics Data System (ADS)

    Gentner, D. R.; Ford, T. B.; Guha, A.; Boulanger, K.; Brioude, J.; Angevine, W. M.; de Gouw, J. A.; Warneke, C.; Gilman, J. B.; Ryerson, T. B.; Peischl, J.; Meinardi, S.; Blake, D. R.; Atlas, E.; Lonneman, W. A.; Kleindienst, T. E.; Beaver, M. R.; St. Clair, J. M.; Wennberg, P. O.; VandenBoer, T. C.; Markovic, M. Z.; Murphy, J. G.; Harley, R. A.; Goldstein, A. H.

    2014-05-01

    Petroleum and dairy operations are prominent sources of gas-phase organic compounds in California's San Joaquin Valley. It is essential to understand the emissions and air quality impacts of these relatively understudied sources, especially for oil/gas operations in light of increasing US production. Ground site measurements in Bakersfield and regional aircraft measurements of reactive gas-phase organic compounds and methane were part of the CalNex (California Research at the Nexus of Air Quality and Climate Change) project to determine the sources contributing to regional gas-phase organic carbon emissions. Using a combination of near-source and downwind data, we assess the composition and magnitude of emissions, and provide average source profiles. To examine the spatial distribution of emissions in the San Joaquin Valley, we developed a statistical modeling method using ground-based data and the FLEXPART-WRF transport and meteorological model. We present evidence for large sources of paraffinic hydrocarbons from petroleum operations and oxygenated compounds from dairy (and other cattle) operations. In addition to the small straight-chain alkanes typically associated with petroleum operations, we observed a wide range of branched and cyclic alkanes, most of which have limited previous in situ measurements or characterization in petroleum operation emissions. Observed dairy emissions were dominated by ethanol, methanol, acetic acid, and methane. Dairy operations were responsible for the vast majority of methane emissions in the San Joaquin Valley; observations of methane were well correlated with non-vehicular ethanol, and multiple assessments of the spatial distribution of emissions in the San Joaquin Valley highlight the dominance of dairy operations for methane emissions. The petroleum operations source profile was developed using the composition of non-methane hydrocarbons in unrefined natural gas associated with crude oil. The observed source profile is

  2. Distribution and mobility of selenium and other trace elements in shallow ground water of the western San Joaquin Valley, California

    SciTech Connect

    Deverel, S.J.; Millard, S.P.

    1986-01-01

    Samples of shallow groundwater that underlies much of the irrigated area in the western San Joaquin Valley of California were analyzed for various major ions and trace elements, including selenium. Concentrations of the major ions generally were similar for groundwater collected in the two primary geologic zones - the alluvial fan and basin trough. Most of the variance in concentrations of major ions, as determined by principal components analysis, was associated with groundwater salinity and the dominant ions - magnesium, sodium, sulfate, and chloride. Most of the variance in trace elements was associated with concentrations of boron, molybdenum, selenium, and vanadium, which are present as mobile oxyanions. The concentrations of oxyanions trace elements were significantly correlated with groundwater salinity, but the correlations between selenium and salinity and molybdenum and salinity were significantly difference in the alluvial fan geologic zone compared with the basin-trough geologic zone. In addition, selenium concentrations are significant higher in the groundwater of the alluvial fan zone than in the basin-trough zone. The Evidence suggests that the main factors influencing selenium concentrations in the shallow groundwater are the degree of groundwater salinity and geologic source of the alluvial soil material. 31 refs., 5 figs., 3 tabs.

  3. San Joaquin kit fox Vulpes macrotis mutica program, Camp Roberts, California

    SciTech Connect

    Not Available

    1991-08-01

    Camp Roberts is a California Army National Guard Training Site located in central California. The San Joaquin kit fox, an endangered subspecies of kit fox, has been known to occur at Camp Roberts since 1960. The population of foxes began to increase in the early 1970's when use of rodenticides decreased. In 1987 the California Army National Guard contracted EG G Energy Measurements to conduct a 3-year study to assess the effects of Camp Roberts activities on the kit fox population. The major objective of the Camp Roberts Environmental Studies Program is to prepare a comprehensive Biological Assessment of the effects of all NGB-authorized activities (includes military training, anticipated construction projects, repair and maintenance activities, and all NGB-authorized non-military activities such as hunting and fishing programs, grazing leases, etc.) on San Joaquin kit fox. The program also provides NGB with the scientific expertise necessary to insure compliance with the Endangered Species Act. The specific objective of this report is to summarize progress and results of the Environmental Studies Program made during Fiscal Years 1989 and 1990 (FY89/90). 32 refs., 9 figs., 14 tabs.

  4. Hydrogeologic characterization of the Modesto Area, San Joaquin Valley, California

    USGS Publications Warehouse

    Burow, Karen R.; Shelton, Jennifer L.; Hevesi, Joseph A.; Weissmann, Gary S.

    2004-01-01

    Hydrogeologic characterization was done to develop an understanding of the hydrogeologic setting near Modesto by maximizing the use of existing data and building on previous work in the region. A substantial amount of new lithologic and hydrologic data are available that allow a more complete and updated characterization of the aquifer system. In this report, geologic units are described, a database of well characteristics and lithology is developed and used to update the regional stratigraphy, a water budget is estimated for water year 2000, a three-dimensional spatial correlation map of aquifer texture is created, and recommendations for future data collection are summarized. The general physiography of the study area is reflected in the soils. The oldest soils, which have low permeability, exist in terrace deposits, in the interfan areas between the Stanislaus, Tuolumne, and Merced Rivers, at the distal end of the fans, and along the San Joaquin River floodplain. The youngest soils have high permeability and generally have been forming on the recently deposited alluvium along the major stream channels. Geologic materials exposed or penetrated by wells in the Modesto area range from pre-Cretaceous rocks to recent alluvium; however, water-bearing materials are mostly Late Tertiary and Quaternary in age. A database containing information from more than 3,500 drillers'logs was constructed to organize information on well characteristics and subsurface lithology in the study area. The database was used in conjunction with a limited number of geophysical logs and county soil maps to define the stratigraphic framework of the study area. Sequences of red paleosols were identified in the database and used as stratigraphic boundaries. Associated with these paleosols are very coarse grained incised valley-fill deposits. Some geophysical well logs and other sparse well information suggest the presence of one of these incised valley-fill deposits along and adjacent to the

  5. Irrigation water supply and demand data for 1976, 1980, and 1984 for the western San Joaquin Valley, California

    USGS Publications Warehouse

    Templin, W.E.; Haltom, T.C.

    1994-01-01

    This report presents the irrigation water supply and demand data for 1976, 1980, and 1984 for 32 water districts in the western San Joaquin Valley, California. Data are provided for each water district or each of the three years if the data were available. The complete data base is given by water district or each township, range, and section in the rectangular system for the subdivision of public lands. These data were complied for use in a ground- water-flow model, compilation of a water-budget, and use by the San Joaquin Valley Drainage Program in a study of water management in the western San Joaquin Valley, California. The data are presented in a computer-readable format to improve data utilization and to condense the information so that it can be more readily distributed to users.

  6. Late Cenozoic stratigraphy and structure of the western margin of the central San Joaquin Valley, California

    USGS Publications Warehouse

    Lettis, William R.

    1982-01-01

    Late Cenozoic Stratigraphy Late Cenozoic deposits in the west-central San Joaquin Valley and adjacent foothills of the Diablo Range consist mainly of unconsolidated, poorly-sorted to well-sorted gravel, sand, silt and clay derived primarily from the Diablo Range and secondarily from the Sierra Nevada. Sedimentary structures, such as channeled contacts, laminated bedding, cross-stratification and clast-imbrication indicate that most of the deposits were transported and laid down by running water. These deposits are described and their facies relationships are illustrated in the 'Late Cenozoic Stratigraphy' section of this report (see Figures 17, and 26, and Table 9). Sediment shed from the Diablo Range accumulated primarily as a complex of coalescing alluvial fans on the piedmont slope of a San Joaquin Valley that at one time extended across the foothill belt to the present margin of the central Diablo Range; and as local fills within stream valleys of the Diablo Range foothills tributary to the San Joaquin Valley. These deposits are well exposed in Interstate-5 roadcuts, California Aqueduct and Delta-Mendota canal cuts, and stream banks along the many ephemeral and intermittent streams draining the Diablo Range. Sediment derived from the Sierra Nevada is confined primarily to the floodbasin of the San Joaquin Valley. It includes arkosic riverine and floodbasin deposits from the San Joaquin River and associated sloughs, as well as local ephemeral and perennial pond, swamp, oxbow-lake and lake deposits. These deposits are well-exposed in stream banks of the San Joaquin River and a few of the larger sloughs such as Salt Slough, Mud Slough and Kings Slough. Well-sorted, fine- and medium-grained, quartzose, cross-bedded sand, presumably derived from the Sierra Nevada, locally interfinger with or underlie fine-grained Coast Range alluvial-fan deposits. The sand probably originated by eolian reworking of Sierran alluvium from the floodbasin of the lower San Joaquin River

  7. Organic chemicals in the environment: Pesticides in the San Joaquin River, California: Inputs from dormant sprayed orchards

    USGS Publications Warehouse

    Domagalski, J.L.; Dubrovsky, N.M.; Kratzer, C.R.

    1997-01-01

    Rainfall-induced runoff mobilized pesticides to the San Joaquin River and its tributaries during a 3.8-cm rainstorm beginning the evening of 7 February and lasting through the morning of 8 Feb. 1993. Two distinct peaks of organophosphate pesticide concentrations were measured at the mouth of the San Joaquin River. These two peaks were attributed to contrasts between the soil texture, basin size, pesticide-use patterns, and hydrology of the eastern and western San Joaquin Valley. The fine soil texture and small size of the western tributary basins contributed to rapid runoff. In western valley streams, diazinon concentrations peaked within hours of the rainfall's end and then decreased because of a combination of dilution with pesticide- free runoff from the nearby Coast Ranges and decreasing concentrations in the agricultural runoff. Peak concentrations for the Merced River, a large tributary of the eastern San Joaquin Valley, occurred at least a day later than those of the western tributary streams. That delay may be due to the presence of well-drained soils in the eastern San Joaquin Valley, the larger size of the Merced River drainage basin, and the management of surface-water drainage networks. A subsequent storm on 18 and 19 February resulted in much lower concentrations of most organophosphate pesticides suggesting that the first storm had mobilized most of the pesticides that were available for rainfall-induced transport.

  8. Streamflow, dissolved solids, suspended sediment, and trace elements, San Joaquin River, California, June 1985-September 1988

    USGS Publications Warehouse

    Hill, B.R.; Gilliom, R.J.

    1993-01-01

    The 1985-88 study period included hydrologic extremes throughout most of central California. Except for an 11-month period during and after the 1986 flood, San Joaquin River streamflows during 1985-88 were generally less than median for 1975-88. The Merced Tuolumne, and Stanislaus Rivers together comprised 56 to 69 percent of the annual San Joaquin River flow, Salt and Mud Sloughs together comprised 6 to 19 percent, the upper San Joaquin River comprised 2 to 25 percent, and unmeasured sources from agricultural discharges and ground water accounted for 13 to 20 percent. Salt and Mud Sloughs and the unmeasured sources contribute most of the dissolved-solids load. The Merced, Tuolumne, and Stanislaus Rivers greatly dilute dissolved-solids concentrations. Suspended-sediment concentration peaked sharply at more than 600 milligrams per liter during the flood of February 1986. Concentrations and loads varied seasonally during low-flow conditions, with concentrations highest during the early summer irrigation season. Trace elements present primarily in dissolved phases are arsenic, boron, lithium, molybdenum, and selenium. Boron concentrations exceeded the irrigation water-quality criterion of 750 micrograms per liter more than 75 percent of the time in Salt and Mud Sloughs and more than 50 percent of the time at three sites on the San Joaquin River. Selenium concentrations exceeded the aquatic-life criterion of 5 micrograms per liter more than 75 percent of the time in Salt Slough and more than 50 percent of the time in Mud Slough and in the San Joaquin River from Salt Slough to the Merced River confluence. Concentrations of dissolved solids, boron, and selenium usually are highest during late winter to early spring, lower in early summer, higher again in mid-to-late summer, and the lowest in autumn, and generally correspond to seasonal inflows of subsurface tile-drain water to Salt and Mud Sloughs. Trace elements present primarily in particulate phases are aluminum

  9. Evaluation of the potential for artificial ground-water recharge in eastern San Joaquin County, California; Phase 3

    USGS Publications Warehouse

    Hamlin, S.N.

    1987-01-01

    Infiltration tests were used to evaluate the potential of basin spreading surface water as a means of artificially recharging the aquifer system in eastern San Joaquin County, California. Two infiltration sites near Lockeford and Linden were selected on the basis of information collected during the first two phases of the study. Data from the infiltration tests indicate that the two sites are acceptable for recharge by the basin-spreading method. Infiltration rates ranged between 6.7 and 10.5 ft/day near Lockeford and between 2.6 and 11.2 ft/day near Linden. Interpretation of these data is limited by lack of information on the response of the saturated zone during testing and by the inherent difficulty in extrapolating the results of small-scale tests to larger long-term operations. Lithology is a major factor that controls infiltration rates at the test sites. The unsaturated zone is characterized by heterogeneous layers of coarse- and fine- grained materials. Clay layers of low hydraulic conductivity commonly form discontinuous lenses that may cause a transient perched water table to develop during recharge. Water level measurements from wells screened in the unsaturated zone indicate that the perched water table could reach the land surface after 2 and 5 months of recharge near Lockeford and Linden, respectively. These figures probably represent the minimum time necessary for saturation of the land. Another major factor that affects infiltration rates is the quality of the recharge water, particularly the suspended sediment content. The clogging action of suspended sediment may be minimized by: (1) pretreatment of recharge water in a settling pond, (2) adherence to a routine program of monitoring and maintenance, and (3) proper design of the recharge facility. Other factors that affect infiltration rates include basin excavation technique, basin shape, and maintenance procedures. Efficient operation of the recharge facility requires careful attention to the

  10. Issues of sustainable irrigated agriculture in the San Joaquin Valley of California in a changing regulatory environment concerning water quality and protection of wildlife

    SciTech Connect

    Quinn, N.W.T.; Delamore, M.L.

    1994-06-01

    Since the discovery of selenium toxicosis in the Kesterson Reservoir in the San Joaquin Valley, California, public perception of irrigated agriculture as a benign competitor for California`s developed water supply has been changed irrevocably. Subsurface return flows from irrigated agriculture were implicated as the source of selenium which led to incidents of reproductive failure in waterfowl and threatened survival of other fish and wildlife species. Stringent water quality objectives were promulgated to protect rivers, tributaries, sloughs and other water bodies receiving agricultural discharges from selenium contamination. Achieving these objectives was left to the agricultural water districts, federal and state agencies responsible for drainage and water quality enforcement in the San Joaquin Basin. This paper describes some of the strategies to improve management of water resources and water quality in response to these new environmental objectives. Similar environmental objectives will likely be adopted by other developed and developing countries with large regions of arid zone agriculture and susceptible wildlife resources. A series of simulation models have been developed over the past four years to evaluate regional drainage management strategies such as: irrigation source control; drainage recycling; selective retirement of agricultural land; regional shallow ground water pumping; coordination of agricultural drainage, wetland and reservoir releases; and short-term ponding of drainage water. A new generation of Geographic Information Service-based software is under development to bridge the gap between planning and program implementation. Use of the decision support system will allow water districts and regulators to continuously monitor drainage discharges to the San Joaquin River in real-time and to assess impacts of management strategies that have been implemented to take advantage of the River`s assimilative capacity for trace elements and salts.

  11. 76 FR 69895 - Approval and Promulgation of Implementation Plans; California; 2008 San Joaquin Valley PM2.5

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-09

    ... (NAAQS) in the San Joaquin Valley (SJV). See 76 FR 41338. California developed this SIP to provide for... Fine Particle Implementation Rule for the 1997 PM 2.5 NAAQS,'' 72 FR 20586 (April 25, 2007) and... April 5, 2015. See 76 FR 41338, 41361. \\3\\ The 2011 Progress Report contained budgets that were...

  12. Water quality and supply issues of irrigated agricultural regions – lessons from the San Joaquin Valley of California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The San Joaquin Valley of California covers 4 million hectares of farmland and produces $25 billion of agricultural products annually, but its average annual rainfall ranges from only 130 mm in the south to 330 mm in the north and nearly all occur in the winter. On the east side of the valley, irrig...

  13. Evaluation of Diazinon and Chlorpyrifos Concentrations and Loads, and other Pesticide Concentrations, at Selected Sites in the San Joaquin Valley, California, April to August, 2001

    USGS Publications Warehouse

    Domagalski, Joseph L.; Munday, Cathy

    2003-01-01

    Twelve sites in the San Joaquin Valley of California were monitored weekly during the growing and irrigation season of 2001 for a total of 51 pesticides and pesticide degradation products, with primary interest on the concentration, load, and basin yield of organophosphorus insecticides, especially diazinon and chlorpyrifos. Diazinon was detected frequently, up to 100 percent of the time, at many of the sampling sites, but with generally low concentrations. For all sites, 75 percent of all measured diazinon concentrations were less than 0.02 mg/L, and 90 percent of all measured diazinon concentrations were less than 0.06 mg/L. The highest diazinon concentrations were measured in samples from two west-side tributaries to the San Joaquin River, Orestimba Creek, and Del Puerto Creek. The median concentration of chlorpyrifos was at or less than the laboratory reporting limit (0.005 mg/L) for most sites with the exceptions of two tributaries to the San Joaquin River: Orestimba Creek and the Tuolumne River. For all sites, 75 percent of all measured chlorpyrifos concentrations were less than 0.03 mg/L and 90 percent of all measured chlorpyrifos concentrations were less than 0.07 mg/L. The total load of diazinon out of the basin was just over 7 kilograms, which accounted for about 0.17 percent of the total agricultural applications. The diazinon load from the monitored upstream tributaries accounted for about 50 percent of the load at the mouth of the San Joaquin River. The streamflow from the selected monitored tributaries accounted for about 83 percent of the streamflow at the mouth of the San Joaquin River. The total load of chlorpyrifos out of the basin was 3.75 kilograms, and this accounted for approximately 0.007 percent of the total amount applied. Other pesticides that were frequently detected during this study included herbicides such as metolachlor, simazine, and trifluralin, and insecticides such as carbaryl, carbofuran, and propargite. At Orestimba Creek, DDE

  14. Pesticide residues in ground water of the San Joaquin Valley, California

    USGS Publications Warehouse

    Domagalski, J.L.; Dubrovsky, N.M.

    1992-01-01

    A regional assessment of non-point-source contamination of pesticide residues in ground water was made of the San Joaquin Valley, an intensively farmed and irrigated structural trough in central California. About 10% of the total pesticide use in the USA is in the San Joaquin Valley. Pesticides detected include atrazine, bromacil, 2.4-DP, diazinon, dibromochloropropane, 1,2-dibromoethane, dicamba, 1,2-dichloropropane, diuron, prometon, prometryn, propazine and simazine. All are soil applied except diazinon. Pesticide leaching is dependent on use patterns, soil texture, total organic carbon in soil, pesticide half-life and depth to water table. Leaching is enhanced by flood-irrigation methods except where the pesticide is foliar applied such as diazinon. Soils in the western San Joaquin Valley are fine grained and are derived primarily from marine shales of the Coast Ranges. Although shallow ground water is present, the fewest number of pesticides were detected in this region. The fine-grained soil inhibits pesticide leaching because of either low vertical permeability or high surface area; both enhance adsorption on to solid phases. Soils of the valley floor tend to be fine grained and have low vertical permeability. Soils in the eastern part of the valley are coarse grained with low total organic carbon and are derived from Sierra Nevada granites. Most pesticide leaching is in these alluvial soils, particularly in areas where depth to ground water is less than 30m. The areas currently most susceptible to pesticide leaching are eastern Fresno and Tulare Counties. Tritium in water molecules is an indicator of aquifer recharge with water of recent origin. Pesticide residues transported as dissolved species were not detected in non-tritiated water. Although pesticides were not detected in all samples containing high tritium, these samples are indicative of the presence of recharge water that interacted with agricultural soils. ?? 1992.

  15. Land subsidence in the San Joaquin Valley, California, as of 1980

    USGS Publications Warehouse

    Ireland, R.L.; Poland, J.F.; Riley, F.S.

    1982-01-01

    Land subsidence due to ground-water overdraft in the San Joaquin Valley began in the mid-1920 's and continued at alarming rates until surface was imported through major canals and aqueducts in the 1950 's and late 1960's. In areas where surface water replaced withdrawal of ground-water, water levels in the confined system rose sharply and subsidence slowed. In the late 1960 's and early 1970 's water levels in wells recovered to levels of the 1940 's and 1950 's throughout most of the western and southern parts of the Valley, in response to the importation of surface water through the California aqueduct. During the 1976-77 drought data collected at water-level and extensometer sites showed the effect of heavy demand on the ground-water resevoir. With the ' water of compaction ' gone, artesian head declined 10 to 20 times as fast as during the first cycle of long-term drawdown that ended in the late 1960's. In the 1978-79 water levels recovered to or above the 1976 pre-drought levels. The report suggests continued monitoring of land subsidence in the San Joaquin Valley. (USGS)

  16. Macroinvertebrate assemblages on woody debris and their relations with environmental variables in the lower Sacramento and San Joaquin River drainages, California

    USGS Publications Warehouse

    Brown, L.R.; May, J.T.

    2000-01-01

    Data from 25 sites were used to evaluate associations between macroinvertebrate assemblages on large woody debris (snags) and environmental variables in the lower San Joaquin and Sacramento River drainages in California as part of the U.S. Geological Survey's National Water Quality Assessment Program. Samples were collected from 1993 to 1995 in the San Joaquin River drainage and in 1996 and 1997 in the Sacramento River drainage. Macroinvertebrate taxa were aggregated to the family (or higher) level of taxonomic organization, resulting in 39 taxa for analyses. Only the 31 most common taxa were used for two-way indicator species analysis (TWINSPAN) and canonical correspondence analysis (CCA). TWINSPAN analysis defined four groups of snag samples on the basis of macroinvertebrate assemblages. Analysis of variance identified differences in environmental and biotic characteristics among the groups. These results combined with the results of CCA indicated that mean dominant substrate type, gradient, specific conductance, water temperature, percentage of the basin in agricultural land use, percentage of the basin in combined agricultural and urban land uses, and elevation were important factors in explaining assemblage structure. Macroinvertebrate assemblages on snags may be useful in family level bioassessments of environmental conditions in valley floor habitats.

  17. Pyrethroid insecticide concentrations and toxicity in streambed sediments and loads in surface waters of the San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Domagalski, J.L.; Weston, D.P.; Zhang, M.; Hladik, M.

    2010-01-01

    Pyrethroid insecticide use in California, USA, is growing, and there is a need to understand the fate of these compounds in the environment. Concentrations and toxicity were assessed in streambed sediment of the San Joaquin Valley of California, one of the most productive agricultural regions of the United States. Concentrations were also measured in the suspended sediment associated with irrigation or storm-water runoff, and mass loads during storms were calculated. Western valley streambed sediments were frequently toxic to the amphipod, Hyalella azteca, with most of the toxicity attributable to bifenthrin and cyhalothrin. Up to 100% mortality was observed in some locations with concentrations of some pyrethroids up to 20 ng/g. The western San Joaquin Valley streams are mostly small watersheds with clay soils, and sediment-laden irrigation runoff transports pyrethroid insecticides throughout the growing season. In contrast, eastern tributaries and the San Joaquin River had low bed sediment concentrations (<1 ng/g) and little or no toxicity because of the preponderance of sandy soils and sediments. Bifenthrin, cyhalothrin, and permethrin were the most frequently detected pyrethroids in irrigation and storm water runoff. Esfenvalerate, fenpropathrin, and resmethrin were also detected. All sampled streams contributed to the insecticide load of the San Joaquin River during storms, but some compounds detected in the smaller creeks were not detected in the San Joaquin River. The two smallest streams, Ingram and Hospital Creeks, which had high sediment toxicity during the irrigation season, accounted for less than 5% of the total discharge of the San Joaquin River during storm conditions, and as a result their contribution to the pyrethroid mass load of the larger river was minimal. ?? 2010 SETAC.

  18. Concentrations of organic contaminants detected during managed flow conditions, San Joaquin River and Old River, California, 2001

    USGS Publications Warehouse

    Orlando, James L.; Kuivila, Kathryn M.

    2005-01-01

    Concentrations of organic contaminants were determined in water samples collected at six surface-water sites located along the San Joaquin and Old Rivers during April through June 2001. Water samples were collected, coincident with salmon smolt caging studies conducted by researchers from the Bodega Marine Laboratory at the University of California at Davis to characterize exposure of the salmon smolt to organic contaminants. Sampling occurred prior to, during, and following the implementation of managed streamflow conditions on the San Joaquin and Old Rivers as part of the Vernalis Adaptive Management Plan. Thirteen pesticides were detected in water samples collected during this study, and at least five pesticides were detected in each sample. The total number of pesticide detections varied little between river systems and between sites, but the maximum concentrations of most pesticides occurred in San Joaquin River samples. The total number of pesticides detected varied little over the three time periods. However, during the period of managed streamflow, the fewest number of pesticides were detected at their absolute maximum concentration. Nine wastewater compounds were detected during this study. Suspended-sediment concentrations were similar for the San Joaquin and Old Rivers except during the period of managed streamflow conditions, when suspended-sediment concentration was higher at sites on the San Joaquin River than at sites on the Old River. Values for water parameters (pH, specific conductance, and hardness) were lowest during the period of managed flows.

  19. Impacts of changing irrigation practices on waterfowl habitat use in the southern San Joaquin Valley, California

    USGS Publications Warehouse

    Barnum, D.A.; Euliss, N. H .

    1991-01-01

    We used diurnal aerial census data to examine habitat use patterns of ducks wintering in the southern San Joaquin Valley, California from 1980-87. We calculated densities (birds/ha) for the northern pintail (Anas acuta), mallard (A. platyrhynchos), green-winged teal (A. crecca), cinnamon teal (A. cyanoptera), shoveler (A. clypeata), ruddy duck (Oxyura jamaicensis), and total ducks in each of 5 habitats. Densities of pintail and total ducks were greater in September than in other months. From October through January, density of teal and total ducks was greatest on Kern National Wildlife Refuge (NWR). Densities of ruddy duck and pintail were greatest on agricultural drainwater evaporation ponds and preirrigated cropland, respectively.

  20. Optimal pumping strategies for managing shallow, poorquality groundwater, western San Joaquin Valley, California

    USGS Publications Warehouse

    Barlow, P.; Wagner, B.; Belitz, K.

    1995-01-01

    Continued agricultural productivity in the western San Joaquin Valley, California, is threatened by the presence of shallow, poor-quality groundwater that can cause soil salinization. We evaluate the management alternative of using groundwater pumping to control the altitude of the water table and provide irrigation water requirements. A transient, three-dimensional, groundwater flow model was linked with nonlinear optimization to simulate management alternatives for the groundwater flow system. Optimal pumping strategies have been determined that substantially reduce the area subject to a shallow water table and bare-soil evaporation (that is, areas with a water table within 2.1 m of land surface) and the rate of drainflow to on-farm drainage systems. Optimal pumping strategies are constrained by the existing distribution of wells between the semiconfined and confined zones of the aquifer, by the distribution of sediment types (and associated hydraulic conductivities) in the western valley, and by the historical distribution of pumping throughout the western valley.

  1. Biogeochemical cycling of selenium in the San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Presser, T.S.; Ohlendorf, H.M.

    1987-01-01

    Subsurface agricultural drainage waters from western San Joaquin Valley, California, were found to contain elevated concentrations of the element selenium in the form of selenate. In 1978, these drainage waters began to replace previous input to Kesterson Reservoir, a pond system within Kesterson National Wildlife Refuge; this substitution was completed by 1982. In the 1983 nesting season, unusual rates of deformity and death in embryos and hatchlings of wild aquatic birds (up to 64% of eared grebe and American coot nests) occurred at the refuge and were attributed to selenium toxicosis. Features necessary for contamination to have taken place included geologic setting, climate, soil type, availability of imported irrigation water, type of irrigation, and the unique chemical properties of selenium. The mechanisms of biogeochemical cycling raise questions about other ecosystems and human exposure.

  2. 77 FR 66548 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is approving revisions to the San Joaquin Valley Unified Air Pollution Control District... State Implementation Plan, San Joaquin Valley Unified Air Pollution Control District's Rule 4352,...

  3. The Sacramento-San Joaquin Delta Conflict: Strategic Insights for California's Policymakers

    NASA Astrophysics Data System (ADS)

    Moazezi, M. R.

    2013-12-01

    The Sacramento-San Joaquin Delta - a major water supply source in California and a unique habitat for many native and invasive species--is on the verge of collapse due to a prolonged conflict over how to manage the Delta. There is an urgent need to expedite the resolution of this conflict because the continuation of the status quo would leave irreversible environmental consequences for the entire state. In this paper a systematic technique is proposed for providing strategic insights into the Sacramento-San Joaquin Delta conflict. Game theory framework is chosen to systematically analyze behavioral characteristics of decision makers as well as their options in the conflict with respect to their preferences using a formal mathematical language. The Graph Model for Conflict Resolution (GMCR), a recent game-theoretic technique, is applied to model and analyze the Delta conflict in order to better understand the options, preferences, and behavioral characteristics of the major decision makers. GMCR II as a decision support system tool based on GMCR concept is used to facilitate the analysis of the problem through a range of non-cooperative game theoretic stability definitions. Furthermore, coalition analysis is conducted to analyze the potential for forming partial coalitions among decision makers, and to investigate how forming a coalition can influence the conflict resolution process. This contribution shows that involvement of the State of California is necessary for developing an environmental-friendly resolution for the Delta conflict. It also indicates that this resolution is only achievable through improving the fragile levee systems and constructing a new water export facility.

  4. Exploration potential of offshore northern California basins

    SciTech Connect

    Bachman, S.B.; Crouch, J.K.

    1988-01-01

    A series of exploratory wells was drilled in the northern California offshore basins in the 1960s following leasing of federal tracts off northern California, Oregon, and Washington. The drilling, although encountering numerous oil shows, was considered at the time to indicate low prospectivity in an area that extended as far south as the offshore Santa Maria basin. However, subsequent major discoveries in this decade in the offshore Santa Maria basin, such as the Point Arguello field, indicate that these offshore basins may be highly prospective exploration targets. Many of the key features of Monterey production in central and southern California are also present in the offshore basins of northern California. A new 5-year leasing plan has scheduled leasing in the northern California OCS starting in early 1989. The first basins on the schedule, the Point Arena and Eel River basins, differ in some respects. The Point Arena basin is more typical of a Monterey basin, with the potential for fractured chert reservoirs and organic-rich sections, deep burial of basinal sections to enhance the generation of higher gravity oils, and complex folding and faulting. The Eel River basin is more clastic-rich in its gas-producing, onshore extension. Key questions in the Eel River basin include whether the offshore, more distal stratigraphy will include Monterey-like biogenic sediments, and whether the basin has oil potential in addition to its proven gas potential. The Outer Santa Cruz basin shares a similar stratigraphy, structure, and hydrocarbon potential with the Point Arena basin. The Santa Cruz-Bodega basin, also with a similar stratigraphy, may have less exploration potential because erosion has thinned the Monterey section in parts of the basin.

  5. Social Disparities in Drinking Water Quality in California's San Joaquin Valley

    NASA Astrophysics Data System (ADS)

    Ray, I.; Balazs, C.; Hubbard, A.; Morello-Frosch, R.

    2011-12-01

    Social Disparities in Drinking Water Quality in California's San Joaquin Valley Carolina Balazs, Rachel Morello-Frosch, Alan Hubbard and Isha Ray Little attention has been given to research on social disparities and environmental justice in access to safe drinking water in the USA. We examine the relationship between nitrate and arsenic concentrations in community water systems (CWS) and the ethnic and socioeconomic characteristics of their customers. We hypothesized that systems in the San Joaquin Valley that serve a higher proportion of minority (especially Latino) residents, and/or lower socioeconomic status (proxied by rates of home ownership) residents, have higher nitrate levels and higher arsenic levels. We used water quality monitoring datasets (1999-2001) to estimate nitrate as well as arsenic levels in CWS, and source location and Census block group data to estimate customer demographics. We found that percent Latino was associated with a .04 mg NO3/L increase in a CWS' estimated nitrate ion concentration (95% CI, -.08, .16) and rate of home ownership was associated with a .16 mg NO3/L decrease (95% CI, -.32, .002). We also found that each percent increase in home ownership rate was associated with a .30 ug As/L decrease in arsenic concentrations (p<.05), but our data showed no significant correlation between arsenic concentration and percent Latino. These results show that exposure disparities and compliance burdens in accordance with EPA standards fell most heavily on socio-economically disadvantaged communities. Selected References Cory DC, Rahman T. 2009. Environmental justice and enforcement of the safe drinking water act: The arizona arsenic experience. Ecological Economics 68: 1825-1837. Krieger N, Williams DR, Moss NE. 1997. Measuring social class in us public health research: Concepts, methodologies, and guidelines. Annual Review of Public Health 18(341-378). Moore E, Matalon E, Balazs C, Clary J, Firestone L, De Anda S, Guzman, M. 2011. The

  6. 75 FR 3996 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-26

    ... Planning, San Joaquin Valley Air Pollution Control District; letter dated and received August 17, 2009... Sadredin, Executive Director/Air Pollution Control Officer of San Joaquin Valley Air Pollution Control...: EPA's Analysis of San Joaquin Valley Unified Air Pollution Control District's Rule 4684,...

  7. An emission inventory of agricultural internal combustion engines for California`s San Joaquin Valley

    SciTech Connect

    Coe, D.; Chinkin, L.; Reiss, R.

    1996-12-31

    Previous work concluded that stationary agricultural internal combustion (IC) engines are a substantial source of criteria pollutants the San Joaquin Valley (SJV). However, due to time and resource restrictions, earlier work did not include a rigorous survey of engine users. Instead, emission estimates were based on interviews with a few knowledgeable experts (e.g., Department of Agricultural Engineering at U.C. Davis, the Agriculture Extension office of U.C. Davis, Farm Bureau, and Water District offices) or were extrapolated from data designed for other purposes. The purpose of the current study, which was sponsored by the San Joaquin Valley Unified Air Pollution Control District, was to improve the estimate of emissions from this source category by conducting a more comprehensive inventory of this source type based on data collected via a telephone survey of engine users. These survey data were then used to estimate and seasonally allocate emissions for this source category. The findings of this current work show that these emissions are much lower than previously estimated.

  8. Transport of sediment-bound organochlorine pesticides to the San Joaquin River, California

    USGS Publications Warehouse

    Kratzer, C.R.

    1999-01-01

    Suspended sediment samples were collected in westside tributaries and the main stem of the San Joaquin River, California, in June 1994 during the irrigation season and in January 1995 during a winter storm. These samples were analyzed for 15 organochlorine pesticides to determine their occurrence and their concentrations on suspended sediment and to compare transport during the irrigation season (April to September) to transport during winter storm runoff (October to March). Ten organochlorine pesticides were detected during the winter storm runoff; seven during the irrigation season. The most frequently detected organochlorine pesticides during both sampling periods were p,p'-DDE, p,p'-DDT, p,p'-DDD, dieldrin, toxaphene, and chlordane. Dissolved samples were analyzed for three organochlorine pesticides during the irrigation season and for 15 during the winter storm. Most calculated total concentrations of p,p'-DDT, chlordane, dieldrin, and toxaphene exceeded chronic criteria for the protection of freshwater aquatic life. At eight sites in common between sampling periods, suspended sediment concentrations and streamflow were greater during the winter storm runoff median concentration of 3,590 mg/L versus 489 mg/and median streamflow of 162 ft3/s versus 11 ft3/s. Median concentrations of total DDT (sum of p,p'-DDD, p,p'-DDE, and p,p'-DDT), chlordane, dieldrin, and toxaphene on suspended sediment were slightly greater during the irrigation season, but instantaneous loads of organochlorine pesticides at the time of sampling were substantially greater during the winter storm. Estimated loads for the entire irrigation season exceeded estimated loads for the January 1995 storm by about 2 to 4 times for suspended transport and about 3 to 11 times for total transport. However, because the mean annual winter runoff is about 2 to 4 times greater than the runoff during the January 1995 storm, mean winter transport may be similar to irrigation season transport. This conclusion

  9. Age Determination of the Remaining Peat in the Sacramento-San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, Judith Z.; de Fontaine, Christian S.; Knifong, Donna L.

    2007-01-01

    Introduction The Sacramento-San Joaquin Delta of California was once a 1,400 square kilometer (km2) tidal marsh, which contained a vast layer of peat ranging up to 15 meters (m) thick (Atwater and Belknap, 1980). Because of its favorable climate and highly fertile peat soils, the majority of the Delta was drained and reclaimed for agriculture during the late 1800s and early 1900s. Drainage of the peat soils changed the conditions in the surface layers of peat from anaerobic (having no free oxygen present) to aerobic (exposed to the atmosphere). This change in conditions greatly increased the decomposition rate of the peat, which consists largely of organic (plant) matter. Thus began the process of land-surface subsidence, which initially was a result of peat shrinkage and compaction, and later largely was a result of oxidation by which organic carbon in the peat essentially vaporized to carbon dioxide (Deverel and others, 1998; Ingebritsen and Ikehara, 1999). Because of subsidence, the land-surface elevation on farmed islands in the Delta has decreased from a few meters to as much as 8 m below local mean sea level (California Department of Water Resources, 1995; Steve Deverel, Hydrofocus, Inc., written commun., 2007). The USGS, in collaboration with the University of California at Davis, and Hydrofocus Inc. of Davis, California, has been studying the formation of the Delta and the impact of wetland reclamation on the peat column as part of a project called Rates and Evolution of Peat Accretion through Time (REPEAT). The purpose of this report is to provide results on the age of the remaining peat soils on four farmed islands in the Delta.

  10. Groundwater-quality data in the Western San Joaquin Valley study unit, 2010 - Results from the California GAMA Program

    USGS Publications Warehouse

    Mathany, Timothy M.; Landon, Matthew K.; Shelton, Jennifer L.; Belitz, Kenneth

    2013-01-01

    Groundwater quality in the approximately 2,170-square-mile Western San Joaquin Valley (WSJV) study unit was investigated by the U.S. Geological Survey (USGS) from March to July 2010, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program's Priority Basin Project (PBP). The GAMA-PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The WSJV study unit was the twenty-ninth study unit to be sampled as part of the GAMA-PBP. The GAMA Western San Joaquin Valley study was designed to provide a spatially unbiased assessment of untreated-groundwater quality in the primary aquifer system, and to facilitate statistically consistent comparisons of untreated groundwater quality throughout California. The primary aquifer system is defined as parts of aquifers corresponding to the perforation intervals of wells listed in the California Department of Public Health (CDPH) database for the WSJV study unit. Groundwater quality in the primary aquifer system may differ from the quality in the shallower or deeper water-bearing zones; shallow groundwater may be more vulnerable to surficial contamination. In the WSJV study unit, groundwater samples were collected from 58 wells in 2 study areas (Delta-Mendota subbasin and Westside subbasin) in Stanislaus, Merced, Madera, Fresno, and Kings Counties. Thirty-nine of the wells were selected by using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and 19 wells were selected to aid in the understanding of aquifer-system flow and related groundwater-quality issues (understanding wells). The groundwater samples were analyzed for organic constituents (volatile organic compounds [VOCs], low-level fumigants, and pesticides and pesticide degradates

  11. Measured flow and tracer-dye data showing the anthropogenic effects on the hydrodynamics of south Sacramento-San Joaquin Delta, California, spring 1996 and 1997

    USGS Publications Warehouse

    Oltmann, Richard N.

    1998-01-01

    Tidal flows were measured using acoustic Doppler current profilers and ultrasonic velocity meters during spring 1996 and 1997 in south Sacramento-San Joaquin Delta, California, when (1) a temporary barrier was installed at the head of Old River to prevent the entrance of migrating San Joaquin River salmon smolts, (2) the rate of water export from the south Delta was reduced for an extended period of time, and (3) a 30-day pulse flow was created on the San Joaquin River to move salmon smolts north away from the export facilities during spring 1997. Tracer-dye measurements also were made under these three conditions.

  12. Groundwater data for selected wells within the Eastern San Joaquin Groundwater Subbasin, California, 2003-8

    USGS Publications Warehouse

    Clark, Dennis A.; Izbicki, John A.; Metzger, Loren F.; Everett, Rhett; Smith, Gregory A.; O'Leary, David R.; Teague, Nicholas F.; Burgess, Matthew K.

    2012-01-01

    Data were collected by the U.S. Geological Survey from 2003 through 2008 in the Eastern San Joaquin Groundwater Subbasin, 80 miles east of San Francisco, California, as part of a study of the increasing chloride concentrations in groundwater processes. Data collected include geologic, geophysical, chemical, and hydrologic data collected during and after the installation of five multiple-well monitoring sites, from three existing multiple-well sites, and from 79 selected public-supply, irrigation, and domestic wells. Each multiple-well monitoring site installed as part of this study contained three to five 2-inch diameter polyvinyl chloride (PVC)-cased wells ranging in depth from 68 to 880 feet below land surface. Continuous water-level data were collected from the 19 wells installed at these 5 sites and from 10 existing monitoring wells at 3 additional multiple-well sites in the study area. Thirty-one electromagnetic logs were collected seasonally from the deepest PVC-cased monitoring well at seven multiple-well sites. About 200 water samples were collected from 79 wells in the study area. Coupled well-bore flow data and depth-dependent water-quality data were collected from 12 production wells under pumped conditions, and well-bore flow data were collected from 10 additional wells under unpumped conditions.

  13. Selenium speciation methods and application to soil saturation extracts from San Joaquin Valley, California

    USGS Publications Warehouse

    Fio, John L.; Fujii, Roger

    1990-01-01

    Methods to determine soluble concentrations of selenite, selenate, and organic Se were evaluated on saturation extracts of soil samples collected from three sites on the Panoche Creek alluvial fan in the western San Joaquin Valley, California. The methods were used in combination with hydride-generation atomic-absorption spectrometry for detection of Se, and included a selective chemical-digestion method and three chromatographic methods using XAD-8 resin, Sep-Pak C18 cartridge, and a combination of XAD-8 resin and activated charcoal. The chromatography methods isolate dissolved organic matter that can inhibit Se detection by hydride-generation atomic-absorption spectrometry. Isolation of hydrophobic organic matter with XAD-8 did not affect concentrations of selenite and selenate, and the isolated organic matter represents a minimal estimation of organic Se. Ninety-eight percent of the Se in the extracts was selenate and about 100% of the isolated organic Se was associated with the humic acid fraction of dissolved organic matter. The depth distribution of Se species in the soil saturation extracts support a hypothesis that the distribution of soluble Se and salinity in these soils is the result of evaporation from a shallow water table and leaching by irrigation water low in Se and salinity.

  14. High-Resolution Digital Terrain Models of the Sacramento/San Joaquin Delta Region, California

    USGS Publications Warehouse

    Coons, Tom; Soulard, Christopher E.; Knowles, Noah

    2008-01-01

    The U.S. Geological Survey (USGS) Western Region Geographic Science Center, in conjunction with the USGS Water Resources Western Branch of Regional Research, has developed a high-resolution elevation dataset covering the Sacramento/San Joaquin Delta region of California. The elevation data were compiled photogrammically from aerial photography (May 2002) with a scale of 1:15,000. The resulting dataset has a 10-meter horizontal resolution grid of elevation values. The vertical accuracy was determined to be 1 meter. Two versions of the elevation data are available: the first dataset has all water coded as zero, whereas the second dataset has bathymetry data merged with the elevation data. The projection of both datasets is set to UTM Zone 10, NAD 1983. The elevation data are clipped into files that spatially approximate 7.5-minute USGS quadrangles, with about 100 meters of overlap to facilitate combining the files into larger regions without data gaps. The files are named after the 7.5-minute USGS quadrangles that cover the same general spatial extent. File names that include a suffix (_b) indicate that the bathymetry data are included (for example, sac_east versus sac_east_b). These files are provided in ESRI Grid format.

  15. Coyote control to protect endangered San Joaquin kit foxes at the Naval Petroleum Reserves, California

    SciTech Connect

    Cypher, B.L.; Scrivner, J.H.

    1992-04-01

    Coyote (Canis latrans) predation is the primary cause of mortality for endangered San Joaquin kit foxes (Vulpes macrotis mutica) at the Naval Petroleum Reserves in California (NPRC). Between 1980 and 1985, the kit fox population on NPRC declined approximately 66% while an increase in coyote abundance was noted. From 1985 to 1990, the US Department of Energy (DOE) sponsored a program to kill coyotes with the objective being to reduce predation on kit foxes and increase fox numbers. During the 5-year effort, 591 coyotes were killed by trapping, shooting, denning, and aerial gunning. Although scent-station indices indicated that coyote abundance declined during the period of control, the contribution of the control effort to this decline is unclear. Kit fox capture indices did not increase after control was initiated. Also, fox survival rates did not increase. The number of coyotes removed annually may not have been sufficient to effectively reduce coyote abundance. Food availability probably was the primary factor influencing the population dynamics of both predators. Control efforts have been deferred pending further consideration of the merits of control and its potential efficacy at NPRC.

  16. Coyote control to protect endangered San Joaquin kit foxes at the Naval Petroleum Reserves, California

    SciTech Connect

    Cypher, B.L.; Scrivner, J.H.

    1992-01-01

    Coyote (Canis latrans) predation is the primary cause of mortality for endangered San Joaquin kit foxes (Vulpes macrotis mutica) at the Naval Petroleum Reserves in California (NPRC). Between 1980 and 1985, the kit fox population on NPRC declined approximately 66% while an increase in coyote abundance was noted. From 1985 to 1990, the US Department of Energy (DOE) sponsored a program to kill coyotes with the objective being to reduce predation on kit foxes and increase fox numbers. During the 5-year effort, 591 coyotes were killed by trapping, shooting, denning, and aerial gunning. Although scent-station indices indicated that coyote abundance declined during the period of control, the contribution of the control effort to this decline is unclear. Kit fox capture indices did not increase after control was initiated. Also, fox survival rates did not increase. The number of coyotes removed annually may not have been sufficient to effectively reduce coyote abundance. Food availability probably was the primary factor influencing the population dynamics of both predators. Control efforts have been deferred pending further consideration of the merits of control and its potential efficacy at NPRC.

  17. Mortality following cotton defoliation: San Joaquin Valley, California, 1970-1990.

    PubMed

    Ames, R G; Gregson, J

    1995-07-01

    A proportional mortality study comparing the cotton-growing areas of the San Joaquin Valley with the rest of the State of California was performed by the Office of Environmental Health Hazard Assessment as a continuation of earlier studies related to mercaptan-releasing pesticides. This mortality study found a pattern of increased proportion of "respiratory causes" mortality (ICD codes 460-519), statistically significant at less than the .05 probability level, for 15 of 21 years between 1970 and 1990, for the time period during and immediately following cotton defoliation. Defoliants which have the potential to produce acute symptoms include DEF and Folex, both of which release odorous butyl mercaptan gas as a degradation product. This paper tests the hypothesis that exposure to cotton defoliant breakdown products may be associated with a disproportionate increase in mortality. Prediction of the mortality proportions by pounds of DEF and Folex used was not statistically significant in the unadjusted models or in models adjusted for air pollution variables. One air pollution adjustment factor, total suspended particulates, was a statistically significant independent mortality proportion predictor. This finding suggests that total suspended particulates, not defoliants, may be related to mortality differentials during defoliation season. Possible confounding by demographic variation of the counties was not controlled in the analysis. PMID:7552465

  18. Mortality following cotton defoliation: San Joaquin Valley, California, 1970-1990.

    PubMed

    Ames, R G; Gregson, J

    1995-07-01

    A proportional mortality study comparing the cotton-growing areas of the San Joaquin Valley with the rest of the State of California was performed by the Office of Environmental Health Hazard Assessment as a continuation of earlier studies related to mercaptan-releasing pesticides. This mortality study found a pattern of increased proportion of "respiratory causes" mortality (ICD codes 460-519), statistically significant at less than the .05 probability level, for 15 of 21 years between 1970 and 1990, for the time period during and immediately following cotton defoliation. Defoliants which have the potential to produce acute symptoms include DEF and Folex, both of which release odorous butyl mercaptan gas as a degradation product. This paper tests the hypothesis that exposure to cotton defoliant breakdown products may be associated with a disproportionate increase in mortality. Prediction of the mortality proportions by pounds of DEF and Folex used was not statistically significant in the unadjusted models or in models adjusted for air pollution variables. One air pollution adjustment factor, total suspended particulates, was a statistically significant independent mortality proportion predictor. This finding suggests that total suspended particulates, not defoliants, may be related to mortality differentials during defoliation season. Possible confounding by demographic variation of the counties was not controlled in the analysis.

  19. Fish communities and their associations with environmental variables, lower San Joaquin River drainage, California

    USGS Publications Warehouse

    Brown, L.R.

    2000-01-01

    Twenty sites in the lower San Joaquin River drainage, California, were sampled from 1993 to 1995 to characterize fish communities and their associations with measures of water quality and habitat quality. The feasibility of developing an Index of Biotic Integrity was assessed by evaluating four fish community metrics, including percentages of native fish, omnivorous fish, fish intolerant of environmental degradation, and fish with external anomalies. Of the thirty-one taxa of fish captured during the study, only 10 taxa were native to the drainage. Multivariate analyses of percentage data identified four site groups characterized by different groups of species. The distributions of fish species were related to specific conductance, gradient, and mean depth; however, specific conductance acted as a surrogate variable for a large group of correlated variables. Two of the fish community metrics - percentage of introduced fish and percentage of intolerant fish - appeared to be responsive to environmental quality but the responses of the other two metrics - percentage of omnivorous fish and percentage of fish with anomalies - were less direct. The conclusion of the study is that fish communities are responsive to environmental conditions, including conditions associated with human-caused disturbances, particularly agriculture and water development. The results suggest that changes in water management and water quality could result in changes in species distributions. Balancing the costs and benefits of such changes poses a considerable challenge to resource managers.

  20. Assemblages of fishes and their associations with environmental variables, lower San Joaquin River drainage, California

    USGS Publications Warehouse

    Brown, Larry R.

    1998-01-01

    Twenty sites in the lower San Joaquin River drainage, California, were sampled from 1993 to 1995 to characterize fish assemblages and their associations with measures of water quality and habitat quality. In addition, four fish community metrics were assessed, including percentages of native fish, omnivorous fish, fish intolerant of environmental degradation, and fish with external anomalies. Of the 31 taxa of fish captured during the study, only 10 taxa were native to the drainage. Multivariate analyses of percentage data identified four site groups characterized by characterized by different groups of species. The distributions of fish species were related to specific conductance, gradient, and mean depth; however, specific conductance acted as a surrogate variable for a large group of correlated variables. Two of the fish community metrics--percentage of introduced fish and percentage of intolerant fish--appeared to be responsive to environmental quality but the responses of the other two metrics--percentage of omnivorous fish and percentage of fish with anomalies--were less direct. The conclusion of the study is that fish assemblages are responsive to environmental conditions, including conditions associated with human-caused disturbances, particularly agriculture and water development. The results suggest that changes in water management and water quality could result in changes in species distributions. Balancing the costs and benefits of such changes poses a considerable challenge to resource managers. different groups of species.

  1. Groundwater flow and solute movement to drain laterals, western San Joaquin Valley, California. 1. Geochemical assessment

    SciTech Connect

    Deverel, S.J.; Fio, J.L. )

    1990-01-01

    A study was undertaken to quantitatively evaluate the hydrologic processes affecting the chemical and isotopic composition of drain lateral water from an agricultural field in the western San Joaquin Valley, California. Results from chemical and isotopic analysis of the samples, and analysis of hydraulic head data and drain lateral flow data, elucidate the process of mixing of deep and shallow groundwater entering the drain laterals. The deep groundwater was subject to partial evaporation prior to drainage system installation and has been displaced downward in the groundwater system. This groundwater is flowing toward the drain laterals. The percentage of deep, isotopically enriched groundwater entering the drain laterals varies with time and between drain laterals. The percentage of the total drain lateral flow, which is deep groundwater flow, is about 30% for the shallow drain lateral and 60% for the deep drain lateral. During irrigation, these percentages decrease to 0 and 30% for the shallow and deep drain laterals. Selenium loads in the drain laterals vary with time and between drain laterals. The selenium load for the shallow drain lateral during 1 year is 21% of the load for the deep drain lateral because it collects less deep, high selenium groundwater and does not flow continuously. Although selenium concentrations in the drain lateral water decreased during irrigation, selenium loads increased substantially during a preplant irrigation because of increased flow into the drain laterals. The selenium loads during 8 days of irrigation represented a substantial percentage of the total selenium load for 1 year.

  2. Distribution of selenium in soils of agricultural fields, western San Joaquin Valley, California

    USGS Publications Warehouse

    Fujii, Roger; Deverel, S.J.; Hatfield, D.B.

    1988-01-01

    Soils from three agricultural fields in the Panoche Creek alluvial fan area in the western San Joaquin Valley, California, were analyzed for soluble, adsorbed, and total concentrations of selenium (Se) to assess the distribution and forms of Se in relation to the leaching of Se from soils. This assessment is needed to evaluate the importance of soil Se in affecting ground water concentrations. Soil samples were collected from three fields with drainage systems of different ages (6, 15, 1.5 yr) and different Se concentrations in drain water (58, 430, 3700 µg L−1, respectively). Concentrations of soluble Se and salinity were highest in soils from the field drained for 1.5 yr and lowest in the field drained for 6 yr. Of the total concentration of soil Se from all three fields, the proportion of adsorbed and soluble Se ranged from 1 to 11% and 2 > 0.68) in saturation extracts of soils sampled from below the water table. In contrast, most soluble salts and Se apparently have been leached from the unsaturated soils in the fields drained for 6 and 15 yr. For the leached soils, dissolution and precipitation of evaporite minerals containing Se may no longer control concentrations of soluble Se.

  3. Economic potential and optimum steamflood strategies for trough reservoirs of San Joaquin Valley, California

    SciTech Connect

    Hong, K.C.; Use, D.J.

    1995-12-31

    Many trough reservoirs in the Western San Joaquin Valley, California, remain undeveloped because reserve bases are relatively small and occur in areas where thermal recovery activities have been low. Reservoir models with different configurations and reserve bases were used to compare the economic potential of these reservoirs and to develop guidelines for selecting reservoirs that can be economically exploited. The models were also used for determining the optimum steamflood strategies for the selected reservoirs. The study showed that, for a trough reservoir to be an economical prospect, it should contain a minimum oil-in-place of 300 MSTB per pattern length along the trough between the synclinal axis and the gas-oil contact. Optimum steamflood strategy for such reservoirs includes: (1) placing the injector away from the synclinal axis and gas-oil contact, (2) having a row of producers updip from the injector and another near the synclinal axis, (3) starting the steamflood with an intermediate rate and high quality of steam, and (4) shutting-in steam injection after 5.5 years of continuous injection at a constant rate. This strategy can result in an annual rate of return of 20%.

  4. Population Structure of Xylella fastidiosa Associated with Almond Leaf Scorch Disease in the San Joaquin Valley of California.

    PubMed

    Lin, Hong; Islam, Md Sajedul; Cabrera-La Rosa, Juan C; Civerolo, Edwin L; Groves, Russell L

    2015-06-01

    Xylella fastidiosa causes disease in many commercial crops, including almond leaf scorch (ALS) disease in susceptible almond (Prunus dulcis). In this study, genetic diversity and population structure of X. fastidiosa associated with ALS disease were evaluated. Isolates obtained from two almond orchards in Fresno and Kern County in the San Joaquin Valley of California were analyzed for two successive years. Multilocus simple-sequence repeat (SSR) analysis revealed two major genetic clusters that were associated with two host cultivars, 'Sonora' and 'Nonpareil', respectively, regardless of the year of study or location of the orchard. These relationships suggest that host cultivar selection and adaptation are major driving forces shaping ALS X. fastidiosa population structure in the San Joaquin Valley. This finding will provide insight into understanding pathogen adaptation and host selection in the context of ALS disease dynamics.

  5. Population Structure of Xylella fastidiosa Associated with Almond Leaf Scorch Disease in the San Joaquin Valley of California.

    PubMed

    Lin, Hong; Islam, Md Sajedul; Cabrera-La Rosa, Juan C; Civerolo, Edwin L; Groves, Russell L

    2015-06-01

    Xylella fastidiosa causes disease in many commercial crops, including almond leaf scorch (ALS) disease in susceptible almond (Prunus dulcis). In this study, genetic diversity and population structure of X. fastidiosa associated with ALS disease were evaluated. Isolates obtained from two almond orchards in Fresno and Kern County in the San Joaquin Valley of California were analyzed for two successive years. Multilocus simple-sequence repeat (SSR) analysis revealed two major genetic clusters that were associated with two host cultivars, 'Sonora' and 'Nonpareil', respectively, regardless of the year of study or location of the orchard. These relationships suggest that host cultivar selection and adaptation are major driving forces shaping ALS X. fastidiosa population structure in the San Joaquin Valley. This finding will provide insight into understanding pathogen adaptation and host selection in the context of ALS disease dynamics. PMID:25807309

  6. Data for ground-water test holes in Fresno County, western San Joaquin Valley, California, June to August 1985

    USGS Publications Warehouse

    Beard, Sherrill; Laudon, Julie

    1988-01-01

    Twenty-four test holes were drilled from June 3 to August 29, 1985, in the western San Joaquin Valley, California, to provide information about groundwater hydraulics and geochemistry. The study area is in western Fresno County, west of the San Joaquin River, and east of the Coast Range. Lithologic, hydrologic, and geophysical data were collected from test holes drilled at two cluster sites and at 13 additional sites. Both cluster sites have five cased test holes. A sixth test hole was drilled at one of the cluster sites but was destroyed. Each of the 10 cased test holes is perforated at a different 10-ft depth interval. Six of the 13 additional test holes were also cased. Lithology logs were constructed from descriptions of cuttings and cores recovered during drilling. Geophysical logs were made of the deepest hole at each cluster site. Initial water level measurements were made at most sites. (Author 's abstract)

  7. 75 FR 28509 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... Association of Home Builders v. San Joaquin Valley Unified Air Pollution Control District, No. 08-17309...

  8. 75 FR 10690 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... is finalizing approval of revisions to the San Joaquin Valley Air Pollution Control District (SJVAPCD...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control... Joaquin Valley Unified Air Pollution Control District. (1) Rule 4104, ``Reduction of Animal Matter,''...

  9. 76 FR 45212 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: In this action, we are proposing to approve San Joaquin Valley Unified Air Pollution Control... the environment. San Joaquin Valley Unified Air Pollution Control District SJVUAPCD is an...

  10. SRTM Perspective View with Landsat Overlay: Mt. Pinos and San Joaquin Valley, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Ask any astronomer where the best stargazing site in Southern California is, and chances are they'll say Mt. Pinos. In this perspective view generated from SRTM elevation data the snow-capped peak is seen rising to an elevation of 2,692 meters (8,831 feet), in stark contrast to the flat agricultural fields of the San Joaquin valley seen in the foreground. Below the summit, but still well away from city lights, the Mt. Pinos parking lot at 2,468 meters (8,100 feet) is a popular viewing area for both amateur and professional astronomers and astro-photographers. For visualization purposes, topographic heights displayed in this image are exaggerated two times.

    The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.

    Distance to Horizon: 176 kilometers (109 miles) Location: 34.83 deg. North lat., 119.25 deg. West lon. View: Toward the Southwest Date Acquired: February 16, 2000 SRTM, December 14, 1984 Landsat

  11. Anthropogenic Methane Emissions in California's San Joaquin Valley: Characterizing Large Point Source Emitters

    NASA Astrophysics Data System (ADS)

    Hopkins, F. M.; Duren, R. M.; Miller, C. E.; Aubrey, A. D.; Falk, M.; Holland, L.; Hook, S. J.; Hulley, G. C.; Johnson, W. R.; Kuai, L.; Kuwayama, T.; Lin, J. C.; Thorpe, A. K.; Worden, J. R.; Lauvaux, T.; Jeong, S.; Fischer, M. L.

    2015-12-01

    Methane is an important atmospheric pollutant that contributes to global warming and tropospheric ozone production. Methane mitigation could reduce near term climate change and improve air quality, but is hindered by a lack of knowledge of anthropogenic methane sources. Recent work has shown that methane emissions are not evenly distributed in space, or across emission sources, suggesting that a large fraction of anthropogenic methane comes from a few "super-emitters." We studied the distribution of super-emitters in California's southern San Joaquin Valley, where elevated levels of atmospheric CH4 have also been observed from space. Here, we define super-emitters as methane plumes that could be reliably detected (i.e., plume observed more than once in the same location) under varying wind conditions by airborne thermal infrared remote sensing. The detection limit for this technique was determined to be 4.5 kg CH4 h-1 by a controlled release experiment, corresponding to column methane enhancement at the point of emissions greater than 20% above local background levels. We surveyed a major oil production field, and an area with a high concentration of large dairies using a variety of airborne and ground-based measurements. Repeated airborne surveys (n=4) with the Hyperspectral Thermal Emission Spectrometer revealed 28 persistent methane plumes emanating from oil field infrastructure, including tanks, wells, and processing facilities. The likelihood that a given source type was a super-emitter varied from roughly 1/3 for processing facilities to 1/3000 for oil wells. 11 persistent plumes were detected in the dairy area, and all were associated with wet manure management. The majority (11/14) of manure lagoons in the study area were super-emitters. Comparing to a California methane emissions inventory for the surveyed areas, we estimate that super-emitters comprise a minimum of 9% of inventoried dairy emissions, and 13% of inventoried oil emissions in this region.

  12. Remote Sensing Soil Salinity Map for the San Joaquin Vally, California

    NASA Astrophysics Data System (ADS)

    Scudiero, E.; Skaggs, T. H.; Anderson, R. G.; Corwin, D. L.

    2015-12-01

    Soil salinization is a major natural hazard to worldwide agriculture. We present a remote imagery approach that maps salinity within a range (i.e., salinities less than 20 dS m-1, when measured as the electrical conductivity of the soil saturation extract), accuracy, and resolution most relevant to agriculture. A case study is presented for the western San Joaquin Valley (WSJV), California, USA (~870,000 ha of farmland) using multi-year Landsat 7 ETM+ canopy reflectance and the Canopy Response Salinity Index (CRSI). Highly detailed salinity maps for 22 fields (542 ha) established from apparent soil electrical conductivity directed sampling were used as ground-truth (sampled in 2013), totaling over 5000 pixels (30×30 m) with salinity values in the range of 0 to 35.2 dS m-1. Multi-year maximum values of CRSI were used to model soil salinity. In addition, soil type, elevation, meteorological data, and crop type were evaluated as covariates. The fitted model (R2=0.73) was validated: i) with a spatial k-folds (i.e., leave-one-field-out) cross-validation (R2=0.61), ii) versus salinity data from three independent fields (sampled in 2013 and 2014), and iii) by determining the accuracy of the qualitative classification of white crusted land as extremely-saline soils. The effect of land use change is evaluated over 2396 ha in the Broadview Water District from a comparison of salinity mapped in 1991 with salinity predicted in 2013 from the fitted model. From 1991 to 2013 salinity increased significantly over the selected study site, bringing attention to potential negative effects on soil quality of shifting from irrigated agriculture to fallow-land. This is cause for concern since over the 3 years of California's drought (2010-2013) the fallow land in the WSJV increased from 12.7% to 21.6%, due to drastic reduction in water allocations to farmers.

  13. Quaternary tephrochronology and deposition in the subsurface Sacramento-San Joaquin Delta, California, U.S.A.

    USGS Publications Warehouse

    Maier, Katherine L.; Gatti, Emma; Wan, Elmira; Ponti, Daniel J.; Pagenkopp, Mark; Starratt, Scott W.; Olson, Holly A.; Tinsley, John

    2015-01-01

    We document characteristics of tephra, including facies and geochemistry, from 27 subsurface sites in the Sacramento-San Joaquin Delta, California, to obtain stratigraphic constraints in a complex setting. Analyzed discrete tephra deposits are correlative with: 1) an unnamed tephra from the Carlotta Formation near Ferndale, California, herein informally named the ash of Wildcat Grade (<~1.450 - >~0.780 Ma), 2) the Rockland ash bed (~0.575 Ma), 3) the Loleta ash bed (~0.390 Ma), and 4) a middle Pleistocene tephra resembling volcanic ash deposits at Tulelake, California, and Pringle Falls, Bend, and Summer Lake, Oregon, herein informally named the dacitic ash of Hood (<~0.211 to >~0.180 Ma, correlated age). All four tephra are derived from Cascades volcanic sources. The Rockland ash bed erupted from the southern Cascades near Lassen Peak, California, and occurs in deposits up to >7 m thick as observed in core samples taken from ~40 m depth below land surface. Tephra facies and tephra age constraints suggest rapid tephra deposition within fluvial channel and overbank settings, likely related to flood events shortly following the volcanic eruption. Such rapidly deposited tephra are important chronostratigraphic markers that suggest varying sediment accumulation rates (~0.07-0.29 m/1000 yr) in Quaternary deposits below the modern Sacramento-San Joaquin Delta. This study provides the first steps in developing a subsurface Quaternary stratigraphic framework necessary for future hazard assessment.

  14. Benthic invertebrate distributions in the San Joaquin River, California, in relation to physical and chemical factors

    USGS Publications Warehouse

    Leland, H.V.; Fend, S.V.

    1998-01-01

    The invertebrate fauna of nontidal portions of the lower San Joaquin River and its major tributaries is described in relation to water quality and habitat using canonical correspondence analysis, autecological metrics, and indicator species analysis. A large-scale (basin-wide) pattern in community response to salinity (sulfate-bicarbonate type) was detected when standardized, stable substratum was sampled. Community structure, taxa richness, and EPT (ephemeropterans, plecopterans, and trichopterans) richness varied with dissolved solids concentration (55-1700 mg total dissolved solids. L-1), and distributions of many taxa indicated salinity optima. Distinct assemblages associated with either high or low salinity were evident over this range. Large-scale patterns in community structure were unrelated to pesticide distributions. Structure and taxa richness of invertebrate assemblages in sand substratum varied both with salinity and with microhabitat heterogeneity. The benthic fauna generally was dominated by a taxa-poor assemblage of specialized psammophilous species, contributing to a weaker relationship between community structure and water quality than was observed using standardized substratum. Habitat types and associated dominant species were characterized using indicator species analysis. Species assemblages did not vary substantially with irrigation regime or fiver discharge, indicating that structure of invertebrate communities was a conservative measure of water quality.

  15. Ground-Water Quality Data in the Southeast San Joaquin Valley, 2005-2006 - Results from the California GAMA Program

    USGS Publications Warehouse

    Burton, Carmen A.; Belitz, Kenneth

    2008-01-01

    Ground-water quality in the approximately 3,800 square-mile Southeast San Joaquin Valley study unit (SESJ) was investigated from October 2005 through February 2006 as part of the Priority Basin Assessment Project of Ground-Water Ambient Monitoring and Assessment (GAMA) Program. The GAMA Statewide Basin Assessment project was developed in response to the Ground-Water Quality Monitoring Act of 2001 and is being conducted by the California State Water Resources Control Board (SWRCB) in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory (LLNL). The SESJ study was designed to provide a spatially unbiased assessment of raw ground-water quality within SESJ, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 99 wells in Fresno, Tulare, and Kings Counties, 83 of which were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study area (grid wells), and 16 of which were sampled to evaluate changes in water chemistry along ground-water flow paths or across alluvial fans (understanding wells). The ground-water samples were analyzed for a large number of synthetic organic constituents (volatile organic compounds [VOCs], pesticides and pesticide degradates, and pharmaceutical compounds), constituents of special interest (perchlorate, N-nitrosodimethylamine, and 1,2,3-trichloropropane), naturally occurring inorganic constituents (nutrients, major and minor ions, and trace elements), radioactive constituents, and microbial indicators. Naturally occurring isotopes (tritium, and carbon-14, and stable isotopes of hydrogen, oxygen, nitrogen, and carbon), and dissolved noble gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, samples for matrix spikes) were collected at approximately 10 percent of the wells, and the results

  16. Chemical analyses for selected wells in San Joaquin County and part of Contra Costa County, California

    USGS Publications Warehouse

    Keeter, Gail L.

    1980-01-01

    The study area of this report includes the eastern valley area of Contra Costa County and all of San Joaquin County, an area of approximately 1,600 square miles in the northern part of the San Joaquin Valley, Calif. Between December 1977 and December 1978, 1,489 wells were selectively canvassed. During May and June in 1978 and 1979, water samples were collected for chemical analysis from 321 of these wells. Field determinations of alkalinity, conductance, pH, and temperature were made, and individual constituents were analyzed. This report is the fourth in a series of baseline data reports on wells in the Sacramento and San Joaquin Valleys. (USGS)

  17. September-March survival of female northern pintails radiotagged in San Joaquin Valley, California

    USGS Publications Warehouse

    Fleskes, J.P.; Jarvis, R.L.; Gilmer, D.S.

    2002-01-01

    To improve understanding of pintail ecology, we radiotagged 191 hatch-year (HY) and 228 after-hatch-year (AHY) female northern pintails (Anas acuta) in the San Joaquin Valley (SJV), and studied their survival throughout central California, USA, during September-March, 1991-1994. We used adjusted Akaike Information Criterion (AICc) values to contrast known-fate models and examine variation in survival rates relative to year, interval, wintering region (AJV, other central California), pintail age, body mass at capture, capture date, capture area, and radio type. The best-fitting model included only interval x year and age x body mass; the next 2 best-fitting models also included wintering region and capture date. Hunting caused 83% of the mortalities we observed, and survival was consistently lower during hunting than nonhunting intervals. Nonhunting and hunting mortality during early winter was highest during the 1991-1992 drought year. Early-winter survival improved during the study along with habitat conditions in the Grassland Ecological Area (EA), where most radiotagged pintails spent early winter. Survival was more closely related to body mass at capture for HY than AHY pintails, even after accounting for the later arrival (based on capture date) of HY pintails, suggesting HY pintails are less adept at improving their condition. Thus, productivity estimates based on harvest age ratios may be biased if relative vulnerability of HY and AHY pintails is assumed to be constant because fall body condition of pintails may vary greatly among years. Cumulative winter survival was 75.6% (95% CI = 68.3% to 81.7%) for AHY and 65.4% (56.7% to 73.1%) for HY female pintails. Daily odds of survival in the cotton-agriculture landscape of the SJV were -21.3% (-40.3% to +3.7%) lower than in the rice-agriculture landscape of the Sacramento Valley (SACV) and other central California areas. Higher hunting mortality may be 1 reason pintails have declined more in SJV than in SACV.

  18. Concentrations and loads of suspended sediment-associated pesticides in the San Joaquin River, California and tributaries during storm events

    USGS Publications Warehouse

    Hladik, M.L.; Domagalski, J.L.; Kuivila, K.M.

    2009-01-01

    Current-use pesticides associated with suspended sediments were measured in the San Joaquin River, California and its tributaries during two storm events in 2008. Nineteen pesticides were detected: eight herbicides, nine insecticides, one fungicide and one insecticide synergist. Concentrations for the herbicides (0.1 to 3000 ng/g; median of 6.1 ng/g) were generally greater than those for the insecticides (0.2 to 51 ng/g; median of 1.5 ng/g). Concentrations in the tributaries were usually greater than in the mainstem San Joaquin River and the west side tributaries were higher than the east side tributaries. Estimated instantaneous loads ranged from 1.3 to 320 g/day for herbicides and 0.03 to 53 g/day for insecticides. The greatest instantaneous loads came from the Merced River on the east side. Instantaneous loads were greater for the first storm of 2008 than the second storm in the tributaries while the instantaneous loads within the San Joaquin River were greater during the second storm. Pesticide detections generally reflected pesticide application, but other factors such as physical-chemical properties and timing of application were also important to pesticide loads.

  19. Effects of flow diversions on water and habitat quality: Examples from California's highly manipulated Sacramento–San Joaquin Delta

    USGS Publications Warehouse

    Monsen, Nancy E.; Cloern, James E.; Burau, Jon R.

    2007-01-01

    We use selected monitoring data to illustrate how localized water diversions from seasonal barriers, gate operations, and export pumps alter water quality across the Sacramento-San Joaquin Delta (California). Dynamics of water-quality variability are complex because the Delta is a mixing zone of water from the Sacramento and San Joaquin Rivers, agricultural return water, and the San Francisco Estuary. Each source has distinct water-quality characteristics, and the contribution of each source varies in response to natural hydrologic variability and water diversions. We use simulations with a tidal hydrodynamic model to reveal how three diversion events, as case studies, influence water quality through their alteration of Delta-wide water circulation patterns and flushing time. Reduction of export pumping decreases the proportion of Sacramento- to San Joaquin-derived fresh water in the central Delta, leading to rapid increases in salinity. Delta Cross Channel gate operations control salinity in the western Delta and alter the freshwater source distribution in the central Delta. Removal of the head of Old River barrier, in autumn, increases the flushing time of the Stockton Ship Channel from days to weeks, contributing to a depletion of dissolved oxygen. Each shift in water quality has implications either for habitat quality or municipal drinking water, illustrating the importance of a systems view to anticipate the suite of changes induced by flow manipulations, and to minimize the conflicts inherent in allocations of scarce resources to meet multiple objectives.

  20. Concentrations and loads of suspended sediment-associated pesticides in the San Joaquin River, California and tributaries during storm events.

    PubMed

    Hladik, Michelle L; Domagalski, Joseph L; Kuivila, Kathryn M

    2009-12-20

    Current-use pesticides associated with suspended sediments were measured in the San Joaquin River, California and its tributaries during two storm events in 2008. Nineteen pesticides were detected: eight herbicides, nine insecticides, one fungicide and one insecticide synergist. Concentrations for the herbicides (0.1 to 3,000 ng/g; median of 6.1 ng/g) were generally greater than those for the insecticides (0.2 to 51 ng/g; median of 1.5 ng/g). Concentrations in the tributaries were usually greater than in the mainstem San Joaquin River and the west side tributaries were higher than the east side tributaries. Estimated instantaneous loads ranged from 1.3 to 320 g/day for herbicides and 0.03 to 53 g/day for insecticides. The greatest instantaneous loads came from the Merced River on the east side. Instantaneous loads were greater for the first storm of 2008 than the second storm in the tributaries while the instantaneous loads within the San Joaquin River were greater during the second storm. Pesticide detections generally reflected pesticide application, but other factors such as physical-chemical properties and timing of application were also important to pesticide loads.

  1. Quaternary geology and geomorphology of the Sacramento-San Joaquin Delta, California: evolution and processes

    NASA Astrophysics Data System (ADS)

    Gatti, E.; Maier, K. L.; Holzer, T. L.; Knudsen, K. L.; Olson, H.; Pagenknopp, M.; Ponti, D. J.; Rosa, C.; Tinsley, J. C.; Wan, E.

    2013-12-01

    The Sacramento-San Joaquin Delta (~1,400 km2) is a combination of tidal marsh, islands and agricultural lands at the confluence of the Sacramento and the San Joaquin Rivers, in northern California. Most of the Delta islands are now 3 to 8 m below sea-level and must be protected by levees from inundation. Because of the Delta's crucial role in conveying fresh water to the State, levee failures can cause substantial economic loss by disrupting this supply. Understanding the evolution of the Delta is fundamental to assess the vulnerability of the Delta islands to seismically-induced levee failure. The modern Delta is a young geological feature that began forming during the middle Holocene. Preceding versions of the Delta hosted a variety of depositional environments as sea level fluctuated, responding to climatically-controlled changes. The rising sea reached the Delta about 8,000 years ago, and modern deltaic evolution continued into Holocene time until present. More accurate stratigraphic studies incorporating depositional ages are required to i) better understand the late Quaternary evolution of the Delta, ii) trace the base of Holocene deposits, iii) identify potentially active faults, and iv) evaluate liquefaction hazard for the Delta . This study uses the large amount of data available on the Delta (collected by the California Department of Water Resources and others during the past 30 years) and merges them into a unified dataset. We have produced a database that includes historic and surficial maps, aerial photographs, boreholes, and CPT data, for the purpose of clarifying the nature of the Quaternary deposits and the evolution of the Late Quaternary Delta. Additionally, we have identified recently discovered Pleistocene tephra as the Rockland ash, ~0.575 Ma, and the Loleta ash, ~0.40-0.37 Ma, which have improved stratigraphic correlations and assessment of subsidence rates. Delta sediments include sequences of glacial and interglacial deposits. Borehole logs

  2. Chlorpyrifos-treated crops in the vicinity of surface water contamination in the San Joaquin Valley, California, USA.

    PubMed

    Starner, Keith; Goh, Kean S

    2013-09-01

    Due to frequent contamination of streams in the San Joaquin Valley, California, USA, with the insecticide chlorpyrifos, researchers are working to identify crop-specific management practices that will reduce the offsite movement of this compound into surface waters. To guide this effort, crops treated with chlorpyrifos in the vicinity of contaminated streams were identified; walnut, alfalfa, and almond were the primary crops identified. Use was higher on walnut and almond, but due to irrigation practices offsite movement in surface runoff may be more likely from alfalfa. Based on these findings, development of management practices to reduce off-site movement of chlorpyrifos in irrigation runoff from treated alfalfa fields is recommended.

  3. Dissolved pesticide data for the San Joaquin River at Vernalis and the Sacramento River at Sacramento, California, 1991-94

    USGS Publications Warehouse

    MacCoy, Dorene E.; Crepeau, Kathryn L.; Kuivila, Kathryn M.

    1995-01-01

    Water samples were collected from sites on the San Joaquin and Sacramento Rivers, California and were analyzed for dissolved organic pesticides. This data collection and analysis are a part of an ongoing project by the U.S. Geological Survey Toxic Contaminants Hydrology program to determine the fate and transport of organic pesticides that enter the San Francisco Bay Estuary. Concentrations of selected pesticides were measured in filtered water samples using solid-phase extraction and gas chromatograph-mass spectrometry at the U.S. Geological Survey organic chemistry laboratory in Sacramento.

  4. Timber resource statistics for the San Joaquin and southern resource areas of California. Forest Service resource bulletin

    SciTech Connect

    Waddell, K.L.; Bassett, P.M.

    1997-05-01

    This report is a summary of timber resource statistics for the San Joaquin and Southern Resource Areas of California. Data were collected as part of a statewide multiresource inventory. The inventory sampled private and public lands except reserved areas and National Forests. The National Forest System provided data from regional inventories of some areas. Area information for parks and other reserves was obtained directly from the organizations managing these areas. Statistical tables summarize all ownerships and provide estimates of land area, timber volume, growth, mortality, and harvest. Estimates of periodic change of timberland area and timber volume are presented for all ownerships outside National Forests.

  5. 76 FR 53640 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-29

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  6. 78 FR 6740 - Revisions to the California State Implementation Plan, San Joaquin Valley United Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-31

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley United Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  7. 76 FR 69135 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-08

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  8. 77 FR 35329 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-13

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control,...

  9. 76 FR 56134 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-12

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... protection, Air pollution control, Intergovernmental relations, Ozone, Reporting and...

  10. 76 FR 37044 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-24

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control..., Air pollution control, Intergovernmental relations, Nitrogen dioxide, Ozone, Particulate...

  11. 77 FR 71109 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-29

    ... Air Pollution Control District (SJVUAPCD) AGENCY: Environmental Protection Agency (EPA). ACTION: Final...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control... Joaquin Valley Unified Air Pollution Control District (SJVUAPCD). (1) The following specified portions...

  12. 76 FR 70886 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  13. 77 FR 35327 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-13

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control,...

  14. 76 FR 47076 - Revision to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-04

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of a revision to the San Joaquin Valley Unified Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  15. 76 FR 33181 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve a revision to the San Joaquin Valley Unified Air Pollution Control..., Air pollution control, Intergovernmental relations, Ozone, Reporting and recordkeeping...

  16. 77 FR 2228 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-17

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... CFR Part 52 Environmental protection, Air pollution control, Incorporation by...

  17. Selenium and sulfur relationships in alfalfa and soil under field conditions, San Joaquin Valley, California

    USGS Publications Warehouse

    Severson, R.C.; Gough, L.P.

    1992-01-01

    Relationships between total Se and S or soluble SeO4 and SO4 in soils and tissue concentrations in alfalfa (Medicago sativa L.), under field conditions in the San Joaquin Valley of California, suggest that the rate of accumulation of Se in alfalfa may be reduced in areas where high Se and S concentrations in soils were measured. These data suggest that the balance between carbonate and sulfate minerals in soil may have a greater influence on uptake of Se by alfalfa than does the balance of SeO4 and SO4 in soil solution. Soil and alfalfa were sampled from areas representing a wide range in soil Se and S concentrations. Specific sampling locations were selected based on a previous study of Se, S, and other elements where 721 soil samples were collected to map landscape variability and distribution of elements. Six multiple-linear regression equations were developed between total and/or soluble soil chemical constituents and tissue concentrations of Se in alfalfa. We chose a regression model that accounted for 72% of the variability in alfalfa Se concentrations based on an association of elements in soil (total C, S, Se, and Sr) determined by factor analysis. To prepare a map showing the spatial distribution of estimated alfalfa Se concentrations, the model was applied to the data from the previously collected 721 soil samples. Estimated alfalfa Se concentrations in most of the study area were within a range that is predicted to produce alfalfa with neither Se deficiency nor toxicity when consumed by livestock. A few small areas are predicted to produce alfalfa that potentially would not meet minimum dietary needs of livestock.

  18. Sensitivity of agricultural runoff to climate change in the San Joaquin Valley watershed of California

    NASA Astrophysics Data System (ADS)

    Ficklin, D. L.; Luo, Y.; Gatzke, S. E.; Zhang, M.

    2008-12-01

    The quantification of the hydrological response to climate change and increasing atmospheric CO2 concentrations is required for the proper management of agricultural systems and water resources. This study simulated variations in CO2, temperature and precipitation to quantify the hydrologic response in an intensive agricultural system. The Soil and Water Assessment Tool (SWAT) was used to assess the impact of climate change on agricultural runoff in the San Joaquin watershed in California. The results of this study suggest that atmospheric CO2, precipitation, and temperature changes have significant effects on the yield of sediment, nitrate, total phosphorus, and two pesticides (diazinon and chlorypyrifos) chosen for consideration. As expected, precipitation had a greater impact on agricultural runoff compared to changes in either CO2 concentration or temperature. A change in precipitation of ±10% and ±20% generally altered agricultural runoff proportionally. In comparison to present day reference scenarios, a simulated increase in CO2 concentration while holding temperature and precipitation constant resulted in an increased nitrate, total phosphorus, and chlorpyrifos yield of 4.2, 7.8, and 6.4%, respectively, and a decreased sediment and diazinon yield of 6.3 and 6.4%, respectively. A temperature increase with no precipitation or CO2 concentration change caused a decrease for all agricultural runoff components. Results from this study provide valuable insight into the effects of various climate change scenarios on agricultural runoff and can direct policy makers and agricultural stakeholders in their efforts to create and comply with water quality legislation in a rapidly changing environment.

  19. Regional nitrate and pesticide trends in ground water in the eastern San Joaquin Valley, California

    USGS Publications Warehouse

    Burow, K.R.; Shelton, James L.; Dubrovsky, N.M.

    2008-01-01

    Protection of ground water for present and future use requires monitoring and understanding of the mechanisms controlling long-term quality of ground water. In this study, spatial and temporal trends in concentrations of nitrate and pesticides in ground water in the eastern San Joaquin Valley, California, were evaluated to determine the long-term effects of agricultural and urban development on regional ground-water quality. Trends in concentrations of nitrate, the nematocide 1,2-dibromo-3-chloropropane, and the herbicide simazine during the last two decades are generally consistent with known nitrogen fertilizer and pesticide use and with the position of the well networks in the regional ground-water flow system. Concentrations of nitrate and pesticides are higher in the shallow part of the aquifer system where domestic wells are typically screened, whereas concentrations are lower in the deep part of the aquifer system where public-supply wells are typically screened. Attenuation processes do not seem to significantly affect concentrations. Historical data indicate that concentrations of nitrate have increased since the 1950s in the shallow and deep parts of the aquifer system. Concentrations of nitrate and detection of pesticides in the deep part of the aquifer system will likely increase as the proportion of highly affected water contributed to these wells increases with time. Because of the time of travel between the water table and the deep part of the aquifer system, current concentrations in public-supply wells likely reflect the effects of 40- to 50-yr-old management practices. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  20. Distribution and mobility of selenium and other trace elements in shallow groundwater of the western San Joaquin Valley, California

    SciTech Connect

    Deverel, S.J.; Millard, S.P.

    1988-06-01

    Samples of shallow groundwater that underlies much of the irrigated area in the western San Joaquin Valley, CA, were analyzed for various major ions and trace elements, including selenium. Concentrations of the major ions generally were similar for groundwater collected in the two primary geologic zones-the alluvial fan and basin trough. Selenium concentrations are significantly higher in the groundwater of the alluvial-fan zone than in that of the basin-trough zone. The concentrations of oxyanion trace elements were significantly correlated with groundwater salinity, but the correlations between selenium and salinity and between molybdenum and salinity were significantly different in the alluvial-fan geologic zone compared with those in the basin-trough geologic zone. The evidence suggests that the main factors affecting selenium concentrations in the shallow groundwater are the degree of groundwater salinity and the geologic source of the alluvial soil material.

  1. Distribution and mobility of selenium and other trace elements in shallow groundwater of the western San Joaquin Valley, California

    USGS Publications Warehouse

    Deverel, S.J.; Milliard, S.P.

    1988-01-01

    Samples of shallow groundwater that underlies much of the irrigated area in the western San Joaquin Valley, CA, were analyzed for various major ions and trace elements, including selenium. Concentrations of the major ions generally were similar for groundwater collected in the two primary geologic zones - the alluvial fan and basin trough. Selenium concentrations are significantly (α = 0.05) higher in the groundwater of the alluvial-fan zone than in that of the basin-trough zone. The concentrations of oxyanion trace elements were significantly correlated (α = 0.05) with groundwater salinity, but the correlations between selenium and salinity and between molybdenum and salinity were significantly different (α = 0.05) in the alluvial-fan geologic zone compared with those in the basin-trough geologic zone. The evidence suggests that the main factors affecting selenium concentrations in the shallow groundwater are the degree of groundwater salinity and the geologic source of the alluvial soil material.

  2. On the observed response of ozone to NOx and VOC reactivity reductions in San Joaquin Valley California 1995-present

    NASA Astrophysics Data System (ADS)

    Pusede, S. E.; Cohen, R. C.

    2012-09-01

    We describe the effects of nitrogen oxide (NOx) and organic reactivity reductions on the frequency of high ozone days in California's San Joaquin Valley. We use sixteen years of observations of ozone, nitrogen oxides, and temperature at sites upwind, within, and downwind of three cities to assess the probability of exceeding the California 8-h average ozone standard of 70.4 ppb at each location. The comprehensive data records in the region and the steep decreases in emissions over the last decade are sufficient to constrain the relative import of NOx and organic reactivity reductions on the frequency of violations. We show that high ozone has a large component that is due to local production, as the probability of exceeding the state standard is lowest for each city at the upwind site, increases in the city center, is highest at downwind locations, and then decreases at the receptor city to the south. We see that reductions in organic reactivity have been very effective in the central and northern regions of the San Joaquin but less so in the southern portion of the Valley. We find evidence for two distinct categories of reactivity sources: one source that has decreased and dominates at moderate temperatures, and a second source that dominates at high temperatures, particularly in the southern San Joaquin, and has not changed over the last twelve years. We show that NOx reductions are already effective or are poised to become so in the southern and central Valley, where violations are most frequent, as conditions in these regions have or are transitioning to NOx-limited chemistry when temperatures are hottest and high ozone most probable.

  3. On the observed response of ozone to NOx and VOC reactivity reductions in San Joaquin Valley California 1995-present

    NASA Astrophysics Data System (ADS)

    Pusede, S. E.; Cohen, R. C.

    2012-04-01

    We present a statistical approach to describe the effects of nitrogen oxide (NOx) and organic reactivity reductions on the frequency of high ozone days. We use sixteen years of observations of ozone, nitrogen oxides, and temperature at sites upwind, within, and downwind of three cities in California's San Joaquin Valley to assess the probability of exceeding of the California 8-h average ozone standard of 70.4 ppb at each location. We demonstrate that the comprehensive data records in the region and the steep decreases in emissions over the last decade are sufficient to constrain the relative import of NOx and organic reactivity reductions on the frequency of violations. We show that high ozone has a large component that is due to local production, as the probability of exceeding the state standard is lowest for each city at the upwind site, increases across the city center, is highest at downwind locations, and then decreases at the receptor city to the south. We see that reductions in organic reactivity have been very effective in the central and northern regions of the San Joaquin but not in the southern portion of the Valley. We find evidence for two distinct categories of reactivity sources: one source that has decreased and dominates at moderate temperatures, and a second source that dominates at high temperatures in the southern San Joaquin, which has not changed over the last twelve years. We show that NOx reductions are already effective or are poised to become so in the southern and central Valley, where violations are most frequent, as conditions in these regions have or are transitioning to NOx-limited chemistry when temperatures are hottest and high ozone most probable.

  4. Regional-scale assessment of a sequence-bounding paleosol on fluvial fans using ground-penetrating radar, eastern San Joaquin Valley, California

    USGS Publications Warehouse

    Bennett, V.G.L.; Weissmann, G.S.; Baker, G.S.; Hyndman, D.W.

    2006-01-01

    Recently developed sequence stratigraphic models for fluvial fans suggest that sequence boundaries in these deposits are marked by laterally extensive paleosols; however, these models were based on paleosol correlations inferred between wells. To test this, we collected ???190 km of ground-penetrating radar (GPR) profiles on three fluvial fans from the eastern San Joaquin Valley, California, to determine the lateral extent and character of a buried near-surface sequence-bounding-paleosol. This paleosol, recognized on GPR by rapid shallow signal attenuation, extends across large areas on all three fluvial fans. Limited areas of significantly increased signal penetration were also identified, and these zones are interpreted to indicate the absence of the paleosol. The zones where the paleosol is missing likely correspond to paleooutwash channel activity on the fan surfaces that, when active, was able to partially or fully scour through the paleosol and deposit coarse-grained channel sediments in place of the sequence boundary. Erosional breaks are most common on the Kings River fan, while few breaks on the Tuolumne and Merced River fans may indicate less paleochannel activity on these fan surfaces during the last outwash event. Differences in channel activity between fans indicate that the Kings River migrated across its fan during the last outwash event, as evidenced by the large number of areas with increased GPR signal penetration and the presence of numerous channel deposits recorded on the soil surveys, while the Tuolumne and Merced Rivers only deposited floodplain fines, with the channels remaining inside a shallow incised valley, as evidenced by the relatively low number of areas with increased GPR signal penetration and the presence of primarily fine-grained material recorded on the soil surveys. Factors controlling these differences may include variable valley subsidence rates and differences in the San Joaquin Basin overall width at each fan location

  5. Distribution of algae in the San Joaquin River, California, in relation to nutrient supply, salinity and other environmental factors

    USGS Publications Warehouse

    Leland, H.V.; Brown, L.R.; Mueller, D.K.

    2001-01-01

    ., were the principal late-summer benthic species upstream in the mainstem and in drainages of the San Joaquin Valley. Many of the other abundant diatoms (Amphora veneta, Bacillaria paxillifer, Navicula symmetrica, Nitzschia amphibia, N. fonticola, N. palea, Pleurosigma salinarum) of late-summer assemblages in these segments also are motile species. While many of these species also were abundant in segments downstream of confluences with rivers draining the Sierra Nevada, the relative abundance of prostrate (Cocconeis placentula var. euglypta, Navicula minima) and erect or stalked (Achnanthidium deflexum, Achnanthes lanceolata, Gomphonema kobayasii, G. parvulum var. lagenula) diatoms and Stigeoclonium sp. was greater in these lower San Joaquin River segments. 5. A weighted-averaging regression model, based on salinity and benthic-algal abundance in the San Joaquin River and segments of its major tributaries within the San Joaquin Valley, yielded a highly significant coefficient-of-determination (r2 = 0.84) and low prediction error between salinity inferred from the species and that observed, indicating that salinity tolerance is a primary constraint on growth and assembly of the phytobenthos. The same measures of predictability indicated poor performance of a model based on inorganic nitrogen. However, with a greater representation of tributaries (including segments within the Sierra Nevada foothills) in the sample set, an inorganic nitrogen model also yielded a highly significant coefficient-of-determination (r2 = 0.87) and low prediction error between the species-inferred and the observed concentration. As with the salinity model (r2 = 0.94) for the enlarged data set, a systematic difference (increased deviation of residuals) existed at high inorganic nitrogen concentrations. These results indicate substantial interaction between salinity and inorganic nitrogen as constraints on the structure of benthic-algal communities of the San Joaquin River basin.

  6. Isotopic Evidence of Nitrate Sources and its Relationship to Algae in the San Joaquin River, California

    NASA Astrophysics Data System (ADS)

    Silva, S. R.; Kendall, C.; Young, M. B.; Stringfellow, W. T.; Borglin, S. E.; Kratzer, C. R.; Dahlgren, R. A.; Schmidt, C.; Rollog, M. E.

    2007-12-01

    Many competing demands have been placed on the San Joaquin River including deep water shipping, use as agricultural and drinking water, transport of agricultural and urban runoff, and recreation. These long-established demands limit the management options and increase the importance of understanding the river dynamics. The relationships among sources of water, nitrate, and algae in the San Joaquin River must be understood before management decisions can be made to optimize aquatic health. Isotopic analyses of water samples collected along the San Joaquin River in 2005-2007 have proven useful in assessing these relationships: sources of nitrate, the productivity of the San Joaquin River, and the relationship between nitrate and algae in the river. The San Joaquin River receives water locally from wetlands and agricultural return flow, and from three relatively large tributaries whose headwaters are in the Sierra Nevada. The lowest nitrate concentrations occur during periods of high flow when the proportion of water from the Sierra Nevada is relatively large, reflecting the effect of dilution from the big tributaries and indicating that a large fraction of the nitrate is of local origin. Nitrogen isotopes of nitrate in the San Joaquin River are relatively high (averaging about 12 per mil), suggesting a significant source from animal waste or sewage and/or the effects of denitrification. The d15N of nitrate varies inversely with concentration, indicating that these high isotopic values are also a local product. The d15N values of nitrate from most of the local tributaries is lower than that in the San Joaquin suggesting that nitrate from these tributaries does not account for a significant fraction of nitrate in the river. The source of the non-tributary nitrate must be either small unmeasured surface inputs or groundwater. To investigate whether groundwater might be a significant source of nitrate to the San Joaquin River, groundwater samples are being collected

  7. Modeling of Reactive Transport of Nitrate in a Heterogeneous Alluvial Fan Aquifer, San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Green, C. T.; Phillips, S. P.

    2005-12-01

    Fate of nitrate in an alluvial fan aquifer in the San Joaquin Valley, California, was investigated with combined laboratory analyses, field measurements, geostatistics, and flow and reactive transport modeling. In the summer of 2003, groundwater wells and lysimeters were installed along a 1-km transect extending upgradient from the Merced River through an unfarmed riparian zone, a corn field, and an orchard. Groundwater levels have been monitored continuously. Saturated and unsaturated pore waters were analyzed quarterly for nutrients, anions, and cations. Sediment core samples from above and below the water table were analyzed for organic matter, nutrients, inorganic chemistry, and potential denitrification using denitrification enzyme assays (DEA's) based on the acetylene block technique. Curve fitting of DEA's provided core-scale estimates of microbial populations and growth coefficients. DEA biomass was similar to values obtained with the most probable number technique. Growth coefficients were found to be relatively uniform across the site, while biomass varied by several orders of magnitude. Age dates estimated from Chlorofluorocarbon (CFC) and Sulfur Hexafluoride (SF6), together with analyses of nitrogen species and excess nitrogen gas, provided approximate aquifer-scale, zero-order denitrification rates. The field and laboratory measurements served as input for geostatistical realizations of sediment properties and simulations of reactive transport of nitrate in the saturated zone. Analyses of cores, drillers' logs, and previous interpretations of the local geology were used to generate transition probability models of hydrofacies distributions within Holocene alluvium and pre-Holocene fans, and maps of the boundaries between these stratigraphic sequences. Multiple 3-D realizations were created and ranked based on lateral and vertical bulk-flow properties. For realizations representing a range of geological conditions, 3-D flow was computed with boundary

  8. Organic matter sources and rehabilitation of the Sacramento-San Joaquin Delta (California, USA)

    USGS Publications Warehouse

    Jassby, A.D.; Cloern, J.E.

    2000-01-01

    1. The Sacramento San Joaquin River Delta, a complex mosaic of tidal freshwater habitats in California, is the focus of a major ecosystem rehabilitation effort because of significant long-term changes in critical ecosystem functions. One of these functions is the production, transport and transformation of organic matter that constitutes the primary food supply, which may be sub-optimal at trophic levels supporting fish recruitment. A long historical data set is used to define the most important organic matter sources, the factors underlying their variability, and the implications of ecosystem rehabilitation actions for these sources. 2. Tributary-borne loading is the largest organic carbon source on an average annual Delta-wide basis; phytoplankton production and agricultural drainage are secondary; wastewater treatment plant discharge, tidal marsh drainage and possibly aquatic macrophyte production are tertiary; and benthic microalgal production, urban run-off and other sources are negligible. 3. Allochthonous dissolved organic carbon must be converted to particulate form - with losses due to hydraulic flushing and to heterotroph growth inefficiency - before it becomes available to the metazoan food web. When these losses are accounted for, phytoplankton production plays a much larger role than is evident from a simple accounting of bulk organic carbon sources, especially in seasons critical for larval development and recruitment success. Phytoplankton-derived organic matter is also an important component of particulate loading to the Delta. 4. The Delta is a net producer of organic matter in critically dry years but, because of water diversion from the Delta, transport of organic matter from the Delta to important, downstream nursery areas in San Francisco Bay is always less than transport into the Delta from upstream sources. 5. Of proposed rehabilitation measures, increased use of floodplains probably offers the biggest increase in organic matter sources. 6

  9. Selenium and other elements in juvenile striped bass from the San Joaquin Valley and San Francisco Estuary, California

    USGS Publications Warehouse

    Saiki, Michael K.; Palawski, Donald U.

    1990-01-01

    Concentrations of selenium and other trace elements were determined in 55 whole body samples of juvenile anadromous striped bass (Morone saxatilis) from the San Joaquin Valley and San Francisco Estuary, California. The fish (≤1 yr old—the predominant life stage in the San Joaquin Valley) were collected in September–December 1986 from 19 sites in the Valley and 3 sites in the Estuary, and analyzed for the following elements: aluminum (Al), arsenic (As), boron (B), barium (Ba), beryllium (Be), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), magnesium (Mg), molybdenum (Mo), nickel (Ni), lead (Pb), selenium (Se), strontium (Sr), vanadium (V), and zinc (Zn). When compared to concentrations in whole freshwater fish measured by surveys from other waters, a few samples contained higher levels, of As, Cd, Cu, Pb, and Se. The median concentrations of Al, As, Cu, Fe, Mg, Se, and Sr also differed significantly (P⩽0.05) among sites. However, only Se concentrations were highest (up to 7.9 μg/g dry weight) in samples from Valley sites exposed to agricultural subsurface (tile) drainwater; concentrations were lower in samples collected elsewhere. Water quality variables—especially those strongly influenced by tile drainwater (conductivity, total dissolved solids, total alkalinity, and total hardness)—were also significantly correlated (P⩽0.05) with Se concentrations in fish. Selenium concentrations in striped bass from the Estuary were only one-fourth to one-half the concentrations measured in the most contaminated fish from the San Joaquin River.

  10. Isotopic and Chemical Analysis of Nitrate Sources and Cycling in the San Joaquin River Near Stockton, California

    NASA Astrophysics Data System (ADS)

    Silva, S. R.; Kendall, C.; Bemis, B.; Wankel, S.; Bergamaschi, B.; Kratzer, C.; Dileanis, P.; Erickson, D.; Avery, E.; Paxton, K.

    2002-12-01

    Fish migration through the deep-water channel in the San Joaquin River at Stockton, California is inhibited by low oxygen concentrations during the summer months. The cause for this condition appears to be stagnation and decomposition of algae with attendant oxygen consumption. Algae growth in the San Joaquin River is promoted by nutrients entering the river mainly in the form of nitrate. Possible significant sources of nitrate include soil, fertilizer from agriculture, manure from dairy operations, and N derived from municipal sewage. A 2000 CALFED pilot study investigated the sources and cycling of nitrate at four sites along the San Joaquin River upstream of Stockton using the carbon and nitrogen isotopes of total dissolved and particulate organic matter, together with hydrological measurements and various concentration data, including chlorophyll-a. The nitrate source, its relationship to phytoplankton, and the effect of the nitrate source and cycling on the N isotopic composition of dissolved and particulate organic matter were the primary concerns of the study. The d15N values of dissolved organic nitrogen (DON) were used as a proxy for nitrate d15N because nitrate comprised about 90% of DON. Chlorophyll-a and C:N ratios indicated that the particulate organic matter (POM) consisted largely of plankton and therefore the d15N of POM was used as a proxy for the d15N of plankton. A tentative interpretation of the pilot study was that nitrate was a major nutrient for the plankton and the nitrate was of anthropogenic origin, possibly sewage or animal waste. To test these assumptions and interpretations, we are currently analyzing a set of samples collected in 2001. In addition to the previous sample types, a subset of samples will be measured directly for nitrate d15N to assess the validity of using d15N of DON as a proxy for nitrate.

  11. Directions and rates of ground-water movement in the vicinity of Kesterson Reservoir, San Joaquin Valley, California

    USGS Publications Warehouse

    Mandle, R.J.; Kontis, A.L.

    1986-01-01

    A three-dimensional groundwater flow model was used to simulate groundwater flow for a 124 sq mi area in the vicinity of Kesterson Reservoir in the San Joaquin Valley, California. Available data were used to calculate a probable range of groundwater flow rates, but calibration and sensitivity analysis were not done for this model. Flow directions, as inferred from measured groundwater levels and simulated hydraulic heads from all model simulations, indicate that regional groundwater flow is from the south to the north. Kesterson Reservoir acts as a recharge mound superimposed on the regional-flow system. Groundwater moves in the horizontal and vertical direction away from Kesterson Reservoir. Mud and Salt Sloughs act as groundwater discharge areas. Simulated groundwater flow from Kesterson Reservoir did not flow beyond these sloughs. Groundwater from west of Mud Slough seems to flow west toward Los Banos Creek and east toward Mud Slough. Groundwater that travels toward Salt Slough from Kesterson Reservoir probably is lost by evapotranspiration near the surface before reaching Salt Slough. Groundwater between Salt Slough and the San Joaquin River seems to flow north and toward Salt Slough and the San Joaquin River. The canals and duck ponds generally act as sources of groundwater recharge. A method was developed for determining flow directions and distance traveled in three dimensions for discrete time increments using simulated groundwater fluxes. Simulated average horizontal pore velocities away from Kesterson range less than 0.01 to 140 ft/year. The simulated average vertical pore velocities range from 0.01 to 14.7 ft/year. (Author 's abstract)

  12. 77 FR 64427 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-22

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... County Air Pollution Control District (VCAPCD) there is no VOC concentration limit for reinjection...

  13. 75 FR 57862 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Incorporation...

  14. 76 FR 68106 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  15. 77 FR 5709 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-06

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  16. 76 FR 40660 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-11

    .... SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Air Pollution Control District....0 for the following terms: Air Pollution Control Officer, Board, Environmental Protection Agency.... New Section 6.3 requires the SJVUAPCD Air Pollution Control Officer (APCO) to prepare and present...

  17. 76 FR 56132 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-12

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... preempt Tribal law. List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  18. 77 FR 50021 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-20

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: In this action, EPA is finalizing approval of San Joaquin Valley Unified Air Pollution Control... plans that are specifically tailored to the nature of the air pollution sources in each state. The...

  19. 76 FR 52623 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-23

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... Title I of the Clean Air Amendments of 1990'' 57 FR 13498, April 16, 1992. 5. ``Preamble, Final Rule...

  20. 75 FR 1715 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-13

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  1. 76 FR 56706 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-14

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... Air Quality Standard,'' 70 FR 71612, Nov. 29, 2005. 6. Letter from William T. Hartnett to Regional...

  2. 77 FR 66429 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-05

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990,'' 57 FR 13498 (April...

  3. 76 FR 26609 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-09

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control... Valley Unified Air Pollution Control District (No. 08-17309)] to overturn a District Court ruling...

  4. 75 FR 2796 - Revisions to the California State Implementation Plan, San Joaquin Valley Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-19

    ... is finalizing approval of revisions to the San Joaquin Valley Air Pollution Control District portion... topcoats; and that Ventura County Air Pollution Control District's (VCAPCD) rule has more stringent VOC...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  5. 75 FR 24408 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-05

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  6. 76 FR 5276 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-31

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  7. 77 FR 24883 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-26

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... Air Act Amendments of 1990,'' 57 FR 13498 (April 16, 1992) (the General Preamble) and 57 FR...

  8. 77 FR 25384 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-30

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: EPA is proposing to approve revisions to the San Joaquin Valley Unified Air Pollution Control... Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990,'' 57 FR 13498 (April...

  9. 76 FR 16696 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-25

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Unified Air Pollution Control...)(2)). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  10. 77 FR 214 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-04

    ... Air Pollution Control District (SJVUAPCD) AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Air Pollution Control... and air districts for evaluating air pollution control economics. 3. Farms can change owners...

  11. 76 FR 67369 - Revisions to the California State Implementation Plan, Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-01

    ... Pollution Control District and Imperial County Air Pollution Control District AGENCY: Environmental... Joaquin Valley Unified Air Pollution Control District (SJVUAPCD) and Imperial County Air Pollution Control... U.S.C. 804(2). List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution...

  12. Organochlorine pesticide residues in bed sediments of the San Joaquin River, California

    USGS Publications Warehouse

    Gilliom, Robert J.; Clifton, Daphne G.

    1990-01-01

    Bed sediments of the San Joaquin River and its tributaries were sampled during October 7–11, 1985, and analyzed for organochiorine pesticide residues in order to determine their areal distribution and to evaluate and prioritize needs for further study. Residues of DDD, DDE, DDT, and dieldrin are widespread in the fine-grained bed sediments of the San Joaquin River and its tributaries despite little or no use of these pesticides for more than 15 years. The San Joaquin River has among the highest bed-sediment concentrations of DDD, DDE, DDT, and dieldrin residues of major rivers in the United States. Concentrations of all four pesticides were correlated with each other and with the amount of organic carbon and fine-grained particles in the bed sediments. The highest concentrations occurred in bed sediments of westside tributary streams. Potential tributary loads of DDD, DDE, DDT, and dieldrin to the San Joaquin River were computed from bed-sediment concentrations and data on streamfiow and suspended-sediment concentration in order to identify the general magnitude of differences between streams and to determine study priorities. The estimated loads indicate that the most important sources of residues during the study period were Salt Slough because of a high load of fine sediment, and Newman Wasteway, Orestimba Creek, and Hospital Creek because of high bed-sediment concentrations. Generally, the highest estimated loads of DDD, DDE, DDT, and dieldrin were in Orestimba and Hospital Creeks.

  13. 76 FR 76112 - Approval and Promulgation of Implementation Plans, State of California, San Joaquin Valley...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-06

    ... powered by an internal combustion engine and used only on the coldest winter nights to provide frost... episodic source of emissions. \\2\\ See District Rule 4702 (``Internal Combustion Engines--Phase 2''), most... (75 FR 26102), we finalized a limited approval and limited disapproval of San Joaquin Valley...

  14. Biological assessment: water hyacinth control program for the Sacramento/ San Joaquin River Delta of California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A detailed Biological Assessment was developed for the proposed Areawide Water Hyacinth Control Program to outline the procedures that will be used to control this invasive aquatic plant in the Sacramento/ San Joaquin River Delta, and to help determine if this action is expected to threaten endanger...

  15. Soil degradation in farmlands of California's San Joaquin Valley resulting from drought-induced land-use changes

    NASA Astrophysics Data System (ADS)

    Scudiero, Elia; Skaggs, Todd; Anderson, Ray; Corwin, Dennis

    2016-04-01

    Irrigation in California's Central Valley (USA) has decreased significantly due to water shortages resulting from the current drought, which began in 2010. In particular, fallow fields in the west side of the San Joaquin Valley (WSJV), which is the southwest portion of the Central Valley, increased from around 12% in the years before the drought (2007-2010) to 20-25% in the following years (2011-2015). We monitored and mapped drought-induced edaphic changes in salinity at two scales: (i) field scale (32.4-ha field in Kings County) and (ii) water district scale (2400 ha at -former- Broadview Water District in Fresno County). At both scales drought-induced land-use changes (i.e., shift from irrigated agriculture to fallow) drastically decreased soil quality by increasing salinity (and sodicity), especially in the root-zone (top 1.2 m). The field study monitors the spatial (three dimensions) changes of soil salinity (and sodicity) in the root-zone during 10 years of irrigation with drainage water followed by 4 years of no applied irrigation water (only rainfall) due to drought conditions. Changes of salinity (and other edaphic properties), through the soil profile (down to 1.2 m, at 0.3-m increments), were monitored and modeled using geospatial apparent electrical conductivity measurements and extensive soil sampling in 1999, 2002, 2004, 2009, 2011, and 2013. Results indicate that when irrigation was applied, salts were leached from the root-zone causing a remarkable improvement in soil quality. However, in less than two years after termination of irrigation, salinity in the soil profile returned to original levels or higher across the field. At larger spatial scales the effect of drought-induced land-use change on root-zone salinity is also evident. Up to spring 2006, lands in Broadview Water District (BWD) were used for irrigated agriculture. Water rights were then sold and the farmland was retired. Soil quality decreased since land retirement, especially during the

  16. Hydraulic and mechanical properties affecting ground-water flow and aquifer-system compaction, San Joaquin Valley, California

    USGS Publications Warehouse

    Sneed, Michelle

    2001-01-01

    This report summarizes hydraulic and mechanical properties affecting ground-water flow and aquifer-system compaction in the San Joaquin Valley, a broad alluviated intermontane structural trough that constitutes the southern two-thirds of the Central Valley of California. These values will be used to constrain a coupled ground-water flow and aquifer-system compaction model of the western San Joaquin Valley called WESTSIM. A main objective of the WESTSIM model is to evaluate potential future land subsidence that might occur under conditions in which deliveries of imported surface water for agricultural use are reduced and ground-water pumping is increased. Storage values generally are components of the total aquifer-system storage and include inelastic and elastic skeletal storage values of the aquifers and the aquitards that primarily govern the potential amount of land subsidence. Vertical hydraulic conductivity values generally are for discrete thicknesses of sediments, usually aquitards, that primarily govern the rate of land subsidence. The data were compiled from published sources and include results of aquifer tests, stress-strain analyses of borehole extensometer observations, laboratory consolidation tests, and calibrated models of aquifer-system compaction.

  17. Report of the Preliminary Archaeological Reconnaissance of the Lawrence Livermore Laboratory Site 300, San Joaquin County, California

    SciTech Connect

    Busby, C

    2009-11-24

    The area subject to this investigation is the existing Lawrence Livermore Laboratory Site 300, located in the region north of Corral Hollow; approximately eight and one half miles southwest of Tracy, San Joaquin County, California. Cartographic location can be determined from the Tracy and Midway USGS 7.5 minute topographic quadrangles, the appropriate portions of which are herein reproduced as Maps 1 and 2. The majority of the approximate 7000 acres of the location lies within San Joaquin County. This includes all of the area arbitrarily designated the 'Eastern Portion' on Map 2 and the majority of the area designated the 'Western Portion' on Map 1. The remaining acreage, along the western boundary of the location, lies within Alameda County. The area is located in the region of open rolling hills immediately north of Corral Hollow, and ranges in elevation from approximately 600 feet, on the flood plain of Corral Hollow Creek, to approximately 1700 feet in the northwest portion of the project location. Proposed for the area under investigation are various, unspecified improvements or modifications to the existing Site 300 facilities. Present facilities consist of scattered buildings, bunkers and magazines, utilized for testing and research purposes, including the necessary water, power, and transportation improvements to support them. The vast majority of the 7000 acres location is presently open space, utilized as buffer zones between test locations and as firing ranges.

  18. Sources and Transport of Nutrients, Organic Carbon, and Chlorophyll-a in the San Joaquin River Upstream of Vernalis, California, during Summer and Fall, 2000 and 2001

    USGS Publications Warehouse

    Kratzer, Charles R.; Dileanis, Peter D.; Zamora, Celia; Silva, Steven R.; Kendall, Carol; Bergamaschi, Brian A.; Dahlgren, Randy A.

    2004-01-01

    Oxidizable materials from the San Joaquin River upstream of Vernalis can contribute to low dissolved oxygen episodes in the Stockton Deep Water Ship Channel that can inhibit salmon migration in the fall. The U.S. Geological Survey collected and analyzed samples at four San Joaquin River sites in July through October 2000 and June through November 2001, and at eight tributary sites in 2001. The data from these sites were supplemented with data from samples collected and analyzed by the University of California at Davis at three San Joaquin River sites and eight tributary sites as part of a separate study. Streamflows in the San Joaquin River were slightly above the long-term average in 2000 and slightly below average in 2001. Nitrate loads at Vernalis in 2000 were above the long-term average, whereas loads in 2001 were close to average. Total nitrogen loads in 2000 were slightly above average, whereas loads in 2001 were slightly below average. Total phosphorus loads in 2000 and 2001 were well below average. These nutrient loads correspond with the flow-adjusted concentration trends--nitrate concentrations significantly increased since 1972 (p 0.05). Loading rates of nutrients and dissolved organic carbon increased in the San Joaquin River in the fall with the release of wetland drainage into Mud Slough and with increased reservoir releases on the Merced River. During August 2000 and September 2001, the chlorophyll-a loading rates and concentrations in the San Joaquin River declined and remained low during the rest of the sampling period. The most significant tributary sources of nutrients were the Tuolumne River, Harding Drain, and Mud Slough. The most significant tributary sources of dissolved organic carbon were Salt Slough, Mud Slough, and the Tuolumne and Stanislaus Rivers. Compared with nutrients and dissolved organic carbon, the tributaries were minor sources of chlorophyll-a, suggesting that most of the chlorophyll-a was produced in the San Joaquin River

  19. Investigating Sources and Emissions of Volatile Organic Compounds in California's San Joaquin Valley

    NASA Astrophysics Data System (ADS)

    Gentner, D. R.; Harley, R. A.; Weber, R.; Karlik, J. F.; Goldstein, A. H.

    2011-12-01

    Emissions of Volatile Organic Compounds (VOCs) are regulated both as primary air pollutants and as precursors to the formation of secondary organic aerosol and tropospheric ozone. The San Joaquin Valley, a non-attainment area for ozone and PM2.5, contains a variety of point, area, and mobile VOC sources that contribute to both primary and secondary pollution. Using ambient measurements of over 100 different VOCs and Intermediate Volatility Organic Compounds (IVOCs) made at multiple field sites, we assess the magnitude and importance of various VOC sources in the San Joaquin Valley. Hourly measurements were made during the spring and summer of 2010 via in-situ gas chromatography in Bakersfield, CA as part of the CalNex experiment and also at a rural site located 100 km north of Bakersfield. Additionally, in-situ measurements of fresh motor vehicle exhaust were made in Oakland's Caldecott tunnel during the summer of 2010. Measurements include a broad array of anthropogenic and biogenic VOCs ranging in size from 1 to 17 carbon atoms, including many compounds with functional groups or substituents (e.g. aldehydes, ketones, alcohols, halogens, sulfur, & nitrogen). Using statistical methods of source apportionment, covariance, source receptor modeling, and air parcel back trajectories, we assess the impact of various sources on observed VOC concentrations at our field sites in the San Joaquin Valley. Prevalent sources include gasoline and diesel-vehicle exhaust, petroleum extraction/refining, biogenic emissions from agricultural crops and natural vegetation, and emissions from dairy operations and animal husbandry. We use measurements of fresh motor vehicle emissions from the Caldecott tunnel to constrain apportionment of gasoline and diesel-related VOCs and IVOCs in the San Joaquin Valley. Initial results from Bakersfield show substantial influence from local anthropogenic VOC sources, but there is evidence for transport of emissions from both anthropogenic and biogenic

  20. Nitrate and pesticides in ground water in the eastern San Joaquin Valley, California : occurrence and trends

    USGS Publications Warehouse

    Burow, Karen R.; Stork, Sylvia V.; Dubrovsky, N.M.

    1998-01-01

    The occurrence of nitrate and pesticides in ground water in California's eastern San Joaquin Valley may be greatly influenced by the long history of intensive farming and irrigation and the generally permeable sediments. This study, which is part of the U.S. Geological Survey National Water-Quality Assessment Program, was done to assess the quality of the ground water and to do a preliminary evaluation of the temporal trends in nitrate and pesticides in the alluvial fans of the eastern San Joaquin Valley. Ground-water samples were collected from 30 domestic wells in 1995 (each well was sampled once during 1995). The results of the analyses of these samples were related to various physical and chemical factors in an attempt to understand the processes that control the occurrence and the concentrations of nitrate and pesticides. A preliminary evaluation of the temporal trends in the occurrence and the concentration of nitrate and pesticides was done by comparing the results of the analyses of the 1995 ground-water samples with the results of the analyses of the samples collected in 1986-87 as part of the U.S. Geological Survey Regional Aquifer-System Analysis Program. Nitrate concentrations (dissolved nitrate plus nitrite, as nitrogen) in ground water sampled in 1995 ranged from less than 0.05 to 34 milligrams per liter, with a median concentration of 4.6 milligrams per liter. Nitrate concentrations exceeded the maximum contaminant level of 10 milligrams per liter (as nitrogen) in 5 of the 30 ground-water samples (17 percent), whereas 12 of the 30 samples (40 percent) had nitrate concentrations less than 3.0 milligrams per liter. The high nitrate concentrations were associated with recently recharged, well-oxygenated ground water that has been affected by agriculture (indicated by the positive correlations between nitrate, dissolved-oxygen, tritium, and specific conductance). Twelve pesticides were detected in 21 of the 30 ground-water samples (70 percent) in 1995

  1. Significance of Late Pliocene-Early Pleistocene stratigraphy to development of Buena Vista field, San Joaquin Valley, California

    SciTech Connect

    Kuespert, J.G.

    1987-05-01

    Late Pliocene to early Pleistocene depositional patterns of upper Etchegoin and lower San Joaquin Formation sand and shale units in the Buena vista field area were controlled by changes in clastic input, eustatic sea level, structural growth, and circulation patterns in the south end of the San Joaquin Valley. Wireline and drill-strip logs, core depositions, paleontology, and petrographic data from these units suggest the interpretation of a series of shallow to marginal marine deposits with distinctive morphologic features and production characteristics. Late Pliocene marginal marine drainage systems transported clastics from southerly sources as structural and/or eustatic changes shoaled the southern area. An erosional hiatus and shallow marine transgression marked the extent of Plio-Pleistocene shoaling and rapid early Pleistocene foundering. Later Pleistocene changes in sediment supply and structural growth isolated the area from marine conditions as the basin filled with nonmarine sediments. Early field development was influenced by the areal distribution and reservoir characteristics of these sands as well as by the timing of such development activity. Depositional models derived from these data are useful in constructing paleogeographic models with regional hydrocarbon significance.

  2. Population density, biomass, and age-class structure of the invasive clam Corbicula fluminea in rivers of the lower San Joaquin River watershed, California

    USGS Publications Warehouse

    Brown, L.R.; Thompson, J.K.; Higgins, K.; Lucas, L.V.

    2007-01-01

    Corbicula fluminea is well known as an invasive filter-feeding freshwater bivalve with a variety of effects on ecosystem processes. However. C. fluminea has been relatively unstudied in the rivers of the western United States. In June 2003, we sampled C. fluminea at 16 sites in the San Joaquin River watershed of California, which was invaded by C. fluminea in the 1940s. Corbicula fluminea was common in 2 tributaries to the San Joaquin River, reaching densities of 200 clams??m-2, but was rare in the San Joaquin River. Biomass followed a similar pattern. Clams of the same age were shorter in the San Joaquin River than in the tributaries. Distribution of clams was different in the 2 tributaries, but the causes of the difference are unknown. The low density and biomass of clams in the San Joaquin River was likely due to stressful habitat or to water quality, because food was abundant. The success of C. fluminea invasions and subsequent effects on trophic processes likely depends on multiple factors. As C. fluminea continues to expand its range around the world, questions regarding invasion success and effects on ecosystems will become important in a wide array of environmental settings.

  3. Remote sensing research for agricultural applications. [San Joaquin County, California and Snake River Plain and Twin Falls area, Idaho

    NASA Technical Reports Server (NTRS)

    Colwell, R. N. (Principal Investigator); Wall, S. L.; Beck, L. H.; Degloria, S. D.; Ritter, P. R.; Thomas, R. W.; Travlos, A. J.; Fakhoury, E.

    1984-01-01

    Materials and methods used to characterize selected soil properties and agricultural crops in San Joaquin County, California are described. Results show that: (1) the location and widths of TM bands are suitable for detecting differences in selected soil properties; (2) the number of TM spectral bands allows the quantification of soil spectral curve form and magnitude; and (3) the spatial and geometric quality of TM data allows for the discrimination and quantification of within field variability of soil properties. The design of the LANDSAT based multiple crop acreage estimation experiment for the Idaho Department of Water Resources is described including the use of U.C. Berkeley's Survey Modeling Planning Model. Progress made on Peditor software development on MIDAS, and cooperative computing using local and remote systems is reported as well as development of MIDAS microcomputer systems.

  4. Population trends of San Joaquin kit fox (Vulpes velox macrotis) at Camp Roberts Army National Guard Training Site, California

    SciTech Connect

    Berry, W.H.; Standley, W.G.

    1992-10-01

    Population trends of a San Joaquin kit fox population (Vulpes velox macrotis) were investigated at Camp Roberts Army National Guard Training Site, California, from November 1989 through August 1991. Six semiannual livetrapping sessions and eight scent-station survey sessions were conducted. Livetrapping results and radiotelemetry data were used to calculate minimum population size, density, and distribution. A total of 175 individual foxes were trapped 463 times. The number of individuals trapped and minimum population size calculations showed a decline over time. The highest minimum population (109) was observed in winter 1988. Summer 1991 had the lowest minimum population size (45). No evidence was found to indicate that the apparent population decline was a result of military-authorized activities.

  5. Health assessment for Sharpe Army Depot, Lathrop, San Joaquin County, California, Region 9. CERCLIS No. CA8210020832. Preliminary report

    SciTech Connect

    Not Available

    1989-04-14

    The Sharpe Army Depot (SHAD), consisting of 720 acres located in San Joaquin County, California, is on the National Priorities List. The site has served as a storage, receiving, packaging, and shipping facility since 1941. In the late 1940s the Depot also served as a maintenance facility for heavy equipment. Available data indicate that the primary contaminant sources are associated with past heavy equipment and aircraft-maintenance operations. Contaminants associated with SHAD include trichloroethene, arsenic, selenium, and bromacil (a herbicide). The site is considered to be of potential public health concern because of the risk to human health caused by the possibility of exposure to hazardous substances via ingestion, dermal contact, or inhalation of contaminants in ground water, subsurface soil, soil-gas, and food-chain entities.

  6. Dynamic modeling of organophosphate pesticide load in surface water in the northern San Joaquin Valley watershed of California.

    PubMed

    Luo, Yuzhou; Zhang, Xuyang; Liu, Xingmei; Ficklin, Darren; Zhang, Minghua

    2008-12-01

    The hydrology, sediment, and pesticide transport components of the Soil and Water Assessment Tool (SWAT) were evaluated on the northern San Joaquin Valley watershed of California. The Nash-Sutcliffe coefficients for monthly stream flow and sediment load ranged from 0.49 to 0.99 over the watershed during the study period of 1992-2005. The calibrated SWAT model was applied to simulate fate and transport processes of two organophosphate pesticides of diazinon and chlorpyrifos at watershed scale. The model generated satisfactory predictions of dissolved pesticide loads relative to the monitoring data. The model also showed great success in capturing spatial patterns of dissolved diazinon and chlorpyrifos loads according to the soil properties and landscape morphology over the large agricultural watershed. This study indicated that curve number was the major factor influencing the hydrology while pesticide fate and transport were mainly affected by surface runoff and pesticide application and in the study area. PMID:18457909

  7. Dissolved-selenium data for wells in the western San Joaquin Valley, California, February to July 1985

    USGS Publications Warehouse

    Neil, J.M.

    1986-01-01

    Water samples were collected for selenium analysis from 63 wells in western San Joaquin Valley, California, during February to July 1985. Results of the data collection indicate that dissolved selenium concentrations ranged from less than 1 to 120 micrograms per liter; more than 50 percent of the wells sampled had concentrations of less than 1 microgram per liter. Four additional samples collected from public supply wells in the western valley had concentrations ranging from less than 1 to 2 micrograms per liter. All samples from five public supply wells east of the study area had concentrations less than 1 microgram per liter. The U.S. Environmental Protection Agency 's drinking-water standard of 10 micrograms per liter for selenium was slightly exceeded in 2 of 39 domestic wells (11 and 13 micrograms per liter) and substantially exceeded in 2 of 11 irrigation and agricultural wells (55 and 120 micrograms per liter). (USGS)

  8. Evaluating a Radar-Based, Non Contact Streamflow Measurement System in the San Joaquin River at Vernalis, California

    USGS Publications Warehouse

    Cheng, Ralph T.; Gartner, Jeffrey W.; Mason, Jr., Robert R.; Costa, John E.; Plant, William J.; Spicer, Kurt R.; Haeni, F. Peter; Melcher, Nick B.; Keller, William C.; Hayes, Ken

    2004-01-01

    Accurate measurement of flow in the San Joaquin River at Vernalis, California, is vital to a wide range of Federal and State agencies, environmental interests, and water contractors. The U.S. Geological Survey uses a conventional stage-discharge rating technique to determine flows at Vernalis. Since the flood of January 1997, the channel has scoured and filled as much as 20 feet in some sections near the measurement site resulting in an unstable stage-discharge rating. In response to recent advances in measurement techniques and the need for more accurate measurement methods, the Geological Survey has undertaken a technology demonstration project to develop and deploy a radar-based streamflow measuring system on the bank of the San Joaquin River at Vernalis, California. The proposed flow-measurement system consists of a ground-penetrating radar system for mapping channel geometries, a microwave radar system for measuring surface velocities, and other necessary infrastructure. Cross-section information derived from ground penetrating radar provided depths similar to those measured by other instruments during the study. Likewise, surface-velocity patterns and magnitudes measured by the pulsed Doppler radar system are consistent with near surface current measurements derived from acoustic velocity instruments. Since the ratio of surface velocity to mean velocity falls to within a small range of theoretical value, using surface velocity as an index velocity to compute river discharge is feasable. Ultimately, the non-contact radar system may be used to make continuous, near-real-time flow measurements during high and medium flows. This report documents the data collected between April 14, 2002 and May 17, 2002 for the purposes of testing this radar based system. Further analyses of the data collected during this field effort will lead to further development and improvement of the system.

  9. Design and implementation of an emergency environmental responsesystem to protect migrating salmon in the lower San Joaquin River,California

    SciTech Connect

    Quinn, Nigel W.T.; Jacobs, Karl C.

    2006-01-30

    In the past decade tens of millions of dollars have beenspent by water resource agencies in California to restore the nativesalmon fishery in the San Joaquin River and its major tributaries. Anexcavated deep water ship channel (DWSC), through which the river runs onits way to the Bay/Delta and Pacific Ocean, experiences episodes of lowdissolved oxygen which acts as a barrier to anadromous fish migration anda threat to the long-term survival of the salmon run. An emergencyresponse management system is under development to forecast theseepisodes of low dissolved oxygen and to deploy measures that will raisedissolved oxygen concentrations to prevent damage to the fisheryresource. The emergency response management system has been designed tointeract with a real-time water quality monitoring network and is servedby a comprehensive data management and forecasting model toolbox. TheBay/Delta and Tributaries (BDAT) Cooperative Data Management System is adistributed, web accessible database that contains terabytes ofinformation on all aspects of the ecology of the Bay/Delta and upperwatersheds. The complexity of the problem dictates data integration froma variety of monitoring programs. A unique data templating system hasbeen constructed to serve the needs of cooperating scientists who wish toshare their data and to simplify and streamline data uploading into themaster database. In this paper we demonstrate the utility of such asystem in providing decision support for management of the San JoaquinRiver fishery. We discuss how the system might be expanded to havefurther utility in coping with other emergencies and threats to watersupply system serving California's costal communities.

  10. Chemical quality of ground water in San Joaquin and part of Contra Costa Counties, California

    USGS Publications Warehouse

    Sorenson, Stephen K.

    1981-01-01

    Chemical water-quality conditions were investigated in San Joaquin and part of Contra Costa Counties by canvassing available wells and sampling water from 324 representative wells. Chemical water types varied, with 73 percent of the wells sampled containing either calcium-magnesium bicarbonate, or calcium-sodium bicarbonate type water. Substantial areas contain ground water exceeding water-quality standards for boron, manganese, and nitrate. Trace elements, with the exception of boron and manganese, were present in negligible amounts. (USGS)

  11. Diazinon concentrations in the Sacramento and San Joaquin Rivers and San Francisco Bay, California, February 1993

    USGS Publications Warehouse

    Kuivila, Kathryn M.

    1993-01-01

    The distribution and possible biological effects of a dormant spray pesticide, diazinon, were examined by measuring pesticide concentrations and estimating toxicity using bioassays at a series of sites in the Sacramento-San Joaquin Delta and San Francisco Bay. Pulses of diazinon were observed in early February 1993 in the Sacramento and San Joaquin Rivers after heavy rains, with elevated concentrations measured for a few days to weeks at a time. The pulse of diazinon in the Sacramento River was followed from Sacramento through Suisun Bay, the eastward embayment of San Francisco Bay. In the central delta, well-defined pulses of diazinon were not observed at the Old and Middle River sites; instead, the concentrations steadily increased throughout February. Ceriodaphnia dubia mortality was 100% in water samples collected for 12 consecutive days (February 8-19) from the San Joaquin River at Vernalis. The bioassay mortality corresponded with the peak diazinon concentrations. Conversely, no toxicity was observed in water collected before or after peaks of diazinon concentration. Other pesticides present also could contribute to the toxicity.

  12. Integrated Hydrosystem Modeling of the California Basin

    NASA Astrophysics Data System (ADS)

    Davison, J. H.; Hwang, H. T.; Sudicky, E. A.; Mallia, D.; Lin, J. C.

    2015-12-01

    The Western United States is facing one of the worst droughts on record. Climate change projections predict warmer temperatures, higher evapotranspiration rates, and no foreseeable increase in precipitation. California, in particular, has supplemented their decreased surface water supplies by mining deep groundwater. However, this supply of groundwater is limited, especially with reduced recharge. These combined factors place California's water-demanding society at dire risk. In an effort to quantify California's risks, we present a fully integrated water cycle model that captures the dynamics of the subsurface, land surface, and atmospheric domains over the entire California basin. Our water cycle model combines HydroGeoSphere (HGS), a 3-D control-volume finite element model that accommodates variably-saturated subsurface and surface water flow with evapotranspiration processes to the Weather Research and Forecasting (WRF) model, a 3-D finite difference nonhydrostatic mesoscale atmospheric simulator. The two-way coupling within our model, referred to as HGS-WRF, tightly integrates the water cycling processes by passing precipitation and potential evapotranspiration data from WRF to HGS, while exchanging actual evapotranspiration and soil saturation data from HGS to WRF. Furthermore, HGS-WRF implements a flexible coupling method that allows each model to use a unique mesh while maintaining mass conservation within and between domains. Our simulation replicated field measured evapotranspiration fluxes and showed a strong correlation between the soil saturation (depth to groundwater table) and latent heat fluxes. Altogether, the HGS-WRF California basin model is currently the most complete water resource simulation framework as it combines groundwater, surface water, the unsaturated zone, and the atmosphere into one coupled system.

  13. Potential of public lands in California's central valley as habitat for the endangered San Joaquin kit fox. [Vulpes macrotis mutica

    SciTech Connect

    O'Farrell, T.P.; McCue, P.; Sauls, M.L.; Kato, T.

    1982-01-01

    As part of an assessment of the impacts of their activities on the endangered San Joaquin kit fox and its essential habitat, the Department of Energy and Bureau of Land Management investigated the potential of public lands in the San Joaquin Valley as suitable habitat for the San Joaquin kit fox. (ACR)

  14. Fleas of the San Joaquin kit fox (Vulpes velox macrotis) on Camp Roberts Army National Guard Training Site, California

    SciTech Connect

    Spencer, K.A.; Egoscue, H.J.

    1992-09-01

    A total of 3,241 fleas, representing seven species, were identified from 398 samples collected from San Joaquin kit foxes (Vulpes velox macrotis), California ground squirrels (Spermophilus beecheyi), and deer mice (Peromyscus maniculatus) at Camp Roberts Army National Guard Training Site, California, from November 1988 through September 1991. Of 3,109 fleas collected from kit foxes 95.7% were Echidnophaga gallinacea, 4.0% Pulex irritans, 0.2% Hoplopsyllus anomolus, and 0.1% Odontopsyllus dentatus. One male Ctenocephalides fells was also collected from a kit fox. The 118 fleas collected from California ground squirrels consisted of Hoplopsyllus anomolus (55.9%), Echidnophaga gallinacea (37.3%), and Oropsylla montanus (6.8%). The 14 fleas collected from deer mice were Aetheca wagneri. Based on the distribution and abundance of flea species collected, and the vector efficiency of these fleas, it appears that kit foxes could play a role in the transfer of natural vectors of sylvatic plague between rodent populations, if the bacterium responsible for plague (Yersinia pestis) were present at Camp Roberts. Little information regarding kit fox food habits was evidenced by the distribution and abundance of small mammal flea species collected from kit foxes.

  15. Groundwater-quality data in the Western San Joaquin Valley study unit, 2010 - Results from the California GAMA Program

    USGS Publications Warehouse

    Mathany, Timothy M.; Landon, Matthew K.; Shelton, Jennifer L.; Belitz, Kenneth

    2013-01-01

    Groundwater quality in the approximately 2,170-square-mile Western San Joaquin Valley (WSJV) study unit was investigated by the U.S. Geological Survey (USGS) from March to July 2010, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program's Priority Basin Project (PBP). The GAMA-PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The WSJV study unit was the twenty-ninth study unit to be sampled as part of the GAMA-PBP. The GAMA Western San Joaquin Valley study was designed to provide a spatially unbiased assessment of untreated-groundwater quality in the primary aquifer system, and to facilitate statistically consistent comparisons of untreated groundwater quality throughout California. The primary aquifer system is defined as parts of aquifers corresponding to the perforation intervals of wells listed in the California Department of Public Health (CDPH) database for the WSJV study unit. Groundwater quality in the primary aquifer system may differ from the quality in the shallower or deeper water-bearing zones; shallow groundwater may be more vulnerable to surficial contamination. In the WSJV study unit, groundwater samples were collected from 58 wells in 2 study areas (Delta-Mendota subbasin and Westside subbasin) in Stanislaus, Merced, Madera, Fresno, and Kings Counties. Thirty-nine of the wells were selected by using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells), and 19 wells were selected to aid in the understanding of aquifer-system flow and related groundwater-quality issues (understanding wells). The groundwater samples were analyzed for organic constituents (volatile organic compounds [VOCs], low-level fumigants, and pesticides and pesticide degradates

  16. Biostratigraphy of the San Joaquin Formation in borrow-source area B-17, Kettleman Hills landfill, North Dome, Kettleman Hills, Kings County, California

    USGS Publications Warehouse

    Powell, Charles L.; Fisk, Lanny H.; Maloney, David F.; Haasl, David M.

    2010-01-01

    The stratigraphic occurrences and interpreted biostratigraphy of invertebrate fossil taxa in the upper San Joaquin Formation and lower-most Tulare Formation encountered at the Chemical Waste Management Kettleman Hills waste disposal facility on the North Dome of the Kettleman Hills, Kings County, California are documented. Significant new findings include (1) a detailed biostratigraphy of the upper San Joaquin Formation; (2) the first fossil occurrence of Modiolus neglectus; (3) distinguishing Ostrea sequens from Myrakeena veatchii (Ostrea vespertina of authors) in the Central Valley of California; (4) differentiating two taxa previously attributed to Pteropurpura festivus; (5) finding a stratigraphic succession between Caesia coalingensis (lower in the section) and Catilon iniquus (higher in the section); and (6) recognizing Pliocene-age fossils from around Santa Barbara. In addition, the presence of the bivalves Anodonta and Gonidea in the San Joaquin Formation, both restricted to fresh water and common in the Tulare Formation, confirm periods of fresh water or very close fresh-water environments during deposition of the San Joaquin Formation.

  17. Fish communities of the Sacramento River Basin: Implications for conservation of native fishes in the Central Valley, California

    USGS Publications Warehouse

    May, J.T.; Brown, L.R.

    2002-01-01

    The associations of resident fish communities with environmental variables and stream condition were evaluated at representative sites within the Sacramento River Basin, California between 1996 and 1998 using multivariate ordination techniques and by calculating six fish community metrics. In addition, the results of the current study were compared with recent studies in the San Joaquin River drainage to provide a wider perspective of the condition of resident fish communities in the Central Valley of California as a whole. Within the Sacramento drainage, species distributions were correlated with elevational and substrate size gradients; however, the elevation of a sampling site was correlated with a suite of water-quality and habitat variables that are indicative of land use effects on physiochemical stream parameters. Four fish community metrics - percentage of native fish, percentage of intolerant fish, number of tolerant species, and percentage of fish with external anomalies - were responsive to environmental quality. Comparisons between the current study and recent studies in the San Joaquin River drainage suggested that differences in water-management practices may have significant effects on native species fish community structure. Additionally, the results of the current study suggest that index of biotic integrity-type indices can be developed for the Sacramento River Basin and possibly the entire Central Valley, California. The protection of native fish communities in the Central Valley and other arid environments continues to be a conflict between human needs for water resources and the requirements of aquatic ecosystems; preservation of these ecosystems will require innovative management strategies.

  18. Character and evolution of the ground-water flow system in the central part of the western San Joaquin Valley, California

    USGS Publications Warehouse

    Belitz, K.R.

    1988-01-01

    The occurrence of selenium in agricultural drain water derived from the western San Joaquin Valley, California, has focused concern on the groundwater flow system of the western valley. Previous work and recently collected texture and water level data were used to evaluate the character and evolution of the regional groundwater flow system in the central part of the western valley, with particular emphasis on the deposits overlying the Corcoran Clay Member of the Tulane Formation. The Corcoran Clay Member, where present, divides the flow system into an upper semiconfined zone and a lower confined zone. Above the Corcoran, three geohydrologic units can be recognized: Coast Range alluvium, Sierran sand, and flood-basin deposits. These units differ in texture, hydrologic properties, and oxidation state. The development of irrigated agriculture in the central part of the western valley has significantly altered the flow system. Percolation of irrigation water past crop roots has caused a rise in the altitude of the water table in mid-fan and distal-fan areas. Pumpage of groundwater from wells has caused a lowering of the water table beneath parts of the fanheads and a lowering of the potentiometric surface of the confined zone over much of the western valley. The combination of percolation and pumpage has resulted in development of a large downward hydraulic head gradient in the semi-confined zone and has created a groundwater divide along the western margin of the valley. Surface water deliveries from the California Aqueduct have allowed a decrease in pumpage and a consequent recovery in hydraulic head throughout the system. (Author 's abstract)

  19. Reactivation of an idle lease to increase heavy oil recovery through application of conventional steam drive technology in a low dip slope and basin reservoir in the Midway-Sunset field, San Joaquin Basin, California. [Quarterly report], June 14, 1995--September 30, 1995

    SciTech Connect

    Schamel, S.

    1996-01-19

    This project will reactivate ARCO`s idle Pru Fee lease in the Midway-Sunset field, California and conduct a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. Cyclic steaming will be used to re-establish baseline production within the reservoir characterization phase of the project. During the demonstration phase, a continuous steamflood enhanced oil recover will be initiated to test the incremental value of this method as an alternative to cyclic steaming. Other economically marginal Class III reservoirs having similar producibility problems will benefit from insight gained in this project. The objectives of the project are: (1) to return the shut-in portion of the reservoir to commercial production; (2) to accurately describe the reservoir and recovery process; and (3) to convey the details of this activity to the domestic petroleum industry, especially to other producers in California, through an aggressive technology transfer program. A summary of technical progress covers: geological and reservoir characterization, and reservoir simulation.

  20. Reactivation of an idle lease to increase heavy oil recovery through application of conventional steam drive technology in a low dip slope and basin reservoir in the Midway-Sunset field, San Joaquin Basin, California. Quarterly report, June 14--September 30, 1995

    SciTech Connect

    Schamel, S.

    1995-12-19

    This project will reactivate ARCO`s idle Pru Fee lease in the Midway-Sunset field, California and conduct a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. Cyclic steaming will be used to reestablish baseline production within the reservoir characterization phase of the project. During the demonstration phase, a continuous steamflood enhanced oil recover will be initiated to test the incremental value of this method as an alternative to cyclic steaming. Other economically marginal Class 3 reservoirs having similar producibility problems will benefit from insight gained in this project. The objectives of the project are: (1) to return the shut-in portion of the reservoir to commercial production; (2) to accurately describe the reservoir and recovery process; and (3) to convey the details of this activity to the domestic petroleum industry, especially to other producers in California, through an aggressive technology transfer program. A summary of technical progress discusses the literature compilation, assembly of digitized log suites, development of a stratigraphic framework, installation of lease production facilities, return wells to production, drill producer and observation wells, and reservoir characterization.

  1. Reactivation of an idle lease to increase heavy oil recovery through application of conventional steam drive technology in a low dip slope and basin reservoir in the Midway-Sunset field, San Joaquin basin, California. Quarterly report, January 1--March 31, 1996

    SciTech Connect

    Schamel, S.

    1996-06-28

    This project will reactivate ARCO`s idle Pru Fee lease in the Midway-Sunset field, California and conduct a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. The objectives of the project are: (1) to return the shut-in portion of the reservoir to commercial production; (2) to accurately describe the reservoir and recovery process; and (3) convey the details of this activity to the domestic petroleum industry, especially to other producers in California, through an aggressive technology transfer program. The producibility problems initially thought to be responsible for the low recovery in the Pru Fee property are: (a) the shallow dip of the bedding; (b) complex reservoir structure, (c) thinning pay zone; and (d) the presence of bottom water. The project is using tight integration of reservoir characterization and simulation modeling to evaluate the magnitude of and alternative solutions to these problems. Two main activities were brought to completion during the first quarter of 1996: (1) lithologic and petrophysical description of the core taken form the new well Pru 101 near the center of the demonstration site and (2) development of a stratigraphic model for the Pru Fee project area. In addition, the first phase of baseline cyclic steaming of the Pru Fee demonstration site was continued with production tests and formation temperature monitoring.

  2. Assessment of interim flow water-quality data of the San Joaquin River restoration program and implications for fishes, California, 2009-11

    USGS Publications Warehouse

    Wulff, Marissa L.; Brown, Larry R.

    2015-01-01

    After more than 50 years of extensive water diversion for urban and agriculture use, a major settlement was reached among the U.S. Departments of the Interior and Commerce, the Natural Resources Defense Council, and the Friant Water Users Authority in an effort to restore the San Joaquin River. The settlement received Federal court approval in October 2006 and established the San Joaquin River Restoration Program, a multi-agency collaboration between State and Federal agencies to restore and maintain fish populations, including Chinook salmon, in the main stem of the river between Friant Dam and the confluence with the Merced River. This is to be done while avoiding or minimizing adverse water supply effects to all of the Friant Division contractors that could result from restoration flows required by the settlement. The settlement stipulates that water- and sediment-quality data be collected to help assess the restoration goals. This report summarizes and evaluates water-quality data collected in the main stem of the San Joaquin River between Friant Dam and the Merced River by the U.S. Bureau of Reclamation for the San Joaquin River Restoration Program during 2009-11. This summary and assessment consider sampling frequency for adequate characterization of variability, sampling locations for sufficient characterization of the San Joaquin River Restoration Program restoration reach, sampling methods for appropriate media (water and sediment), and constituent reporting limits. After reviewing the water- and sediment-quality results for the San Joaquin River Restoration Program, several suggestions were made to the Fisheries Management Work Group, a division of the San Joaquin River Restoration Program that focuses solely on the reintroduction strategies and health of salmon and other native fishes in the river. Water-quality results for lead and total organic carbon exceeded the Surface Water Ambient Monitoring Program Basin Plan Objectives for the San Joaquin Basin

  3. Map showing Tertiary stratigraphy and structure of the Northern San Joaquin Valley, California

    USGS Publications Warehouse

    Bartow, J.A.

    1985-01-01

    The emphasis in this report is on the Tertiary rocks of the northern part of the San Joaquin Valley, although pre-Tertiary stratigraphic units are shown on the cross sections where information was available. They serve to emphasize the discordance between the Neogene and the older units. Correlations of units in the Great Valley sequence (Late Jurassic to earliest Tertiary) are based mostly, with some modification, on the work of Hoffman (1964) and Callaway (1964), although the informal stratigraphic names used by those workers are not applied here.

  4. Effects of an agricultural drainwater bypass on fishes inhabiting the Grassland Water District and the lower San Joaquin River, California

    USGS Publications Warehouse

    Saiki, M.K.; Martin, B.A.; Schwarzbach, S.E.; May, T.W.

    2001-01-01

    The Grassland Bypass Project, which began operation in September 1996, was conceived as a means of diverting brackish selenium-contaminated agricultural drainwater away from canals and sloughs needed for transporting irrigation water to wetlands within the Grassland Water District (the Grasslands), Merced County, California. The seleniferous drainwater is now routed into the San Luis Drain for conveyance to North Mud Slough and eventual disposal in the San Joaquin River. The purpose of this study was to determine the extent to which the Grassland Bypass Project has affected fishes in sloughs and other surface waters within and downstream from the Grasslands. During September-October 1997, 9,795 fish representing 25 species were captured at 13 sampling sites. Although several species exhibited restricted spatial distributions, association analysis and cluster analysis failed to identify more than one fish species assemblage inhabiting the various sites. However, seleniferous drainwater from the San Luis Drain has influenced selenium concentrations in whole fish within North Mud Slough and the San Joaquin River. The highest concentrations of selenium (12-23 ??g/g, dry weight basis) were measured in green sunfish Lepomis cyanellus from the San Luis Drain where seleniferous drainwater is most concentrated, whereas the second highest concentrations occurred in green sunfish (7.6-17 ??g/g) and bluegills Lepomis macrochirus (14-18 ??g/g) from North Mud Slough immediately downstream from the drain. Although there was some variation, fish in the San Joaquin River generally contained higher body burdens of selenium when captured immediately below the mouth of North Mud Slough (3.1-4.8 ??g/g for green sunfish, 3.7-5.0 ??g/g for bluegills) than when captured upstream from the mouth (0.67-3.3 ??g/g for green sunfish, 0.59-3.7 ??g/g for bluegills). Waterborne selenium was the single most important predictor of selenium concentrations in green sunfish and bluegills, as judged by

  5. PEAT ACCRETION HISTORIES DURING THE PAST 6000 YEARS IN MARSHES OF THE SACRAMENTO - SAN JOAQUIN DELTA, CALIFORNIA, USA

    SciTech Connect

    Drexler, J Z; de Fontaine, C S; Brown, T A

    2009-07-20

    Peat cores were collected in 4 remnant marsh islands and 4 drained, farmed islands throughout the Sacramento - San Joaquin Delta of California in order to characterize the peat accretion history of this region. Radiocarbon age determination of marsh macrofossils at both marsh and farmed islands showed that marshes in the central and western Delta started forming between 6030 and 6790 cal yr BP. Age-depth models for three marshes were constructed using cubic smooth spline regression models. The resulting spline fit models were used to estimate peat accretion histories for the marshes. Estimated accretion rates range from 0.03 to 0.49 cm yr{sup -1} for the marsh sites. The highest accretion rates are at Browns Island, a marsh at the confluence of the Sacramento and San Joaquin rivers. Porosity was examined in the peat core from Franks Wetland, one of the remnant marsh sites. Porosity was greater than 90% and changed little with depth indicating that autocompaction was not an important process in the peat column. The mean contribution of organic matter to soil volume at the marsh sites ranges from 6.15 to 9.25% with little variability. In contrast, the mean contribution of inorganic matter to soil volume ranges from 1.40 to 8.45% with much greater variability, especially in sites situated in main channels. These results suggest that marshes in the Delta can be viewed as largely autochthonous vs. allochthonous in character. Autochthonous sites are largely removed from watershed processes, such as sediment deposition and scour, and are dominated by organic production. Allochthonous sites have greater fluctuations in accretion rates due to the variability of inorganic inputs from the watershed. A comparison of estimated vertical accretion rates with 20th century rates of global sea-level rise shows that currently marshes are maintaining their positions in the tidal frame, yet this offers little assurance of sustainability under scenarios of increased sea-level rise in

  6. Geomorphic Response to Global Warming in the Anthropocene: Levee Breaches in California's Sacramento-San Joaquin Watershed

    NASA Astrophysics Data System (ADS)

    Florsheim, J. L.; Dettinger, M.; Malamud-Roam, F.; Ingram, B.; Mount, J.

    2006-12-01

    Geomorphic processes in rivers are likely to be influenced by global warming through alterations of flood, erosion, and sedimentation processes and rates. In California's Sierra Nevada, warming scenarios imply future increases in magnitudes and durations (and changes in timing) of floods as snow packs diminish and rainfall runoff increasingly dominates flow into the Central Valley fluvial system. Geomorphic processes are likely to differ from processes that dominated during the Holocene due to the influence both of projected global warming and land use alterations including levee construction that narrows and separates Sacramento-San Joaquin Rivers and tributaries from floodplains and flow regulation downstream of numerous large dams. Whereas Holocene floods induced overbank flow and avulsion processes that led to vertical floodplain accretion and variability of stages in aggrading multiple-channel systems, modern floods largely transport flow and sediment within incised channels confined by levees. Because the scenarios of warming are developed at coarse scales, only an understanding of the relations between large-scale hydrology and climate on the one hand, and the incidence of levee breaches on the other, will make it possible to project likely geomorphic responses to future warming and flooding. A historical record of catastrophic levee breaks on the Sacramento and San Joaquin Rivers has been developed to allow analyses of these connections. In the current work, we develop statistical relations between historical levee break events and flow discharge, as well as with climatic phenomena such as El Nino and La Nina phases of the ENSO cycle, positive and negative phases of the Pacific Decadal Oscillation, and seasonal propensities towards "pineapple-express" storms. Preliminary results suggest strong relations between levee breaches and discharge, but poor relations to ENSO. Further investigation of these data will provide insight to help inform models and river

  7. Multimedia transport and risk assessment of organophosphate pesticides and a case study in the northern San Joaquin Valley of California.

    PubMed

    Luo, Yuzhou; Zhang, Minghua

    2009-05-01

    This paper presents a framework for cumulative risk characterization of human exposure to pesticides through multiple exposure pathways. This framework is illustrated through a case study of selected organophosphate (OP) pesticides in the northern San Joaquin Valley of California. Chemical concentrations in environmental media were simulated using a multimedia environmental fate model, and converted to contamination levels in exposure media. The risk characterization in this study was based on a residential-scale exposure to residues of multiple pesticides through everyday activities. Doses from a mixture of OP pesticides that share a common mechanism of toxicity were estimated following US Environmental Protection Agency guidelines for cumulative risk analysis. Uncertainty in the human exposure parameters was included in the Monte Carlo simulation in order to perform stochastic calculations for intakes and corresponding risks of OP pesticides. Risk of brain acetylcholinesterase inhibition was reported as margins of exposure (MOEs) of the 99.9th population percentile for two age groups living in the northern San Joaquin Valley during 1992-2005. Diet was identified as the dominant exposure pathway in cumulative exposure and risk, while the temporal trend and spatial variation in total MOE levels were associated with exposures to contaminated drinking water and ambient air. Uniformly higher risks were observed for children because of their greater inhalation and ingestion rates per body weight, relative to adults. The results indicated that exposures for children were about twice of those estimated for adults. Concerns over children's exposure to OP pesticide through food and water ingestion were suggested based on the spatiotemporal variations predicted for the subchronic MOEs at the 99.9th percentile of exposure in the study area.

  8. Determination of the biogenic emission rates of species contributing to VOC in the San Joaquin Valley OF California

    NASA Astrophysics Data System (ADS)

    Tanner, Roger L.; Zielinska, Barbara

    As part of an extensive effort to characterize biogenic hydrocarbon emission rates in the San Joaquin Valley and surrounding areas during the SJVAQS/AUSPEX field experimental period, July-August 1990, measurements were made for the first time of isoprene, terpene, and other VOC emission rates from blue oak ( Quercus douglasii), foothill pine ( Pinus sabiniana), and a ground cover plant called tarweed ( Holocarpha sp.) at a rural site near Mariposa, CA. A flow-through plant enclosure method was used to measure the emission flux rates from these species; the plant limb or whole plant was flushed with clean air just prior to hydrocarbon sampling. Samples of the plant emissions were collected on Tenax GC or Tenax GC-Carbosieve S-I1 cartridges and analysed by gas chromatography- Fourier transform infrared-mass spectrometry (GC-FTIR-MS). Quantifiable biogenic emissions from two blue oak specimens consisted only of isoprene, with an average emission rate of 8.4 μg g -1 dry biomass h -1. Emission rates (above the detection of about 0.05 μg -1 h -1) from two foothill pine specimens consisted mostly of α-pinene; an average emission rate of 0.64 μg -1 h -1 of α-pinene was observed. The tarweed species emitted both α- and β-pinenes, along with other terpene and oxygenated species, some of which have been tentatively identified. The emission rates of biogenic hydrocarbons from foothill pine and blue oak species as determined in this study make these species potentially significant contributors to summertime VOC levels in the San Joaquin Valley of California, based on vegetation classification data and the predominant summer meteorology.

  9. Aquatic Insect Emergence in Post-Harvest Flooded Agricultural Fields in the Southern San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Moss, R. C.; Blumenshine, S.; Fleskes, J.

    2005-05-01

    California's Southern San Joaquin Valley is one of the most important waterbird areas in North America, but has suffered a disproportionate loss of wetlands when compared to other California regions. This project analyzes the habitat value of post-harvest flooded cropland by measuring the emergence of aquatic insects across multiple crop types. Aquatic insect emergence was sampled from post-harvest flooded fields of four crop types (alfalfa, corn, tomato, wheat), August-October, 2003-2004. Emergence was measured using traps deployed with a stratified random distribution to sample between and within field variation. Emergence rate and emergent biomass was significantly higher in flooded tomato fields. Results from corn fields indicate that flooding depth was correlated (r=0.095) with both diel temperature fluctuation and emergence rate. Chironomus dilutus larvae were grown in environmental chambers, under two thermal treatments with the same mean but different amplitudes (high: 15°-32°C, low: 20°-26°C) to investigate thermal fluctuation effects on survival and biomass. Larval survival (4x) and biomass (2x) were significantly greater in the low versus high temperature fluctuation treatment. This research has the potential to affect agricultural management throughout the 12,600 km2 region, increase aquatic insect production and aid in the recovery of declining bird populations.

  10. Ramp-style deposition of Oligocene Marine Vedder formation, San Joaquin Valley, California

    SciTech Connect

    Bloch, R.B.

    1986-04-01

    The Oligocene Vedder formation consists of well-sorted medium to fine-grained marine sand and shale in the subsurface of the eastern San Joaquin Valley. Updip, this formation interfingers with nonmarine/lagoonal facies known as the Walker Formation. This relationship appears to be transgressive because the marine Vedder generally overlies the Walker Formation. Downdip, the Vedder sands interfinger with middle to lower bathyal shale in a progradational manner, forming upward-coarsening patterns in well logs. Depositional water depths for the shale were determined from benthic foraminifera assemblages. The Vedder formation is approximately 750 ft thick along its updip part, and gradually thickens to 1500 ft downdip. Overall deposition geometry, determined from well-log correlations and seismic data, is generally parallel and downlapping. A prominent shelf-slope break is not evident. Rather, depositional surfaces are tabular or broadly lobate, with a depositional slope of 5/sup 0/-10/sup 0/. This geometry of constant slope between nonmarine and deep marine water depth is termed a ramp. The depositional style and geometry are similar to that of the Oligocene upper Pleito Formation, which crops out in the San Emigdio Mountains on the southern margin of the San Joaquin Valley. The Vedder formation was deposited subsequent to a period of rapid subsidence (about 50 cm/1000 years), as determined from geohistory analysis of well data on the Bakersfield arch. This rapid subsidence may have induced deposition in a ramp geometry, rather than a shelf-slope configuration.

  11. Sources of High-Chloride Water to Wells, Eastern San Joaquin Ground-Water Subbasin, California

    USGS Publications Warehouse

    Izbicki, John A.; Metzger, Loren F.; McPherson, Kelly R.; Everett, Rhett; Bennett, George L.

    2006-01-01

    As a result of pumping and subsequent declines in water levels, chloride concentrations have increased in water from wells in the Eastern San Joaquin Ground-Water Subbasin, about 80 miles east of San Francisco (Montgomery Watson, Inc., 2000). Water from a number of public-supply, agricultural, and domestic wells in the western part of the subbasin adjacent to the San Joaquin Delta exceeds the U.S. Environmental Protection Agency Secondary Maximum Contaminant Level (SMCL) for chloride of 250 milligrams per liter (mg/L) (fig. 1) (link to animation showing chloride concentrations in water from wells, 1984 to 2004). Some of these wells have been removed from service. High-chloride water from delta surface water, delta sediments, saline aquifers that underlie freshwater aquifers, and irrigation return are possible sources of high-chloride water to wells (fig. 2). It is possible that different sources contribute high-chloride water to wells in different parts of the subbasin or even to different depths within the same well.

  12. San Joaquin kit fox (Vulpes velox macrotis) program, Camp Roberts, California

    SciTech Connect

    Not Available

    1992-10-01

    Military training activities, new construction projects, and routine repair and maintenance activities conducted at Camp Roberts could adversely affect the endangered San Joaquin kit fox population. The Endangered Species Act of 1973 (as amended) states that all Federal agencies are to ensure that any actions authorized, funded, or carried out by the agency are not likely to have any detrimental effects on endangered species or their habitat. The major objective of the Camp Roberts Environmental Studies Program was to prepare a comprehensive Biological Assessment of the effects of all NGB-authorized activities on San Joaquin kit fox (military training, anticipated construction projects, repair and maintenance activities, and all NGB-authorized non-military activities such as a hunting and fishing program, grazing leases, etc.). The program also provided NGB with the scientific expertise necessary to ensure compliance with the Endangered Species Act. The objective of this report is to summarize the progress and results of the Environmental Studies Program during Fiscal Years 1991 and 1992 (FY91/92).

  13. Use of ground-water reservoirs for storage of surface water in the San Joaquin Valley, California

    USGS Publications Warehouse

    Davis, G.H.; Lofgren, B.E.; Mack, Seymour

    1964-01-01

    The San Joaquin Valley includes roughly the southern two-thirds of the Central Valley of California, extending 250 miles from Stockton on the north to Grapevine at the foot of the Tehachapi Mountains. The valley floor ranges in width from 25 miles near Bakersfield to about 55 miles near Visalia; it has a surface area of about 10,000 square miles. More than one-quarter of all the ground water pumped for irrigation in the United States is used in this highly productive valley. Withdrawal of ground water from storage by heavy pumping not only provides a needed irrigation water supply, but it also lowers the ground-water level and makes storage space available in which to conserve excess water during periods of heavy runoff. A storage capacity estimated to be 93 million acre-feet to a depth of 200 feet is available in this ground-water reservoir. This is about nine times the combined capacity of the existing and proposed surface-water reservoirs in the San Joaquin Valley under the California Water Plan. The landforms of the San Joaquin Valley include dissected uplands, low plains and fans, river flood plains and channels, and overflow lands and lake bottoms. Below the land surface, unconsolidated sediments derived from the surrounding mountain highlands extend downward for hundreds of feet. These unconsolidated deposits, consisting chiefly of alluvial deposits, but including some widespread lacustrine sediments, are the principal source of ground water in the valley. Ground water occurs under confined and unconfined conditions in the San Joaquin Valley. In much of the western, central, and southeastern parts of the valley, three distinct ground-water reservoirs are present. In downward succession these are 1) a body of unconfined and semiconfined fresh water in alluvial deposits of Recent, Pleistocene, and possibly later Pliocene age, overlying the Corcoran clay member of the Tulare formation; 2) a body of fresh water confined beneath the Corcoran clay member, which

  14. Integration of subsidence, deformation, and groundwater-level measurements to characterize land subsidence in the San Joaquin Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Sneed, M.; Solt, M.; Brandt, J.

    2012-12-01

    Extensive groundwater withdrawal from unconsolidated deposits in the San Joaquin Valley caused widespread aquifer-system compaction and resultant land subsidence that locally exceeded 8 meters (m) from 1926 to 1970. The importation of surface water in the early 1970s resulted in decreased pumping, recovery of water levels, and a reduced rate of compaction in some areas. However, reduced surface-water availability during droughts (1976-77, 1987-92, and 2007-09) caused increased pumping, water-level declines, and renewed compaction. Land subsidence resulting from this compaction has reduced freeboard and flow capacity of the Delta-Mendota Canal (DMC), the California Aqueduct, and other canals that deliver irrigation water and transport floodwater. The location and magnitude of vertical land-surface changes during 2006-11 in the northwestern and central San Joaquin Valley were determined using Interferometric Synthetic Aperture Radar (InSAR), Global Positioning System (GPS), and extensometer techniques. Results of the InSAR analysis indicate that a 3,200 square-kilometer area, including parts of the DMC, the San Joaquin River, and the Eastside Bypass, was affected by at least 20 millimeters (mm) of subsidence during 2008-10. Within that area, InSAR analysis also indicates a localized maximum subsidence of at least 540 mm. Furthermore, InSAR results for 2006-10 indicate that subsidence rates doubled around 2008. GPS surveys in 2008 and 2010 confirm the high rates of subsidence measured using InSAR; GPS surveys in late 2011 indicate that these high rates continued through the next year. A comparison of data from extensometers (anchored near the top of the Corcoran Clay) and a continuous GPS station near Mendota indicates that most of the aquifer-system compaction occurred below the top of the Corcoran Clay (CC). The lack of correlation between continuous GPS data near Los Banos, which show subsidence, and water levels from nearby wells screened above the CC, which show

  15. Tomographic Rayleigh wave group velocities in the Central Valley, California, centered on the Sacramento/San Joaquin Delta

    NASA Astrophysics Data System (ADS)

    Fletcher, Jon B.; Erdem, Jemile; Seats, Kevin; Lawrence, Jesse

    2016-04-01

    If shaking from a local or regional earthquake in the San Francisco Bay region were to rupture levees in the Sacramento/San Joaquin Delta, then brackish water from San Francisco Bay would contaminate the water in the Delta: the source of freshwater for about half of California. As a prelude to a full shear-wave velocity model that can be used in computer simulations and further seismic hazard analysis, we report on the use of ambient noise tomography to build a fundamental mode, Rayleigh wave group velocity model for the region around the Sacramento/San Joaquin Delta in the western Central Valley, California. Recordings from the vertical component of about 31 stations were processed to compute the spatial distribution of Rayleigh wave group velocities. Complex coherency between pairs of stations was stacked over 8 months to more than a year. Dispersion curves were determined from 4 to about 18 s. We calculated average group velocities for each period and inverted for deviations from the average for a matrix of cells that covered the study area. Smoothing using the first difference is applied. Cells of the model were about 5.6 km in either dimension. Checkerboard tests of resolution, which are dependent on station density, suggest that the resolving ability of the array is reasonably good within the middle of the array with resolution between 0.2 and 0.4°. Overall, low velocities in the middle of each image reflect the deeper sedimentary syncline in the Central Valley. In detail, the model shows several centers of low velocity that may be associated with gross geologic features such as faulting along the western margin of the Central Valley, oil and gas reservoirs, and large crosscutting features like the Stockton arch. At shorter periods around 5.5 s, the model's western boundary between low and high velocities closely follows regional fault geometry and the edge of a residual isostatic gravity low. In the eastern part of the valley, the boundaries of the low

  16. Mercury in sport fish from the Sacramento-San Joaquin Delta region, California, USA.

    PubMed

    Davis, Jay A; Greenfield, Ben K; Ichikawa, Gary; Stephenson, Mark

    2008-02-25

    Total mercury (Hg) concentrations were determined in fillet tissue of sport fish captured in the Sacramento-San Joaquin River Delta and surrounding tributaries, a region particularly impacted by historic gold and mercury mining activity. In 1999 and 2000, mercury concentrations were measured in 767 samples from ten fish species. Largemouth bass (Micropterus salmoides), the primary target species, exhibited a median Hg concentration of 0.53 mug g(-1) (N=406). Only 23 largemouth bass (6%) were below a 0.12 mug g(-1) threshold corresponding to a 4 meals per month safe consumption limit. Most of the largemouth bass (222 fish, or 55% of the sample) were above a 0.47 mug g(-1) threshold corresponding to a 1 meal per month consumption limit. Striped bass (Morone saxatilis), channel catfish (Ictalurus punctatus), white catfish (Ameirus catus), and Sacramento pikeminnow (Ptychocheilus grandis) also had relatively high concentrations, with 31% or more of samples above 0.47 mug g(-1). Concentrations were lowest in redear (Lepomis microlophus) and bluegill (Lepomis macrochirus) sunfish, with most samples below 0.12 mug g(-1), suggesting that targeting these species for sport and subsistence fishing may reduce human dietary exposure to Hg in the region. An improved method of analysis of covariance was performed to evaluate spatial variation in Hg in largemouth bass captured in 2000, while accounting for variability in fish length. Using this approach, Hg concentrations were significantly elevated in the Feather River, northern Delta, lower Cosumnes River, and San Joaquin River regions. In spite of elevated Hg concentrations on all of its tributaries, the central Delta had concentrations that were low both in comparison to safe consumption guidelines and to other locations. PMID:18063015

  17. An evaluation of the regional acid deposition model surface module for ozone uptake at three sites in the San Joaquin Valley of California

    NASA Technical Reports Server (NTRS)

    Massman, W. J.; Pederson, J.; Delany, A.; Grantz, D.; Hertog, G. Den; Neumann, H. H.; Oncley, S. P.; Pearson, R., Jr.; Shaw, R. H.

    1994-01-01

    Plants and soils act as major sinks for the destruction of tropospheric ozone, especially during daylight hours when plant stomata open and are thought to provide the dominant pathway for the uptake of ozone. The present study, part of the California Ozone Deposition Experiment, compares predictions of the regional acid deposition model ozone surface conductance module with surface conductance data derived from eddy covariance measurements of ozone flux taken at a grape, a cotton, and a grassland site in the San Joaquin Valley of California during the summer of 1991. Results indicate that the model (which was developed to provide long-term large-area estimates for the eastern United States) significantly overpredicts the surface conductance at all times of the day for at least two important types of plant cover of the San Joaquin Valley and that it incorrectly partitions the ozone flux between transpiring and nontranspiring components of the surface at the third site. Consequently, the model either overpredicts or inaccurately represents the observed deposition velocities. Other results indicate that the presence of dew does not reduce the rate of ozone deposition, contradicting to model assumptions, and that model assumptions involving the dependency of stomata upon environmental temperature are unnecessary. The effects of measurement errors and biases, arising from the presence of the roughness sublayer and possible photochemical reactions, are also discussed. A simpler model for ozone surface deposition (at least for the San Joaquin Valley) is proposed and evaluated.

  18. Sources and concentrations of dissolved solids and selenium in the San Joaquin River and its tributaries, California, October 1985 to March 1987

    SciTech Connect

    Clifton, D.G.; Gilliom, R.J.

    1989-01-01

    Sources and concentrations of dissolved solids and selenium in the San Joaquin River and its tributaries, California, were assessed by a mass-balance approach to determine the effects of tile-drain water and irrigation-return flows on the river. The study included low-flow periods from October 1985 to mid-February 1986 and mid-May 1986 through March 1987, and a high-flow period from mid-February to mid-May 1985. During the combined low-flow period, the dissolved-solids load from eastside tributaries and the upper San Joaquin River accounted for only 18% of the total load at Vernalis, located farthest downstream, even though they accounted for 71% of the stream flow. Salt and Mud Sloughs contributed 40% of the dissolved-solids load but only 9% of stream flow. Unmeasured sources of dissolved solids contributed about 42% of the total load during low flow. In contrast, Salt and Mud Sloughs, which receive most of the tile-drain water that enters the river, contributed almost 80% of the total selenium load to the river, and loading of selenium concentrations were highest in Salt and Mud Sloughs and decreased downstream in the San Joaquin River with dilution from eastside tributaries. A State standard for dissolved solids of 500 mg/L was exceeded 11% of the time in the San Joaquin River at Vernalis. The US Environmental Protection Agency's 4-day average aquatic-life criterion of 5 micrograms/L of selenium was exceeded in more than 60% of the samples from the sloughs and in about 20% of the samples from the San Joaquin River, just downstream of the Merced River. 23 refs., 8 figs., 6 tabs.

  19. Groundwater contributions of flow, nitrate, and dissolved organic carbon to the lower San Joaquin River, California, 2006-08

    USGS Publications Warehouse

    Zamora, Celia; Dahlgren, Randy A.; Kratzer, Charles R.; Downing, Bryan D.; Russell, Ann D.; Dileanis, Peter D.; Bergamaschi, Brian A.; Phillips, Steven P.

    2013-01-01

    The influence of groundwater on surface-water quality in the San Joaquin River, California, was examined for a 59-mile reach from the confluence with Salt Slough to Vernalis. The primary objective of this study was to quantify the rate of groundwater discharged to the lower San Joaquin River and the contribution of nitrate and dissolved organic carbon concentrations to the river. Multiple lines of evidence from four independent approaches were used to characterize groundwater contributions of nitrogen and dissolved organic carbon. Monitoring wells (in-stream and bank wells), streambed synoptic surveys (stream water and shallow groundwater), longitudinal profile surveys by boat (continuous water-quality parameters in the stream), and modeling (MODFLOW and VS2DH) provided a combination of temporal, spatial, quantitative, and qualitative evidence of groundwater contributions to the river and the associated quality. Monitoring wells in nested clusters in the streambed (in-stream wells) and on both banks (bank wells) along the river were monitored monthly from September 2006 to January 2009. Nitrate concentrations in the bank wells ranged from less than detection—that is, less than 0.01 milligrams per liter (mg/L) as nitrogen (N)—to approximately 13 mg/L as N. Nitrate was not detected at 17 of 26 monitoring wells during the study period. Dissolved organic carbon concentrations among monitoring wells were highly variable, but they generally ranged from 1 to 4 mg/L. In a previous study, 14 bank wells were sampled once in 1988 following their original installation. With few exceptions, specific conductivity and nitrate concentrations measured in this study were virtually identical to those measured 20 years ago. Streambed synoptic measurements were made by using a temporarily installed drive-point piezometer at 113 distinct transects across the stream during 4 sampling events. Nitrate concentrations exceeded the detection limit of 0.01 mg/L as N in 5 percent of

  20. The legacy of wetland drainage on the remaining peat in the Sacramento San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, J.Z.; De Fontaine, C. S.; Deverel, S.J.

    2009-01-01

    Throughout the world, many extensive wetlands, such as the Sacramento-San Joaquin Delta of California (hereafter, the Delta), have been drained for agriculture, resulting in land-surface subsidence of peat soils. The purpose of this project was to study the in situ effects of wetland drainage on the remaining peat in the Delta. Peat cores were retrieved from four drained, farmed islands and four relatively undisturbed, marsh islands. Core samples were analyzed for bulk density and percent organic carbon. Macrofossils in the peat were dated using radiocarbon age determination. The peat from the farmed islands is highly distinct from marsh island peat. Bulk density of peat from the farmed islands is generally greater than that of the marsh islands at a given organic carbon content. On the farmed islands, increased bulk density, which is an indication of compaction, decreases with depth within the unoxidized peat zone, whereas, on the marsh islands, bulk density is generally constant with depth except near the surface. Approximately 5580 of the original peat layer on the farmed islands has been lost due to land-surface subsidence. For the center regions of the farmed islands, this translates into an estimated loss of between 29005700 metric tons of organic carbon/hectare. Most of the intact peat just below the currently farmed soil layer is over 4000 years old. Peat loss will continue as long as the artificial water table on the farmed islands is held below the land surface. ?? 2009 The Society of Wetland Scientists.

  1. The legacy of wetland drainage on the remaining peat in the Sacramento-San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, Judith Z.; Christian S. de Fontaine,; Steven J. Deverel,

    2009-01-01

    Throughout the world, many extensive wetlands, such as the Sacramento-San Joaquin Delta of California (hereafter, the Delta), have been drained for agriculture, resulting in land-surface subsidence of peat soils. The purpose of this project was to study the in situ effects of wetland drainage on the remaining peat in the Delta. Peat cores were retrieved from four drained, farmed islands and four relatively undisturbed, marsh islands. Core samples were analyzed for bulk density and percent organic carbon. Macrofossils in the peat were dated using radiocarbon age determination. The peat from the farmed islands is highly distinct from marsh island peat. Bulk density of peat from the farmed islands is generally greater than that of the marsh islands at a given organic carbon content. On the farmed islands, increased bulk density, which is an indication of compaction, decreases with depth within the unoxidized peat zone, whereas, on the marsh islands, bulk density is generally constant with depth except near the surface. Approximately 55–80% of the original peat layer on the farmed islands has been lost due to landsurface subsidence. For the center regions of the farmed islands, this translates into an estimated loss of between 2900-5700 metric tons of organic carbon/hectare. Most of the intact peat just below the currently farmed soil layer is over 4000 years old. Peat loss will continue as long as the artificial water table on the farmed islands is held below the land surface.

  2. Temporal trends in concentrations of DBCP and nitrate in groundwater in the eastern San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Burow, K.R.; Dubrovsky, N.M.; Shelton, James L.

    2007-01-01

    Temporal monitoring of the pesticide 1,2-dibromo-3-chloropropane (DBCP) and nitrate and indicators of mean groundwater age were used to evaluate the transport and fate of agricultural chemicals in groundwater and to predict the long-term effects in the regional aquifer system in the eastern San Joaquin Valley, California. Twenty monitoring wells were installed on a transect along an approximate groundwater flow path. Concentrations of DBCP and nitrate in the wells were compared to concentrations in regional areal monitoring networks. DBCP persists at concentrations above the US Environmental Protection Agency's maximum contaminant level (MCL) at depths of nearly 40 m below the water table, more than 25 years after it was banned. Nitrate concentrations above the MCL reached depths of more than 20 m below the water table. Because of the intensive pumping and irrigation recharge, vertical flow paths are dominant. High concentrations (above MCLs) in the shallow part of the regional aquifer system will likely move deeper in the system, affecting both domestic and public-supply wells. The large fraction of old water (unaffected by agricultural chemicals) in deep monitoring wells suggests that it could take decades for concentrations to reach MCLs in deep, long-screened public-supply wells, however. ?? Springer-Verlag 2007.

  3. Evapotranspiration rates and crop coefficients for a restored marsh in the Sacramento-San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, J.Z.; Anderson, F.E.; Snyder, R.L.

    2008-01-01

    The surface renewal method was used to estimate evapotranspiration (ET) for a restored marsh on Twitchell Island in the Sacramento-San Joaquin Delta, California, USA. ET estimates for the marsh, together with reference ET measurements from a nearby climate station, were used to determine crop coefficients over a 3-year period during the growing season. The mean ET rate for the study period was 6 mm day-1, which is high compared with other marshes with similar vegetation. High ET rates at the marsh may be due to the windy, semi-arid Mediterranean climate of the region, and the permanently flooded nature of the marsh, which results in very low surface resistance of the vegetation. Crop coefficient (Kc) values for the marsh ranged from 0.73 to 1.18. The mean Kc value over the entire study period was 0-95. The daily Kc values for any given month varied from year to year, and the standard deviation of daily Kc values varied between months. Although several climate variables were undoubtedly responsible for this variation, our analysis revealed that wind direction and the temperature of standing water in the wetland were of particular importance in determining ET rates and Kc values.

  4. Effects of ground-water chemistry and flow on quality of drainflow in the western San Joaquin Valley, California

    USGS Publications Warehouse

    Fio, John L.; Leighton, David A.

    1994-01-01

    Chemical and geohydrologic data were used to assess the effects of regional ground-water flow on the quality of on-farm drainflows in a part of the western San Joaquin Valley, California. Shallow ground water beneath farm fields has been enriched in stable isotopes and salts by partial evaporation from the shallow water table and is being displaced by irrigation, drainage, and regional ground-water flow. Ground-water flow is primarily downward in the study area but can flow upward in some down- slope areas. Transitional areas exist between the downward and upward flow zones, where ground water can move substantial horizontal distances (0.3 to 3.6 kilometers) and can require 10 to 90 years to reach the downslope drainage systems. Simulation of ground-water flow to drainage systems indicates that regional ground water contributes to about 11 percent of annual drainflow. Selenium concentrations in ground water and drainwater are affected by geologic source materials, partial evaporation from a shallow water table, drainage-system, and regional ground-water flow. Temporal variability in drainflow quality is affected in part by the distribution of chemical constituents in ground water and the flow paths to the drainage systems. The mass flux of selenium in drainflows, or load, generally is proportional to flow, and reductions in drainflow quantity should reduce selenium loads over the short-term. Uncertain changes in the distribution of ground-water quality make future changes in drainflow quality difficult to quantify.

  5. Effects of human alterations on the hydrodynamics and sediment transport in the Sacramento-San Joaquin Delta, California

    USGS Publications Warehouse

    Marineau, Mathieu D.; Wright, Scott A.

    2015-01-01

    The Sacramento-San Joaquin Delta, California, (Delta) has been significantly altered since the mid-nineteenth century. Many existing channels have been widened or deepened and new channels have been created for navigation and water conveyance. Tidal marshes have been drained and leveed to form islands that have subsided, some of which have permanently flooded. To understand how these alterations have affected hydrodynamics and sediment transport in the Delta, we analysed measurements from 27 sites, along with other spatial data, and previous literature. Results show that: (a) the permanent flooding of islands results in an increase in the shear velocity of channels downstream, (b) artificial widening and deepening of channels generally results in a decrease in shear velocity except when the channel is also located downstream of a flooded island, (c) 1.5 Mt/year of sediment was deposited in the Delta (1997–2010), and of this deposited sediment, 0.31 Mt/year (21%) was removed through dredging.

  6. Geochemical evidence for Se mobilization by the weathering of pyritic shale, San Joaquin Valley, California, U.S.A.

    USGS Publications Warehouse

    Presser, T.S.; Swain, W.C.

    1990-01-01

    Acidic (pH 4) seeps issue from the weathered Upper Cretaceous-Paleocene marine sedimentary shales of the Moreno Formation in the semi-arid Coast Ranges of California. The chemistry of the acidic solutions is believed to be evidence of current reactions ultimately yielding hydrous sodium and magnesium sulfate salts, e.g. mirabilite and bloedite, from the oxidation of primary pyrite. The selenate form of Se is concentrated in these soluble salts, which act as temporary geological sinks. Theoretically, the open lattice structures of these hydrous minerals could incorporate the selenate (SeO4-2) anion in the sulfate (SO4-2) space. When coupled with a semi-arid to arid climate, fractional crystallization and evaporative concentration can occur creating a sodium-sulfate fluid that exceeds the U.S. Environmental Protection Agency limit of 1000 ??g l-1 for a toxic Se waste. The oxidative alkaline conditions necessary to ensure the concentration of soluble selenate are provided in the accompanying marine sandstones of the Panoche and Lodo Formations and the eugeosynclinal Franciscan assemblage. Runoff and extensive mass wasting in the area reflect these processes and provide the mechanisms which transport Se to the farmlands of the west-central San Joaquin Valley. Subsurface drainage from these soils consequently transports Se to refuge areas in amounts elevated to cause a threat to wildlife. ?? 1990.

  7. Blood characteristics of San Joaquin kit fox (Vulpes velox macrotis) at Camp Roberts Army National Guard Training Site, California

    SciTech Connect

    Standley, W.G.; McCue, P.M.

    1992-09-01

    Hematology, serum chemistry, and prevalence of antibodies against selected, pathogens in a San Joaquin kit fox population (Vulpes velox macrotis) were investigated at Camp Roberts Army National Guard Training Site, California, in 1989 and 1990. Samples from 18 (10 female, 8 male) adult kit foxes were used to establish normal hematology and serum chemistry values for this population. Average values were all within the normal ranges reported for kit foxes in other locations. Three hematology parameters had significant differences between male and female values; males had higher total white blood cell and neutrophil counts, and lower lymphocyte counts. There were no significant differences between serum chemistry values from male and female foxes. Prevalence of antibodies was determined from serum samples from 47 (26 female, 21 male) adult kit foxes and eight (4 female, 4 male) juveniles. Antibodies were detected against five of the eight pathogens tested: canine parvovirus, Toxoplasma gondii Leptospira interrogans, canine distemper virus, and canine hepatitis virus. Antibodies were not detected against Brucella, canis, Coccidioides immitis, or Yersinia pestis.

  8. Implications from a study of the timing of oil entrapment in Monterey siliceous shales, Lost Hills, San Joaquin Valley, California

    SciTech Connect

    Julander, D.R. )

    1992-01-01

    The oil and gas-rich upper Miocene siliceous shales of the Monterey Group are the primary development target in the Lost Hills Oil Field, San Joaquin Valley, California. As a result of diagenesis, the siliceous shales can be subdivided by opal phase into three sections (from shallow to deep): the Opal-A diatomites which are rich in oil saturation; the Opal-CT porcellanites which are predominantly wet but include pockets of moderate oil saturation; and the Quartz cherts and porcellanites which in some places are highly oil saturated immediately below the Opal CT section. Productivity trends in each of the three sections have been established through drilling and production testing, but a predictive model was not available until a study of the timing of oil entrapment at Lost Hills was recently completed. The study included an analysis of the depositional history of the siliceous shales and timing of: (1) structural growth of the Lost Hills fold, (2) source-rock maturation, and (3) development of the opal-phase segregation of the Monterey shales. The study led to enhanced understanding of the known oil saturation and production trends in the three opal-phase sections and yielded a predictive model that is being used to identify areas in the field with remedial or delineation potential. The study also produced evidence of fold axis rotation during the Pliocene and Pleistocene that helps explain differences in fracture orientations within the Monterey shales.

  9. Dissolved pesticide concentrations in the Sacramento-San Joaquin Delta and Grizzly Bay, California, 2011-12

    USGS Publications Warehouse

    Orlando, James L.; McWayne, Megan; Sanders, Corey; Hladik, Michelle

    2013-01-01

    Surface-water samples were collected from sites within the Sacramento-San Joaquin Delta and Grizzly Bay, California, during the spring in 2011 and 2012, and they were analyzed by the U.S. Geological Survey for a suite of 99 current-use pesticides and pesticide degradates. Samples were collected and analyzed as part of a collaborative project studying the occurrence and characteristics of phytoplankton in the San Francisco Estuary. Samples were analyzed by two separate laboratory methods employing gas chromatography/mass spectrometry or liquid chromatography with tandem mass spectrometry. Method detection limits ranged from 0.9 to 10.5 nanograms per liter (ng/L). Eighteen pesticides were detected in samples collected during 2011, and the most frequently detected compounds were the herbicides clomazone, diuron, hexazinone and metolachlor, and the diuron degradates 3,4-dichloroaniline and N-(3,4-dichlorophenyl)-N’-methylurea (DCPMU). Concentrations for all compounds were less than 75 ng/L, except for the rice herbicide clomazone and the fungicide tetraconazole, which had maximum concentrations of 535 and 511 ng/L, respectively. In samples collected in 2012, a total of 16 pesticides were detected. The most frequently detected compounds were the fungicides azoxystrobin and boscalid and the herbicides diuron, hexazinone, metolachlor, and simazine. Maximum concentrations for all compounds detected in 2012 were less than 75 ng/L, except for the fungicide azoxystrobin and the herbicides hexazinone and simazine, which were detected at up to 188, 134, and 140 ng/L, respectively.

  10. Effects of human alterations on the hydrodynamics and sediment transport in the Sacramento-San Joaquin Delta, California

    NASA Astrophysics Data System (ADS)

    Marineau, M. D.; Wright, S. A.

    2015-03-01

    The Sacramento-San Joaquin Delta, California, (Delta) has been significantly altered since the mid-nineteenth century. Many existing channels have been widened or deepened and new channels have been created for navigation and water conveyance. Tidal marshes have been drained and leveed to form islands that have subsided, some of which have permanently flooded. To understand how these alterations have affected hydrodynamics and sediment transport in the Delta, we analysed measurements from 27 sites, along with other spatial data, and previous literature. Results show that: (a) the permanent flooding of islands results in an increase in the shear velocity of channels downstream, (b) artificial widening and deepening of channels generally results in a decrease in shear velocity except when the channel is also located downstream of a flooded island, (c) 1.5 Mt/year of sediment was deposited in the Delta (1997-2010), and of this deposited sediment, 0.31 Mt/year (21%) was removed through dredging.

  11. Water Hyacinth Identification Using CART Modeling With Hyperspectral Data in the Sacramento-San Joaquin River Delta of California

    NASA Astrophysics Data System (ADS)

    Khanna, S.; Hestir, E. L.; Santos, M. J.; Greenberg, J. A.; Ustin, S. L.

    2007-12-01

    Water hyacinth (Eichhornia crassipes) is an invasive aquatic weed that is causing severe economic and ecological impacts in the Sacramento-San Joaquin River Delta (California, USA). Monitoring its distribution using remote sensing is the crucial first step in modeling its predicted spread and implementing control and eradication efforts. However, accurately mapping this species is confounded by its several phenological forms, namely a healthy vegetative canopy, flowering canopy with dense conspicuous terminal flowers above the foliage, and floating dead and senescent forms. The full range of these phenologies may be simultaneously present at any time, given the heterogeneity of environmental and ecological conditions in the Delta. There is greater spectral variation within water hyacinth than between any of the co-occurring species (pennywort and water primrose), so classification approaches must take these different phenological stages into consideration. We present an approach to differentiating water hyacinth from co-occurring species based on knowledge of relevant variation in leaf chlorophyll, floral pigments, foliage water content, and variation in leaf structure using a classification and regression tree (CART) applied to airborne hyperspectral remote sensing imagery.

  12. Temporal trends in concentrations of DBCP and nitrate in groundwater in the eastern San Joaquin Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Burow, K. R.; Dubrovsky, N. M.; Shelton, J. L.

    2007-08-01

    Temporal monitoring of the pesticide 1,2-dibromo-3-chloropropane (DBCP) and nitrate and indicators of mean groundwater age were used to evaluate the transport and fate of agricultural chemicals in groundwater and to predict the long-term effects in the regional aquifer system in the eastern San Joaquin Valley, California. Twenty monitoring wells were installed on a transect along an approximate groundwater flow path. Concentrations of DBCP and nitrate in the wells were compared to concentrations in regional areal monitoring networks. DBCP persists at concentrations above the US Environmental Protection Agency’s maximum contaminant level (MCL) at depths of nearly 40 m below the water table, more than 25 years after it was banned. Nitrate concentrations above the MCL reached depths of more than 20 m below the water table. Because of the intensive pumping and irrigation recharge, vertical flow paths are dominant. High concentrations (above MCLs) in the shallow part of the regional aquifer system will likely move deeper in the system, affecting both domestic and public-supply wells. The large fraction of old water (unaffected by agricultural chemicals) in deep monitoring wells suggests that it could take decades for concentrations to reach MCLs in deep, long-screened public-supply wells, however.

  13. Reproduction of the San Joaquin kit fox (Vulpes velox macrotis) on Camp Roberts Army National Guard Training Site, California

    SciTech Connect

    Spencer, K A; Berry, W H; Standley, W G; O`Farrell, T P

    1992-09-01

    The reproduction of a San Joaquin kit fox population (Vulpes velox macrotis) was investigated at Camp Roberts Army National Guard Training Site, California, from November 1988 through September 1991. Of 38 vixens radiocollared prior to parturition, 12 (32%) were successful in raising pups from conception to the point where pups were observed above ground. No yearling vixens were known tb be reproductively active. The mean litter size during 1989 - 1991 was 3.0 (n = 21, SE = 0.28) and ranged from one to six pups. Both the proportion of vixens successfully raising pups and the mean litter size observed at Camp Roberts during this study were lower than those reported at other locations. Sex ratios of kit fox pups were male biased two of the three years, but did not differ statistically from 1:1 throughout the study. Whelping was estimated to occur between February 15 and March 5. Results of this study support previous reports that kit foxes are primarily monogamous, although one case of polygamy may have occurred. Both the proportion of dispersing radiocollared juveniles (26%) and the mean dispersal distance (5.9 km) of juveniles at Camp Roberts appeared low compared to other locations.

  14. Calculation of a water budget and delineation of contributing sources to drainflows in the western San Joaquin Valley, California

    USGS Publications Warehouse

    Fio, John L.

    1994-01-01

    Geohydrologic data and a ground-water flow model were used to calculate a water budget and evaluate the contribution of regional ground-water flow to on-farm drainflow in a part of the western San Joaquin Valley, California. Regional ground-water flow is affected by the distribution of unconsoli- dated coarse- and fine- grained sediment. Predomi- nantly coarse-grained sediment in the upslope areas results in a water table more than 3 meters below land surface, but the low-lying areas are underlain by predominantly fine-grained sediments and have a water table within 3 meters of land surface. The vertical component of flow is downward in the upslope areas, but upward at some locations in the low-lying areas. Model simulation results indicate that about 89 percent of the drainflow (18.5 times 10(6) cubic meters per year) originates as recharge within the fields that overlie the drainage systems, and 11 percent of the drainflow (2.3 times 10(6) cubic meters per year) is lateral-flowing ground water and upward deept percolation originating as recharge at fields upslope from the drainage systems. The lateral-flow and upward deep perco- lation can move substantial distances (as great as 3.6 kilometers horizontally and from depths greater than 29 meters below land surface), and require from 10 to more than 90 years to reach the drainage systems. (USGS)

  15. Boron, molybdenum, and selenium in aquatic food chains from the lower San Joaquin River and its tributaries, California

    USGS Publications Warehouse

    Saiki, Michael K.; Jennings, Mark R.; Brumbaugh, William G.

    1993-01-01

    Boron (B), molybdenum (Mo), and selenium (Se) were measured in water, sediment, particulate organic detritus, and in various biota—filamentous algae, net plankton, macroinvertebrates, and fishes—to determine if concentrations were elevated from exposure to agricultural subsurface (tile) drainage during the spring and fall 1987, in the San Joaquin River, California. Concentrations of B and Se, but not Mo, were higher in most samples from reaches receiving tile drainage than in samples from reaches receiving no tile drainage. Maximum concentrations of Se in water (0.025 μg/mL), sediment (3.0 μg/g), invertebrates (14 μg/g), and fishes (17 μg/g) measured during this study exceeded concentrations that are detrimental to sensitive warmwater fishes. Toxic threshold concentrations of B and Mo in fishes and their foods have not been identified. Boron and Mo were not biomagnified in the aquatic food chain, because concentrations of these two elements were usually higher in filamentous algae and detritus than in invertebrates and fishes. Concentrations of Se were lower in filamentous algae than in invertebrates and fishes; however, concentrations of Se in or on detritus were similar to or higher than in invertebrates and fishes. These observations suggest that high concentrations of Se accumulated in invertebrates and fishes through food-chain transfer from Se-enriched detritus rather than from filamentous algae.

  16. Mortality of San Joaquin kit fox (Vulpes velox macrotis) at Camp Roberts Army National Guard Training Site, California

    SciTech Connect

    Standley, W.G.; Berry, W.H.; O`Farrell, T.P.; Kato, T.T.

    1992-09-01

    Sources and rates of mortality of a San Joaquin kit fox population (Vulpes velox macrotis) were investigated at Camp Roberts Army National Guard Training Site, California, from November 1988 through September 1991. National Guard-authorized activities, including military training, caused the death of three of the 94 (3%) kit foxes radiocollared, and do not appear to jeopardize the continued existence of the population. Predation by larger carnivores, primarily coyotes (Canis latrans), caused the death of 75% of the 32 radiocollared kit foxes recovered dead for which a cause of death could be determined; vehicle impacts, disease (rabies), poisoning, and shooting were each responsible for the deaths of 6.3%. Adult annual mortality rate was 0.47 and the juvenile mortality rate was 0.80, and both rates are similar to rates reported for kit foxes in other locations. There was no significant difference between male and female mortality rates in either age class. The proportions of dead kit foxes recovered in different habitat types were similar to the availability of the habitat types within the distribution of kit fox on the installation.

  17. Movements and home range of San Joaquin kit foxes on the Naval Petroleum Reserves, Kern County, California

    SciTech Connect

    Zoellick, B.W.; O'Farrell, T.P.; Kato, T.T.

    1987-09-01

    Movements and home range use of San Joaquin kit foxes (Vulpes macrotis mutica) were studied on and adjacent to the Naval Petroleum Reserves (NPR-1 and NPR-2), Kern County, California, between June 1984 and September 1985. Foxes were studied in an undeveloped area of Buena Vista Valley centered on the border between the Reserves, and in an area of intensive petroleum development in NPR-2 adjacent to the city of Taft. Distances moved nightly did not differ between sexes or between level of petroleum development. Nightly movements averaged 9.4 miles in length during the breeding season, and were significantly longer than the average nightly movements for the pup-rearing (6.4 miles) and pup-dispersal (6.5 miles) seasons. Convex polygon home ranges averaged 1144 acres in size and did not differ between sexes or level of petroleum development. Home ranges of paired males and females overlapped an average of 78%. Home ranges of nonpaired males and females, adjacent males, and adjacent females overlapped an average of 31 to 48%. Although kit foxes were not strongly territorial, home range overlap of paired males and females was significantly greater than that of either nonpaired males and females and males with adjacent home ranges. Home range overlap did not differ between foxes inhabiting developed and undeveloped areas. 42 refs., 10 figs., 9 tabs.

  18. Paleobathymetric maps of tertiary La Honda Basin and implications for offset along San Andreas fault in central California

    SciTech Connect

    Stanley, R.G.

    1987-05-01

    Paleobathymetric maps of the La Honda basin of central California were constructed for ten intervals of geologic time from late Paleocene (Nezian) to middle Miocene (Luisian). The maps are based on analyses of benthic foraminiferal biofacies in more than 800 faunal lists compiled from the literature and from subsurface data provided by oil companies. The sequence of paleobathymetric maps shows the paleogeographic evolution of the La Honda basin. From the late Paleocene (Ynezian) to the early Oligocene (early Zemorrian), deep-sea sands and muds accumulated at water depths of 2000 m and more on a surface that sloped gently to the north and northeast. Striking changes in the configuration of the La Honda basin occurred during the late Oligocene and early Miocene (late Zemorrian). Much of the basin floor remained at water depths of 2000 m and greater, but submarine volcanic rocks locally built up to form seamounts, and movement along the Zayante-Vergeles fault led to shoaling and development of a narrow shelf and very steep slope along the southwestern margin of the basin. During the early and middle Miocene (Relizian and Luisian), the entire basin shoaled to depths of less than 1500 m. Comparison of paleobathymetric maps of the La Honda and San Joaquin basins lends support to the notion that the two basins were once contiguous but have been separated by about 320 to 330 km of right-lateral displacement along the San Andreas fault since the earliest Miocene (late Zemorrian and Saucesian).

  19. California basin study (CaBS)

    SciTech Connect

    Hickey, B.M.

    1990-01-01

    Previous studies of geochemical recycling processes in the upper water column in the Southern California Bight focused on the seasonal cycle. Inspection of satellite sea surface color images as well as information from studies in other areas suggest that the cycling processes have significant variability on time scales of hours and days. To allow our seasonal studies to be examined in the context of the higher frequency variability, an interdisciplinary mooring was maintained near the midpoint of Santa Monica basin (known as station 305) from January to July, 1990. The Hickey group had the primary responsibility of deploying and recovering the mooring. The mooring consisted of a vector measuring wind recorder mounted above a toroidal buoy, below which were suspended two current/temperature recorders, a trnasmissometer, and two PAR sensors. The PAR sensors, which provide an estimate of phytoplankton growth rates, were deployed as part of the Trees proposal. At two additional nearby moorings, sediment traps were deployed at selected depths throughout the water column by Landry and by Soutar. To allow some investigation of lateral advection of material, current meters were deployed at the same depths as several of the sediment traps both at this site and also at the site farther along the basin axis. The data from these experiments have not yet been processed. 6 refs., 10 figs.

  20. 76 FR 41745 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-15

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule... Valley Unified Air Pollution Control District portion of the California State Implementation Plan (SIP... Valley Unified Air Pollution Control District (SJVUAPCD) Rule 4682, Polystyrene, Polyethylene,...

  1. Airborne measurements of air pollution chemistry and transport. 1: Initial survey of major air basins in California

    NASA Technical Reports Server (NTRS)

    Gloria, H. R.; Pitts, J. N., Jr.; Behar, J. V.; Bradburn, G. A.; Reinisch, R. F.; Zafonte, L.

    1972-01-01

    An instrumented aircraft has been used to study photochemical air pollution in the State of California. Simultaneous measurements of the most important chemical constituents (ozone, total oxidant, hydrocarbons, and nitrogen oxides, as well as several meteorological variables) were made. State-of-the-art measurement techniques and sampling procedures are discussed. Data from flights over the South Coast Air Basin, the San Francisco Bay Area, the San Joaquin Valley, the Santa Clara and Salinas Valleys, and the Pacific Ocean within 200 miles of the California coast are presented. Pollutants were found to be concentrated in distant layers up to at least 18,000 feet. In many of these layers, the pollutant concentrations were much higher than at ground level. These findings bring into serious question the validity of the present practice of depending solely on data from ground-based monitoring stations for predictive models.

  2. Technical Analysis of In-Valley Drainage Management Strategies for the Western San Joaquin Valley, California

    USGS Publications Warehouse

    Presser, Theresa S.; Schwarzbach, Steven E.

    2008-01-01

    The western San Joaquin Valley is one of the most productive farming areas in the United States, but salt-buildup in soils and shallow groundwater aquifers threatens this area?s productivity. Elevated selenium concentrations in soils and groundwater complicate drainage management and salt disposal. In this document, we evaluate constraints on drainage management and implications of various approaches to management considered in: *the San Luis Drainage Feature Re-Evaluation (SLDFRE) Environmental Impact Statement (EIS) (about 5,000 pages of documentation, including supporting technical reports and appendices); *recent conceptual plans put forward by the San Luis Unit (SLU) contractors (i.e., the SLU Plans) (about 6 pages of documentation); *approaches recommended by the San Joaquin Valley Drainage Program (SJVDP) (1990a); and *other U.S. Geological Survey (USGS) models and analysis relevant to the western San Joaquin Valley. The alternatives developed in the SLDFRE EIS and other recently proposed drainage plans (refer to appendix A for details) differ from the strategies proposed by the San Joaquin Valley Drainage Program (1990a). The Bureau of Reclamation (USBR) in March 2007 signed a record of decision for an in-valley disposal option that would retire 194,000 acres of land, build 1,900 acres of evaporation ponds, and develop a treatment system to remove salt and selenium from drainwater. The recently proposed SLU Plans emphasize pumping drainage to the surface, storing approximately 33% in agricultural water re-use areas, treating selenium through biotechnology, enhancing the evaporation of water to concentrate salt, and identifying ultimate storage facilities for the remaining approximately 67% of waste selenium and salt. The treatment sequence of reuse, reverse osmosis, selenium bio-treatment, and enhanced solar evaporation is unprecedented and untested at the scale needed to meet plan requirements. All drainage management strategies that have been proposed

  3. Modeling the long-term fate of agricultural nitrate in groundwater in the San Joaquin Valley, California

    USGS Publications Warehouse

    Chapelle, Francis H.; Campbell, Bruce G.; Widdowson, Mark A.; Landon, Mathew K.

    2013-01-01

    Nitrate contamination of groundwater systems used for human water supplies is a major environmental problem in many parts of the world. Fertilizers containing a variety of reduced nitrogen compounds are commonly added to soils to increase agricultural yields. But the amount of nitrogen added during fertilization typically exceeds the amount of nitrogen taken up by crops. Oxidation of reduced nitrogen compounds present in residual fertilizers can produce substantial amounts of nitrate which can be transported to the underlying water table. Because nitrate concentrations exceeding 10 mg/L in drinking water can have a variety of deleterious effects for humans, agriculturally derived nitrate contamination of groundwater can be a serious public health issue. The Central Valley aquifer of California accounts for 13 percent of all the groundwater withdrawals in the United States. The Central Valley, which includes the San Joaquin Valley, is one of the most productive agricultural areas in the world and much of this groundwater is used for crop irrigation. However, rapid urbanization has led to increasing groundwater withdrawals for municipal public water supplies. That, in turn, has led to concern about how contaminants associated with agricultural practices will affect the chemical quality of groundwater in the San Joaquin Valley. Crop fertilization with various forms of nitrogen-containing compounds can greatly increase agricultural yields. However, leaching of nitrate from soils due to irrigation has led to substantial nitrate contamination of shallow groundwater. That shallow nitrate-contaminated groundwater has been moving deeper into the Central Valley aquifer since the 1960s. Denitrification can be an important process limiting the mobility of nitrate in groundwater systems. However, substantial denitrification requires adequate sources of electron donors in order to drive the process. In many cases, dissolved organic carbon (DOC) and particulate organic carbon

  4. Mesocarnivore Surveys on Lawrence Livermore National Laboratory Site 300, Alameda and San Joaquin Counties, California

    SciTech Connect

    Clark, H O; Smith, D A; Cypher, B L; Kelly, P A; Woollett, J S

    2004-11-16

    Lawrence Livermore National Laboratory (LLNL), operated under cooperative agreement between the University of California and the U. S. Department of Energy, administers and operates an approximately 11 mi{sup 2} (28 km{sup 2}) test site in the remote hills at the northern end of the South Coast Ranges of Central California (Figure 1). Known as Site 300, this expanse of rolling hills and canyons supports a diverse array of grassland communities typical of lowland central California. The facility serves a variety of functions related to testing non-nuclear explosives, lasers, and weapons subsystems. The primary purpose of this project was to determine the presence of any mesocarnivores on Site 300 that use the property for foraging, denning, and other related activities. The surveys occurred from mid-September to mid-October, 2002.

  5. Hydrocarbon transport and shearing processes in the Antelope Shale, Monterey Formation, San Joaquin Valley, California

    SciTech Connect

    Dholakia, S.K.; Aydin, A.; Pollard, D.D. )

    1996-01-01

    An essential component of the development and management of a fractured reservoir is the basic understanding of the fracture system and its effect on hydrocarbon flow. In the Antelope Shale, a siliceous shale member of the Monterey Formation in the Buena Vista Hills field (BVH), San Joaquin Valley (SJV), the relationship between the fracture system and hydrocarbon productivity is poorly understood. An integrative approach, employing both geological and geophysical methods, to fracture characterization in the Antelope Shale is important for a better understanding of the connected fracture network and for identifying hydrocarbon-carrying fractures. This knowledge will aid in future reservoir management plans for the BVH field, specifically CO[sub 2] enhanced oil recovery from the existing reservoir. Field studies of the Antelope Shale at Chico Martinez Creek in the SJV demonstrate the importance of shearing processes for the migration of hydrocarbons. Hydrocarbons primarily occur in brecciated zones which are oriented parallel to bedding. The internal architecture of early stage breccia zones is well-organized with sets of hydrocarbon-stained fractures oriented both at high angles and parallel to bedding. In later stage breccia zones, internal organization is disrupted and consists of fragments of the host rock surrounded by hydrocarbons. Subsurface studies which include core and FMS data demonstrate comparable shear-related features in the Monterey Formation. Oil-stained breccia zones are observed in core from the Antelope Shale from a field near BVH. Breccia zones are documented in FMS data from offshore Monterey fields and similar features are being sought in FMS data from SJV in Antelope Shale.

  6. Hydrocarbon transport and shearing processes in the Antelope Shale, Monterey Formation, San Joaquin Valley, California

    SciTech Connect

    Dholakia, S.K.; Aydin, A.; Pollard, D.D.

    1996-12-31

    An essential component of the development and management of a fractured reservoir is the basic understanding of the fracture system and its effect on hydrocarbon flow. In the Antelope Shale, a siliceous shale member of the Monterey Formation in the Buena Vista Hills field (BVH), San Joaquin Valley (SJV), the relationship between the fracture system and hydrocarbon productivity is poorly understood. An integrative approach, employing both geological and geophysical methods, to fracture characterization in the Antelope Shale is important for a better understanding of the connected fracture network and for identifying hydrocarbon-carrying fractures. This knowledge will aid in future reservoir management plans for the BVH field, specifically CO{sub 2} enhanced oil recovery from the existing reservoir. Field studies of the Antelope Shale at Chico Martinez Creek in the SJV demonstrate the importance of shearing processes for the migration of hydrocarbons. Hydrocarbons primarily occur in brecciated zones which are oriented parallel to bedding. The internal architecture of early stage breccia zones is well-organized with sets of hydrocarbon-stained fractures oriented both at high angles and parallel to bedding. In later stage breccia zones, internal organization is disrupted and consists of fragments of the host rock surrounded by hydrocarbons. Subsurface studies which include core and FMS data demonstrate comparable shear-related features in the Monterey Formation. Oil-stained breccia zones are observed in core from the Antelope Shale from a field near BVH. Breccia zones are documented in FMS data from offshore Monterey fields and similar features are being sought in FMS data from SJV in Antelope Shale.

  7. Dispersion mechanisms of a tidal river junction in the Sacramento–San Joaquin Delta, California

    DOE PAGESBeta

    Gleichauf, Karla T.; Wolfram, Philip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

    2014-12-17

    In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Dopplermore » Current Profile (ADCP) boat transecting and moored ADCPs over a spring–neap tidal cycle (May to June 2012) monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011) advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales). Thus, the study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby changing the junction flow phasing.« less

  8. Dispersion mechanisms of a tidal river junction in the Sacramento–San Joaquin Delta, California

    SciTech Connect

    Gleichauf, Karla T.; Wolfram, Philip J.; Monsen, Nancy E.; Fringer, Oliver B.; Monismith, Stephen G.

    2014-12-17

    In branching channel networks, such as in the Sacramento–San Joaquin River Delta, junction flow dynamics contribute to dispersion of ecologically important entities such as fish, pollutants, nutrients, salt, sediment, and phytoplankton. Flow transport through a junction largely arises from velocity phasing in the form of divergent flow between junction channels for a portion of the tidal cycle. Field observations in the Georgiana Slough junction, which is composed of the North and South Mokelumne rivers, Georgiana Slough, and the Mokelumne River, show that flow phasing differences between these rivers arise from operational, riverine, and tidal forcing. A combination of Acoustic Doppler Current Profile (ADCP) boat transecting and moored ADCPs over a spring–neap tidal cycle (May to June 2012) monitored the variability of spatial and temporal velocity, respectively. Two complementary drifter studies enabled assessment of local transport through the junction to identify small-scale intrajunction dynamics. We supplemented field results with numerical simulations using the SUNTANS model to demonstrate the importance of phasing offsets for junction transport and dispersion. Different phasing of inflows to the junction resulted in scalar patchiness that is characteristic of MacVean and Stacey’s (2011) advective tidal trapping. Furthermore, we observed small-scale junction flow features including a recirculation zone and shear layer, which play an important role in intra-junction mixing over time scales shorter than the tidal cycle (i.e., super-tidal time scales). Thus, the study period spanned open- and closed-gate operations at the Delta Cross Channel. Synthesis of field observations and modeling efforts suggest that management operations related to the Delta Cross Channel can strongly affect transport in the Delta by modifying the relative contributions of tidal and riverine flows, thereby changing the junction flow phasing.

  9. Bathymetric survey and digital elevation model of Little Holland Tract, Sacramento-San Joaquin Delta, California

    USGS Publications Warehouse

    Snyder, Alexander G.; Lacy, Jessica R.; Stevens, Andrew W.; Carlson, Emily M.

    2016-06-10

    The U.S. Geological Survey conducted a bathymetric survey in Little Holland Tract, a flooded agricultural tract, in the northern Sacramento-San Joaquin Delta (the “Delta”) during the summer of 2015. The new bathymetric data were combined with existing data to generate a digital elevation model (DEM) at 1-meter resolution. Little Holland Tract (LHT) was historically diked off for agricultural uses and has been tidally inundated since an accidental levee breach in 1983. Shallow tidal regions such as LHT have the potential to improve habitat quality in the Delta. The DEM of LHT was developed to support ongoing studies of habitat quality in the area and to provide a baseline for evaluating future geomorphic change. The new data comprise 138,407 linear meters of real-time-kinematic (RTK) Global Positioning System (GPS) elevation data, including both bathymetric data collected from personal watercraft and topographic elevations collected on foot at low tide. A benchmark (LHT15_b1) was established for geodetic control of the survey. Data quality was evaluated both by comparing results among surveying platforms, which showed systematic offsets of 1.6 centimeters (cm) or less, and by error propagation, which yielded a mean vertical uncertainty of 6.7 cm. Based on the DEM and time-series measurements of water depth, the mean tidal prism of LHT was determined to be 2,826,000 cubic meters. The bathymetric data and DEM are available at http://dx.doi.org/10.5066/F7RX9954. 

  10. Distribution of selenium in soils of agricultural fields, western San Joaquin Valley, California

    USGS Publications Warehouse

    Fujii, Roger; Deverel, S.J.; Hatfield, D.B.

    1987-01-01

    Soils from three agricultural fields in the western San Joaquin Valley were analyzed for soluble, adsorbed, and total concentrations of selenium (Se) to assess the distribution and forms of Se, and the relation of the distribution and forms of Se to the leaching of Se from soils. Soil samples were collected in three fields with drainage systems of different ages (6, 15, 1.5 yr) and different Se concentrations in drain water (58, 430, 3700 micrograms/L respectively). Preliminary methods to determine total Se and estimate adsorbed Se were developed. Of the three fields, concentrations of soluble Se and salinity were highest in soils from the field drained for 1.5 yr and lowest in the field drained for 6 yr. The field drained for 1.5 yr also had the highest concentration of total Se in soil; a median of 1.2 microgram/gm. Of the total concentration of Se in soil from all three fields, the proportion of adsorbed Se and soluble Se ranged from 1 to 11% and < 1 to 63%, respectively. Most of the variance in soluble Se is explained by salinity ( r sq > 0.68) in saturation extracts of soils sampled from below the water table, reflecting evaporative concentration of Se and salinity. In contrast, most soluble salts and Se apparently have been leached from the unsaturated soils in the fields drained for 6 and 15 yr; therefore, the correlation was lower between Se and salinity in saturation extracts of those soils (r sq < 0.33). Among soils from all three fields, the ratio of Se to salinity in saturation extracts increased with increasing salinity. (Author 's abstract)

  11. Land subsidence in the San Joaquin Valley, California, USA, 2007-2014

    NASA Astrophysics Data System (ADS)

    Sneed, M.; Brandt, J. T.

    2015-11-01

    Rapid land subsidence was recently measured using multiple methods in two areas of the San Joaquin Valley (SJV): between Merced and Fresno (El Nido), and between Fresno and Bakersfield (Pixley). Recent land-use changes and diminished surface-water availability have led to increased groundwater pumping, groundwater-level declines, and land subsidence. Differential land subsidence has reduced the flow capacity of water-conveyance systems in these areas, exacerbating flood hazards and affecting the delivery of irrigation water. Vertical land-surface changes during 2007-2014 were determined by using Interferometric Synthetic Aperture Radar (InSAR), Continuous Global Positioning System (CGPS), and extensometer data. Results of the InSAR analysis indicate that about 7600 km2 subsided 50-540 mm during 2008-2010; CGPS and extensometer data indicate that these rates continued or accelerated through December 2014. The maximum InSAR-measured rate of 270 mm yr-1 occurred in the El Nido area, and is among the largest rates ever measured in the SJV. In the Pixley area, the maximum InSAR-measured rate during 2008-2010 was 90 mm yr-1. Groundwater was an important part of the water supply in both areas, and pumping increased when land use changed or when surface water was less available. This increased pumping caused groundwater-level declines to near or below historical lows during the drought periods 2007-2009 and 2012-present. Long-term groundwater-level and land-subsidence monitoring in the SJV is critical for understanding the interconnection of land use, groundwater levels, and subsidence, and evaluating management strategies that help mitigate subsidence hazards to infrastructure while optimizing water supplies.

  12. Bathymetric survey and digital elevation model of Little Holland Tract, Sacramento-San Joaquin Delta, California

    USGS Publications Warehouse

    Snyder, Alexander G.; Lacy, Jessica R.; Stevens, Andrew W.; Carlson, Emily M.

    2016-01-01

    The U.S. Geological Survey conducted a bathymetric survey in Little Holland Tract, a flooded agricultural tract, in the northern Sacramento-San Joaquin Delta (the “Delta”) during the summer of 2015. The new bathymetric data were combined with existing data to generate a digital elevation model (DEM) at 1-meter resolution. Little Holland Tract (LHT) was historically diked off for agricultural uses and has been tidally inundated since an accidental levee breach in 1983. Shallow tidal regions such as LHT have the potential to improve habitat quality in the Delta. The DEM of LHT was developed to support ongoing studies of habitat quality in the area and to provide a baseline for evaluating future geomorphic change. The new data comprise 138,407 linear meters of real-time-kinematic (RTK) Global Positioning System (GPS) elevation data, including both bathymetric data collected from personal watercraft and topographic elevations collected on foot at low tide. A benchmark (LHT15_b1) was established for geodetic control of the survey. Data quality was evaluated both by comparing results among surveying platforms, which showed systematic offsets of 1.6 centimeters (cm) or less, and by error propagation, which yielded a mean vertical uncertainty of 6.7 cm. Based on the DEM and time-series measurements of water depth, the mean tidal prism of LHT was determined to be 2,826,000 cubic meters. The bathymetric data and DEM are available at http://dx.doi.org/10.5066/F7RX9954. 

  13. 75 FR 60623 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-01

    ... Air Pollution Control District AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule... Valley Unified Air Pollution Control District (SJVUAPCD) portion of the California State Implementation... Ventura County Air Pollution Control District (VCAPCD) Rule 74.15 (as amended November 8, 1994)....

  14. 77 FR 74355 - Approval of Air Quality Implementation Plans; California; San Joaquin Valley; Attainment Plan for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-14

    ... Federal Regulations (CFR) at 40 CFR 52.220(c). See 77 FR 12652 (March 1, 2012). The regulatory text for... beginning of this regulatory text (77 FR 12672) did not identify this paragraph and as a result this... the California Air Resources Board's commitment to update the air quality modeling in the San...

  15. Early, middle, and late Miocene basin development, California

    SciTech Connect

    Bachman, S.B.

    1988-03-01

    Contrary to earlier models of progressive basin development related to northward migration of the Mendocino triple junction, it can now be documented that the major basins of coastal California developed at about the same time in the late Oligocene to early Miocene. This basin development is marked by rapid deepening of basin floors, subsequent changes in depositional facies from nonmarine and shallow marine to deep marine, and widespread volcanism dated at 23-20 Ma. The coastal basins likely formed by rifting and subsidence linked to the proximity of the Farallon-pacific spreading ridge and the subduction of hot young oceanic crust, but cannot be correlated to any existing models of triple junction migration. Indeed, strike-slip restored positions of the coastal basins at their inception indicate that the basins were spread out over about 800 km of the southern coast of California. The Miocene basins were likely larger than the present coastal basins, although their configurations are obscured by late Neogene faulting and erosion. It is likely, however, that paleohighs separated at least some of the margin into proximal and distal basins. With local exceptions, structuring in the Miocene basins was primarily extensional, with widespread strike-slip and thrust tectonics restricted mainly to latest Miocene and younger events. Plate reconstructions suggest several hundred kilometers of transform motion occurred along the California margin during the Miocene, but there is only limited evidence of this movement in the known history of either the basins or the major faults of California. Sedimentation during the Miocene was controlled by both oceanic conditions (biogenic component) and the relative abundance of clastic input. The clastic input was controlled by a combination of proximal vs distal basinal positions, eustatic sea level changes, and local tectonics.

  16. Fish consumption and advisory awareness among low-income women in California's Sacramento-San Joaquin Delta.

    PubMed

    Silver, Elana; Kaslow, Jessica; Lee, Diana; Lee, Sun; Lynn Tan, May; Weis, Erica; Ujihara, Alyce

    2007-07-01

    Fishing is a culturally important activity to the ethnically diverse population living in California's Sacramento-San Joaquin Delta. Due to runoff from abandoned gold mines, certain Delta fish are contaminated with methylmercury, a neurodevelopmental toxin. A state health advisory recommends limited consumption of certain Delta fish, to be followed in conjunction with a federal advisory for commercial and sport fish. We conducted a survey of low-income women at a Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) clinic, to characterize commercial and sport fish consumption patterns and advisory awareness. Ninety-five percent of women consumed commercial fish. Thirty-two percent consumed sport fish; this proportion was much higher in Hmong (86%) and Cambodian (75%) women. Ninety-nine percent of sport fish consumers also consumed commercial fish. The overall fish consumption rate among consumers was 27.9 g/day (geometric mean, past 30 days, cooked portion); commercial and sport fish consumption rates were 26.3 and 10.5 g/day, respectively. We found ethnic differences in overall fish consumption rates, which were highest in African Americans (41.2 g/day) and Asians (35.6 g/day), particularly Vietnamese and Cambodians. Pregnant women ate less fish overall than other women (16.8 vs. 30.0 g/day, p=0.0001), as did women who demonstrated specific advisory awareness (23.3 vs. 30.3 g/day, p=0.02). Twenty-nine percent of all women exceeded federal fish consumption advisory limits. These results highlight the need for culturally and linguistically appropriate interventions that address both commercial and sport fish consumption.

  17. Present-day oxidative subsidence of organic soils and mitigation in the Sacramento-San Joaquin Delta, California, USA

    NASA Astrophysics Data System (ADS)

    Deverel, Steven J.; Ingrum, Timothy; Leighton, David

    2016-05-01

    Subsidence of organic soils in the Sacramento-San Joaquin Delta threatens sustainability of the California (USA) water supply system and agriculture. Land-surface elevation data were collected to assess present-day subsidence rates and evaluate rice as a land use for subsidence mitigation. To depict Delta-wide present-day rates of subsidence, the previously developed SUBCALC model was refined and calibrated using recent data for CO2 emissions and land-surface elevation changes measured at extensometers. Land-surface elevation change data were evaluated relative to indirect estimates of subsidence and accretion using carbon and nitrogen flux data for rice cultivation. Extensometer and leveling data demonstrate seasonal variations in land-surface elevations associated with groundwater-level fluctuations and inelastic subsidence rates of 0.5-0.8 cm yr-1. Calibration of the SUBCALC model indicated accuracy of ±0.10 cm yr-1 where depth to groundwater, soil organic matter content and temperature are known. Regional estimates of subsidence range from <0.3 to >1.8 cm yr-1. The primary uncertainty is the distribution of soil organic matter content which results in spatial averaging in the mapping of subsidence rates. Analysis of leveling and extensometer data in rice fields resulted in an estimated accretion rate of 0.02-0.8 cm yr-1. These values generally agreed with indirect estimates based on carbon fluxes and nitrogen mineralization, thus preliminarily demonstrating that rice will stop or greatly reduce subsidence. Areas below elevations of -2 m are candidate areas for implementation of mitigation measures such as rice because there is active subsidence occurring at rates greater than 0.4 cm yr-1.

  18. Ammonia and methane dairy emissions in the San Joaquin Valley of California from individual feedlot to regional scale

    DOE PAGESBeta

    Miller, David J.; Sun, Kang; Tao, Lei; Nowak, John B.; Liu, Zhen; Diskin, Glenn; Sasche, Glen; Beyersdorf, Andreas; Ferrare, Richard; Scarino, Amy Jo; et al

    2015-09-27

    Agricultural ammonia (NH3) emissions are highly uncertain, with high spatiotemporal variability and a lack of widespread in situ measurements. Regional NH3 emission estimates using mass balance or emission ratio approaches are uncertain due to variable NH3 sources and sinks as well as unknown plume correlations with other dairy source tracers. We characterize the spatial distributions of NH3 and methane (CH4) dairy plumes using in situ surface and airborne measurements in the Tulare dairy feedlot region of the San Joaquin Valley, California, during the NASA Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality 2013more » field campaign. Surface NH3 and CH4 mixing ratios exhibit large variability with maxima localized downwind of individual dairy feedlots. The geometric mean NH3:CH4 enhancement ratio derived from surface measurements is 0.15 ± 0.03 ppmv ppmv–1. Individual dairy feedlots with spatially distinct NH3 and CH4 source pathways led to statistically significant correlations between NH3 and CH4 in 68% of the 69 downwind plumes sampled. At longer sampling distances, the NH3:CH4 enhancement ratio decreases 20–30%, suggesting the potential for NH3 deposition as a loss term for plumes within a few kilometers downwind of feedlots. Aircraft boundary layer transect measurements directly above surface mobile measurements in the dairy region show comparable gradients and geometric mean enhancement ratios within measurement uncertainties, even when including NH3 partitioning to submicron particles. Individual NH3 and CH4 plumes sampled at close proximity where losses are minimal are not necessarily correlated due to lack of mixing and distinct source pathways. As a result, our analyses have important implications for constraining NH3 sink and plume variability influences on regional NH3 emission estimates and for improving NH3 emission inventory spatial allocations.« less

  19. Concentrations of chlorinated organic compounds in biota and bed sediment in streams of the lower San Joaquin River drainage, California

    USGS Publications Warehouse

    Brown, Larry R.

    1998-01-01

    Samples of resident biota and bed sediments were collected in 1992 from 18 sites on or near the floor of the San Joaquin Valley, California, for analysis of 33 organochlorine compounds. The sites were divided into five groups on the basis of physiographic region and land use. Ten compounds were detected in tissue, and 16 compounds were detected in bed sediment. The most frequently detected compound in both media was p,p'-DDE. Concentrations of total DDT (sum of o,p'- and p,p'-forms of DDD, DDE, and DDT) were statistically different among groups of sites for tissue and sediment (Kruskal-Wallis, P < 0.05). Concentrations in both media were highest in streams draining the west side of the valley. Concentrations of total DDT in tissue were significantly correlated with specific conductance, pH, and total alkalinity (P < 0.05), which are indicators of the proportion of irrigation-return flows in stream discharge. Concentrations in sediment on a dry-weight basis were not correlated with these water-quality parameters, but total-organic- carbon (TOC) normalized concentrations were significantly correlated with specific conductance and pH (P < 0.05). Regressions of the concentration of total DDT in tissue as a function of total DDT in bed sediment were significant and explained as much as 76 percent of the variance in the data. The concentration of total DDT in sediment may be related to mechanisms of soil transport to surface water with bioavailability of compounds related to the concentration of TOC in sediment.

  20. Concentrations of chlorinated organic compounds in biota and bed sediment in streams of the San Joaquin Valley, California

    USGS Publications Warehouse

    Brown, L.R.

    1997-01-01

    Samples of resident biota and bed sediments were collected in 1992 from 18 sites on or near the floor of the San Joaquin Valley, California, for analysis of 33 organochlorine compounds. The sites were divided into five groups on the basis of physiographic region and land use. Ten compounds were detected in tissue, and 15 compounds were detected in bed sediment. The most frequently detected compound in both media was p,p'-DDE. Concentrations of ??DDT (sum of o,p'- and p, p' forms of DDD, DDE, and DDT) were statistically different among groups of sites for both tissue and sediment (Kruskal- Wallis, p < 0.05). Concentrations in both media were highest in streams draining the west side of the valley. Concentrations of ??DDT in tissue were significantly correlated with specific conductance, pH, and total alkalinity (p < 0.05), which are indicators of the proportion of irrigation return flows in stream discharge. Concentrations in sediment on a dry-weight basis were not correlated with these water-quality parameters, but total organic carbon (TOC) normalized concentrations were significantly correlated with specific conductance and pH (p < 0.05). Regressions of the concentration of ??DDT in tissue, as a function of ??DDT in bed sediment, were significant and explained up to 76% of the variance in the data. The concentration of ??DDT in sediment may be related to mechanisms of soil transport to surface water with bioavailability of compounds related to the concentration of TOC in sediment. The results of this study did not indicate any clear advantage to using either bed sediment or tissues in studies of organochlorine chemicals in the environment. Some guidelines for protection of fish and wildlife were exceeded. Concentrations of organochlorine chemicals in biota, and perhaps sediment, have declined from concentrations measured in the 1970s and 1980s, but remain high compared to other regions of the United States.

  1. Calibration of a texture-based model of a ground-water flow system, western San Joaquin Valley, California

    USGS Publications Warehouse

    Phillips, Steven P.; Belitz, Kenneth

    1991-01-01

    The occurrence of selenium in agricultural drain water from the western San Joaquin Valley, California, has focused concern on the semiconfined ground-water flow system, which is underlain by the Corcoran Clay Member of the Tulare Formation. A two-step procedure is used to calibrate a preliminary model of the system for the purpose of determining the steady-state hydraulic properties. Horizontal and vertical hydraulic conductivities are modeled as functions of the percentage of coarse sediment, hydraulic conductivities of coarse-textured (Kcoarse) and fine-textured (Kfine) end members, and averaging methods used to calculate equivalent hydraulic conductivities. The vertical conductivity of the Corcoran (Kcorc) is an additional parameter to be evaluated. In the first step of the calibration procedure, the model is run by systematically varying the following variables: (1) Kcoarse/Kfine, (2) Kcoarse/Kcorc, and (3) choice of averaging methods in the horizontal and vertical directions. Root mean square error and bias values calculated from the model results are functions of these variables. These measures of error provide a means for evaluating model sensitivity and for selecting values of Kcoarse, Kfine, and Kcorc for use in the second step of the calibration procedure. In the second step, recharge rates are evaluated as functions of Kcoarse, Kcorc, and a combination of averaging methods. The associated Kfine values are selected so that the root mean square error is minimized on the basis of the results from the first step. The results of the two-step procedure indicate that the spatial distribution of hydraulic conductivity that best produces the measured hydraulic head distribution is created through the use of arithmetic averaging in the horizontal direction and either geometric or harmonic averaging in the vertical direction. The equivalent hydraulic conductivities resulting from either combination of averaging methods compare favorably to field- and laboratory

  2. Plant community, primary productivity, and environmental conditions following wetland re-establishment in the Sacramento-San Joaquin Delta, California

    USGS Publications Warehouse

    Miller, R.L.; Fujii, R.

    2010-01-01

    Wetland restoration can mitigate aerobic decomposition of subsided organic soils, as well as re-establish conditions favorable for carbon storage. Rates of carbon storage result from the balance of inputs and losses, both of which are affected by wetland hydrology. We followed the effect of water depth (25 and 55 cm) on the plant community, primary production, and changes in two re-established wetlands in the Sacramento San-Joaquin River Delta, California for 9 years after flooding to determine how relatively small differences in water depth affect carbon storage rates over time. To estimate annual carbon inputs, plant species cover, standing above- and below-ground plant biomass, and annual biomass turnover rates were measured, and allometric biomass models for Schoenoplectus (Scirpus) acutus and Typha spp., the emergent marsh dominants, were developed. As the wetlands developed, environmental factors, including water temperature, depth, and pH were measured. Emergent marsh vegetation colonized the shallow wetland more rapidly than the deeper wetland. This is important to potential carbon storage because emergent marsh vegetation is more productive, and less labile, than submerged and floating vegetation. Primary production of emergent marsh vegetation ranged from 1.3 to 3.2 kg of carbon per square meter annually; and, mid-season standing live biomass represented about half of the annual primary production. Changes in species composition occurred in both submerged and emergent plant communities as the wetlands matured. Water depth, temperature, and pH were lower in areas with emergent marsh vegetation compared to submerged vegetation, all of which, in turn, can affect carbon cycling and storage rates. ?? Springer Science+Business Media B.V. 2009.

  3. Characterizing the ozone formation potential of agricultural sources in California's San Joaquin Valley: A computational and experimental approach

    NASA Astrophysics Data System (ADS)

    Howard, Cody Jerome

    The global pattern of expanding urban centers and increasing agricultural intensity is leading to more frequent interactions between air pollution emissions from urban and agricultural sources. The confluence of these emissions that traditionally have been separated by hundreds of kilometers is creating new air quality challenges in numerous regions across the United States. An area of particular interest is California's San Joaquin Valley (SJV), which has an agricultural output higher than many countries, a rapidly expanding human population, and ozone concentrations that are already higher than many dense urban areas. New regulations in the SJV restrict emissions of reactive organic gases (ROG) from animal sources in an attempt to meet Federal and State ozone standards designed to protect human health. A transportable "smog" chamber was developed and tested to directly measure the ozone formation potential of a variety of agricultural emissions in representative urban and rural atmospheres. After validation of the experimental procedure, four animal types were examined: beef cattle, dairy cattle, swine, and poultry, as well as six commonly used animal feeds: cereal silage (wheat grain and oat grain), alfalfa silage, corn silage, high moisture ground corn, almond shells, almond hulls, and total mixed ration. The emitted ROG composition was also measured so that the theoretical incremental reactivity could be calculated for a variety of atmospheres and directly compared with the measured ozone formation potential (OFP) under the experimental conditions. A computational model was created based on a modified form of the Caltech Atmospheric Chemistry Mechanism and validated against experimental results. After validation, the computational model was used to predict OFP across a range of NOx and ROG concentrations. The ROG OFP measurements combined with adjusted agricultural ROG emissions inventory estimates were used to predict the actual ozone production in the SJV

  4. Potential exposure of larval and juvenile delta smelt to dissolved pesticides in the Sacramento-San Joaquin Delta, California

    USGS Publications Warehouse

    Kuivila, K.M.; Moon, G.E.

    2004-01-01

    The San Francisco Estuary is critical habitat for delta smelt Hypomesus transpacificus, a fish whose abundance has declined greatly since 1983 and is now listed as threatened. In addition, the estuary receives drainage from the Central Valley, an urban and agricultural region with intense and diverse pesticide usage. One possible factor of the delta smelt population decline is pesticide toxicity during vulnerable larval and juvenile stages, but pesticide concentrations are not well characterized in delta smelt spawning and nursery habitat. The objective of this study was to estimate the potential exposure of delta smelt during their early life stages to dissolved pesticides. For 3 years (1998-2000), water samples from the Sacramento-San Joaquin Delta were collected during April-June in coordination with the California Department of Fish and Game's delta smelt early life stage monitoring program. Samples were analyzed for pesticides using solid-phase extraction and gas chromatography/mass spectrometry. Water samples contained multiple pesticides, ranging from 2 to 14 pesticides in each sample. In both 1999 and 2000, elevated concentrations of pesticides overlapped in time and space with peak densities of larval and juvenile delta smelt. In contrast, high spring outflows in 1998 transported delta smelt away from the pesticide sampling sites so that exposure could not be estimated. During 2 years, larval and juvenile delta smelt were potentially exposed to a complex mixture of pesticides for a minimum of 2-3 weeks. Although the measured concentrations were well below short-term (96-h) LC50 values for individual pesticides, the combination of multiple pesticides and lengthy exposure duration could potentially have lethal or sublethal effects on delta smelt, especially during early larval development.

  5. Ammonia and Methane Dairy Emission Plumes in the San Joaquin Valley of California from Individual Feedlot to Regional Scales

    NASA Technical Reports Server (NTRS)

    Miller, David J.; Sun, Kang; Pan, Da; Zondlo, Mark A.; Nowak, John B.; Liu, Zhen; Diskin, Glenn; Sachse, Glen; Beyersdorf, Andreas; Ferrare, Richard; Scarino, Amy J.

    2015-01-01

    Agricultural ammonia (NH3) emissions are highly uncertain, with high spatiotemporal variability and a lack of widespread in situ measurements. Regional NH3 emission estimates using mass balance or emission ratio approaches are uncertain due to variable NH3 sources and sinks as well as unknown plume correlations with other dairy source tracers. We characterize the spatial distributions of NH3 and methane (CH4) dairy plumes using in situ surface and airborne measurements in the Tulare dairy feedlot region of the San Joaquin Valley, California, during the NASA Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality 2013 field campaign. Surface NH3 and CH4 mixing ratios exhibit large variability with maxima localized downwind of individual dairy feedlots. The geometric mean NH3:CH4 enhancement ratio derived from surface measurements is 0.15 +/- 0.03 ppmv ppmv-1. Individual dairy feedlots with spatially distinct NH3 and CH4 source pathways led to statistically significant correlations between NH3 and CH4 in 68% of the 69 downwind plumes sampled. At longer sampling distances, the NH3:CH4 enhancement ratio decreases 20-30%, suggesting the potential for NH3 deposition as a loss term for plumes within a few kilometers downwind of feedlots. Aircraft boundary layer transect measurements directly above surface mobile measurements in the dairy region show comparable gradients and geometric mean enhancement ratios within measurement uncertainties, even when including NH3 partitioning to submicron particles. Individual NH3 and CH4 plumes sampled at close proximity where losses are minimal are not necessarily correlated due to lack of mixing and distinct source pathways. Our analyses have important implications for constraining NH3 sink and plume variability influences on regional NH3 emission estimates and for improving NH3 emission inventory spatial allocations.

  6. Water Quality and Supply Issues of Irrigated Agricultural Regions - Lessons from the San Joaquin Valley of California

    NASA Astrophysics Data System (ADS)

    Suen, C. J.; Wang, D.

    2014-12-01

    The San Joaquin Valley of California covers 4 million hectares of farmland and produces $25 billion of agricultural products annually, but its average annual rainfall ranges from only 130 mm in the south to 330 mm in the north and nearly all occur in the winter. On the east side of the valley, irrigation water is mostly derived from the Sierra snow melt. On the west side, water is imported from the northern part of the state through the Sacramento Delta and a network of canals and aqueducts. Ground water is also used for both east and west sides of the valley to supplement surface water sources, especially during droughts. After years of intense irrigation, a number of water supply and water quality issues have emerged. They include groundwater overdraft, land subsidence, water contamination by agricultural drainage laden with selenium, salinity buildup in soil and water, nutrients contamination from fertilizers and livestock production, competition for water with megalopolis and environmental use and restoration. All these problems are intensified by the effect of climate change that has already taken place and other geological hazards, such as earthquakes that can bring the water supply system to a complete halt. In addition to scientific and technical considerations, solutions for these complex issues necessarily involve management planning, public policy and actions. Currently, they include furloughing marginally productive lands, groundwater recharge and banking, water reuse and recycle, salinity and nutrient management, integrated regional water management planning, and public education and outreach. New laws have been enacted to better monitor groundwater elevations, and new bond measures to improve storage, infrastructures, and reliability, have been placed on the public ballot. The presentation will discuss these complex water issues.

  7. Ammonia and methane dairy emission plumes in the San Joaquin Valley of California from individual feedlot to regional scales

    NASA Astrophysics Data System (ADS)

    Miller, David J.; Sun, Kang; Tao, Lei; Pan, Da; Zondlo, Mark A.; Nowak, John B.; Liu, Zhen; Diskin, Glenn; Sachse, Glen; Beyersdorf, Andreas; Ferrare, Richard; Scarino, Amy Jo

    2015-09-01

    Agricultural ammonia (NH3) emissions are highly uncertain, with high spatiotemporal variability and a lack of widespread in situ measurements. Regional NH3 emission estimates using mass balance or emission ratio approaches are uncertain due to variable NH3 sources and sinks as well as unknown plume correlations with other dairy source tracers. We characterize the spatial distributions of NH3 and methane (CH4) dairy plumes using in situ surface and airborne measurements in the Tulare dairy feedlot region of the San Joaquin Valley, California, during the NASA Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality 2013 field campaign. Surface NH3 and CH4 mixing ratios exhibit large variability with maxima localized downwind of individual dairy feedlots. The geometric mean NH3:CH4 enhancement ratio derived from surface measurements is 0.15 ± 0.03 ppmv ppmv-1. Individual dairy feedlots with spatially distinct NH3 and CH4 source pathways led to statistically significant correlations between NH3 and CH4 in 68% of the 69 downwind plumes sampled. At longer sampling distances, the NH3:CH4 enhancement ratio decreases 20-30%, suggesting the potential for NH3 deposition as a loss term for plumes within a few kilometers downwind of feedlots. Aircraft boundary layer transect measurements directly above surface mobile measurements in the dairy region show comparable gradients and geometric mean enhancement ratios within measurement uncertainties, even when including NH3 partitioning to submicron particles. Individual NH3 and CH4 plumes sampled at close proximity where losses are minimal are not necessarily correlated due to lack of mixing and distinct source pathways. Our analyses have important implications for constraining NH3 sink and plume variability influences on regional NH3 emission estimates and for improving NH3 emission inventory spatial allocations.

  8. Overwintering Survival of Drosophila suzukii (Diptera: Drosophilidae) and the Effect of Food on Adult Survival in California's San Joaquin Valley.

    PubMed

    Kaçar, Gülay; Wang, Xin-Geng; Stewart, Thomas J; Daane, Kent M

    2016-08-01

    The overwintering survival and development of Drosophila suzukii Matsumura were investigated in California's San Joaquin Valley. Drosophila suzukii were exposed to overwintering conditions in cages hung in a citrus orchard, and the pupae were buried in the soil. Eggs exposed from late November to January did not survive; a low percentage (<3%) of larvae and pupae developed into adults. Survival of pupae was significantly higher when buried in the soil than on the citrus tree. From late January to March, all life stages developed into adults and overwintered adult female D. suzukii produced eggs when provided with 10% honey-water and sliced oranges. Adult survival varied among fruit juice provision treatments and overwintering exposure periods, ranging from 3.4 ± 0.9 d (water) to 44.1 ± 3.0 d (10% honey-water). Fruit juices of apple, cherry, grape, orange, and pomegranate were tested as adult food sources; results showed that adult female and male D. suzukii lived only 2 d with water only, whereas adults survived from 14.2 to 34.8 d with fruit juice treatments and the 10% honey-water control. An unexpected event was the oviposition and immature development of D. suzukii with the fruit juice. In a follow-up laboratory trial, when 10% honey-water or orange juice were provided along with an artificial diet for oviposition and immature development, female D. suzukii survived for 21.6 ± 2.4 or 21.6 ± 1.5 d, and produced 106.8 ± 14.1 or 98.5 ± 13.1 offspring, respectively. We discuss factors potentially influencing overwintering survival of D. suzukii. PMID:26654917

  9. Dissolved pesticide concentrations entering the Sacramento-San Joaquin Delta from the Sacramento and San Joaquin Rivers, California, 2012-13

    USGS Publications Warehouse

    Orlando, James L.; McWayne, Megan; Sanders, Corey; Hladik, Michelle

    2014-01-01

    Surface-water samples were collected from the Sacramento and San Joaquin Rivers where they enter the Sacramento–San Joaquin Delta, and analyzed by the U.S. Geological Survey for a suite of 99 current-use pesticides and pesticide degradates. Samples were collected twice per month from May 2012 through July 2013 and from May 2012 through April 2013 at the Sacramento River at Freeport, and the San Joaquin River near Vernalis, respectively. Samples were analyzed by two separate laboratory methods by using gas chromatography with mass spectrometry or liquid chromatography with tandem mass spectrometry. Method detection limits ranged from 0.9 to 10.5 nanograms per liter (ng/L). A total of 37 pesticides and degradates were detected in water samples collected during the study (18 herbicides, 11 fungicides, 7 insecticides, and 1 synergist). The most frequently detected pesticides overall were the herbicide hexazinone (detected in 100 percent of the samples); 3,4-dichloroaniline (97 percent), which is a degradate of the herbicides diuron and propanil; the fungicide azoxystrobin (83 percent); and the herbicides diuron (72 percent), simazine (66 percent), and metolachlor (64 percent). Insecticides were rarely detected during the study. Pesticide concentrations varied from below the method detection limits to 984 ng/L (hexazinone). Twenty seven pesticides and (or) degradates were detected in Sacramento River samples, and the average number of pesticides per sample was six. The most frequently detected compounds in these samples were hexazinone (detected in 100 percent of samples), 3,4-dichloroaniline (97 percent), azoxystrobin (88 percent), diuron (56 percent), and simazine (50 percent). Pesticides with the highest detected maximum concentrations in Sacramento River samples included the herbicide clomazone (670 ng/L), azoxystrobin (368 ng/L), 3,4-dichloroaniline (364 ng/L), hexazinone (130 ng/L), and propanil (110 ng/L), and all but hexazinone are primarily associated with

  10. Sources and Cycling of Dissolved Organic Matter in the Sacramento - San Joaquin Delta, California, Using Carbon, Nitrogen, and Sulfur Isotopes

    NASA Astrophysics Data System (ADS)

    Silva, S. R.; Kendall, C.; Doctor, D. H.; Bergamaschi, B. A.; Fram, M. S.; Kraus, T.

    2006-12-01

    An important water quality concern of the Sacramento-San Joaquin Delta portion of the Calfed Bay-Delta restoration program is the generation of disinfection byproducts (DBP) as a result of chlorination or ozonation of San Francisco Bay Delta drinking water. One means of reducing DBPs is through monitoring and control of water sources from the various delta environments entering the California aqueduct with the objective of reducing the quantity of dissolved organic matter (DOM) and lowering the fraction with the highest DBP formation potential. The purpose of this study is to investigate the use of carbon, nitrogen, and sulfur isotopic compositions of DOM to help differentiate DOM sources and interpret seasonal variations. For this purpose, water samples collected from five general delta environments between December 1999 and June 2001 were analyzed for d13C, d15N, and d34S of DOM as well as for various chemical and optical properties. Monthly averages of d13C and d15N values for DOM retained on XAD-4 and XAD-8 resins show distinctive compositions for island drain and wetland environments throughout the year which reflect the agriculturally- related terrestrial sources of DOM from island drains, and the aquatic sources for the wetland areas. On average, the d13C values of DOM from open water (flooded island) environments, channels, and the Sacramento River water are indistinguishable from each other from spring through fall and show a progressive increase in d13C, which is likely controlled by the cycle of aquatic production through the growing season. The isotopic values from these environments diverge in the winter reflecting a change in the relative importance of the various mechanisms (sources and cycling) controlling DOM production. Sulfur isotopes show both the effects of sulfate reduction and the influence of seawater sulfate on local biota. The d13C, d15N, and d34S values show a number of correlations related to both environment and season, reflecting the

  11. Simulation of Multiscale Ground-Water Flow in Part of the Northeastern San Joaquin Valley, California

    USGS Publications Warehouse

    Phillips, Steven P.; Green, Christopher T.; Burow, Karen R.; Shelton, Jennifer L.; Rewis, Diane L.

    2007-01-01

    The transport and fate of agricultural chemicals in a variety of environmental settings is being evaluated as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment Program. One of the locations being evaluated is a 2,700-km2 (square kilometer) regional study area in the northeastern San Joaquin Valley surrounding the city of Modesto, an area dominated by irrigated agriculture in a semi-arid climate. Ground water is a key source of water for irrigation and public supply, and exploitation of this resource has altered the natural flow system. The aquifer system is predominantly alluvial, and an unconfined to semiconfined aquifer overlies a confined aquifer in the southwestern part of the study area; these aquifers are separated by the lacustrine Corcoran Clay. A regional-scale 16-layer steady-state model of ground-water flow in the aquifer system in the regional study area was developed to provide boundary conditions for an embedded 110-layer steady-state local-scale model of part of the aquifer system overlying the Corcoran Clay along the Merced River. The purpose of the local-scale model was to develop a better understanding of the aquifer system and to provide a basis for simulation of reactive transport of agricultural chemicals. The heterogeneity of aquifer materials was explicitly incorporated into the regional and local models using information from geologic and drillers? logs of boreholes. Aquifer materials were differentiated in the regional model by the percentage of coarse-grained sediments in a cell, and in the local model by four hydrofacies (sand, silty sand, silt, and clay). The calibrated horizontal hydraulic conductivity values of the coarse-grained materials in the zone above the Corcoran Clay in the regional model and of the sand hydrofacies used in the local model were about equal (30?80 m/d [meter per day]), and the vertical hydraulic conductivity values in the same zone of the regional model (median of 0.012 m/d), which is

  12. Salt toxicosis in ruddy ducks that winter on an agricultural evaporation basin in California.

    PubMed

    Gordus, Andrew G; Shivaprasad, H L; Swift, Pamela K

    2002-01-01

    Agricultural evaporation basins are used as a means to dispose of highly saline underground-tile-drainage water in the San Joaquin Valley (California, USA). The hypersaline water conditions encourage high aquatic invertebrate production, primarily brine shrimp (Artemia franciscana), which attract birds to these sites. Cool winter temperatures (< 4 C) and hypersaline water conditions (> 70,000 mumhos/cm) resulted in feather salt encrustation and salt toxicosis in ruddy ducks (Oxyura jamaicensis). During December 1998 and January 1999, approximately 200 dead and sick ruddy ducks were collected from an evaporation basin and five healthy control ruddy ducks were collected from a freshwater wetland. Brains contained > or = 1,890 ppm sodium (wet tissue mass) in seven dead birds and contained < or = 1,150 ppm sodium in the control birds. Liver arsenic, lead, and mercury concentrations were < 1 ppm in all birds examined. Manganese, molybdenum, and copper liver concentrations did not differ significantly (P > 0.05) between the two groups of ducks. The dead ducks had significantly higher liver selenium, cadmium, iron, and zinc than the controls, but the concentrations were not sufficient to cause toxicity. Significant gross and microscopic lesions in most of the dead birds included conjunctivitis, lens opacity and cataract formation, vascular congestion in various organs most notably in the meninges of the brain, and myocardial and skeletal muscle degeneration.

  13. Using the Soil and Water Assessment Tool (SWAT) to Simulate Runoff in Mustang Creek Basin, California

    USGS Publications Warehouse

    Saleh, Dina K.; Kratzer, Charles R.; Green, Colleen H.; Evans, David G.

    2009-01-01

    This study is an evaluation of the calibration and validation of the Soil and Water Assessment Tool (SWAT) version 2005 watershed model for the Mustang Creek Basin, San Joaquin Valley, California. The study is part of a national study on the process of agricultural chemical movement through the hydrologic system, which is being done by the U.S. Geological Survey (USGS) National Water-Quality Assessment program. The SWAT model was used to simulate streamflow in the Mustang Creek Basin on the basis of a set of model inputs derived and modified from various data sources. The 2005 version of the model was calibrated for 29 days in February 2004, and validated for 58 days in January and February 2005. Measured streamflow for a USGS gaging station was used for model calibration and validation. Results of the simulated monthly streamflow had a Nash Sutcliffe efficiency value of 0.72 during the calibration period. The 2005 version of the model was unsuccessful in simulating streamflow during the validation period, as indicated by a Nash Sutcliffe efficiency value of 0.33. This lack of a successful simulation probably is due to the limited amount of measured streamflow data available for calibration, the ephemeral nature of flows in Mustang Creek, and the fact that the SWAT model was developed primarily for long time period (2 years and more) simulations and not for limited monthly simulations as used in Mustang Creek.

  14. 2000 yr record of Sacramento-San Joaquin river inflow to San Francisco Bay estuary, California

    SciTech Connect

    Ingram, B.L.; Ingle, J.C.; Conrad, M.E.

    1996-04-01

    Oxygen and carbon isotopic measurements of fossil bivalves (Macoma nasuta) contained in estuarine sediment are used to reconstruct a late Holocene record of salinity and stream flow in San Francisco Bay. Discharge into the bay is a particularly good indicator of paleoclimate in California because the bay`s influent streams drain 40% of the state. The isotopic record suggests that between about 1670 and 1900 calendar years (yr cal) B.P. inflow to the bay was substantially greater than the estimated prediversion inflow of 1100 M{sup 3}/s. An unconformity representing a 900 yr hiatus is present in the core between 1670 and 750 yr cal B.P., possibly caused by a major hydrological event. Over the past 750 yr, stream flow to San Francisco Bay has varied with a period of 200 yr; alternate wet and dry (drought) intervals typically have lasted 40 to 160 yr. 27 refs., 7 figs.

  15. A 2000 yr record of Sacramento San Joaquin River inflow to San Francisco Bay estuary, California

    SciTech Connect

    Ingram, B.L.; Ingle, J.C.; Conrad, M.E.

    1995-10-01

    Oxygen and carbon isotopic measurements of fossil bivalves (Macoma nasuta) contained in estuarine sediment are used to reconstruct a late Holocene record of salinity and stream flow in San Francisco Bay. Discharge into the bay is a particularly good indicator of paleoclimate in California because the bay's influent streams drain 40 percent of the state, The isotopic record suggests that between about 1670 and 1900 calendar years (yr cal) B.P. inflow to the bay was substantially greater than the estimated prediversion inflow of 1100 m(3)/s, An unconformity representing a 900 yr hiatus is present in the core between 1670 and 750 yr cal B.P., possibly caused by a major hydrological event. Over the past 750 yr, stream flow to San Francisco Bay has varied with a period of 200 yr; alternate wet and dry (drought) intervals typically have lasted 40 to 160 yr.

  16. Bioaccumulation of selenium by snakes and frogs in the San Joaquin Valley, California

    USGS Publications Warehouse

    Ohlendorf, H.M.; Hothem, R.L.; Aldrich, T.W.

    1988-01-01

    Livers of gopher snakes (Pituophis melanoleucus) from Kesterson Reservoir (Merced County, California) contained significantly higher mean selenium concentrations (11.1 .mu.g/g, dry weight) than those from two nearby reference sites (2.05 and 2.14 .mu.g/g). Livers of bullfrogs (Rana catesbeiana) collected from the San Luis Drain at Kersterson Reservoir also contained significantly higher mean selenium concentrations (45.0 .mu.g/g) than those from nearby reference sites (6.22 .mu.g/g). The high levels of selenium bioaccumulation in these snakes and frogs at Kersterson Reservoir reflected the elevated levels found in their food organisms. We did not examine that snakes or frogs from Kesterson for signs of ill health, but the concentrations we found were sufficiently high to warrant concern about potential adverse effects in these animals and their predators.

  17. Groundwater contributions of flow, nitrate, and dissolved organic carbon to the lower San Joaquin River, California, 2006-08

    USGS Publications Warehouse

    Zamora, Celia; Dahlgren, Randy A.; Kratzer, Charles R.; Downing, Bryan D.; Russell, Ann D.; Dileanis, Peter D.; Bergamaschi, Brian A.; Phillips, Steven P.

    2013-01-01

    The influence of groundwater on surface-water quality in the San Joaquin River, California, was examined for a 59-mile reach from the confluence with Salt Slough to Vernalis. The primary objective of this study was to quantify the rate of groundwater discharged to the lower San Joaquin River and the contribution of nitrate and dissolved organic carbon concentrations to the river. Multiple lines of evidence from four independent approaches were used to characterize groundwater contributions of nitrogen and dissolved organic carbon. Monitoring wells (in-stream and bank wells), streambed synoptic surveys (stream water and shallow groundwater), longitudinal profile surveys by boat (continuous water-quality parameters in the stream), and modeling (MODFLOW and VS2DH) provided a combination of temporal, spatial, quantitative, and qualitative evidence of groundwater contributions to the river and the associated quality. Monitoring wells in nested clusters in the streambed (in-stream wells) and on both banks (bank wells) along the river were monitored monthly from September 2006 to January 2009. Nitrate concentrations in the bank wells ranged from less than detection—that is, less than 0.01 milligrams per liter (mg/L) as nitrogen (N)—to approximately 13 mg/L as N. Nitrate was not detected at 17 of 26 monitoring wells during the study period. Dissolved organic carbon concentrations among monitoring wells were highly variable, but they generally ranged from 1 to 4 mg/L. In a previous study, 14 bank wells were sampled once in 1988 following their original installation. With few exceptions, specific conductivity and nitrate concentrations measured in this study were virtually identical to those measured 20 years ago. Streambed synoptic measurements were made by using a temporarily installed drive-point piezometer at 113 distinct transects across the stream during 4 sampling events. Nitrate concentrations exceeded the detection limit of 0.01 mg/L as N in 5 percent of

  18. Similarities and differences in PM 10 chemical source profiles for geological dust from the San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Chow, Judith C.; Watson, John G.; Ashbaugh, Lowell L.; Magliano, Karen L.

    A systematic sampling and analysis approach was followed to acquire chemical source profiles for six types of geological dust in California's San Joaquin Valley. Forty-seven samples from 37 locations included: (1) urban and rural paved roads, (2) residential and agricultural unpaved roads and parking areas, (3) almond, cotton, grape, safflower, and tomato fields, (4) dairy and feedlot surfaces, (5) salt-laden lake and irrigation canal drainage deposits, and (6) building and roadway construction/earthmoving soil. These samples were dried, sieved, resuspended, sampled through a PM 10 inlet onto filters, and chemically analyzed to construct PM 10 source profiles (fractional mass abundances and uncertainties) for 40 elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Y, Zr, Mo, Pd, Ag, Cd, In, Sn, Sb, Ba, La, Au, Hg, Tl, Pb, and U), 7 ions (Cl -, NO 3-, PO 42-, SO 42-, Na +, K +, and NH 4+), organic and elemental carbon (OC and EC), 8 carbon fractions (OC1, OC2, OC3, OC4, OP, EC1, EC2, and EC3), and carbonate carbon. Individual source profiles with analytical precisions were averaged and compared to quantify differences in chemical abundances for: (1) duplicate laboratory resuspension sampling, (2) multiple sampling within the same agricultural field, (3) sampling at different locations for the same land-use activity, (4) sampling of different activities regardless of location, and (5) grouping of different activities into generalized emission inventory source categories. Distinguishing features were found among composite source profiles of six source types. Elemental carbon and Pb marked paved road dust; Na +, Na, S, and SO 42- marked salt deposits; OC, PO 42-, P, K +, K, and Ca characterized animal husbandry; and several metals (Ti, V, Mn) marked construction soil, with abundances 2-10 times higher than those of other profiles. High-sensitivity X-ray fluorescence analysis resulted in detectable alkali and rare earth

  19. Determination of channel capacity of the Mokelumne River downstream from Camanche Dam, San Joaquin and Sacramento Counties, California

    USGS Publications Warehouse

    Simpson, R.G.

    1972-01-01

    This study evaluates the adequacy of a 39-mile reach of the Mokelumne River in San Joaquin and Sacramento Counties, California, to carry planned flood releases between Camanche Reservoir and the Bensons Ferry Bridge near Thornton. The flood releases from Camanche Reservoir are to be restricted, insofar as possible, so that the flows in the Mokelumne River will not exceed 5,000 cfs (cubic feet per second) as measured at the gaging station below Camanche Dam. Areas of inundation and computed floodwater profiles are based on channel conditions in late 1970 and on observed water-surface profiles during flood releases of about 5,000 cfs in January 1969 and January 1970. The inundated area shown on the maps (appendix A) and the water-surface elevations indicated on the cross sections (appendix G) are for the flood releases of those dates. The following conclusions are contingent on there being no levee failures during periods of high flow and no significant channel changes since the flood release of January 1970. 1. High tides in San Francisco Bay and, to a greater degree, flood stages on the Cosumnes River, cause backwater in the study reach. Severe backwater conditions occurring simultaneously with a flow of 5,000 cfs in the Mokelumne River can increase the flood stage 4 to 6 feet at Bensons Ferry Bridge (cross section 1). Backwater effects decrease in an upstream direction and are less than 0.5 foot at cross section 35, a river distance of 8.6 miles upstream from cross section 1, and 1.5 miles downstream from the Peltier Road bridge. 2. In the reach between cross sections 1 and 35, a 5,000 cfs release from Camanche Reservoir with maximum backwater effect (measured at cross section 1 at the mouth of the Cosumnes River) is confined within the natural or leveed banks except on the right bank flood plain between cross sections 12 and 19. 3. Upstream from cross section 35, there is overbank flooding at a flow of 5,000 cfs between cross sections 48 and 51, and 62 and 67

  20. Biogenic polycyclic aromatic hydrocarbons in sediments of the San Joaquin River in California (USA), and current paradigms on their formation.

    PubMed

    Wakeham, Stuart G; Canuel, Elizabeth A

    2016-06-01

    Biogenic perylene and higher plant pentacyclic triterpenoid-derived alkylated and partially aromatized tetra- and pentacyclic derivatives of chrysene (3,4,7-trimethyl- and 3,3,7-trimethyl-1,2,3,4-tetrahydrochrysene, THC) and picene (1,2,9-trimethyl- and 2,2,9-trimethyl-1,2,3,4-tetrahydropicene, THP) were two- to four-fold more abundant than pyrogenic PAH in two sediment cores from the San Joaquin River in Northern California (USA). In a core from Venice Cut (VC), located in the river, PAH concentrations varied little downcore and the whole-core PAH concentration (biogenics + pyrogenics) was 250.6 ± 73.7 ng g(-1) dw; biogenic PAH constituted 67 ± 4 % of total PAH. THC were 26 ± 9 % of total biogenic PAH, THP were 36 ± 7 %, and perylene was 38 ± 7 %. PAH distributions in a core from Franks Tract (FT), a former wetland that was converted to an agricultural tract in the late 1800s and flooded in 1938, were more variable. Surface sediments were dominated by pyrogenic PAH so that biogenic PAH were only ~30 % of total PAH. Deeper in the core, biogenic PAH constituted 60-93 % of total PAH; THC, THP and perylene were 31 ± 28 %, 24 ± 32 %, and 45 ± 36 % of biogenic PAH. At 100-103 cm depth, THP constituted 80 % of biogenic PAH and at 120-123 cm perylene was 95 % of biogenic PAH. Current concepts related to precursors and transformation processes responsible for the diagenetic generation of perylene and triterpenoid-derived PAH are discussed. Distributions of biogenic PAH in VC and FT sediments suggest that they may not form diagenetically within these sediments but rather might be delivered pre-formed from the river's watershed.

  1. Ammonia and methane dairy emissions in the San Joaquin Valley of California from individual feedlot to regional scale

    SciTech Connect

    Miller, David J.; Sun, Kang; Tao, Lei; Nowak, John B.; Liu, Zhen; Diskin, Glenn; Sasche, Glen; Beyersdorf, Andreas; Ferrare, Richard; Scarino, Amy Jo; Zondlo, Mark A.; Pan, Da

    2015-09-27

    Agricultural ammonia (NH3) emissions are highly uncertain, with high spatiotemporal variability and a lack of widespread in situ measurements. Regional NH3 emission estimates using mass balance or emission ratio approaches are uncertain due to variable NH3 sources and sinks as well as unknown plume correlations with other dairy source tracers. We characterize the spatial distributions of NH3 and methane (CH4) dairy plumes using in situ surface and airborne measurements in the Tulare dairy feedlot region of the San Joaquin Valley, California, during the NASA Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality 2013 field campaign. Surface NH3 and CH4 mixing ratios exhibit large variability with maxima localized downwind of individual dairy feedlots. The geometric mean NH3:CH4 enhancement ratio derived from surface measurements is 0.15 ± 0.03 ppmv ppmv–1. Individual dairy feedlots with spatially distinct NH3 and CH4 source pathways led to statistically significant correlations between NH3 and CH4 in 68% of the 69 downwind plumes sampled. At longer sampling distances, the NH3:CH4 enhancement ratio decreases 20–30%, suggesting the potential for NH3 deposition as a loss term for plumes within a few kilometers downwind of feedlots. Aircraft boundary layer transect measurements directly above surface mobile measurements in the dairy region show comparable gradients and geometric mean enhancement ratios within measurement uncertainties, even when including NH3 partitioning to submicron particles. Individual NH3 and CH4 plumes sampled at close proximity where losses are minimal are not necessarily correlated due to lack of mixing and distinct source pathways. As a result, our analyses have

  2. Biogenic polycyclic aromatic hydrocarbons in sediments of the San Joaquin River in California (USA), and current paradigms on their formation.

    PubMed

    Wakeham, Stuart G; Canuel, Elizabeth A

    2016-06-01

    Biogenic perylene and higher plant pentacyclic triterpenoid-derived alkylated and partially aromatized tetra- and pentacyclic derivatives of chrysene (3,4,7-trimethyl- and 3,3,7-trimethyl-1,2,3,4-tetrahydrochrysene, THC) and picene (1,2,9-trimethyl- and 2,2,9-trimethyl-1,2,3,4-tetrahydropicene, THP) were two- to four-fold more abundant than pyrogenic PAH in two sediment cores from the San Joaquin River in Northern California (USA). In a core from Venice Cut (VC), located in the river, PAH concentrations varied little downcore and the whole-core PAH concentration (biogenics + pyrogenics) was 250.6 ± 73.7 ng g(-1) dw; biogenic PAH constituted 67 ± 4 % of total PAH. THC were 26 ± 9 % of total biogenic PAH, THP were 36 ± 7 %, and perylene was 38 ± 7 %. PAH distributions in a core from Franks Tract (FT), a former wetland that was converted to an agricultural tract in the late 1800s and flooded in 1938, were more variable. Surface sediments were dominated by pyrogenic PAH so that biogenic PAH were only ~30 % of total PAH. Deeper in the core, biogenic PAH constituted 60-93 % of total PAH; THC, THP and perylene were 31 ± 28 %, 24 ± 32 %, and 45 ± 36 % of biogenic PAH. At 100-103 cm depth, THP constituted 80 % of biogenic PAH and at 120-123 cm perylene was 95 % of biogenic PAH. Current concepts related to precursors and transformation processes responsible for the diagenetic generation of perylene and triterpenoid-derived PAH are discussed. Distributions of biogenic PAH in VC and FT sediments suggest that they may not form diagenetically within these sediments but rather might be delivered pre-formed from the river's watershed. PMID:26403247

  3. SRTM Anaglyph with Landsat Overlay: Los Angeles to San Joaquin Valley, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    California's topography poses challenges for road builders. Northwest of Los Angeles, deformation of Earth's crust along the Pacific-North American crustal plate boundary has made transportation difficult. Direct connection between metropolitan Los Angeles (image lower left) and California's Central Valley (image top center) through the rugged terrain seen on the left side of this image was long avoided in favor of longer but easier paths. However, over the last century, three generations of roads have traversed this terrain. The first was 'The Ridge Route', a two-lane road, built in 1915, which followed long winding ridge lines that included 697curves. The second, built in 1933, was to become four-lane U.S. Highway 99. It generally followed widened canyon bottoms. The third is the current eight lane Interstate 5 freeway, built in the 1960s, which is generally notched into hillsides, but also includes a stretch of several miles where the two directions of travel are widely separated and driving is 'on the left', a rarity in the United States. Such an unusual highway configuration was necessary in order to optimize the road grades for uphill and downhill traffic in this topographically challenging setting.

    This anaglyph was generated by first draping a Landsat satellite image over a preliminary topographic map from the Shuttle Radar Topography Mission, then generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30 meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive.

    The elevation data used in this image was acquired by the Shuttle Radar Topography

  4. SRTM Stereo Pair with Landsat Overlay: Los Angeles to San Joaquin Valley, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    California's topography poses challenges for road builders. Northwest of Los Angeles, deformation of Earth's crust along the Pacific-North American crustal plate boundary has made transportation difficult. Direct connection between metropolitan Los Angeles (image lower left) and California's Central Valley (image top center) through the rugged terrain seen on the left side of this image was long avoided in favor of longer, but easier paths. However, over the last century, three generations of roads have traversed this terrain. The first was 'The Ridge Route', a two-lane road, built in 1915, which followed long winding ridge lines that included 697curves. The second, built in 1933, was to become four-lane U.S. Highway 99. It generally followed widened canyon bottoms. The third is the current eight lane Interstate 5 freeway, built in the 1960s, which is generally notched into hillsides, but also includes a stretch of several miles where the two directions of travel are widely separated and driving is 'on the left', a rarity in the United States. Such an unusual highway configuration was necessary in order to optimize the road grades for uphill and downhill traffic in this topographically challenging setting.

    This stereoscopic image was generated by draping a Landsat satellite image over a preliminary SRTM elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing), or by downloading and printing the image pair, and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30 meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive

  5. Transpressional piggyback basin in southern Diablo Range, California

    SciTech Connect

    Rentschler, M.S.

    1986-04-01

    Piggyback basins, as defined by G.G. Ori and P.F. Friend, are basins that are trapped when a thrust system propagates into its foredeep. Strata of the newly formed piggyback basin lap onto the growing outer thrust ridge that separates it from the foredeep. As thrust movement continues, piggyback basin fill passes from deep-water to shallow-water facies, and depositional sequences become progressively decoupled from those in the foredeep. Neogene structural evolution and depositional sequences in the southern Diablo Range between Panoche and Coalinga show a similar history. The southern Diablo Range consists of three structural domains: (1) a band along the San Andreas fault where the major structures are subparallel to the fault, (2) an intermediate zone where major fold axes are arranged en echelon, and (3) the eastern front of the range, which trends subparallel to the San Andreas fault. The en echelon folds of domain 2 suggest that it is a zone of dextral transpression. Northeast-directed thrust faults probably underlie domain 3, suggesting that the southern Diablo Range as a whole is a northeast-verging transpressional fold and thrust belt. Deposition occurred synchronously with transpression in the Vallecitos syncline of the southern Diablo Range. The Saucesian and Relizian Temblor Formation of the eastern syncline, as deep as upper bathyal, thins and laps onto flanking en echelon folds and onto the growing, intermittently exposed eastern range front. Marine deposition in the Vallecitos ended near the close of the Relizian; in contrast, marine conditions to the east in the San Joaquin basin persisted into the early Mohnian. A thick sequence of post-Luisian(.) lacustrine shales in the eastern Vallecitos suggests continued fold growth and increased isolation of the depocenter as a transpressional piggyback basin.

  6. Potential for Carbon Dioxide Sequestration and Enhanced Oil Recovery in the Vedder Formation, Greeley Field, San Joaquin Valley, California.

    NASA Astrophysics Data System (ADS)

    Jameson, S.

    2015-12-01

    Most scientists agree that greenhouse gases (GHG) such as carbon dioxide (CO2), Methane (CH4), and nitrous oxide (N2O) are major contributors to the global warming trend and climate change. One effort to mitigate anthropogenic sourced CO2 is through carbon capture and sequestration. Depleted oil and gas reservoirs due to their known trapping capability, in-place infrastructure, and proximity to carbon emission sources are good candidates for possible CO2 storage. The Vedder formation is one of three reservoirs identified in the San Joaquin Basin that meets standards for possible storage. An analysis of net fluid production data (produced minus injected) from discovery to the present is used to determine the reservoir volume available for CO2 storage. Data regarding reservoir pressure response to injection and production of fluids include final shut-in pressures from drill stem test, static bottom-hole pressure measurements from well completion histories, and idle well fluid level measurements for recent pressure data. Proprietary experimental pressure, volume and temperature data (PVT), gas oil ratios (GOR), well by well permeability, porosity, and oil gravity, and relative permeability and perforation intervals are used to create static and dynamic multiphase fluid flow models. All data collected was logged and entered into excel spreadsheets and mapping software to create subsurface structure, reservoir thickness and pressure maps, cross sections, production/injection charts on a well-by-well basis, and both static and dynamic flow models. This data is used to determine storage capacity and the amount of pressure variance within the field to determine how the reservoir will react to CO2 injection and to gain insight into the subsurface fluid movement of CO2. Results indicate a homogenous field with a storage capacity of approximately 26 Million Metric Tons of CO2. Analysis of production by stream and pressure change through time indicates a strong water drive

  7. Organic metamorphism in the California petroleum basins; Chapter B, Insights from extractable bitumen and saturated hydrocarbons

    USGS Publications Warehouse

    Price, Leigh C.

    2000-01-01

    Seventy-five shales from the Los Angeles, Ventura, and Southern San Joaquin Valley Basins were extracted and analyzed. Samples were chosen on the basis of ROCK-EVAL analyses of a much larger sample base. The samples ranged in burial temperatures from 40 ? to 220 ? C, and contained hydrogen-poor to hydrogen-rich organic matter (OM), based on OM visual typing and a correlation of elemental kerogen hydrogen to carbon ratios with ROCK-EVAL hydrogen indices. By extractable bitumen measurements, rocks with hydrogen- poor OM in the Los Angeles Basin began mainstage hydrocarbon (HC) generation by 90 ? C. The HC concentrations maximized by 165 ? C, and beyond 165 ? C, HC and bitumen concentrations and ROCK-EVAL hydrogen indices all began decreasing to low values reached by 220 ? C, where HC generation was largely complete. Rocks with hydrogen-poor OM in the Southern San Joaquin Valley Basin commenced mainstage HC generation at 135 ? C and HC concentrations maximized by 180 ? C. Above 180 ? C, HC and bitumen concentrations and ROCK-EVAL hydrogen indices all decreased to low values reached by 214 ? C, again the process of HC generation being largely complete. In both cases, bell-shaped HC-generation curves were present versus depth (burial temperature). Mainstage HC generation had not yet begun in Ventura Basin rocks with hydrogen-poor OM by 140 ? C. The apparent lower temperature for initiation of mainstage generation in the Los Angeles Basin is attributed to very recent cooling in that basin from meteoric-water flow. Thus, HC generation there most probably occurred at higher burial temperatures. In contrast, mainstage HC generation, and all aspects of organic metamorphism, were strongly suppressed in rocks with hydrogen-rich OM at temperatures as high as 198 ? C. For example, shales from the Wilmington field (Los Angeles Basin) from 180 ? to 198 ? C retained ROCK-EVAL hydrogen indices of 550- 700 and had saturated-HC coefficients of only 4-15 mg/g organic carbon. The rocks

  8. Groundwater quality in the San Francisco Bay groundwater basins, California

    USGS Publications Warehouse

    Parsons, Mary C.; Kulongoski, Justin T.; Belitz, Kenneth

    2013-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Selected groundwater basins of the San Francisco Bay area constitute one of the study units being evaluated.

  9. Groundwater quality in the South Coast Interior Basins, California

    USGS Publications Warehouse

    Parsons, Mary C.; Belitz, Kenneth

    2014-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s untreated groundwater quality and increases public access to groundwater-quality information. The South Coast Interior Basins constitute one of the study units being evaluated.

  10. Estimated agricultural ground-water pumpage in parts of the San Joaquin Valley, California, 1975-77

    USGS Publications Warehouse

    Mitten, Hugh T.

    1980-01-01

    The report lists agricultural groundwater pumpage for 1975-77 in parts of Merced, Madera, Fresno, Kings, Tulare, and Kern Counties, San Joaquin Valley, Calif. The method of estimating pumpage was based on electric-power consumption at the agricultural wells. (USGS)

  11. Biological assessment:Egeria densa control program for the Sacramento/San Joaquin River Delta of California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A detailed Biological Assessment was developed for the proposed Area wide Egeria densa Control Program to outline the procedures that will be used to control this submerged invasive aquatic plant in the Sacramento/ San Joaquin River Delta, and to help determine if this action is expected to threaten...

  12. California Basin Studies (CaBS). Final contract report

    SciTech Connect

    Gorsline, D.S.

    1991-12-31

    The California Continental Borderland`s present configuration dates from about 4 to 5 X 10{sup 6} years Before Present (B.P.) and is the most recent of several configurations of the southern California margin that have evolved after the North America Plate over-rode the East Pacific Rise about 30 X 10{sup 6} years ago. The present morphology is a series of two to three northwest-southeast trending rows of depressions separated by banks and insular ridges. Two inner basins, Santa Monica and San Pedro, have been the site for the Department of Energy-funded California Basin Study (CaBS) Santa Monica and San Pedro Basins contain post-Miocene sediment thicknesses of about 2.5 and 1.5 km respectively. During the Holocene (past 10,000 years) about 10-12 m have accumulated. The sediment entered the basin by one or a combination of processes including particle infall (mainly as bioaggregates) from surface waters, from nepheloid plumes (surface, mid-depths and near-bottom), from turbidity currents, mass movements, and to a very minor degree direct precipitation. In Santa Monica Basin, during the last century, particle infall and nepheloid plume transport have been the most common processes. The former dominates in the central basin floor in water depths from 900 to 945 m. where a characteristic silt-clay with a typical mean diameter of about 0.006 mm, phi standard deviation.

  13. Pragmatic consideration of geologic carbon storage design based upon historic pressure response to oil and gas production in the southern San Joaquin basin

    NASA Astrophysics Data System (ADS)

    Jordan, P. D.

    2015-12-01

    Annual CO2 emissions from large fixed sources in the southern San Joaquin Valley and vicinity in California are about 20 million metric tons per year (MMT/Y). Cumulative net fluid production due to oil and gas extracted from below the minimum depth for geologic carbon storage (taken as 1,500 m) was 1.4 billion m3 at reservoir conditions as of 2010. At an average CO2 storage density of 0.5 metric tons per m3, this implies 35 years of storage capacity at current emission rates just to refill the vacated volume, neglecting possible reservoir consolidation. However, the production occurred from over 300 pools. The production rate relative to average pressure decline in the more productive pools analyzed suggests they could receive about 2 MMT/Y raising the field average pressure to nearly the fracturing pressure. This would require well fields as extensive as those used for production, instead of the single to few wells per project typically envisioned. Even then, the actual allowable injection rate to the larger pools would be less than 2 MMT/Y in order to keep pressures at the injection well below the fracture pressure. This implies storing 20 MMT/Y would require developing storage operations in tens of pools with hundreds, if not over a thousand, wells. This utilization of one of the basins with the most storage capacity in the state would result in reducing the state's fixed source emissions by only one eighth relative to current emissions. The number of fields and wells involved in achieving this suggests a different strategy might provide more capacity at similar cost. Specifically, staging wells that initially produce water in the vicinity of fewer injection wells could result in both more storage. This water could be directed to a shallower zone, or supplied to the surface at a similar cost. The commencement of ocean water desalination in the state indicates the economics of water supply might support treating this water for beneficial use, particularly if it

  14. Produced water disposal in the southern San Joaquin Basin: a direct analog for brine leakage in response to carbon storage

    NASA Astrophysics Data System (ADS)

    Jordan, P. D.; Gillespie, J.

    2013-12-01

    Injection of CO2 during geologic carbon storage pressurizes reservoir fluid, which can cause its migration. Migration of saline water from the reservoir into underground sources of drinking water (USDW) via pathways such as permeable wells and faults is one concern. As of 2010, 2 billion cubic meters (MMMm3) of oil, 10 MMMm3 of water, and 400 MMMm3 of gas had been produced in the southern San Joaquin Valley. A considerable portion of the gas and a majority of the water were injected into production zones for pressure support, water flooding, or as steam for thermal recovery. However a portion of the produced water was disposed of by injection into zones without economic quantities of hydrocarbons, termed saline aquifers in the geologic carbon storage community. These zones often had the shallowest activity in a field, and so had no overlying pressure sink due to production and all oil and gas-related wells in the field encountered or passed through them. The subset of such zones at CO2 storage depths received disposed water volumes equivalent to tens of megatons (MT) of CO2 injected at overpressures of many MPa. For instance a water volume equivalent to over 20 MT of CO2 was injected at a depth of 900 m and an average wellhead pressure of 6 MPa in the Fruitvale oil field, which had almost a thousand wells. Use of USDW for irrigation and consumption is widespread in the area. An increase in total dissolved solids (TDS) in well water is acutely detectable either by taste or effect on crops. Consequently the produced water disposal injection in the southern San Joaquin Valley provides an analog for assessing the occurrence of water leakage impacts due to reservoir pressurization. Almost 230 articles regarding groundwater contamination published from 2000 to 2013 by The Bakersfield Californian, the main newspaper in the area, were assessed. These were written by 71 authors including 38 staff writers, covered 53 different types of facilities or activities that either

  15. Greenhouse gas sources in the southern San Joaquin Valley of California derived from Positive Matrix Factorization of CalNex 2010 observations

    NASA Astrophysics Data System (ADS)

    Guha, A.; Gentner, D. R.; Weber, R.; Baer, D. S.; Gardner, A.; Provencal, R. A.; Goldstein, A. H.

    2012-12-01

    Quantifying the contributions of methane (CH4) and nitrous oxide (N2O) emission from sources in the southern San Joaquin valley is important for validation of the statewide greenhouse gas (GHG) inventory and subsequent AB32 law (California Global Warming Solutions Act 2006) implementation. The state GHG inventory is largely based on activity data and emission factor based estimates. The "bottom-up" emission factors for CH4 and N2O have large uncertainties and there is a lack of adequate "top-down" measurements to characterize emission rates from sources. Emissions from non-CO2 GHG sources display spatial heterogeneity and temporal variability, and are thus, often, poorly characterized. The Central Valley of California is an agriculture and industry intensive region with large concentration of dairies, refineries and active oil fields which are known CH4 sources while agricultural soil management and vehicular combustion are known sources of N2O. In summer of 2010, GHG sources in the southern San Joaquin valley were investigated as part of the CalNex (California at the Nexus of Air Quality and Climate Change) campaign. Measurements of GHG gases (CO2, CH4, and N2O) and the combustion tracer CO were performed at the Bakersfield super-site over a period of six weeks using fast response lasers based on cavity enhanced absorption spectroscopy (LGR Inc. CA). Coincident measurements of hundreds of volatile organic compounds (VOCs) served as anthropogenic and biogenic tracers of the GHG sources at local and regional levels. We present the results of Positive Matrix Factorization (PMF) analysis applied to the GHGs, CO, and 60 VOCs to define dominant source emission profiles. Seven source factors were identified and used to attribute the contribution of regional sources to enhancements above the background. Dairy operations were found to be the largest CH4 source in the region with approximately 80% of the regional emissions attributed to the 'dairy' factor. Factors dominated

  16. Ground-water and surface-water-level data at Rindge Tract on the Stockton Deep Water Ship Channel, San Joaquin County, California, 1983-84

    USGS Publications Warehouse

    Pierce, Michael J.; Johnson, Karen L.

    1986-01-01

    The Sacramento-San Joaquin Delta is formed at the confluence of the two major rivers that drain the Central Valley of California. The Sacramento and San Joaquin Rivers and many interconnecting sloughs meandered back and forth across the tidelands, frequently overflowing their banks. Approximately 1 ,100 miles of levees were constructed to form about 60 tracts or islands that protect these lands from periodic flooding. The levees were constructed of sand, silt, and peat dredged from the channel bottom and are subject to erosion and failure. Owing to compaction, oxidation of the peat, and other related conditions, the islands are subsiding at rates of up to 0.25 ft/yr. The altitude of the land surface of the islands is often below sea level and below the surface water level in the channel. This condition causes stresses that may contribute to high groundwater levels and levee failure. The U.S. Army Corps of Engineers requested that the U.S. Geological Survey install and maintain continuous recorders to monitor water levels in each of four wells. Monitoring which began in July 1983 also provided data to show the relation between surface water levels in the channel and groundwater levels in the wells. Dredging began in the area of the Rindge Tract site during the latter part of July 1983. Water levels in all four wells dropped 1.5 to 2 ft between September 1983 and September 1984 and continued to drop thorough December 1984. (Lantz-PTT)

  17. Quaternary geology of Alameda County, and parts of Contra Costa, Santa Clara, San Mateo, San Francisco, Stanislaus, and San Joaquin counties, California: a digital database

    USGS Publications Warehouse

    Helley, E.J.; Graymer, R.W.

    1997-01-01

    Alameda County is located at the northern end of the Diablo Range of Central California. It is bounded on the north by the south flank of Mount Diablo, one of the highest peaks in the Bay Area, reaching an elevation of 1173 meters (3,849 ft). San Francisco Bay forms the western boundary, the San Joaquin Valley borders it on the east and an arbitrary line from the Bay into the Diablo Range forms the southern boundary. Alameda is one of the nine Bay Area counties tributary to San Francisco Bay. Most of the country is mountainous with steep rugged topography. Alameda County is covered by twenty-eight 7.5' topographic Quadrangles which are shown on the index map. The Quaternary deposits in Alameda County comprise three distinct depositional environments. One, forming a transgressive sequence of alluvial fan and fan-delta facies, is mapped in the western one-third of the county. The second, forming only alluvial fan facies, is mapped in the Livermore Valley and San Joaquin Valley in the eastern part of the county. The third, forming a combination of Eolian dune and estuarine facies, is restricted to the Alameda Island area in the northwestern corner of the county.

  18. Diet of the San Joaquin kit fox, Vulpes macrotis mutica, on Naval Petroleum Reserve No. 1, Kern County, California, 1980-1984

    SciTech Connect

    Scrivner, J.H.; O'Farrell, T.P.; Kato, T.T.; Johnson, M.K.

    1987-06-01

    A total of 1430 scats of the San Joaquin kit fox, Vulpes macrotis mutica, were collected between 1980 and 1984 on Naval Petroleum Reserve No. 1, Kern County, California, and analyzed to determine frequency of occurrence of prey items. Lagomorphs (black-tailed jackrabbits and desert cotton-tails) were the primary prey species (frequency of occurrence = 73%); while kangaroo rats (Dipodomys spp.) were the next most common (13%). The proportions of lagomorphs and kangaroo rats in the diet did not differ between sexes of foxes, periods of the year, or topography. Intensity of petroleum developments had no observable influence on food habits. There were annual differences in diet: proportions of lagomorphs declined, and proportions of kangaroo rats increased between 1980-1984. Changes in the frequency of occurrence of lagomorphs were significantly correlated with changes in their relative abundance in undeveloped-flat habitat. The frequency of occurrence of kangaroo rats was not significantly correlated with their relative abundance. San Joaquin kit fox on NPR-1 fed primarily on lagomorphs, and had the ability to sustain themselves on kangaroo rats and other secondary prey when their primary prey declined.

  19. Distribution and Joint Fish-Tag Survival of Juvenile Chinook Salmon Migrating through the Sacramento-San Joaquin River Delta, California, 2008

    USGS Publications Warehouse

    Holbrook, Christopher M.; Perry, Russell W.; Adams, Noah S.

    2009-01-01

    Acoustic telemetry was used to obtain the movement histories of 915 juvenile fall-run Chinook salmon (Oncorhynchus tshawytscha) through the lower San Joaquin River and Sacramento-San Joaquin Delta, California, in 2008. Data were analyzed within a release-recapture framework to estimate survival, route distribution, and detection probabilities among three migration pathways through the Delta. The pathways included the primary route through the San Joaquin River and two less direct routes (Old River and Turner Cut). Strong inferences about survival were limited by premature tag failure, but estimates of fish distribution among migration routes should be unaffected by tag failure. Based on tag failure tests (N = 66 tags), we estimated that only 55-78 percent of the tags used in this study were still functioning when the last fish was detected exiting the study area 15 days after release. Due to premature tag failure, our 'survival' estimates represent the joint probability that both the tag and fish survived, not just survival of fish. Low estimates of fish-tag survival could have been caused by fish mortality or fish travel times that exceeded the life of the tag, but we were unable to differentiate between the two. Fish-tag survival through the Delta (from Durham Ferry to Chipps Island by all routes) ranged from 0.05 +or- 0.01 (SE) to 0.06 +or- 0.01 between the two weekly release groups. Among the three migration routes, fish that remained in the San Joaquin River exhibited the highest joint fish-tag survival (0.09 +or- 0.02) in both weeks, but only 22-33 percent of tagged fish used this route, depending on the week of release. Only 4-10 percent (depending on week) of tagged fish traveled through Turner Cut, but no tagged fish that used this route were detected exiting the Delta. Most fish (63-68 percent, depending on week of release) migrated through Old River, but fish-tag survival through this route (0.05 +or- 0.01) was only about one-half that of fish that

  20. California's Adjudicated Groundwater Basins: History, Current Conditions, Potential Reforms

    NASA Astrophysics Data System (ADS)

    Langridge, R.; Brown, A.; Rudestam, K.; Conrad, E.

    2015-12-01

    Groundwater adjudications are one approach to managing a groundwater basin in California. While the 2014 Sustainable Groundwater Management Act (SGMA) established new management requirements for 127 high and medium priority groundwater basins, it exempted all 26 of the state's adjudicated groundwater basins from the Act. The State Water Resources Control Board prioritized the evaluation of these adjudicated basins to assist in aligning the processes and outcomes of adjudication with SGMA's goals for the sustainable management of groundwater. Working with the Board, our research evaluated the history and current condition of all of California's adjudicated basins along with potential future improvements to the adjudication process. Our presentation will provide a summary of our findings and highlight some successful features of the adjudication process along with the challenges adjudicated basins face to achieve long-term sustainable groundwater management. Our discussion will include a review of: whether most adjudications result in groundwater extractions at or near a basins' designated safe yield; whether overdraft conditions are reduced or eliminated over the long term; and the degree of collaboration and inclusion of community stakeholders in the adjudication process. In addition to this overview, we will highlight 3-4 basins with particularly interesting management challenges and solutions. For each of these basins, we will describe the problem that precipitated the need for the adjudication and how adjudication outcomes were influenced by: how the judgment defined and distributed water rights; the management structure and strategies to manage the basin; how safe yield and overdraft are defined and determined; and, importantly, the effectiveness of the adjudication in halting or reversing groundwater overdraft.

  1. Effects of two contrasting agricultural land uses on shallow groundwater quality in the San Joaquin Valley, California; design and preliminary interpretation

    USGS Publications Warehouse

    Dubrovsky, N.M.; Burow, Karen R.; Gronberg, Jo Ann M.

    1995-01-01

    From 1992 through 1994, the San Joaquin-Tulare Basins Study team of the USGS National Water Quality Assessment program investigated the occurrence and distribution of water quality con- stituents in shallow groundwater underlying two areas of different agricultural land uses: almond orchards and vineyards. The study was restricted to the alluvial fans of the eastern San Joaquin Valley, the area of most groundwater use in the valley. A geographic information system (GIS) was used to delineate the distribution of the two target land uses, to evaluate ancillary data, and to select candidate wells that fit prescribed criteria. Twenty domestic water supply wells were sampled in each of the two areas. In addition, pairs of observation wells were installed and sampled at five of the sites in each area to evaluate whether the water quality in the domestic wells reflects that of the shallow groundwater underlying the target land use. A preliminary evaluation of the results shows that nitrate concentrations in the shallow groundwater are significantly higher in the almond orchard areas than in the vineyard area (p=0.005). In contrast, concentrations of 1,2-dibromo-3-chloropropane (DBCP) were higher in the vineyard area than in the almond orchard area (p=0.032). The most frequently detected pesticides in groundwater underlying both areas were simazine, atrazine, and desethylatrazine (an atrazine degradation product). These observations are explained, in part, by differences in chemical application and hydrogeologic factors.

  2. Data for selected pesticides and volatile organic compounds for wells in the western San Joaquin Valley, California, February to July 1985

    USGS Publications Warehouse

    Neil, J.M.

    1987-01-01

    During February to July 1985, water samples were collected from 55 wells in the western San Joaquin Valley, California, for chemical analysis to determine if 20 selected pesticides and 26 volatile organic compounds were present. Twenty-six of the sampled wells are completed in the shallow unconfined regional aquifer and 29 wells are completed in the deep confined regional aquifer. Water from six of the sampled wells, four of which are completed in the shallow unconfined aquifer, contained detectable levels of the pesticides or volatile organic compounds. Four samples contained a single pesticide, one sample contained two pesticides, and one sample contained 5.9 microgm/liter of toluene, a volatile organic compound. Five of the six pesticides detected were triazine herbicides; the maximum concentration was 0.2 microgm/liter. Four samples with detectable concentrations of triazine herbicides are from wells used for domestic water supply; however, drinking-water standards have not been established for triazine herbicides. (USGS)

  3. Organic metamorphism in the California petroleum basins; Chapter A, Rock-Eval and vitrinite reflectance

    USGS Publications Warehouse

    Price, Leigh C.; Pawlewicz, Mark J.; Daws, Ted A.

    1999-01-01

    The results of ROCK-EVAL and vitrinite reflectance analyses of a large sample base from more than 70 wells located in three oil-rich California petroleum basins are reported. The cores from these wells have a wide range of present-day burial temperatures (40 ? to 220 ? C). The rocks in these basins were deposited under highly variable conditions, sometimes resulting in substantially different organic matter (OM) types in rocks tens of meters vertically apart from each other in one well. The kinetic response of these different OM types to equivalent wellknown burial histories is a pivotal point of this study. In the Los Angeles and Ventura Basins, rock organic-richness significantly increased with depth, as did kerogen hydrogen content, and the percentage of fine-grained versus coarsegrained rocks. The shales in these basins are perceived as containing primarily hydrogen-rich amorphous OM. In actuality, the shallowest 2,000 to 3,000 m of rocks in the basins, and at least the upper 6,000 m of rocks in parts of the Los Angeles Basin central syncline, are dominated by type III/IV OM. In the Los Angeles Basin, mainstage hydrocarbon (HC) generation commences in the type III/IV OM at present-day burial temperatures of 85 ? to 110 ? C, most likely around 100 ? C, and is largely complete by 220 ? C. In the Southern San Joaquin Valley Basin, mainstage HC generation commences in type III/IV OM at 150 ? C and is also largely complete by 220 ? C. In the Ventura Basin, mainstage HC generation commences above 140 ? C in type III/IV OM. The apparent lower temperatures for commencement of HC generation in the Los Angeles Basin are attributed to the fact that parts of the basin were cooled from maximal burial temperatures by increased meteoric water flows during the last glaciations. All aspects of organic metamorphism, including mainstage HC generation, are strongly suppressed in rocks with hydrogenrich OM in these basins. For example, ROCK-EVAL data suggest that mainstage HC

  4. Numerical simulation of ground-water flow in the central part of the western San Joaquin Valley, California

    USGS Publications Warehouse

    Belitz, Kenneth; Phillips, Steven P.; Gronberg, Jo Ann M.

    1993-01-01

    The occurrence of selenium in agricultural drain water in the central part of the western San Joaquin Valley, California, has focused concern on strategies for managing shallow, saline ground water. To assess alternatives to agricultural drains, a three-dimensional, finite-difference numerical model of the regional groundwater flow system was developed. This report documents the mathematical approach used to model the flow system, the data base on which the model is based, and the methods used to calibrate the model. The 550-square-mile study area includes parts of the Panoche Creek alluvial fan and parts of the Little Panoche Creek and Cantua Creek alluvial fans. The model simulates transient flow in the semiconfined and confined zones above and below the Corcoran Clay Member of the Tulare Formation of Pleistocene age. The model incorporates areally distributed ground-water recharge, areally and vertically distributed pumping, regional-collector drains in the Wesdands Water District (operative from 1980 to 1985), on-farm drains in parts of the Panoche, Broadview, and Firebaugh Water Districts, and bare-soil evaporation (which occurs if the water table is within 7 feet of land surface). The model also incorporates texture-based estimates of hydraulic conductivity, where texture is defined as the fraction of coarse-grained deposits present in a given subsurface interval. The numerical model was developed using hydrologic data from 1972 to 1988. Most of the parameters incorporated into the model were evaluated independently of the model, including system geometry, the distribution of texture, the altitudes of the water table and potentiometric surface of the confined zone in 1972 (initial condition), the hydraulic conductivity of coarse-grained deposits derived from the Coast Ranges, the hydraulic conductivity of coarse-grained deposits derived from the Sierra Nevada, specific storage, recharge, pumping, and parameters needed to incorporate drains and bare

  5. Wildlife studies of Site 300 emphasizing rare and endangered species: Lawrence Livermore National Laboratory, San Joaquin County, California

    SciTech Connect

    Orloff, S.

    1986-11-01

    The primary purpose of this project was to determine the presence and status of any endangered, threatened, fully protected, or otherwise sensitive wildlife species on Site 300 that might be affected by Site operations and developments. We directed our studies mainly toward the federally endangered San Joaquin kit fox (Vulpes macrotis mutica), but also toward another 15 special status species that potentially occur on site, including the state threatened Alameda striped racer (Masticophis lateralis euryxanthus).

  6. Benthic macroinvertebrate assemblages and their relations with environmental variables in the Sacramento and San Joaquin River drainages, California, 1993-1997

    USGS Publications Warehouse

    Brown, Larry R.; May, Jason T.

    2000-01-01

    Data were collected in the San Joaquin and Sacramento river drainages to evaluate associations between macroinvertebrate assemblages and environmental variables as part of the National Water-Quality Assessment Program of the U.S. Geological Survey. Samples were collected at 53 sites from 1993 to 1995 in the San Joaquin River drainage and in 1996 and 1997 in the Sacramento River drainage. Macroinvertebrates were collected from riffles or from large woody debris (snags) when riffles were absent. Macroinvertebrate taxa were aggregated to the family (or higher) level of taxonomic organization, resulting in 81 taxa for analyses. Only the 50 most common taxa were used for two-way indicator species analysis (TWINSPAN) and canonical correspondence analysis. TWINSPAN analysis defined four groups of riffle samples and four groups of snag samples based on macroinvertebrate assemblages. Analysis of variance identified differences in environmental and biotic characteristics of the groups. These results combined with the results of canonical correspondence analysis indicated that patterns in riffle sample assemblage structure were highly correlated with a gradient in physical and chemical conditions associated with elevation. The results also suggested that flow regulation associated with large storage reservoirs has negative effects on the total number of taxa and density of macroinvertebrates below foothill dams. Analysis of the snag samples showed that, although elevation remained a significant variable, mean dominant substrate size, gradient, specific conductance, water temperature, percentage of the basin in agricultural land use, and percentage of the basin in combined agricultural and urban land uses were more important factors in explaining assemblage structure. Macroinvertebrate assemblages on snags may be useful in family level bioassessments of environmental conditions in valley floor habitats. In the Sierra Nevada and its foothills, the strong influence of elevation

  7. Precipitation-runoff processes in the Feather River basin, northeastern California, and streamflow predictability, water years 1971-97

    USGS Publications Warehouse

    Koczot, Kathryn M.; Jeton, Anne E.; McGurk, Bruce; Dettinger, Michael D.

    2005-01-01

    Precipitation-runoff processes in the Feather River Basin of northern California determine short- and long-term streamflow variations that are of considerable local, State, and Federal concern. The river is an important source of water and power for the region. The basin forms the headwaters of the California State Water Project. Lake Oroville, at the outlet of the basin, plays an important role in flood management, water quality, and the health of fisheries as far downstream as the Sacramento-San Joaquin Delta. Existing models of the river simulate streamflow in hourly, daily, weekly, and seasonal time steps, but cannot adequately describe responses to climate and land-use variations in the basin. New spatially detailed precipitation-runoff models of the basin have been developed to simulate responses to climate and land-use variations at a higher spatial resolution than was available previously. This report characterizes daily rainfall, snowpack evolution, runoff, water and energy balances, and streamflow variations from, and within, the basin above Lake Oroville. The new model's ability to predict streamflow is assessed. The Feather River Basin sits astride geologic, topographic, and climatic divides that establish a hydrologic character that is relatively unusual among the basins of the Sierra Nevada. It straddles a north-south geologic transition in the Sierra Nevada between the granitic bedrock that underlies and forms most of the central and southern Sierra Nevada and volcanic bedrock that underlies the northernmost parts of the range (and basin). Because volcanic bedrock generally is more permeable than granitic, the northern, volcanic parts of the basin contribute larger fractions of ground-water flow to streams than do the southern, granitic parts of the basin. The Sierra Nevada topographic divide forms a high altitude ridgeline running northwest to southeast through the middle of the basin. The topography east of this ridgeline is more like the rain

  8. Comparing Groundwater Contamination Vulnerability in Large, Urbanized Basins of California

    NASA Astrophysics Data System (ADS)

    Moran, J. E.; Hudson, G. B.; Leif, R.; Eaton, G. F.

    2002-12-01

    We have sampled over 700 public drinking water wells as part of a study to assess relative contamination susceptibility of the major groundwater basins in California. The parameters used to rank wells according to vulnerability are groundwater age dates (using the tritium-3helium method), stable isotopes of the water molecule (for water source determination), and occurrence of low level Volatile Organic Compounds (VOCs). Long-screened production wells supply clean, high quality samples, and sample the resource that is being used. However, the groundwater age distribution from production wells may be quite broad, and comparisons to the predicted initial tritium value for the measured mean age, along with analysis of radiogenic 4Helium are used to de-convolute the mixed age. Results from the Los Angeles and Orange County Basins, and Santa Clara Valley, will be presented. A large volume of both imported and locally captured water is artificially recharged in these intensively managed basins. An effective confining unit in the Santa Clara Valley basin prevents widespread vertical transport of contaminants down to drinking water wells. In the southern California basins, groundwater age and the frequency of occurrence of low-level VOCs are spatially correlated, with more recently recharged water likely to have VOC detections. 'Pre-modern' water is nearly always free of VOCs, except when a suspected 'short circuit', (e.g., loss of integrity in well casing) allows near surface contamination to reach 'old' water. Methyl-tertiary-Butyl Ether (MTBE) can be a useful time marker in groundwater basins, with water recharged after the 1980's showing traces of MTBE. Water resource managers can use these vulnerability assessments to focus monitoring efforts, site new wells, plan land use, and evaluate remediation activities. This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under

  9. Effect of Microclimates on Evapotranspiration Rates, Energy Balance, and Water Use Estimation in the Sacramento-San Joaquin Delta, California, USA

    NASA Astrophysics Data System (ADS)

    Anderson, F.; Bergamaschi, B. A.; Von Dessonneck, T.; Keating, K.; Verfaillie, J. G.; Hatala, J.; Knox, S.; Baldocchi, D. D.; Fujii, R.

    2012-12-01

    Research involving the atmospheric-surface exchange of greenhouse gases in California's Sacramento-San Joaquin Delta (Delta) has primarily focused on peat oxidation and resulting subsidence from over a century of agricultural land management practices. Currently there is a network of flux towers used to investigate management plans to mitigate subsidence and, in some cases, increase land elevation. Nevertheless, Delta land elevations have decreased by over 10m and water resources are largely allocated to maintain levee stability and prevent salt-water intrusion into the Delta, the source of fresh water to over to 22 million Southern Californians. These water allocations are potentially modeled using outdated evapotranspiration (ET) rates. The network of flux towers in the Delta has provided researchers the ability to calculate the atmospheric exchange of water vapor from a variety of land surfaces. From these results, ET rates are found to be reduced compared to the same land surface measurements outside the Delta region and are most likely due to the Delta's unique microclimate. In the summertime, this area is an oasis of cool, moist air (Delta Breeze) when compared to other areas in the Sacramento and San Joaquin Valleys, where daytime high temperatures are often 5 to 10°C higher. The air mass that influences the delta region is formed from a complex interaction between the sub-tropical Pacific High pressure system, upwelling along the California coast, upper atmospheric westerlies, and the unique break in the California Coastal range (i.e. the San Francisco Bay). In general, ET rates are lower than the surrounding geography, as the onset of the "Delta Breeze" occurs in the afternoons, increasing the sensible heat exchange and reducing the energy available for latent heat. Current ET rates were calculated using eddy covariance flux systems for a variety of land uses within the Delta: agricultural crops (corn, rice, alfalfa, and irrigated pasture), a newly

  10. Environmental factors associated with long-term changes in chlorophyll concentration in the Sacramento-San Joaquin delta and Suisun Bay, California

    SciTech Connect

    Lehman, P.W. )

    1992-09-01

    Long-term changes in chlorophyll concentration were predicted from environmental variables using Box-Jenkins transfer function models for the Sacramento and San Joaquin rivers and Suisun Bay. The indication that oceanic phytoplankton biomass for the California regions is associated with climatic phenomena produced by El Nino and the Southern Oscillation (ENSO) was one of several factors used to standardize the dataset. Data used for the analyses were collected continuously on a semimonthly or monthly basis over the 17-yr period between 1971 and 1987. Groups of highly correlated environmental variables were summarized along three environmental axes using principal component analysis. The first environmental axis summarized river flow and specific conductance. The second environmental axis summarized water transparency and the third environmental axis summarized air and water temperature. Chlorophyll concentration was significantly cross-correlated with environmental axes and individual environmental variables. Transfer function models developed to describe changes in chlorophyll concentration over time were characterized by lag responses and described between 41% and 51% of the data variation. Significant cross-correlations between environmental axes and the California climate index (CA SLP) were used to develop a conceptual model of the link between regional climate and estuarine production. 50 refs., 5 figs.

  11. Character and evolution of the ground-water flow system in the central part of the western San Joaquin Valley, California

    SciTech Connect

    Belitz, K.

    1988-01-01

    The occurrence of selenium in agricultural drain water derived from the western San Joaquin Valley, California, has focused concern on the groundwater flow system of the western valley. Previous work and recently collected texture and water level data were used to evaluate the character and evolution of the regional groundwater flow system in the central part of the western valley, with particular emphasis on the deposits overlying the Corcoran Clay Member of the Tulane Formation. The development of irrigated agriculture in the central part of the western valley has significantly altered the flow system. Percolation of irrigation water past crop roots has caused a rise in the altitude of the water table in mid-fan and distal-fan areas. Pumpage of groundwater from wells has caused a lowering of the water table beneath parts of the fanheads and a lowering of the potentiometric surface of the confined zone over much of the western valley. The combination of percolation and pumpage has resulted in development of a large downward hydraulic head gradient in the semi-confined zone and has created a groundwater divide along the western margin of the valley. Surface water deliveries from the California Aqueduct have allowed a decrease in pumpage and a consequent recovery in hydraulic head throughout the system. 30 refs., 24 figs.

  12. Prey abundance and food habits of San Joaquin kit fox (Vulpes velox macrotis) at Camp Roberts Army National Guard Training site, California

    SciTech Connect

    Logan, C.G.; Berry, W.H.; Standley, W.G.; Kato, T.T.

    1992-09-01

    Prey abundance and food habits of the San Joaquin kit fox (Vulpes velox macrotis) were investigated at Camp Roberts Army National Guard Training site, California, from November 1988 through September 1991. The sampling methods initially used to assess abundance of prey species resulted in indices too low to be of value. Because of this, the relationship between relative abundance and frequency of occurrence of prey species could not be examined. Six hundred forty-nine fecal samples (scats) were analyzed to determine the frequency of occurrence of prey items. California ground squirrels (Spermophilus beecheyi) and lagomorphs primarily desert cottontails (Sylvilagus audubonii) and black-tailed jackrabbits (Lepus californicus) were the most frequently occurring mammalian prey items found in scats (35.0% and 12.2%, respectively). The frequency of occurrence of ground squirrel (but not lagomorph) remains in scats collected from juveniles was significantly higher than in scats collected from adults. The frequency of occurrence of ground squirrel and lagomorph remains in scats collected from males was not significant different than in scats collected from females. There were significant variations in the frequency of ground squirrel remains among the years 1989--1991 and during the June--November periods between 1989 and 1990 and between 1990 and 1991. The frequency of lagomorph remains collected during the June--November period differed significantly among the years 1989--1991 and between 1990 and 1991.

  13. Implications for future survival of delta smelt from four climate change scenarios for the Sacramento–San Joaquin Delta, California

    USGS Publications Warehouse

    Brown, Larry R.; Bennett, William A.; Wagner, R. Wayne; Morgan-King, Tara; Knowles, Noah; Feyrer, Frederick; Schoellhamer, David H.; Stacey, Mark T.; Dettinger, Mike

    2013-01-01

    Changes in the position of the low salinity zone, a habitat suitability index, turbidity, and water temperature modeled from four 100-year scenarios of climate change were evaluated for possible effects on delta smelt Hypomesus transpacificus, which is endemic to the Sacramento–San Joaquin Delta. The persistence of delta smelt in much of its current habitat into the next century appears uncertain. By mid-century, the position of the low salinity zone in the fall and the habitat suitability index converged on values only observed during the worst droughts of the baseline period (1969–2000). Projected higher water temperatures would render waters historically inhabited by delta smelt near the confluence of the Sacramento and San Joaquin rivers largely uninhabitable. However, the scenarios of climate change are based on assumptions that require caution in the interpretation of the results. Projections like these provide managers with a useful tool for anticipating long-term challenges to managing fish populations and possibly adapting water management to ameliorate those challenges.

  14. San Joaquin kit fox (Vulpes velox macrotis) program, Camp Roberts, California. Progress report, fiscal years 1991--1992

    SciTech Connect

    Not Available

    1992-10-01

    Military training activities, new construction projects, and routine repair and maintenance activities conducted at Camp Roberts could adversely affect the endangered San Joaquin kit fox population. The Endangered Species Act of 1973 (as amended) states that all Federal agencies are to ensure that any actions authorized, funded, or carried out by the agency are not likely to have any detrimental effects on endangered species or their habitat. The major objective of the Camp Roberts Environmental Studies Program was to prepare a comprehensive Biological Assessment of the effects of all NGB-authorized activities on San Joaquin kit fox (military training, anticipated construction projects, repair and maintenance activities, and all NGB-authorized non-military activities such as a hunting and fishing program, grazing leases, etc.). The program also provided NGB with the scientific expertise necessary to ensure compliance with the Endangered Species Act. The objective of this report is to summarize the progress and results of the Environmental Studies Program during Fiscal Years 1991 and 1992 (FY91/92).

  15. Groundwater quality in the Coastal Los Angeles Basin, California

    USGS Publications Warehouse

    Fram, Miranda S.; Belitz, Kenneth

    2012-01-01

    The Coastal Los Angeles Basin study unit is approximately 860 square miles and consists of the Santa Monica, Hollywood, West Coast, Central, and Orange County Coastal Plain groundwater basins (California Department of Water Resources, 2003). The basins are bounded in part by faults, including the Newport-Inglewood fault zone, and are filled with Holocene-, Pleistocene-, and Pliocene-age marine and alluvial sediments. The Central Basin and Orange County Coastal Plain are divided into a forebay zone on the northeast and a pressure zone in the center and southwest. The forebays consist of unconsolidated coarser sediment, and the pressure zones are characterized by lenses of coarser sediment divided into confined to semi-confined aquifers by lenses of finer sediments. The primary aquifer system in the study unit is defined as those parts of the aquifer system corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database of public-supply wells. The majority of public-supply wells are drilled to depths of 510 to 1,145 feet, consist of solid casing from the land surface to a depth of about 300 to 510 feet, and are perforated below the solid casing. Water quality in the primary aquifer system may differ from that in the shallower and deeper parts of the aquifer systems.

  16. Groundwater quality in the Colorado River basins, California

    USGS Publications Warehouse

    Dawson, Barbara J. Milby; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Four groundwater basins along the Colorado River make up one of the study areas being evaluated. The Colorado River study area is approximately 884 square miles (2,290 square kilometers) and includes the Needles, Palo Verde Mesa, Palo Verde Valley, and Yuma groundwater basins (California Department of Water Resources, 2003). The Colorado River study area has an arid climate and is part of the Sonoran Desert. Average annual rainfall is about 3 inches (8 centimeters). Land use in the study area is approximately 47 percent (%) natural (mostly shrubland), 47% agricultural, and 6% urban. The primary crops are pasture and hay. The largest urban area is the city of Blythe (2010 population of 21,000). Groundwater in these basins is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay deposited by the Colorado River or derived from surrounding mountains. The primary aquifers in the Colorado River study area are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells in the Colorado River basins are completed to depths between 230 and 460 feet (70 to 140 meters), consist of solid casing from the land surface to a depth of 130 of 390 feet (39 to 119 meters), and are screened or perforated below the solid casing. The main source of recharge to the groundwater systems in the Needles, Palo Verde Mesa, and Palo Verde Valley basins is the Colorado River; in the Yuma basin, the main source of recharge is from

  17. Bouse Formation in the Bristol basin near Amboy, California, USA

    USGS Publications Warehouse

    Miller, David M.; Reynolds, Robert E.; Bright, Jordan E.; Starratt, Scott W.

    2014-01-01

    Limestone beds underlain and overlain by alluvial fan conglomerate near Amboy, California, are very similar in many respects to parts of the Bouse Formation, suggesting that an arm of the Pliocene Bouse water body extended across a wide part of the southern Mojave Desert. The deposits are north of the town of Amboy at and below an elevation of 290 m, along the northern piedmont of the Bristol “dry” Lake basin. The Amboy outcrops contain the Lawlor Tuff (4.83 Ma), which is also found in an outcrop of the Bouse Formation in the Blythe basin near Buzzards Peak in the Chocolate Mountains, 180 km southeast of Amboy. Bouse exposures near Amboy are ∼3.4 m thick, white, distinctly bedded, with limestone and calcareous sandstone as well as stromatolite mounds; we interpret these as nearshore deposits. The Bouse at Amboy contains ostracodes, diatoms, and mollusks that indicate saline lake or estuarine environments with an admixture of fresh-water forms. Along with wading bird tracks and a spine from a marine fish, these fossils suggest that the deposits formed in saline waters near a fresh-water source such as a perennial stream. Beds of the outcrop dip southward and are 113 m above the surface of Bristol Playa, where similar age sediments are buried 270+ m deep, indicating significant faulting and vertical tectonics in this part of the Eastern California Shear Zone during the past 5 m.y. Confirmation of the Bouse Formation at Amboy strengthens previous assignments to the Bouse Formation for mudstones in driller logs at Danby “dry” Lake, California, and suggests that areally extensive arms of the Bouse water body were west of the Blythe basin. The Bristol basin arm of the lower Bouse basin probably was restricted from the main water body by narrow passages, but Bouse sediment there is similar to that in the Blythe basin, suggesting generally similar water chemistry and environmental conditions. Examining the degree to which Bouse deposits in the western arms

  18. Distribution and status of the endangered San Joaquin kit fox, Vulpes macrotis mutica, on Fort Hunter Liggett and Camp Roberts, California

    SciTech Connect

    O'Farrell, T.P.; Berry, W.H.; Warrick, G.D.

    1987-10-01

    The distribution and status of the endangered San Joaquin kit fox (Vulpes macrotis mutica) was determined for Fort Hunter Liggett and Camp Roberts, California, using canid scent station transects, spotlight surveys, and live-trapping and radiotelemetry. At Fort Hunter Liggett kit foxes were distributed only in a narrow corridor along the San Antonio River from the Mission to the B-9 Tank Range. Three other areas of potentially suitable habitat were observed but no evidence of kit foxes was obtained in them. The species was widely distributed on Camp Roberts and they appeared to be common to abundant over large areas, including the Main Garrison. Characteristics of dens used by radiocollared foxes were seldom consistent with previously published descriptions because many dens were enlarged burrows of California ground squirrels (Spermophilus beecheyi). California ground squirrels were the most frequently occurring prey remains (48.2%) in scats collected at Camp Roberts; remains of insects were observed in 25.9% of the scats. Frequencies of occurrence of lagomorphs (5.9%) and kangaroo rats (Dipodomys sp.) (l.2%), preferred kit fox prey elsewhere, were unexpectedly low. The proportions of prey items in scats varied between locations. Vehicles killed 22% of the foxes found dead, 11% were killed by predators, 1 fox became trapped in a verticle pipe and died, and a cause could not be determined for 56% of the deaths. Evidence showing that foxes bred successfully was gathered for both posts. Recommendations were made to restrict aerial applications of rodenticides to those areas outside the known distributions of the kit fox and a 1.6-km buffer, and to implement a program to monitor effects on nontarget species. 25 refs., 21 figs., 15 tabs.

  19. Nature of basement rocks under the Los Angeles Basin, southern California, as inferred from aeromagnetic data

    SciTech Connect

    Langenheim, V.E.; Jachens, R.C. . Branch of Geophysics)

    1993-04-01

    The Los Angeles (L.A.) Basin, one of the world's richest oil-producing basins, is underlain by at least two basement assemblages. Because the thickness of the basin sediments reaches up to a minimum of 10 km, magnetic data allow a more regional view of the juxtaposition and nature of basement rocks than do available drill-hole data. Aeromagnetic data indicate that a zone of magnetic rocks extends along the coast east of the Newport-Inglewood fault zone from the San Joaquin Hills northwest to the Santa Monica Mountains. The magnetic highs produced by these rocks appear to be a continuation of intense magnetic highs that are present over exposed rocks of the Peninsular Ranges batholith to the southwest. Modeling of a 180 nT magnetic high over the San Joaquin Hills indicates that the tops of two concealed magnetic sources are at about 1.5 km and 4.5 km depth, which places these bodies at or beneath the basement surface. Modeling of magnetic highs over the exposed batholithic rocks to the south reveals a source with similar geometry and magnetic properties. The associated gravity highs of the San Joaquin Hills suggest that the probable lithology of these concealed magnetic bodies is a dense crystalline rock such as gabbro.

  20. Feasibility study of the use of the acoustic velocity meter for measurement of net outflow from the Sacramento-San Joaquin Delta in California

    USGS Publications Warehouse

    Smith, Winchell

    1969-01-01

    A reliable measure of the fresh-water outflow from the Sacramento-San Joaquin delta is needed for the operation of the California Water Project and for the evaluation of the interrelated water problems of the delta and San Francisco Bay regions. The Chipps Island channel, immediately downstream from the confluence of the Sacramento and San Joaquin Rivers, is the most promising site for this flow measurement, but the conventional techniques used for evaluating steady flows cannot be employed there because the channel reach is in the tidal zone, and reversals of flow occur during each tidal cycle. Net outflows, which may be as little-as 2,000 cubic feet per second must necessarily be computed as the difference between the large ebbflow and floodflow volumes that move back and forth between the delta region and San Francisco Bay. Discharges during peak periods of the ebb and flood tidal cycles may exceed 300,000 cubic feet per second. In consequence, a very high degree of precision must be maintained in the gross flow measurements if meaningful computations of net outflow are to be made. This report evaluates the probable accuracies that might be achieved by use of an AVM (acoustic velocity meter), a device which measures the stream velocity along a diagonal line across the channel. The study indicates that this line velocity will provide a stable index of the mean velocity in the channel and that such an index could be used as a primary parameter for the computation of discharge. Therefore, net outflows probably could be computed with the required accuracy by the use of such a device. The significant factors controlling the precision of measurement would be the stability of the channel geometry and streamline orientation, the precision with which the current-meter measurements needed for calibration of the system could be made, the instrumental calibration stability of the AVM system, and the length of period over which net outflows were computed. The AVM system

  1. Peat formation processes through the millennia in tidal marshes of the Sacramento-San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, Judith Z.

    2011-01-01

    The purpose of this study was to determine peat formation processes throughout the millennia in four tidal marshes in the Sacramento-San Joaquin Delta. Peat cores collected at each site were analyzed for bulk density, loss on ignition, and percent organic carbon. Core data and spline fit age-depth models were used to estimate inorganic sedimentation, organic accumulation, and carbon sequestration rates in the marshes. Bulk density and percent organic matter content of peat fluctuated through time at all sites, suggesting that peat formation processes are dynamic and responsive to watershed conditions. The balance between inorganic sedimentation and organic accumulation at the sites also varied through time, indicating that marshes may rely more strongly on either norganic or organic matter for peat formation at particular times in their existence. Mean carbon sequestration rates found in this study (0.38-0.79 Mg C ha-1 year-1) were similar to other long-term estimates for temperate peatlands.

  2. Determination of bench-mark elevations at Bethel Island and vicinity, Contra Costa and San Joaquin counties, California, 1987

    USGS Publications Warehouse

    Blodgett, J.C.; Ikehara, M.E.; McCaffrey, William F.

    1988-01-01

    Elevations of 49 bench marks in the southwestern part of the Sacramento-San Joaquin River Delta were determined during October and November 1987. A total of 58 miles of level lines were run in the vicinity of Bethel Island and the community of Discovery Bay. The datum of these surveys is based on a National Geodetic Survey bench mark T934 situated on bedrock 10.5 mi east of Mount Diablo and near Marsh Creek Reservoir. The accuracy of these levels, based on National Geodetic Survey standards, was of first, second, and third order, depending on the various segments surveyed. Several bench marks were noted as possibly being stable, but most show evidence of instability. (USGS)

  3. Source, Distribution, and Management of Arsenic in Water from Wells, Eastern San Joaquin Ground-Water Subbasin, California

    USGS Publications Warehouse

    Izbicki, John A.; Stamos, Christina L.; Metzger, Loren F.; Halford, Keith J.; Kulp, Thomas R.; Bennett, George L.

    2008-01-01

    Between 1974 and 2001 water from as many as one-third of wells in the Eastern San Joaquin Ground Water Subbasin, about 80 miles east of San Francisco, had arsenic concentrations greater than the U.S. Environmental Protection Agency Maximum Contaminant Level (MCL) for arsenic of 10 micrograms per liter (ug/L). Water from some wells had arsenic concentrations greater than 60 ug/L. The sources of arsenic in the study area include (1) weathering of arsenic bearing minerals, (2) desorption of arsenic associated with iron and manganese oxide coatings on the surfaces of mineral grains at pH's greater than 7.6, and (3) release of arsenic through reductive dissolution of iron and manganese oxide coatings in the absence of oxygen. Reductive dissolution is responsible for arsenic concentrations greater than the MCL. The distribution of arsenic varied areally and with depth. Concentrations were lower near ground-water recharge areas along the foothills of the Sierra Nevada; whereas, concentrations were higher in deeper wells at the downgradient end of long flow paths near the margin of the San Joaquin Delta (fig. 1). Management opportunities to control high arsenic concentrations are present because water from the surface discharge of wells is a mixture of water from the different depths penetrated by wells. On the basis of well-bore flow and depth-dependent water-quality data collected as part of this study, the screened interval of a public-supply well having arsenic concentrations that occasionally exceed the MCL was modified to reduce arsenic concentrations in the surface discharge of the well. Arsenic concentrations from the modified well were about 7 ug/L. Simulations of ground-water flow to the well showed that although upward movement of high-arsenic water from depth within the aquifer occurred, arsenic concentrations from the well are expected to remain below the MCL.

  4. Tectonic evolution of Honey Lake basin, northeastern California

    SciTech Connect

    Wagner, D.L. ); Saucedo, G.J. ); Grose, T.L.T. . Dept. of Geology and Geological Engineering)

    1993-04-01

    New geologic mapping in northeastern California provides additional data on the age and tectonic evolution of the Honey Lake Basin. Rhylitic ash flow tuffs of latest Oligocene to early Miocene age (30 to 22 Ma) occur in the Fort Sage Mountains and in the Sierra Nevada but are not apparent in wells drilled in the Honey Lake basin. Though other interpretations can be made, the authors take this as evidence that the basin did not exist at that time. Volcanic rocks as old as 12 Ma do occur in the basin indicating initiation in mid-Miocene time probably as a graben due to block faulting. Syntectonic andesitic and basaltic volcanism occurred along faults bounding the Sierra Nevada block at 9 to 10 Ma. Lava issuing from these fractures flowed westward along Tertiary drainages indicating that the Sierran block had been uplifted and tilted westward. Andesites erupted during this time north and east of the basin are lithologically distinct from Sierran andesites. Strike-slip faulting began to dominate the tectonic setting of the region during late Pliocene and Quaternary time with the development of the Honey Lake Fault Zone. Holocene strike-slip displacement is indicated by offsets of the 12,000 year old Lake Lahontan shoreline and deposits containing a 7,000 year old ash.

  5. Manganese geochemistry in the Guaymas basin, Gulf of California

    SciTech Connect

    Campbell, A.C.; Gieskes, J.M.; Lupton, J.E.; Lonsdale, P.F.

    1988-02-01

    Manganese geochemistry in the Guaymas Basin, Gulf of California is dominated by hydrothermal processes. The concentration of particulate Mn in the subsill basin is about four times higher than in the non-hydrothermally active basins of the southern Gulf. This excess Mn closely matches the predicted anomaly from a model of hydrothermal fluxes based on dissolved silica and /sup 3/He. The hot spring flux of Mn is about 4 times greater than the benthic flux from the sediments on the slopes of the basin. Dissolved hydrothermal Mn has a residence time of about one week in the water column. The particulate Mn phase consist of 2-5 ..mu..m size particles that are distinct from all other suspended particulate matter. These Mn-rich particles are responsible for the observed turbidity in the water column (hydrothermal clouds) above vents and chimneys in the Guaymas Basin and bear a striking resemblance to the Mn oxidizing bacterium Metallogenium. The rapid conversion of Mn to a particulate phase in these clouds is consistent with bacterial catalysis. This contrasts with the particles at 21/sup 0/N, East Pacific Rise, where Mn is more slowly co-precipitated with or adsorbed onto an iron oxyhydroxide phase.

  6. New identification and interpreted correlation, deposition, and significance of widespread Quaternary volcanic ash in the Sacramento-San Joaquin Delta, California

    NASA Astrophysics Data System (ADS)

    Maier, K. L.; Gatti, E.; Wan, E.; Ponti, D. J.; Tinsley, J. C.; Starratt, S. W.; Hillhouse, J.; Pagenkopp, M.; Olson, H. A.; Burtt, D.; Rosa, C. M.; Holzer, T. L.

    2013-12-01

    We recently identified and correlated volcanic ash deposits buried in the Sacramento-San Joaquin Delta, California, with widespread ash in the Pacific Northwest. The Sacramento-San Joaquin Delta (herein, the Delta) contains stratigraphic records of climate change, sea level variability, and tectonic processes. It drains the interior of central and northern California, covers ~1400 km2, and is underlain by Quaternary deposits that are difficult to correlate and date. Tephrochronology provides maximal depositional ages and regional sequence stratigraphic correlations. Using Electron Microprobe analysis, we identified the Loleta (0.390 Ma), the Rockland (~0.575 Ma), and an unnamed volcanic ash (>0.78-<1.45 Ma) in ten samples from eight boreholes in the Delta drilled by the California Department of Water Resources. These tephra correlate chemostratigraphically with widespread volcanic ash found in California, Nevada, and the Pacific Northwest. Major and minor element compositions of glass shards from each tephra sample also indicate that these deposits derive from Cascade Range volcanic sources. The Rockland ash erupted from the southern Cascades near Lassen Peak, California. The Loleta ash is the distal equivalent of the Bend pumice tuff that probably originated from the Three Sisters volcanoes, Oregon. The unnamed, but chemically distinctive, ash bed also resembles Cascade -type tephra. The ash layers are identified in 27 boreholes in the northern to central Delta that we correlate using facies. Grain-size distributions and sedimentary structures are inconsistent within the tephra units and indicate variations in concentrations, deposition rates, and depositional environments. Much of the Delta tephra was transported and deposited in fluvial settings. The tephra deposits occur as three facies: 1) volcanic ash, in thick deposits containing silt- to sand-size glass shards; 2) pumice, in thick deposits of bedded and variably current-structured coarse-sand to pebble

  7. The Effectiveness of Cattlemans Detention Basin, South Lake Tahoe, California

    USGS Publications Warehouse

    Green, Jena M.

    2006-01-01

    Lake Tahoe (Nevada-California) has been designated as an 'outstanding national water resource' by the U.S. Environmental Protection Agency, in part, for its exceptional clarity. Water clarity in Lake Tahoe, however, has been declining at a rate of about one foot per year for more than 35 years. To decrease the amount of sediment and nutrients delivered to the lake by way of alpine streams, wetlands and stormwater detention basins have been installed at several locations around the lake. Although an improvement in stormwater and snowmelt runoff quality has been measured, the effectiveness of the detention basins for increasing the clarity of Lake Tahoe needs further study. It is possible that poor ground-water quality conditions exist beneath the detention basins and adjacent wetlands and that the presence of the basins has altered ground-water flow paths to nearby streams. A hydrogeochemical and ground-water flow modeling study was done at Cattlemans detention basin, situated adjacent to Cold Creek, a tributary to Lake Tahoe, to determine whether the focusing of storm and snowmelt runoff into a confined area has (1) modified the ground-water flow system beneath the detention basin and affected transport of sediment and nutrients to nearby streams and (2) provided an increased source of solutes which has changed the distribution of nutrients and affected nutrient transport rates beneath the basin. Results of slug tests and ground-water flow modeling suggest that ground water flows unrestricted northwest across the detention basin through the meadow. The modeling also indicates that seasonal flow patterns and flow direction remain similar from year to year under transient conditions. Model results imply that about 34 percent (0.004 ft3/s) of the total ground water within the model area originates from the detention basin. Of the 0.004 ft3/s, about 45 percent discharges to Cold Creek within the modeled area downstream of the detention basin. The remaining 55 percent

  8. Effects of ozone on photosynthesis, vegetative growth, and development of woody perennials in the San Joaquin Valley of California. Final report

    SciTech Connect

    Williams, L.E.; DeJong, T.M.; Retzlaff, W.A.

    1989-10-31

    Nursery stock of nine fruit and nut tree species were planted in open-top chambers on April 1, 1988 at the University of California's Kearney Agricultural Center located in the San Joaquin Valley. The trees were then exposed to three levels of atmospheric ozone partial pressures (charcoal filtered air, ambient air, or ambient air + ozone) from 1 August to 17 November 1988. The relationship between leaf net CO2 assimilation rate and 12-hour mean ozone partial pressure decreased linearly with increasing ozone partial pressure for the almond, plum, apricot, pear and apple cultivars. Stomatal conductances of apricot, prune, apple, almond, and plum also decreased linearly with increasing ozone partial pressure. Cross-sectional area relative growth rates of almond, plum, apricot, pear and apple declined linearly with increasing ozone partial pressure. Net CO2 assimilation rate, stomatal conductance, and trunk growth of cherry, peach, and nectarine were unaffected by the ozone treatments. The results indicate that decreases in leaf gas exchange were probably contributors to decreases in young tree growth of the susceptible species/cultivars.

  9. Evaluation of a floating fish guidance structure at a hydrodynamically complex river junction in the Sacramento–San Joaquin River Delta, California, USA

    USGS Publications Warehouse

    Romine, Jason G.; Perry, Russell W.; Pope, Adam C; Stumpner, Paul; Liedtke, Theresa L.; Kumagai, Kevin K; Reeves, Ryan L

    2016-01-01

    Survival of out-migrating juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento–San Joaquin River delta, California, USA, varies by migration route. Survival of salmonids that enter the interior and southern Delta can be as low as half that of salmonids that remain in the main-stem Sacramento River. Reducing entrainment into the higher-mortality routes, such as Georgiana Slough, should increase overall survival. In spring 2014, a floating fish-guidance structure (FFGS) designed to reduce entrainment into Georgiana Slough was deployed just upstream of the Georgiana Slough divergence. We used acoustic telemetry to evaluate the effect of the FFGS on Chinook entrainment to Georgiana Slough. At intermediate discharge (200–400 m3 s–1), entrainment into Georgiana Slough was five percentage points lower when the FFGS was in the on state (19.1% on; 23.9% off). At higher discharge (>400 m3 s–1), entrainment was higher when the FFGS was in the on state (19.3% on; 9.7% off), and at lower discharge (0–200 m3 s–1) entrainment was lower when the FFGS was in the on state (43.7% on; 47.3% off). We found that discharge, cross-stream fish position, time of day, and proportion of flow remaining in the Sacramento River contributed to the probability of being entrained to Georgiana Slough.

  10. Residential agricultural pesticide exposures and risk of neural tube defects and orofacial clefts among offspring in the San Joaquin Valley of California.

    PubMed

    Yang, Wei; Carmichael, Suzan L; Roberts, Eric M; Kegley, Susan E; Padula, Amy M; English, Paul B; Shaw, Gary M

    2014-03-15

    We examined whether early gestational exposures to pesticides were associated with an increased risk of anencephaly, spina bifida, cleft lip with or without cleft palate (CLP), or cleft palate only. We used population-based data along with detailed information from maternal interviews. Exposure estimates were based on residential proximity to agricultural pesticide applications during early pregnancy. The study population derived from the San Joaquin Valley, California (1997-2006). Analyses included 73 cases with anencephaly, 123 with spina bifida, 277 with CLP, and 117 with cleft palate only in addition to 785 controls. A total of 38% of the subjects were exposed to 52 chemical groups and 257 specific chemicals. There were relatively few elevated odds ratios with 95% confidence intervals that excluded 1 after adjustment for relevant covariates. Those chemical groups included petroleum derivatives for anencephaly, hydroxybenzonitrile herbicides for spina bifida, and 2,6-dinitroaniline herbicides and dithiocarbamates-methyl isothiocyanate for CLP. The specific chemicals included 2,4-D dimethylamine salt, methomyl, imidacloprid, and α-(para-nonylphenyl)-ω-hydroxypoly(oxyethylene) phosphate ester for anencephaly; the herbicide bromoxynil octanoate for spina bifida; and trifluralin and maneb for CLP. Adjusted odds ratios ranged from 1.6 to 5.1. Given that such odds ratios might have arisen by chance because of the number of comparisons, our study showed a general lack of association between a range of agricultural pesticide exposures and risks of selected birth defects.

  11. Residential agricultural pesticide exposures and risk of neural tube defects and orofacial clefts among offspring in the San Joaquin Valley of California.

    PubMed

    Yang, Wei; Carmichael, Suzan L; Roberts, Eric M; Kegley, Susan E; Padula, Amy M; English, Paul B; Shaw, Gary M

    2014-03-15

    We examined whether early gestational exposures to pesticides were associated with an increased risk of anencephaly, spina bifida, cleft lip with or without cleft palate (CLP), or cleft palate only. We used population-based data along with detailed information from maternal interviews. Exposure estimates were based on residential proximity to agricultural pesticide applications during early pregnancy. The study population derived from the San Joaquin Valley, California (1997-2006). Analyses included 73 cases with anencephaly, 123 with spina bifida, 277 with CLP, and 117 with cleft palate only in addition to 785 controls. A total of 38% of the subjects were exposed to 52 chemical groups and 257 specific chemicals. There were relatively few elevated odds ratios with 95% confidence intervals that excluded 1 after adjustment for relevant covariates. Those chemical groups included petroleum derivatives for anencephaly, hydroxybenzonitrile herbicides for spina bifida, and 2,6-dinitroaniline herbicides and dithiocarbamates-methyl isothiocyanate for CLP. The specific chemicals included 2,4-D dimethylamine salt, methomyl, imidacloprid, and α-(para-nonylphenyl)-ω-hydroxypoly(oxyethylene) phosphate ester for anencephaly; the herbicide bromoxynil octanoate for spina bifida; and trifluralin and maneb for CLP. Adjusted odds ratios ranged from 1.6 to 5.1. Given that such odds ratios might have arisen by chance because of the number of comparisons, our study showed a general lack of association between a range of agricultural pesticide exposures and risks of selected birth defects. PMID:24553680

  12. Serologic survey for disease in endangered San Joaquin kit fox, Vulpes macrotis mutica, inhabiting the Elk Hills Naval Petroleum Reserve, Kern County, California

    SciTech Connect

    McCue, P.M.; O'Farrell, T.P.

    1986-07-01

    Serum from endangered San Joaquin kit foxes, Vulpes macrotis mutica, and sympatric wildlife inhabiting the Elk Hills Petroleum Reserve, Kern County, and Elkhorn Plain, San Luis Obispo County, California, was collected in 1981 to 1982 and 1984, and tested for antibodies against 10 infectious disease pathogens. Proportions of kit fox sera containing antibodies against diseases were: canine parvovirus, 100% in 1981 to 1982 and 67% in 1984; infectious canine hepatitis, 6% in 1981 to 1982 and 21% in 1984; canine distemper, 0 in 1981 to 1982 and 14% in 1984; tularemia, 8% in 1981 to 1982 and 31% in 1984; Brucella abortus, 8% in 1981 to 1982 and 3% in 1984; Brucella canis, 14% in 1981 to 1982 and 0 in 1984; toxoplasmosis, 6% in 1981 to 1982; coccidioidomycosis, 3% in 1981 to 1982; and plague and leptospirosis, 0 in 1981 to 1982. High population density, overlapping home ranges, ability to disperse great distances, and infestation by ectoparasites were cited as possible factors in the transmission and maintenance of these diseases in kit fox populations.

  13. Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Landon, Matthew K.; Green, Christopher T.; Belitz, Kenneth; Singleton, Michael J.; Esser, Bradley K.

    2011-09-01

    In a 2,700-km2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO3 and oxic redox conditions, but some zones have anoxic or mixed redox conditions. Anoxic conditions were associated with long residence times that occurred near the valley trough and in areas of historical groundwater discharge with shallow depth to water. Anoxic conditions also were associated with interactions of shallow, modern groundwater with soils. NO3 concentrations were significantly lower in anoxic than oxic or mixed redox groundwater, primarily because residence times of anoxic waters exceed the duration of increased pumping and fertilizer use associated with modern agriculture. Effects of redox reactions on NO3 concentrations were relatively minor. Dissolved N2 gas data indicated that denitrification has eliminated >5 mg/L NO3-N in about 10% of 39 wells. Increasing NO3 concentrations over time were slightly less prevalent in anoxic than oxic or mixed redox groundwater. Spatial and temporal trends of NO3 are primarily controlled by water and NO3 fluxes of modern land use.

  14. Distribution of reduction-oxidation conditions and relation to trends in nitrate in groundwater, Central-Eastside San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Landon, M. K.; Green, C. T.; Belitz, K.

    2010-12-01

    A 2,700 km2 study area in the eastern San Joaquin Valley near Modesto, California, was investigated to: describe three-dimensional reduction-oxidation (redox) conditions by using water chemistry data compiled from multiple sources; analyze relations of redox conditions to explanatory factors; and determine relations between nitrate (NO3) trends and redox conditions and other factors. Redox conditions are primarily oxic, but increasingly anoxic conditions were correlated with proximity to the valley center, decreased depth to water, and areas of historical groundwater discharge. Anoxic conditions in areas with shallow depths to water occur in both modern recharge, which has abundant organic carbon as an electron donor due to interactions of the shallow water table with soils, and pre-modern groundwater in discharge areas. Although NO3 concentrations were significantly less in wells with anoxic than oxic or mixed redox conditions, dissolved N2 gas data from 39 wells indicate that denitrification caused NO3 concentrations to decrease from above to below the drinking water threshold in only 1 well (maximum excess N2-N of 11 mg/L), indicating that denitrification does not currently protect many wells from NO3 contamination. Trends in NO3 concentrations showed only minor relations to redox conditions. Although NO3 concentrations and trends in the study area are primarily controlled by loading from agricultural land use rather than by redox conditions, greater understanding of the factors controlling the distribution of redox conditions contributes to efforts to simulate NO3 transport at a regional scale.

  15. Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Landon, M.K.; Green, C.T.; Belitz, K.; Singleton, M.J.; Esser, B.K.

    2011-01-01

    In a 2,700-km2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO3 and oxic redox conditions, but some zones have anoxic or mixed redox conditions. Anoxic conditions were associated with long residence times that occurred near the valley trough and in areas of historical groundwater discharge with shallow depth to water. Anoxic conditions also were associated with interactions of shallow, modern groundwater with soils. NO3 concentrations were significantly lower in anoxic than oxic or mixed redox groundwater, primarily because residence times of anoxic waters exceed the duration of increased pumping and fertilizer use associated with modern agriculture. Effects of redox reactions on NO3 concentrations were relatively minor. Dissolved N2 gas data indicated that denitrification has eliminated gt;5 mg/L NO3-N in about 10% of 39 wells. Increasing NO3 concentrations over time were slightly less prevalent in anoxic than oxic or mixed redox groundwater. Spatial and temporal trends of NO3 are primarily controlled by water and NO3 fluxes of modern land use. ?? 2011 Springer-Verlag (outside the USA).

  16. Relations of hydrogeologic factors, groundwater reduction-oxidation conditions, and temporal and spatial distributions of nitrate, Central-Eastside San Joaquin Valley, California, USA

    USGS Publications Warehouse

    Landon, Matthew K.; Green, Christopher T.; Belitz, Kenneth; Singleton, Michael J.; Esser, Bradley K.

    2011-01-01

    In a 2,700-km2 area in the eastern San Joaquin Valley, California (USA), data from multiple sources were used to determine interrelations among hydrogeologic factors, reduction-oxidation (redox) conditions, and temporal and spatial distributions of nitrate (NO3), a widely detected groundwater contaminant. Groundwater is predominantly modern, or mixtures of modern water, with detectable NO3 and oxic redox conditions, but some zones have anoxic or mixed redox conditions. Anoxic conditions were associated with long residence times that occurred near the valley trough and in areas of historical groundwater discharge with shallow depth to water. Anoxic conditions also were associated with interactions of shallow, modern groundwater with soils. NO3 concentrations were significantly lower in anoxic than oxic or mixed redox groundwater, primarily because residence times of anoxic waters exceed the duration of increased pumping and fertilizer use associated with modern agriculture. Effects of redox reactions on NO3 concentrations were relatively minor. Dissolved N2 gas data indicated that denitrification has eliminated >5 mg/L NO3–N in about 10% of 39 wells. Increasing NO3 concentrations over time were slightly less prevalent in anoxic than oxic or mixed redox groundwater. Spatial and temporal trends of NO3 are primarily controlled by water and NO3 fluxes of modern land use.

  17. Land subsidence along the Delta-Mendota Canal in the northern part of the San Joaquin Valley, California, 2003-10

    USGS Publications Warehouse

    Sneed, Michelle; Brandt, Justin; Solt, Mike

    2013-01-01

    Extensive groundwater withdrawal from the unconsolidated deposits in the San Joaquin Valley caused widespread aquifer-system compaction and resultant land subsidence from 1926 to 1970—locally exceeding 8.5 meters. The importation of surface water beginning in the early 1950s through the Delta-Mendota Canal and in the early 1970s through the California Aqueduct resulted in decreased pumping, initiation of water-level recovery, and a reduced rate of compaction in some areas of the San Joaquin Valley. However, drought conditions during 1976–77 and 1987–92, and drought conditions and regulatory reductions in surface-water deliveries during 2007–10, decreased surface-water availability, causing pumping to increase, water levels to decline, and renewed compaction. Land subsidence from this compaction has reduced freeboard and flow capacity of the Delta-Mendota Canal, the California Aqueduct, and other canals that deliver irrigation water and transport floodwater. The U.S. Geological Survey, in cooperation with the U.S. Bureau of Reclamation and the San Luis and Delta-Mendota Water Authority, assessed land subsidence in the vicinity of the Delta-Mendota Canal as part of an effort to minimize future subsidence-related damages to the canal. The location, magnitude, and stress regime of land-surface deformation during 2003–10 were determined by using extensometer, Global Positioning System (GPS), Interferometric Synthetic Aperture Radar (InSAR), spirit leveling, and groundwater-level data. Comparison of continuous GPS, shallow extensometer, and groundwater-level data, combined with results from a one-dimensional model, indicated the vast majority of the compaction took place beneath the Corcoran Clay, the primary regional confining unit. Land-surface deformation measurements indicated that much of the northern portion of the Delta-Mendota Canal (Clifton Court Forebay to Check 14) was fairly stable or minimally subsiding on an annual basis; some areas showed

  18. Eustatic control of tertiary hydrocarbon deposits, Central California borderline basins

    SciTech Connect

    Cousminer, H.L. )

    1994-04-01

    In the central California borderland basins, the Vail-Haq Cenozoic Global Eustatic Cycle appears to have influenced depositional patterns that have fundamental significance in the present distribution of hydrocarbon source and reservoir beds. Coupled with tectonic events, traps were created that now control the distribution of hydrocarbon accumulations. Seismic data combined with subsurface lithostratigraphic, biostratigraphic, and log data from wells drilled on the central California outer continental shelf (OCS) were used to date and correlate Tertiary stratigraphic sequences in the Santa Maria, Bodega-La Honda, and Point Arena basins. Benthic foraminiferal assemblages also served to reconstruct each basin's paleobathymetric history. The west coast benthic foram stages, commerically used to solve subsurface stratigraphic problems for over 60 yr, occur with planktonic microfossil groups that now serve to calibrate the provincial stages with the absolute geologic time scale. The Miocene through Pliocene stratigraphic sequences in these three depocenters are markedly similar, and record a parallel marine onlap and offlap pattern that correlates closely with the Vail-Haq Cenozoic Global Eustatic Cycle. The highstand depositional cycles are generally dominated by organic-rich sediments of good to excellent are generally dominated by organic-rich sediments of good to excellent source-bed potential. Lowstand regressive to transgressive clastic deposits have good reservoir potential. The middle Miocene siliceous Monterey Formation was deposited during maximum Tertiary global sea levels and is present in all of these basins. In addition to being a prolific source bed, the Monterey is unique in that when diagnetically altered, it fractures and also becomes an excellent hydrocarbon reservoir.

  19. The nature of organic carbon in density-fractionated sediments in the Sacramento-San Joaquin River Delta (California)

    NASA Astrophysics Data System (ADS)

    Wakeham, S. G.; Canuel, E. A.

    2015-10-01

    Rivers are the primary means by which sediments and carbon are transported from the terrestrial biosphere to the oceans but gaps remain in our understanding of carbon associations from source to sink. Bed sediments from the Sacramento-San Joaquin River Delta (CA) were fractionated according to density and analyzed for sediment mass distribution, elemental (C and N) composition, mineral surface area, and stable carbon and radiocarbon isotope compositions of organic carbon (OC) and fatty acids to evaluate the nature of organic carbon in river sediments. OC was unevenly distributed among density fractions. Mass and TOC were in general concentrated in mesodensity (1.6-2.0 and 2.0-2.5 g cm-3) fractions, comprising 84.0 ± 1.3 % of total sediment mass and 80.8 ± 13.3 % of total OC (TOC). Low density (< 1.6 g cm-3) material, although rich in OC (34.0 ± 2.0 % OC) due to woody debris, constituted only 17.3 ± 12.8 % of TOC. High density (> 2.5 g cm-3) organic-poor, mineral material made-up 13.7 ± 1.4 % of sediment mass and 2.0 ± 0.9 % of TOC. Stable carbon isotope compositions of sedimentary OC were relatively uniform across bulk and density fractions (δ13C -27.4 ± 0.5 ‰). Radiocarbon content varied from Δ14C values of -382 (radiocarbon age 3800 yr BP) to +94 ‰ (modern) indicating a~mix of young and pre-aged OC. Fatty acids were used to further constrain the origins of sedimentary OC. Short-chain n-C14-n-C18 fatty acids of algal origin were depleted in δ13C (δ13C -37.5 to -35.2 ‰) but were enriched in 14C (Δ14C > 0) compared to long-chain n-C24-n-C28 acids of vascular plant origins with higher δ13C (-33.0 to -31.0 ‰) but variable Δ14C values (-180 and 61 ‰). These data demonstrate the potentially complex source and age distributions found within river sediments and provide insights about sediment and organic matter supply to the Sacramento-San Joaquin River Delta.

  20. Decision analysis framing study; in-valley drainage management strategies for the western San Joaquin Valley, California

    USGS Publications Warehouse

    Presser, Theresa S.; Jenni, Karen E.; Nieman, Timothy; Coleman, James

    2010-01-01

    Constraints on drainage management in the western San Joaquin Valley and implications of proposed approaches to management were recently evaluated by the U.S. Geological Survey (USGS). The USGS found that a significant amount of data for relevant technical issues was available and that a structured, analytical decision support tool could help optimize combinations of specific in-valley drainage management strategies, address uncertainties, and document underlying data analysis for future use. To follow-up on USGS's technical analysis and to help define a scientific basis for decisionmaking in implementing in-valley drainage management strategies, this report describes the first step (that is, a framing study) in a Decision Analysis process. In general, a Decision Analysis process includes four steps: (1) problem framing to establish the scope of the decision problem(s) and a set of fundamental objectives to evaluate potential solutions, (2) generation of strategies to address identified decision problem(s), (3) identification of uncertainties and their relationships, and (4) construction of a decision support model. Participation in such a systematic approach can help to promote consensus and to build a record of qualified supporting data for planning and implementation. In December 2008, a Decision Analysis framing study was initiated with a series of meetings designed to obtain preliminary input from key stakeholder groups on the scope of decisions relevant to drainage management that were of interest to them, and on the fundamental objectives each group considered relevant to those decisions. Two key findings of this framing study are: (1) participating stakeholders have many drainage management objectives in common; and (2) understanding the links between drainage management and water management is necessary both for sound science-based decisionmaking and for resolving stakeholder differences about the value of proposed drainage management solutions. Citing

  1. California Basin study (CaBS): DOE west coast basin program

    SciTech Connect

    Small, L.F.

    1990-01-01

    The overall objective of our research continues to be elucidation of the transport pathways and transformations of organic matter in the California Basins region, with particular reference to the role of macrozooplankton in upper waters. We have concentrated on C and N pathways and fluxes to data, and will continue to investigate these further (seasonal aspects, and the role of zooplankton carnivory in zooplankton-medicated C and N flux, for example).

  2. A millennial-scale record of Pb and Hg contamination in peatlands of the Sacramento-San Joaquin Delta of California, USA.

    PubMed

    Drexler, Judith Z; Alpers, Charles N; Neymark, Leonid A; Paces, James B; Taylor, Howard E; Fuller, Christopher C

    2016-05-01

    In this paper, we provide the first record of millennial patterns of Pb and Hg concentrations on the west coast of the United States. Peat cores were collected from two micro-tidal marshes in the Sacramento-San Joaquin Delta of California. Core samples were analyzed for Pb, Hg, and Ti concentrations and dated using radiocarbon and (210)Pb. Pre-anthropogenic concentrations of Pb and Hg in peat ranged from 0.60 to 13.0μgg(-1)and from 6.9 to 71ngg(-1), respectively. For much of the past 6000+ years, the Delta was free from anthropogenic pollution, however, beginning in ~1425CE, Hg and Pb concentrations, Pb/Ti ratios, Pb enrichment factors (EFs), and HgEFs all increased. Pb isotope compositions of the peat suggest that this uptick was likely caused by smelting activities originating in Asia. The next increases in Pb and Hg contamination occurred during the California Gold Rush (beginning ~1850CE), when concentrations reached their highest levels (74μgg(-1) Pb, 990ngg(-1) Hg; PbEF=12 and HgEF=28). Lead concentrations increased again beginning in the ~1920s with the incorporation of Pb additives in gasoline. The phase-out of lead additives in the late 1980s was reflected in changes in Pb isotope ratios and reductions in Pb concentrations in the surface layers of the peat. The rise and subsequent fall of Hg contamination was also tracked by the peat archive, with the highest Hg concentrations occurring just before 1963CE and then decreasing during the post-1963 period. Overall, the results show that the Delta was a pristine region for most of its ~6700-year existence; however, since ~1425CE, it has received Pb and Hg contamination from both global and regional sources.

  3. A millennial-scale record of Pb and Hg contamination in peatlands of the Sacramento-San Joaquin Delta of California, USA

    USGS Publications Warehouse

    Drexler, Judith; Alpers, Charles N.; Neymark, Leonid; Paces, James B.; Taylor, Howard E.; Fuller, Christopher C.

    2016-01-01

    In this paper, we provide the first record of millennial patterns of Pb and Hg concentrations on the west coast of the United States. Peat cores were collected from two micro-tidal marshes in the Sacramento-San Joaquin Delta of California. Core samples were analyzed for Pb, Hg, and Ti concentrations and dated using radiocarbon, 210Pb, and 137Cs. Pre-anthropogenic concentrations of Pb and Hg in peat ranged from 0.60 to 13.0 µg g-1and from 6.9 to 71 ng g-1, respectively. For much of the past 6000+ years, the Delta was free from anthropogenic pollution, however, beginning in ~1425 CE, Hg and Pb concentrations, Pb/Ti ratios, Pb enrichment factors (EFs), and HgEFs all increased. Pb isotope compositions of the peat suggest that this uptick was likely caused by smelting activities originating in Asia. The next increases in Pb and Hg contamination occurred during the California Gold Rush (beginning ~1850 CE), when concentrations reached their highest levels (74 µg g-1 Pb, 990 ng g-1 Hg; PbEF = 12 and HgEF = 28). Lead concentrations increased again beginning in the ~1920s with the incorporation of Pb additives in gasoline. The phase-out of lead additives in the late 1980s was reflected in Pb isotope ratios and reductions in Pb concentrations in the surface layers of the peat. The rise and fall of Hg contamination was also tracked by the peat archive, with the highest Hg concentrations occurring just before 1963 CE and then decreasing during the post-1963 period. Overall, the results show that the Delta was a pristine region for most of its ~6700-year existence; however, since ~1425 CE, it has received Pb and Hg contamination from both global and regional sources.

  4. A millennial-scale record of Pb and Hg contamination in peatlands of the Sacramento-San Joaquin Delta of California, USA.

    PubMed

    Drexler, Judith Z; Alpers, Charles N; Neymark, Leonid A; Paces, James B; Taylor, Howard E; Fuller, Christopher C

    2016-05-01

    In this paper, we provide the first record of millennial patterns of Pb and Hg concentrations on the west coast of the United States. Peat cores were collected from two micro-tidal marshes in the Sacramento-San Joaquin Delta of California. Core samples were analyzed for Pb, Hg, and Ti concentrations and dated using radiocarbon and (210)Pb. Pre-anthropogenic concentrations of Pb and Hg in peat ranged from 0.60 to 13.0μgg(-1)and from 6.9 to 71ngg(-1), respectively. For much of the past 6000+ years, the Delta was free from anthropogenic pollution, however, beginning in ~1425CE, Hg and Pb concentrations, Pb/Ti ratios, Pb enrichment factors (EFs), and HgEFs all increased. Pb isotope compositions of the peat suggest that this uptick was likely caused by smelting activities originating in Asia. The next increases in Pb and Hg contamination occurred during the California Gold Rush (beginning ~1850CE), when concentrations reached their highest levels (74μgg(-1) Pb, 990ngg(-1) Hg; PbEF=12 and HgEF=28). Lead concentrations increased again beginning in the ~1920s with the incorporation of Pb additives in gasoline. The phase-out of lead additives in the late 1980s was reflected in changes in Pb isotope ratios and reductions in Pb concentrations in the surface layers of the peat. The rise and subsequent fall of Hg contamination was also tracked by the peat archive, with the highest Hg concentrations occurring just before 1963CE and then decreasing during the post-1963 period. Overall, the results show that the Delta was a pristine region for most of its ~6700-year existence; however, since ~1425CE, it has received Pb and Hg contamination from both global and regional sources. PMID:26918488

  5. Wintertime vertical variations in particulate matter (PM) and precursor concentrations in the San Joaquin Valley during the California Regional Coarse PM/Fine PM Air Quality Study.

    PubMed

    Brown, Steven G; Roberts, Paul T; McCarthy, Michael C; Lurmann, Frederick W; Hyslop, Nicole P

    2006-09-01

    Air quality monitoring was conducted at a rural site with a tower in the middle of California's San Joaquin Valley (SJV) and at elevated sites in the foothills and mountains surrounding the SJV for the California Regional PM10/ PM2.5 Air Quality Study. Measurements at the surface and n a tower at 90 m were collected in Angiola, CA, from December 2000 through February 2001 and included hourly black carbon (BC), particle counts from optical particle counters, nitric oxide, ozone, temperature, relative humidity, wind speed, and direction. Boundary site measurements were made primarily using 24-hr integrated particulate matter (PM) samples. These measurements were used to understand the vertical variations of PM and PM precursors, the effect of stratification in the winter on concentrations and chemistry aloft and at the surface, and the impact of aloft-versus-surface transport on PM concentrations. Vertical variations of concentrations differed among individual species. The stratification may be important to atmospheric chemistry processes, particularly nighttime nitrate formation aloft, because NO2 appeared to be oxidized by ozone in the stratified aloft layer. Additionally, increases in accumulation-mode particle concentrations in the aloft layer during a fine PM (PM2.5) episode corresponded with increases in aloft nitrate, demonstrating the likelihood of an aloft nighttime nitrate formation mechanism. Evidence of local transport at the surface and regional transport aloft was found; transport processes also varied among the species. The distribution of BC appeared to be regional, and BC was often uniformly mixed vertically. Overall, the combination of time-resolved tower and surface measurements provided important insight into PM stratification, formation, and transport.

  6. A Survey of \\delta18O and \\delta15N Ratios in Ground Water from an Agricultural Community in the San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Glowacki, S. D.; Suen, C. J.

    2004-12-01

    We studied ground water samples from domestic and monitoring wells in an agricultural community in the eastern side of the San Joaquin Valley, California. The study area is rich in alluvial soils creating an extremely fertile farmland. Livestock farms and agricultural fields are abundant in the area. Fifty-four ground water samples were analyzed for \\delta18O and \\delta15N in dissolved nitrate, in addition to nutrients and major minerals. Nitrate concentration levels in groundwater are elevated and affected by agricultural and other activities. Possible sources of nutrients include: a municipal waste-water treatment facility, a raisin processing plant, a meat processing plant, a turkey farm, diary operations, and agricultural fields. However, except for the turkey farm and a diary, we found no statistical significant contribution of nitrate from the other facilities as compared to the rest of the area. The \\delta18O versus \\delta15N ratios plot of dissolved ground water nitrate shows most samples clustered around an area consistent with soil organic nitrogen. In addition, the rest of the samples show a trend that is indicative of denitrification process. Generally, high \\delta15N values are associated with low nitrate concentrations. The isotopic signal of denitrification is particularly pronounced in samples in the vicinity of the waste water treatment facility, where the highest values of \\delta15N and the lowest nitrate concentrations are observed. However, these samples also have elevated chloride concentrations indicating a waste-water source. These data suggest that the denitrification in the subsurface may have been enhanced by bacteria species introduced by the effluence of the plant. [This study was performed with the collaboration of Steven R Silva of USGS, Menlo Park, and Iris Yamagata and Holly Jo Ferrin of California Department of Water Resources.

  7. Innovation in monitoring: The U.S. Geological Survey Sacramento–San Joaquin River Delta, California, flow-station network

    USGS Publications Warehouse

    Burau, Jon; Ruhl, Cathy; Work, Paul

    2016-01-01

    The U.S. Geological Survey (USGS) installed the first gage to measure the flow of water into California’s Sacramento–San Joaquin River Delta from the Sacramento River in the late 1800s. Today, a network of 35 hydro-acoustic meters measure flow throughout the delta. This region is a critical part of California’s freshwater supply and conveyance system. With the data provided by this flow-station network—sampled every 15 minutes and updated to the web every hour—state and federal water managers make daily decisions about how much freshwater can be pumped for human use, at which locations, and when. Fish and wildlife scientists, working with water managers, also use this information to protect fish species affected by pumping and loss of habitat. The data are also used to help determine the success or failure of efforts to restore ecosystem processes in what has been called the “most managed and highly altered” watershed in the country.

  8. Innovation in monitoring: The U.S. Geological Survey Sacramento–San Joaquin River Delta, California, flow-station network

    USGS Publications Warehouse

    Burau, Jon; Ruhl, Cathy; Work, Paul

    2016-01-29

    The U.S. Geological Survey (USGS) installed the first gage to measure the flow of water into California’s Sacramento–San Joaquin River Delta from the Sacramento River in the late 1800s. Today, a network of 35 hydro-acoustic meters measure flow throughout the delta. This region is a critical part of California’s freshwater supply and conveyance system. With the data provided by this flow-station network—sampled every 15 minutes and updated to the web every hour—state and federal water managers make daily decisions about how much freshwater can be pumped for human use, at which locations, and when. Fish and wildlife scientists, working with water managers, also use this information to protect fish species affected by pumping and loss of habitat. The data are also used to help determine the success or failure of efforts to restore ecosystem processes in what has been called the “most managed and highly altered” watershed in the country.

  9. Peat Formation Processes Through the Millennia in Tidal Marshes of the Sacramento-San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, J.Z.

    2011-01-01

    The purpose of this study was to determine peat formation processes throughout the millennia in four tidal marshes in the Sacramento-San Joaquin Delta. Peat cores collected at each site were analyzed for bulk density, loss on ignition, and percent organic carbon. Core data and spline fit age-depth models were used to estimate inorganic sedimentation, organic accumulation, and carbon sequestration rates in the marshes. Bulk density and percent organic matter content of peat fluctuated through time at all sites, suggesting that peat formation processes are dynamic and responsive to watershed conditions. The balance between inorganic sedimentation and organic accumulation at the sites also varied through time, indicating that marshes may rely more strongly on either inorganic or organic matter for peat formation at particular times in their existence. Mean carbon sequestration rates found in this study (0. 38-0. 79 Mg C ha-1 year-1) were similar to other long-term estimates for temperate peatlands. ?? 2011 Coastal and Estuarine Research Federation (outside the USA).

  10. A multiple metrics approach to prioritizing strategies for measuring and managing reactive nitrogen in the San Joaquin Valley of California

    NASA Astrophysics Data System (ADS)

    Horowitz, Ariel I.; Moomaw, William R.; Liptzin, Daniel; Gramig, Benjamin M.; Reeling, Carson; Meyer, Johanna; Hurley, Kathleen

    2016-06-01

    Human alteration of the nitrogen cycle exceeds the safe planetary boundary for the use of reactive nitrogen (Nr). We complement global analysis by analyzing regional mass flows and the relative consequences of multiple chemical forms of Nr as they ‘cascade’ through multiple environmental media. The goals of this paper are (1) to identify the amounts of Nr that flow through a specific nitrogen rich region, (2) develop multiple metrics to characterize and compare multiple forms of Nr and the different damages that they cause, and (3) to use these metrics to assess the most societally acceptable and cost effective means for addressing the many dimensions of Nr damage. This paper uses a multiple metrics approach that in addition to mass flows considers economic damage, health and mitigation costs and qualitative damages to evaluate options for mitigating Nr flows in California’s San Joaquin Valley (SJV). Most analysis focuses attention on agricultural Nr because it is the largest flow in terms of mass. In contrast, the multiple metrics approach identifies mobile source Nr emissions as creating the most economic and health damage in the SJV. Emissions of Nr from mobile sources are smaller than those from crop agriculture and dairy in the SJV, but the benefits of abatement are greater because of reduced health impacts from air pollution, and abatement costs are lower. Our findings illustrate the benefit of a comprehensive multiple metrics approach to Nr management.

  11. Ozone trends in California`s South Coast Air Basin, 1976--1996

    SciTech Connect

    Cohanim, S.; Cassmassi, J.; Bassett, M.

    1998-12-31

    The South Coast Air Basin (Basin) of Southern California exhibits the worst air quality in the nation, as measured by the annual number of days exceeding the 1-hour National Ambient Air Quality Standard (NAAQS) for ozone. Hourly pollutant concentration data collected by the South Coast Air Quality Management District`s air monitoring network are compared to the existing 1-hour and new 8-hour federal ozone ambient air quality standards to depict ozone trends and compliance in the Basin. Results of trend analyses for the different areas of the Basin are presented for the 1-hour and 8-hour standards, and the relative stringency of the existing and new federal standards is examined. Based on an analysis of the effect of the recently adopted federal standard on ozone compliance in the Basin, ozone concentrations exceed the new federal 8-hour standard level more often than the existing 1-hour standard in most locations. However, examination of the trends in design values for the 1-hour and 8-hour ozone standards suggests that for most locations in the Basin the new standard probably should not be significantly more difficult to attain than the existing standard. The weather-adjusted ozone trend analysis in the Basin confirms the fact that the downtrends in ozone concentrations and number of days exceeding standards are real and independent of annual variation in weather. An analysis of weekday/weekend differences in exceedances for the existing 1-hour and new 8-hour ozone standards show a higher number of days exceeding both standards on weekends for most locations in the Basin, with differences being more evident in the 1990s than in the late 1970s and 1980s

  12. 33 CFR 117.191 - San Joaquin River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false San Joaquin River. 117.191 Section 117.191 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.191 San Joaquin River. (a) The...

  13. 33 CFR 117.191 - San Joaquin River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false San Joaquin River. 117.191 Section 117.191 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.191 San Joaquin River. (a) The...

  14. 33 CFR 117.191 - San Joaquin River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false San Joaquin River. 117.191 Section 117.191 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.191 San Joaquin River. (a) The...

  15. 33 CFR 117.191 - San Joaquin River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false San Joaquin River. 117.191 Section 117.191 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.191 San Joaquin River. (a) The...

  16. 33 CFR 117.191 - San Joaquin River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false San Joaquin River. 117.191 Section 117.191 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.191 San Joaquin River. (a) The draw of the Port of Stockton railroad bridge,...

  17. Occurrence of nitrate and pesticides in ground water beneath three agricultural land-use settings in the eastern San Joaquin Valley, California, 1993-1995

    USGS Publications Warehouse

    Burow, Karen R.; Shelton, Jennifer L.; Dubrovsky, Neil M.

    1998-01-01

    The processes that affect nitrate and pesticide occurrence may be better understood by relating ground-water quality to natural and human factors in the context of distinct, regionally extensive, land- use settings. This study assesses nitrate and pesticide occurrence in ground water beneath three agricultural land-use settings in the eastern San Joaquin Valley, California. Water samples were collected from 60 domestic wells in vineyard, almond, and a crop grouping of corn, alfalfa, and vegetable land-use settings. Each well was sampled once during 1993?1995. This study is one element of the U.S. Geological Survey?s National Water-Quality Assessment Program, which is designed to assess the status of, and trends in, the quality of the nation?s ground- and surface-water resources and to link the status and trends with an understanding of the natural and human factors that affect the quality of water. The concentrations and occurrence of nitrate and pesticides in ground-water samples from domestic wells in the eastern alluvial fan physiographic region were related to differences in chemical applica- tions and to the physical and biogeochemical processes that charac- terize each of the three land-use settings. Ground water beneath the vineyard and almond land-use settings on the coarse-grained, upper and middle parts of the alluvial fans is more vulnerable to nonpoint- source agricultural contamination than is the ground water beneath the corn, alfalfa, and vegetable land-use setting on the lower part of the fans, near the basin physiographic region. Nitrate concentrations ranged from less than 0.05 to 55 milligrams per liter, as nitrogen. Nitrate concentrations were significantly higher in the almond land-use setting than in the vineyard land-use setting, whereas concentrations in the corn, alfalfa, and vegetable land-use setting were intermediate. Nitrate concentrations exceeded the maximum contaminant level in eight samples from the almond land- use setting (40

  18. Groundwater quality in the Central Sierra Nevada, California

    USGS Publications Warehouse

    Fram, Miranda S.; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. Two small watersheds of the Fresno and San Joaquin Rivers in the Central Sierra Nevada constitute one of the study units being evaluated.

  19. Documentation of a groundwater flow model (SJRRPGW) for the San Joaquin River Restoration Program study area, California

    USGS Publications Warehouse

    Traum, Jonathan A.; Phillips, Steven P.; Bennett, George Luther; Zamora, Celia; Metzger, Loren F.

    2014-01-01

    To better understand the potential effects of restoration flows on existing drainage problems, anticipated as a result of the San Joaquin River Restoration Program (SJRRP), the U.S. Geological Survey (USGS), in cooperation with the U.S. Bureau of Reclamation (Reclamation), developed a groundwater flow model (SJRRPGW) of the SJRRP study area that is within 5 miles of the San Joaquin River and adjacent bypass system from Friant Dam to the Merced River. The primary goal of the SJRRP is to reestablish the natural ecology of the river to a degree that restores salmon and other fish populations. Increased flows in the river, particularly during the spring salmon run, are a key component of the restoration effort. A potential consequence of these increased river flows is the exacerbation of existing irrigation drainage problems along a section of the river between Mendota and the confluence with the Merced River. Historically, this reach typically was underlain by a water table within 10 feet of the land surface, thus requiring careful irrigation management and (or) artificial drainage to maintain crop health. The SJRRPGW is designed to meet the short-term needs of the SJRRP; future versions of the model may incorporate potential enhancements, several of which are identified in this report. The SJRRPGW was constructed using the USGS groundwater flow model MODFLOW and was built on the framework of the USGS Central Valley Hydrologic Model (CVHM) within which the SJRRPGW model domain is embedded. The Farm Process (FMP2) was used to simulate the supply and demand components of irrigated agriculture. The Streamflow-Routing Package (SFR2) was used to simulate the streams and bypasses and their interaction with the aquifer system. The 1,300-square mile study area was subdivided into 0.25-mile by 0.25-mile cells. The sediment texture of the aquifer system, which was used to distribute hydraulic properties by model cell, was refined from that used in the CVHM to better represent

  20. 2001-2002 Wet Season Branchiopod Survey Report, Lawrence Livermore National Laboratory, Site 300, Alameda and San Joaquin Counties, California

    SciTech Connect

    Weber, W; Woollett, J

    2004-11-16

    Condor County Consulting on behalf of Lawrence Livermore National Laboratory (LLNL) has performed wet season surveys for listed branchiopods at Site 300, located in eastern Alameda County and western San Joaquin County. LLNL is collecting information for the preparation of an EIS covering ongoing explosives testing and related activities on Site 300. Related activities include maintenance of fire roads and annual control burns of approximately 607 hectares (1500 acres). Control burns typically take place on the northern portion of the site. Because natural branchiopod habitat is sparse on Site 300, it is not surprising that listed branchiopods were not observed during this 2001-2002 wet season survey. Although the site is large, a majority of it has topography and geology that precludes the formation of static seasonal pools. Even the relatively gentle topography of the northern half of the site contains few areas where water pools for more than two weeks. The rock outcrops found on the site did not provide suitable habitat for listed branchiopods. Most of the habitat available to branchiopods on the site is puddles that form in roadbeds and dry quickly. The one persistent pool on the site, the larger of the two modified vernal pools and the only one to fill this season, is occupied by two branchiopod species that require long-lived pools to reach maturity. In short, there is little habitat available on the site for branchiopods and most of the habitat present is generally too short-lived to support the branchiopod species that do occur at Site 300.

  1. Erosion Characteristics and Horizontal Variability for Small Erosion Depths in the Sacramento - San Joaquin River Delta, California, USA

    NASA Astrophysics Data System (ADS)

    Schoellhamer, D. H.; Manning, A. J.; Work, P. A.

    2015-12-01

    Cohesive sediment in the Sacramento-San Joaquin River Delta affects pelagic fish habitat, contaminant transport, and marsh accretion. Observations of suspended-sediment concentration in the delta indicate that about 0.05 to 0.20 kg/m2 are eroded from the bed during a tidal cycle. If erosion is horizontally uniform, the erosion depth is about 30 to 150 microns, the typical range in diameter of suspended flocs. Application of an erosion microcosm produces similarly small erosion depths. In addition, core erodibility in the microcosm calculated with a horizontally homogeneous model increases with depth, contrary to expectations for a consolidating bed, possibly because the eroding surface area increases as applied shear stress increases. Thus, field observations and microcosm experiments, combined with visual observation of horizontally varying biota and texture at the surface of sediment cores, indicate that a conceptual model of erosion that includes horizontally varying properties may be more appropriate than assuming horizontally homogeneous erosive properties. To test this hypothesis, we collected five cores and measured the horizontal variability of shear strength within each core in the top 5.08 cm with a shear vane. Small tubes built by a freshwater worm and macroalgae were observed on the surface of all cores. The shear vane was inserted into the sediment until the top of the vane was at the top of the sediment, torque was applied to the vane until the sediment failed and the vane rotated, and the corresponding dial reading in Nm was recorded. The dial reading was assumed to be proportional to the surface strength. The horizontal standard deviation of the critical shear stress was about 30% of the mean. Results of the shear vane test provide empirical evidence that surface strength of the bed varies horizontally. A numerical simulation of erosion with an areally heterogeneous bed reproduced erosion characteristics observed in the microcosm.

  2. Estimates of suspended sediment entering San Francisco Bay from the Sacramento and San Joaquin Delta, San Francisco Bay, California

    USGS Publications Warehouse

    McKee, L.J.; Ganju, N.K.; Schoellhamer, D.H.

    2006-01-01

    This study demonstrates the use of suspended-sediment concentration (SSC) data collected at Mallard Island as a means of determining suspended-sediment load entering San Francisco Bay from the Sacramento and San Joaquin River watersheds. Optical backscatter (OBS) data were collected every 15 min during water years (WYs) 1995-2003 and converted to SSC. Daily fluvial advective sediment load was estimated by combining estimated Delta outflow with daily averaged SSC. On days when no data were available, SSC was estimated using linear interpolation. A model was developed to estimate the landward dispersive load using velocity and SSC data collected during WYs 1994 and 1996. The advective and dispersive loads were summed to estimate the total load. Annual suspended-sediment load at Mallard Island averaged 1.2??0.4 Mt (million metric tonnes). Given that the average water discharge for the 1995-2003 period was greater than the long -term average discharge, it seems likely that the average suspended-sediment load may be less than 1.2??0.4 Mt. Average landward dispersive load was 0.24 Mt/yr, 20% of the total. On average during the wet season, 88% of the annual suspended-sediment load was discharged through the Delta and 43% occurred during the wettest 30-day period. The January 1997 flood transported 1.2 Mt of suspended sediment or about 11% of the total 9-year load (10.9 Mt). Previous estimates of sediment load at Mallard Island are about a factor of 3 greater because they lacked data downstream from riverine gages and sediment load has decreased. Decreasing suspended-sediment loads may increase erosion in the Bay, help to cause remobilization of buried contaminants, and reduce the supply of sediment for restoration projects. ?? 2005 Elsevier B.V. All rights reserved.

  3. Assessment of the Impact of the California Water Project on the West Side of the San Joaquin Valley

    NASA Technical Reports Server (NTRS)

    Estes, J. E.

    1972-01-01

    Changes in the regional scale parameters used to characterize the nature of area transformation caused by the California State Water Project are analyzed. Data were taken from Mission 164 and ERTS high flight simulation imagery. Indicators considered cover general and urban oriented land use, general and problem oriented vegetation, irrigation systems, and identification of crops.

  4. Passive remote sensing of large-scale methane emissions from Oil Fields in California's San Joaquin Valley and validation by airborne in-situ measurements - Results from COMEX

    NASA Astrophysics Data System (ADS)

    Gerilowski, Konstantin; Krautwurst, Sven; Thompson, David R.; Thorpe, Andrew K.; Kolyer, Richard W.; Jonsson, Haflidi; Krings, Thomas; Frankenberg, Christian; Horstjann, Markus; Leifer, Ira; Eastwood, Michael; Green, Robert O.; Vigil, Sam; Fladeland, Matthew; Schüttemeyer, Dirk; Burrows, John P.; Bovensmann, Heinrich

    2016-04-01

    The CO2 and MEthane EXperiment (COMEX) was a NASA and ESA funded campaign in support of the HyspIRI and CarbonSat mission definition activities. As a part of this effort, seven flights were performed between June 3 and September 4, 2014 with the Methane Airborne MAPper (MAMAP) remote sensing instrument (operated by the University of Bremen in cooperation with the German Research Centre for Geosciences - GFZ) over the Kern River, Kern Front, and Poso Creek Oil Fields located in California's San Joaquin Valley. MAMAP was installed for the flights aboard the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft, together with: a Picarro fast in-situ greenhouse gas (GHG) analyzer operated by the NASA Ames Research Center, ARC; a 5-hole turbulence probe; and an atmospheric measurement package operated by CIRPAS measuring aerosols, temperature, dew-point, and other atmospheric parameters. Three of the flights were accompanied by the Next Generation Airborne Visual InfraRed Imaging Spectrometer (AVIRIS-NG), operated by the Jet Propulsion Laboratory (JPL), California Institute of Technology, installed aboard a second Twin Otter aircraft. Large-scale, high-concentration CH4 plumes were detected by the MAMAP instrument over the fields and tracked over several kilometers. The spatial distribution of the MAMAP observed plumes was compared to high spatial resolution CH4 anomaly maps derived by AVIRIS-NG imaging spectroscopy data. Remote sensing data collected by MAMAP was used to infer CH4 emission rates and their distributions over the three fields. Aggregated emission estimates for the three fields were compared to aggregated emissions inferred by subsequent airborne in-situ validation measurements collected by the Picarro instrument. Comparison of remote sensing and in-situ flux estimates will be presented, demonstrating the ability of airborne remote sensing data to provide accurate emission estimates for concentrations above the

  5. Biological assessment of the effects of activities conducted at Camp Roberts Army National Guard training site, Monterey and San Luis Obispo Counties, California, on the endangered san joaquin kit fox, Vulpes macrotis mutica

    SciTech Connect

    Not Available

    1989-12-01

    Section 7 of the Endangered Species Act of 1973 imposes several requirements on federal agencies concerning listed threatened and endangered species and their designated critical habitat. Camp Roberts is operated by the California Army National Guard (CA ARNG) with funding from the National Guard Bureau (NGB). Its primary mission to provide a site where military training requirements of the western United States can be met. The presence of the endangered San Joaquin kit fox (Vulpes macrotis mutica) was confirmed in 1960 and the distribution and abundance of the species increased over the next two decades. The Secretary of Interior has not designated any critical habitat for San Joaquin kit fox. The major objective of this Biological Assessment is to provide FWS with sufficient information concerning the possible impacts that routine military training, maintenance and repair activities, and proposed construction projects may have on the San Joaquin kit fox and its essential habitat at Camp Roberts so that formal consultation with NGB and CA ARNG can begin. FWS will use this information as part of the basis for issuing a Biological Opinion which will include an incidental take provision. 45 refs., 8 figs., 1 tab.

  6. Information technology and decision support tools for stakeholder-driven river basin salinity management

    SciTech Connect

    Quinn, N.W.T; Cozad, D.B.; Lee, G.

    2010-01-01

    Innovative strategies for effective basin-scale salinity management have been developed in the Hunter River Basin of Australia and more recently in the San Joaquin River Basin of California. In both instances web-based stakeholder information dissemination has been a key to achieving a high level of stakeholder involvement and the formulation of effective decision support salinity management tools. A common element to implementation of salinity management strategies in both river basins has been the concept of river assimilative capacity for controlling export salt loading and the potential for trading of the right to discharge salt load to the river - the Hunter River in Australia and the San Joaquin River in California. Both rivers provide basin drainage and the means of exporting salt to the ocean. The paper compares and contrasts the use of monitoring, modeling and information dissemination in the two basins to achieve environmental compliance and sustain irrigated agriculture in an equitable and socially and politically acceptable manner.

  7. The nature of organic carbon in density-fractionated sediments in the Sacramento-San Joaquin River Delta (California)

    NASA Astrophysics Data System (ADS)

    Wakeham, S. G.; Canuel, E. A.

    2016-02-01

    Rivers are the primary means by which sediments and carbon are transported from the terrestrial biosphere to the oceans but gaps remain in our understanding of carbon associations from source to sink. Bed sediments from the Sacramento-San Joaquin River Delta (CA) were fractionated according to density and analyzed for sediment mass distribution, elemental (C and N) composition, mineral surface area, and stable carbon and radiocarbon isotope compositions of organic carbon (OC) and fatty acids to evaluate the nature of organic carbon in river sediments. OC was unevenly distributed among density fractions. Mass and OC were in general concentrated in mesodensity (1.6-2.0 and 2.0-2.5 g cm-3) fractions, comprising 84.0 ± 1.3 % of total sediment mass and 80.8 ± 13.3 % of total OC (TOC). Low-density (< 1.6 g cm-3) material, although rich in OC (34.0 ± 2.0 % OC) due to woody debris, constituted only 17.3 ± 12.8 % of TOC. High-density (> 2.5 g cm-3) organic-poor, mineral-rich material made-up 13.7 ± 1.4 % of sediment mass and 2.0 ± 0.9 % of TOC. Stable carbon isotope compositions of sedimentary OC were relatively uniform across bulk and density fractions (δ13C -27.4 ± 0.5 ‰). Radiocarbon content varied from Δ14C values of -382 (radiocarbon age 3800 yr BP) to +94 ‰ (modern) indicating a mix of young and old OC. Fatty acids were used to further constrain the origins of sedimentary OC. Short-chain n-C14-n-C18 fatty acids of algal origin were depleted in 13C (δ13C -37.5 to -35.2 ‰) but were enriched in 14C (Δ14C > 0) compared to long-chain n-C24-n-C28 acids of vascular plant origins with higher δ13C (-33.0 to -31.0 ‰) but variable Δ14C values (-180 and 61 ‰). These data demonstrate the potentially complex source and age distributions found within river sediments and provide insights about sediment and organic matter supply to the Delta.

  8. Implications for sustainability of a changing agricultural mosaic in the Sacramento-San Joaquin Delta, California, USA

    NASA Astrophysics Data System (ADS)

    Lucero, C. E.; Deverel, S. J.; Jacobs, P.; Kelsey, R.

    2015-12-01

    Transformed from the largest wetland system on the west coast of the United States to agriculture, the Sacramento-San Joaquin Delta is an extreme teaching example of anthropogenic threats to sustainability. For over 6,000 years, over 280,000 ha of intertidal freshwater marsh accreted due to seal level rise and sediment deposition. Farming of organic soils since 1850 resulted in land subsidence caused primarily by oxidation. Over 2 billion cubic meters of soil were lost resulting in elevations on Delta islands ranging from -1 to -8 m and increased risk of levee failures and water supply disruption. Alteration of water flows and habitat caused dramatic declines in aquatic species. A cycle in which oxidation of organic soils leads to deepening of drainage ditches to maintain an aerated root zone which in turn results in sustained oxidation and subsidence is perpetuated by the momentum of the status quo despite evidence that agricultural practices are increasingly unsustainable. Flooding of the soils breaks the oxidation/subsidence cycle. We assessed alternate land uses and the carbon market as a potential impetus for change. Using the peer-reviewed and locally calibrated SUBCALC model, we estimated net global warming potential for a range of scenarios for a representative island, from status quo to incorporating significant proportions of subsidence-mitigating land use. We analyzed economic implications by determining profit losses or gains when a simulated GHG offset market is available for wetlands using a regional agricultural production and economic optimization model, We estimated baseline GHG emissions at about 60,000 tons CO2-e per year. In contrast, modeled implementation of rice and wetlands resulted in substantial emissions reductions to the island being a net GHG sink. Subsidence would be arrested or reversed where these land uses are implemented. Results of economic modeling reveal that conversion to wetlands can have significant negative farm financial

  9. Greenhouse gas emissions and carbon sequestration potential in restored freshwater marshes in the Sacramento San-Joaquin Delta, California

    NASA Astrophysics Data System (ADS)

    Knox, S. H.; Sturtevant, C. S.; Oikawa, P. Y.; Matthes, J. H.; Dronova, I.; Anderson, F. E.; Verfaillie, J. G.; Baldocchi, D. D.

    2015-12-01

    Wetlands can be effective carbon sinks due to limited decomposition rates in anaerobic soil. As such there is a growing interest in the use of restored wetlands as biological carbon sequestration projects for greenhouse gas (GHG) emission reduction programs. However, using wetlands to offset emissions requires accurate accounting of both carbon dioxide (CO2) and methane (CH4) exchange since wetlands are also sources of CH4. To date few studies have quantified CO2 and CH4 exchange from restored wetlands or assessed how these fluxes vary during ecosystem development. In this study, we report on multiple years of eddy covariance measurements of CO2 and CH4 fluxes from two restored freshwater marshes of differing ages (one restored in 1997 and the other in 2010) in the Sacramento-San Joaquin Delta, CA. Measurements at the younger restored wetland started in October 2010 and began in April 2011 at the older site. The younger restored wetland showed considerable year-to-year variability in the first 4 years following restoration, with CO2 uptake ranging from 12 to 420 g C-CO2 m-2 yr-1. Net CO2 uptake at the older wetland was overall greater than at the younger site, ranging from 292 to 585 g C-CO2 m-2 yr-1. Methane emissions were on average higher at the younger wetland (46 g C-CH4 m-2 yr-1) relative to the older one (33 g C-CH4 m-2 yr-1). In terms of the GHG budgets (assuming a global warming potential of 34), the younger wetland was consistently a GHG source, emitting on average 1439 g CO2 eq m-2 yr-1, while the older wetland was a GHG sink in two of the years of measurement (sequestering 651 and 780 g CO2 eq m-2 yr-1 in 2012 and 2013, respectively) and a source of 750 g CO2 eq m-2 yr-1 in 2014. This study highlights how dynamic CO2 and CH4 fluxes are in the first years following wetland restoration and suggests that restored wetlands have the potential to act as GHG sinks but this may depend on time since restoration.

  10. Diurnal variability in riverine dissolved organic matter composition determined by in situ optical measurement in the San Joaquin River (California, USA)

    USGS Publications Warehouse

    Spencer, R.G.M.; Pellerin, B.A.; Bergamaschi, B.A.; Downing, B.D.; Kraus, T.E.C.; Smart, D.R.; Dahlgren, R.A.; Hernes, P.J.

    2007-01-01

    Dissolved organic matter (DOM) concentration and composition in riverine and stream systems are known to vary with hydrological and productivity cycles over the annual and interannual time scales. Rivers are commonly perceived as homogeneous with respect to DOM concentration and composition, particularly under steady flow conditions over short time periods. However, few studies have evaluated the impact of short term variability (<1 day) on DOM dynamics. This study examined whether diurnal processes measurably altered DOM concentration and composition in the hypereutrophic San Joaquin River (California) during a relatively quiescent period. We evaluated the efficacy of using optical in situ measurements to reveal changes in DOM which may not be evident from bulk dissolved organic carbon (DOC) measurement alone. The in situ optical measurements described in this study clearly showed for the first time diurnal variations in DOM measurements, which have previously been related to both composition and concentration, even though diurnal changes were not well reflected in bulk DOC concentrations. An apparent asynchronous trend of DOM absorbance and chlorophyll-a in comparison to chromophoric dissolved organic matter (CDOM) fluorescence and spectral slope S290-350 suggests that no one specific CDOM spectrophotometric measurement explains absolutely DOM diurnal variation in this system; the measurement of multiple optical parameters is therefore recommended. The observed diurnal changes in DOM composition, measured by in situ optical instrumentation likely reflect both photochemical and biologically-mediated processes. The results of this study highlight that short-term variability in DOM composition may complicate trends for studies aiming to distinguish different DOM sources in riverine systems and emphasizes the importance of sampling specific study sites to be compared at the same time of day. The utilization of in situ optical technology allows short-term variability

  11. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Tulare Lake bed area, southern San Joaquin Valley, California, 1986-87

    USGS Publications Warehouse

    Schroeder, R.A.; Palawski, D.U.; Skorupa, J.P.

    1988-01-01

    Concentrations of numerous toxic trace elements and pesticides were measured during 1986 in water, sediment, and biota from three areas near the Tulare Lake Bed, southern San Joaquin Valley, California: Kern National Wildlife Refuge, Pixley National Wildlife Refuge, and Westfarmers evaporation ponds about 5 mi west of Kern National Wildlife Refuge, to determine whether toxic constituents in agricultural-irrigation drainage pose a threat to beneficial uses of water, especially to uses by wildlife. Pesticide residues were found to be low at all three areas. Trace element concentrations were found to be comparatively low at the Kern and Pixley National Wildlife Refuge areas and high at the Westfarmers evaporation ponds. Dissolved selenium concentrations were < 1 micrograms/L (ug/L) in areas on and adjacent to the refuges, but ranged from 110 to 360 ug/L in the saline drainwater impounded in the evaporation ponds. The ratio of mean selenium concentrations in biota from Westfarmers ponds compared to biota from Kesterson National Wildlife Refuge (where adverse effects have been documented) is 5 for waterboatman, 2 for avocet liver, 1 for avocet eggs, and < 1 for widgeongrass. The low concentrations measured at Kern and Pixley National Wildlife Refuges suggest that trace elements and pesticides pose little threat to wildlife there; however, impounded subsurface drainage from agricultural irrigation does pose a threat to wildlife at the nearby Westfarmers ponds. Preliminary results of surveys conducted in 1987 indicated that there are adverse biological effects on shorebirds nesting at the ponds, although interpretation of the magnitude of the effects is premature, pending completion of ongoing studies by the U.S. Fish and Wildlife Service. (Author 's abstract)

  12. Drainage-return, surface-water withdrawal, and land-use data for the Sacramento-San Joaquin Delta, with emphasis on Twitchell Island, California

    USGS Publications Warehouse

    Templin, William E.; Cherry, Daniel E.

    1997-01-01

    Partial data on drainage returns and surface-water withdrawals are presented for areas of the Sacramento-San Joaquin Delta, California, for March 1994 through February 1996. These areas cover most of the delta. Data are also presented for all drainage returns and some surface-water withdrawals for Twitchell Island, which is in the western part of the delta. Changes in land use between 1968 and 1991 are also presented for the delta. Measurements of monthly drainage returns and surface-water withdrawals were made using flowmeters installed in siphons and drain pipes on Twitchell Island. Estimates of monthly returns throughout the delta were made using electric power-consumption data with pump-efficiency-test data. For Twitchell Island, monthly measured drainage returns for the 1995 calendar year totaled about 11,200 acre-feet, whereas drainage returns estimated from power-consumption data totaled 5 percent less at about 10,600 acre-feet. Monthly surface-water withdrawals onto Twitchell Island through 12 of the 21 siphons totaled about 2,400 acre-feet for 1995. For most of the delta, the monthly estimated drainage returns for 1995 totaled about 430,000 acre-feet. The area consisting of Bouldin, Brannan, Staten, Tyler, and Venice Islands had the largest estimated drainage returns for calendar year 1995. Between 1968 and 1991, native vegetation in the delta decreased by 25 percent (about 40,000 acres), and grain and hay crops increased by 340 percent (about 71,000 acres). For Twitchell Island, native vegetation decreased about 77 percent (about 850 acres), while field crop acreage increased by about 44 percent (about 780 acres).

  13. Littoral fish assemblages of the alien-dominated Sacramento-San Joaquin Delta, California, 1980-1983 and 2001-2003

    USGS Publications Warehouse

    Brown, L.R.; Michniuk, D.

    2007-01-01

    We analyzed monthly boat electrofishing data to characterize the littoral fish assemblages of five regions of the Sacramento-San Joaquin Delta (northern, southern, eastern, western, and central), California, during two sampling periods, 1980-1983 (1980s) and 2001-2003 (2000s), to provide information pertinent to the restoration of fish populations in this highly altered estuary. During the 1980s, almost 11,000 fish were captured, including 13 native species and 24 alien species. During the 2000s, just over 39,000 fish were captured, including 15 native species and 24 alien species. Catch per unit effort (CPUE) of total fish, alien fish, and centrarchid fish were greater in the 2000s compared with the 1980s, largely because of increased centrarchid fish CPUE. These differences in CPUE were associated with the spread of submerged aquatic vegetation (SAV), particularly an alien aquatic macrophyte Egeria densa. Native fish CPUE declined from the 1980s to the 2000s, but there was no single factor that could explain the decline. Native fish were most abundant in the northern region during both sampling periods. Nonmetric multidimensional scaling indicated similar patterns of fish assemblage composition during the two sampling periods, with the northern and western regions characterized by the presence of native species. The separation of the northern and western regions from the other regions was most distinct in the 2000s. Our results suggest that native fish restoration efforts will be most successful in the northern portion of the Delta. Management decisions on the Delta should include consideration of possible effects on SAV in littoral habitats and the associated fish assemblages and ecological processes. ?? 2007 Estuarine Research Federation.

  14. Agriculture, irrigation, and drainage on the west side of the San Joaquin Valley, California: Unified perspective on hydrogeology, geochemistry and management

    SciTech Connect

    Narasimhan, T.N.; Quinn, N.W.T.

    1996-03-01

    The purpose of this report is to provide a broad understanding of water-related issues of agriculture and drainage on the west side of the San Joaquin Valley. To this end, an attempt is made to review available literature on land and water resources of the San Joaquin Valley and to generate a process-oriented framework within which the various physical-, chemical-, biological- and economic components of the system and their interactions are placed in mutual perspective.

  15. Computeer-based decision support tools for evaluation of actions affecting flow and water quality in the San Joaquin Basin

    SciTech Connect

    Quinn, N.W.T.

    1993-01-01

    This document is a preliminary effort to draw together some of the important simulation models that are available to Reclamation or that have been developed by Reclamation since 1987. This document has also attempted to lay out a framework by which these models might be used both for the purposes for which they were originally intended and to support the analysis of other issues that relate to the hydrology and to salt and water quality management within the San Joaquin Valley. To be successful as components of a larger Decision Support System the models should to be linked together using custom designed interfaces that permit data sharing between models and that are easy to use. Several initiatives are currently underway within Reclamation to develop GIS - based and graphics - based decision support systems to improve the general level of understanding of the models currently in use, to standardize the methodology used in making planning and operations studies and to permit improved data analysis, interpretation and display. The decision support systems should allow greater participation in the planning process, allow the analysis of innovative actions that are currently difficult to study with present models and should lead to better integrated and more comprehensive plans and policy decisions in future years.

  16. A Millennial-Scale Record of Mercury and Lead Contamination in Peatlands of the Sacramento-San Joaquin Delta of California

    NASA Astrophysics Data System (ADS)

    Drexler, J. Z.; Alpers, C. N.; Neymark, L. A.; Paces, J. B.; Fuller, C.

    2015-12-01

    Peat cores from two micro-tidal marshes in the Sacramento-San Joaquin Delta of California (the landward end of the San Francisco Estuary) were used to track the onset of anthropogenic pollution on the west coast of the United States. Cores were sectioned into 2-cm depth intervals and analyzed for lead (Pb), mercury (Hg), and titanium (Ti) concentrations and Pb isotope compositions. Peat profiles were dated using radiocarbon, 210Pb, and 137Cs. Pre-anthropogenic concentrations of Pb and Hg in peat ranged from 0.60 to 13.0 μg g-1and from 6.9 to 71 ng g-1, respectively. For much of the past 6,000+ years, the Delta was free from anthropogenic pollution; however, beginning in ~1425 CE, Hg and Pb concentrations, Pb/Ti ratios, Pb enrichment factors (EFs), and HgEFs all increased. Pb isotope compositions of the peat suggest that this uptick was likely caused by mining and smelting activities originating in Asia. The next increases in Pb and Hg contamination occurred during the California Gold Rush (beginning ~1850 CE), when concentrations reached their highest levels (74 μg g-1 Pb, 990 ng g-1 Hg; PbEF = 12 and HgEF = 28). Pb concentrations increased again beginning in the ~1920s with the incorporation of Pb additives in gasoline. The phase-out of lead additives in the late 1980s was reflected in Pb isotope ratios and reductions in Pb concentrations in the surface layers of the peat. The rise and fall of Hg contamination was also tracked by the peat archive, with the highest Hg concentrations occurring just before 1963 CE and then decreasing during the post-1963 period. Overall the results show that the Delta was a pristine region for most of its ~6,700-year existence; however, since ~1425 CE, it has received Pb and Hg contamination from both global and regional sources. This study demonstrates that micro-tidal peatlands can be a highly useful archive for establishing the onset of anthropogenic contamination and chronicling the transition from a pristine to a polluted

  17. Floods of November-December 1950 in the Central Valley basin, California

    USGS Publications Warehouse

    Paulsen, C.G.

    1953-01-01

    The flood of November-December 1950 in the Central Valley basin was the greatest in most parts of the basin since the turn of the century and probably was exceeded in the lower San Joaquin River basin only by the historic flood of 1862. In respect to monetary loss, the 1950 flood was the most disastrous in the history of the basin. Loss of life was remarkably small when one considers the extensive damage and destruction to homes and other property, which is estimated at 33 million dollars. Outstanding features of the flood were its unprecedented occurrence so early in the winter flood season, its magnitude in respect to both peak and volume in most major tributaries, and the occurrence of a succession of near-peak flows with a period of three weeks. The flood was caused by a series of storms during the period November 16 to December 8, which brought exceptionally warm, moisture-laden air inland against the Sierra Nevada range and caused intense rainfall, instead of snowfall, at unusually high altitudes. Basin-wide totals of rainfall during the period ranged from 30 inches over the Yuba and American River basins to 13 inches over the upper Sacramento and Feather River basins. Based on continuous records of discharge on major tributaries for periods ranging from 22 to 55 years and averaging about 43 years, the 1950 flood peaks were the greatest of record on the American, Cosumnes, Mokelumne, Stanislaus, Tuolumne, Merced, Chowchilla, Fresno, lower San Joaquin, Kings, Kaweah, Tule, and Kern Rivers. Second highest peak of record occurred during the flood of March 1928 on the Yuba, American and Mokelumne Rivers; the flood of Marcn 1940 on Cosumnes River; the flood of January 1911 on the Stanislaus and Tuolumne Rivers; the flood of December 1937 on the Merced, Kings, and Kaweah Rivers; the flood of March 1938 on the Chowchilla, Fresno, and lower San Joaquin Rivers; and the flood of March 1943 on the Tule and Kern Rivers. Peak discharges for 1950 did not exceed previous

  18. Present-day oxidative subsidence of organic soils and mitigation in the Sacramento-San Joaquin Delta, California, USA.

    PubMed

    Deverel, Steven J; Ingrum, Timothy; Leighton, David

    L’affaissement des sols organiques dans le Delta de Sacramento-San Joaquin menace la durabilité du système d’approvisionnement en eau et de l’agriculture de la Californie (Etats-Unis d’Amérique). Des données d’altitude de la surface topographique ont été collectées dans le but d’estimer le taux d’affaissement actuel des sols et d’évaluer l’occupation des sols par des rizières en tant que moyen d’atténuation de l’affaissement des sols. Pour décrire les taux actuels d’affaissement des sols à l’échelle du Delta, le modèle SUBCALC développé précédemment a été affiné et calé grâce à l’utilisation des données récentes sur les émissions de CO2 et des variations d’altitude de la surface topographique enregistrées par des extensomètres. Les données de variations d’altitude de la surface topographique ont été évaluées par rapport aux estimations indirectes de l’affaissement du sol et de son accroissement basées sur les données de flux de carbone et d’azote au niveau des rizières. Les données d’extensiométrie et de nivellement montrent que les variations saisonnières de l’altitude de la surface topographique associées aux fluctuations des niveaux piézométriques et des taux d’affaissement inélastique du sol compris entre 0.5 et 0.8 cm an(–1). Le calage du modèle SUBCALC indique une précision de ±0.10 cm an (–1) là où la profondeur de la nappe, la teneur en matière organique du sol et la température sont connues. Les estimations régionales de l’affaissement du sol sont compris entre <0.3 à >1.8 cm an(–1). L’incertitude principale est la distribution de la teneur en matière organique du sol qui conduit à un lissage spatial dans la cartographie des taux d’affaissement des sols. L’analyse des données de nivellement et d’extensiométrie dans les rizières conduit à un taux d’accroissement estimé entre 0.02 et 0.8 cm an(–1). Ces valeurs sont généralement en

  19. Groundwater Contributions of Flow, Nitrate, and Dissolved Organic Carbon to the lower San Joaquin River, California, during 2006-2008

    NASA Astrophysics Data System (ADS)

    Zamora, C.; Dahlgren, R. A.; Kratzer, C. R.; Downing, B. D.; Russell, A. D.; Dileanis, P.; Bergamaschi, B. A.; Phillips, S. P.

    2011-12-01

    The influence of groundwater (GW) on surface-water quality in the San Joaquin River (SJR), CA was examined for a 59-mile reach from the confluence with Salt Slough to Vernalis from September 2006 to January 2009. Previous studies have estimated that GW may contribute 5-10% of downstream flow during the summer. However, there is a paucity of information concerning the chemical composition of GW discharge in the lower SJR, which hinders the estimation of nitrogen and dissolved organic carbon (DOC) loads from groundwater sources. Excess nitrate in the lower SJR stimulates algal growth that affects the river's use as a drinking water source and as aquatic habitat. The sources and reactivity of DOC are critical to water quality, because during the drinking water treatment process (i.e., chlorination and ozonation) components of the DOC pool react to form toxic compounds. We conducted streambed synoptic measurements that spanned the 59-mile study reach during 4 sampling events and estimated GW discharge rates using MODFLOW to characterize GW contributions of nutrients and DOC to the SJR. Nitrogen species and DOC concentrations were determined for GW samples collected at two depths, 1 ft and 3 or 6 ft below the streambed at a total of 115 distinct stream cross-sections. GW had no detectable nitrate (NO3) (<0.01 mg N/L) for 95% of the streambed samples. The lack of NO3 is attributed to denitrification, which results in the loss of NO3 to nitrogen gases under the anoxic conditions prevalent in the streambed sediments. We conclude that GW is not an important direct source of NO3 to the surface waters of the lower SJR, and that the streambed and riparian zone of the SJR acts as an anoxic barrier to NO3 transport. However, appreciable concentrations of ammonium (NH4) were measured in streambed samples and are believed to originate from anoxic mineralization of streambed sediments. This NH4 may contribute to surface water NO3 loads following nitrification in the aerobic water

  20. Water-quality investigation, Upper Santa Clara River Basin, California

    USGS Publications Warehouse

    Bowers, James C.; Irwin, G.A.

    1978-01-01

    Water-quality data are summarized for the upper Santa Clara River basin, California from studies beginning August 1974 through June 1976 and during past monitoring programs. Data were collected for nitrogen, phosphorus, total organic carbon, trace elements, detergents, and pesticide compounds. Because of the limited number of samples, the data are only an estimate of conditions that existed in the basin. Sampling was designed so that samples from each site would represent seasonal variations in discharge. Most constituents were fairly low in concentration near the headwaters at Ravenna and higher below the urban and agricultural area near Saugus. Mean specific conductance in the river ranged from 745 micromhos per centimeter at 25 deg C below the headwaters near Lang to 2,640 micromhos at the Los Angeles-Ventura County line. Results also indicate that discharge was not the single factor controlling the concentration variance for most constituents. Regression analyses indicated a high correlation between specific conductance and most major inorganic chemical constituents, and between specific conductance and discharge. (Woodard-USGS)

  1. Jurassic through Oligocene pre-basin stratigraphy in the Santa Maria basin area, California

    SciTech Connect

    Fritsche, A.E. ); Yamashiro, D.A. )

    1991-02-01

    Compilation from published records of 30 pre-Miocene stratigraphic columns in the Santa Maria basin area of California (west of the Sur-Nacimiento fault and north of the Santa Ynez fault) reveals two basement units and 22 overlying sedimentary units. This article displays the stratigraphic columns and includes descriptions and environmental interpretations of the 24 rock units. The basement rocks include an Upper Jurassic ophiolite sequence and the Lower Jurassic through Upper Cretaceous Franciscan Complex. Most of the 22 sedimentary units were deposited along a subduction-type margin prior to development of the late Tertiary Santa Maria basin. Overlying and generally in fault contact with the basement rocks are four Upper Jurassic through Lower Cretaceous units that were deposited in basin plain and out continental margin environments. Unconformably overlying these units are eight Upper Cretaceous units that were deposited in a wide range of environments that ranged from trench, slope, and submarine fan up through shelf and nonmarine fluvial environments. Lower Tertiary units onlap unconformably onto the Cretaceous rocks and were deposited only in the southernmost part of the area. These rocks include lower Eocene basin plain and outer submarine fan deposits; middle Eocene mid-fan and slope deposits; upper Eocene inner fan, shelf, shoreface, and foreshore deposits; and Oligocene shoreface, foreshore, and nonmarine fluvial deposits.

  2. Three-dimensional geologic mapping of the Cenozoic basin fill, Amargosa Desert basin, Nevada and California

    USGS Publications Warehouse

    Taylor, Emily M.; Sweetkind, Donald S.

    2014-01-01

    Understanding the subsurface geologic framework of the Cenozoic basin fill that underlies the Amargosa Desert in southern Nevada and southeastern California has been improved by using borehole data to construct three-dimensional lithologic and interpreted facies models. Lithologic data from 210 boreholes from a 20-kilometer (km) by 90-km area were reduced to a limited suite of descriptors based on geologic knowledge of the basin and distributed in three-dimensional space using interpolation methods. The resulting lithologic model of the Amargosa Desert basin portrays a complex system of interfingered coarse- to fine-grained alluvium, playa and palustrine deposits, eolian sands, and interbedded volcanic units. Lithologic units could not be represented in the model as a stacked stratigraphic sequence due to the complex interfingering of lithologic units and the absence of available time-stratigraphic markers. Instead, lithologic units were grouped into interpreted genetic classes, such as playa or alluvial fan, to create a three-dimensional model of the interpreted facies data. Three-dimensional facies models computed from these data portray the alluvial infilling of a tectonically formed basin with intermittent internal drainage and localized regional groundwater discharge. The lithologic and interpreted facies models compare favorably to resistivity, aeromagnetic, and geologic map data, lending confidence to the interpretation.

  3. Mercury and Methylmercury concentrations and loads in Cache Creek Basin, California, January 2000 through May 2001

    USGS Publications Warehouse

    Domagalski, Joseph L.; Alpers, Charles N.; Slotton, Darrell G.; Suchanek, Thomas H.; Ayers, Shaun M.

    2004-01-01

    Concentrations and mass loads of total mercury and methylmercury in streams draining abandoned mercury mines and near geothermal discharge in Cache Creek Basin, California, were measured during a 17-month period from January 2000 through May 2001. Rainfall and runoff averages during the study period were lower than long-term averages. Mass loads of mercury and methylmercury from upstream sources to downstream receiving waters, such as San Francisco Bay, were generally the highest during or after winter rainfall events. During the study period, mass loads of mercury and methylmercury from geothermal sources tended to be greater than those from abandoned mining areas because of a lack of large precipitation events capable of mobilizing significant amounts of either mercury-laden sediment or dissolved mercury and methylmercury from mine waste. Streambed sediments of Cache Creek are a source of mercury and methylmercury to downstream receiving bodies of water such as the Delta of the San Joaquin and Sacramento Rivers. Much of the mercury in these sediments was deposited over the last 150 years by erosion and stream discharge from abandoned mines or by continuous discharges from geothermal areas. Several geochemical constituents were useful as natural tracers for mining and geothermal areas. These constituents included aqueous concentrations of boron, chloride, lithium, and sulfate, and the stable isotopes of hydrogen and oxygen in water. Stable isotopes of water in areas draining geothermal discharges were enriched with more oxygen-18 relative to oxygen-16 than meteoric waters, whereas the enrichment by stable isotopes of water from much of the runoff from abandoned mines was similar to that of meteoric water. Geochemical signatures from stable isotopes and trace-element concentrations may be useful as tracers of total mercury or methylmercury from specific locations; however, mercury and methylmercury are not conservatively transported. A distinct mixing trend of

  4. Refurbished extensometer sites improve the quality and frequency of aquifer-system compaction and groundwater-level measurements, San Joaquin Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Sneed, M.; Brandt, J.; Solt, M.

    2012-12-01

    Extensive groundwater withdrawal from unconsolidated deposits in the San Joaquin Valley caused widespread aquifer-system compaction and land subsidence locally exceeding 8 meters (m) between 1926 and 1970. To identify the extent of subsidence, a network of 31 extensometers was installed in the 1960s. Importation of surface water in the early 1970s resulted in decreased groundwater pumping, a steady water-level recovery, and a reduced rate of compaction; consequently, data collection was sharply reduced. However, reduced surface-water availability during 1976-77, 1987-92, and 2007-09 caused increased groundwater pumping, lowered water levels, and renewed compaction. The resulting land subsidence has reduced freeboard and flow capacity of the Delta-Mendota Canal (DMC), the California Aqueduct (AQ), and other canals. Four deep (>300-m) cable-type extensometers from the old network, located along the DMC and AQ, were refurbished to identify existing and future subsidence, and to improve the quality and frequency of compaction measurements. Measurement quality was improved at three of these sites by replacing the existing reference tables, which sit atop concrete pads, with new reference tables cemented in 5.5-m boreholes and decoupled from the concrete pads to minimize the measurement of near-surface deformation. A new reference table could not be constructed at the fourth site due to restrictive drill-rig access. Insulated metal shelters were constructed to protect the equipment against environmental exposure at all sites. The frequencies of compaction and water-level measurements at the extensometer sites were improved by instrumenting each with a linear potentiometer and one or more submersible pressure transducers, respectively. An analog dial gauge was installed on each extensometer to provide data continuity in cases of electronic data interruption and to provide verification of potentiometer data. Aquifer-system compaction data from all four sites show

  5. Desegregation in the South San Joaquin Valley.

    ERIC Educational Resources Information Center

    Serrano, Rodolfo G.

    Notably isolated from the large metropolitan centers by geography and predominantly agricultural in its economy, Kern County is California's third largest county in land area. About one-third of the county is situated on the flat valley floor at the extreme southern end of the San Joaquin Valley. The area relies heavily on Chicano and Black manual…

  6. Groundwater quality in the San Fernando--San Gabriel groundwater basins, California

    USGS Publications Warehouse

    Kulongoski, Justin T.; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California's drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State's groundwater quality and increases public access to groundwater-quality information. The San Fernando and San Gabriel groundwater basins constitute one of the study units being evaluated.

  7. Projecting cumulative benefits of multiple river restoration projects: an example from the Sacramento-San Joaquin River system in California

    USGS Publications Warehouse

    Kondolf, G. Mathias; Angermeier, Paul L.; Cummins, Kenneth; Dunne, Thomas; Healey, Michael; Kimmerer, Wim; Moyle, Peter B.; Murphy, Dennis; Patten, Duncan; Railsback, Steve F.; Reed, Denise J.; Spies, Robert; Twiss, Robert

    2008-01-01

    Despite increasingly large investments, the potential ecological effects of river restoration programs are still small compared to the degree of human alterations to physical and ecological function. Thus, it is rarely possible to “restore” pre-disturbance conditions; rather restoration programs (even large, well-funded ones) will nearly always involve multiple small projects, each of which can make some modest change to selected ecosystem processes and habitats. At present, such projects are typically selected based on their attributes as individual projects (e.g., consistency with programmatic goals of the funders, scientific soundness, and acceptance by local communities), and ease of implementation. Projects are rarely prioritized (at least explicitly) based on how they will cumulatively affect ecosystem function over coming decades. Such projections require an understanding of the form of the restoration response curve, or at least that we assume some plausible relations and estimate cumulative effects based thereon. Drawing on our experience with the CALFED Bay-Delta Ecosystem Restoration Program in California, we consider potential cumulative system-wide benefits of a restoration activity extensively implemented in the region: isolating/filling abandoned floodplain gravel pits captured by rivers to reduce predation of outmigrating juvenile salmon by exotic warmwater species inhabiting the pits. We present a simple spreadsheet model to show how different assumptions about gravel pit bathymetry and predator behavior would affect the cumulative benefits of multiple pit-filling and isolation projects, and how these insights could help managers prioritize which pits to fill.

  8. Projecting Cumulative Benefits of Multiple River Restoration Projects: An Example from the Sacramento-San Joaquin River System in California

    NASA Astrophysics Data System (ADS)

    Kondolf, G. Mathias; Angermeier, Paul L.; Cummins, Kenneth; Dunne, Thomas; Healey, Michael; Kimmerer, Wim; Moyle, Peter B.; Murphy, Dennis; Patten, Duncan; Railsback, Steve; Reed, Denise J.; Spies, Robert; Twiss, Robert

    2008-12-01

    Despite increasingly large investments, the potential ecological effects of river restoration programs are still small compared to the degree of human alterations to physical and ecological function. Thus, it is rarely possible to “restore” pre-disturbance conditions; rather restoration programs (even large, well-funded ones) will nearly always involve multiple small projects, each of which can make some modest change to selected ecosystem processes and habitats. At present, such projects are typically selected based on their attributes as individual projects (e.g., consistency with programmatic goals of the funders, scientific soundness, and acceptance by local communities), and ease of implementation. Projects are rarely prioritized (at least explicitly) based on how they will cumulatively affect ecosystem function over coming decades. Such projections require an understanding of the form of the restoration response curve, or at least that we assume some plausible relations and estimate cumulative effects based thereon. Drawing on our experience with the CALFED Bay-Delta Ecosystem Restoration Program in California, we consider potential cumulative system-wide benefits of a restoration activity extensively implemented in the region: isolating/filling abandoned floodplain gravel pits captured by rivers to reduce predation of outmigrating juvenile salmon by exotic warmwater species inhabiting the pits. We present a simple spreadsheet model to show how different assumptions about gravel pit bathymetry and predator behavior would affect the cumulative benefits of multiple pit-filling and isolation projects, and how these insights could help managers prioritize which pits to fill.

  9. Projecting cumulative benefits of multiple river restoration projects: an example from the Sacramento-San Joaquin River system in California.

    PubMed

    Kondolf, G Mathias; Angermeier, Paul L; Cummins, Kenneth; Dunne, Thomas; Healey, Michael; Kimmerer, Wim; Moyle, Peter B; Murphy, Dennis; Patten, Duncan; Railsback, Steve; Reed, Denise J; Spies, Robert; Twiss, Robert

    2008-12-01

    Despite increasingly large investments, the potential ecological effects of river restoration programs are still small compared to the degree of human alterations to physical and ecological function. Thus, it is rarely possible to "restore" pre-disturbance conditions; rather restoration programs (even large, well-funded ones) will nearly always involve multiple small projects, each of which can make some modest change to selected ecosystem processes and habitats. At present, such projects are typically selected based on their attributes as individual projects (e.g., consistency with programmatic goals of the funders, scientific soundness, and acceptance by local communities), and ease of implementation. Projects are rarely prioritized (at least explicitly) based on how they will cumulatively affect ecosystem function over coming decades. Such projections require an understanding of the form of the restoration response curve, or at least that we assume some plausible relations and estimate cumulative effects based thereon. Drawing on our experience with the CALFED Bay-Delta Ecosystem Restoration Program in California, we consider potential cumulative system-wide benefits of a restoration activity extensively implemented in the region: isolating/filling abandoned floodplain gravel pits captured by rivers to reduce predation of outmigrating juvenile salmon by exotic warmwater species inhabiting the pits. We present a simple spreadsheet model to show how different assumptions about gravel pit bathymetry and predator behavior would affect the cumulative benefits of multiple pit-filling and isolation projects, and how these insights could help managers prioritize which pits to fill. PMID:18810527

  10. 77 FR 45652 - Final Program Environmental Impact Statement/Environmental Impact Report for the San Joaquin...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-01

    ... San Joaquin River Restoration Program, California AGENCY: Bureau of Reclamation, Interior. ACTION... Stipulation of Settlement's restoration and water management goals. DATES: The Bureau of Reclamation will not... California (Court) on October 23, 2006. The Settlement establishes two primary goals: Restoration...

  11. Field-scale monitoring of the long-term impact and sustainability of drainage water reuse on the west side of California's San Joaquin Valley.

    PubMed

    Corwin, Dennis L

    2012-05-01

    Diminishing freshwater resources have brought attention to the reuse of degraded water as a water resource rather than a disposal problem. Drainage water from tile-drained, irrigated agricultural land is degraded water that is often in large supply, but the long-term impact and sustainability of its reuse on soil is unknown. Similarly, nothing is known of the ramifications of terminating drainage water reuse. The objective of this study is (i) to monitor the long-term impact on soil chemical properties and thereby the sustainability of drainage water reuse on a marginally productive, saline-sodic, 32.4 ha field located on the west side of California's productive San Joaquin Valley and (ii) to assess spatially what happens to soil when drainage water reuse is terminated. The monitoring and assessment were based on spatial chemical data for soil collected during 10 years of irrigation with drainage water followed by 2 years of no applied irrigation water (only rainfall). Geo-referenced measurements of apparent soil electrical conductivity (EC(a)) were used to direct the soil sampling design to characterize spatial variability of impacted soil properties. Chemical analyses of soil samples were used (i) to characterize the spatial variability of salinity, Na, B, and Mo, which were previously identified as critical to the yield and quality of Bermuda grass (Cynodon dactylon (l.) Pers.) grown for livestock consumption and (ii) to monitor their change during the 12 year study. Soil samples were taken at 0.3 m increments to a depth of 1.2 m at each of 40 sample sites on five occasions: August 1999, April 2002, November 2004, August 2009, and May 2011. Drainage water varying in salinity (1.8-16.3 dS m(-1)), SAR (5.2-52.4), Mo (80-400 μg L(-1)), and B (0.4-15.1 mg L(-1)) was applied from July 2000 to June 2009. Results indicate that salts, Na, Mo, and B were leached from the root zone causing a significant improvement in soil quality from 1999 to 2009. Salinity and SAR

  12. Field-scale monitoring of the long-term impact and sustainability of drainage water reuse on the west side of California's San Joaquin Valley.

    PubMed

    Corwin, Dennis L

    2012-05-01

    Diminishing freshwater resources have brought attention to the reuse of degraded water as a water resource rather than a disposal problem. Drainage water from tile-drained, irrigated agricultural land is degraded water that is often in large supply, but the long-term impact and sustainability of its reuse on soil is unknown. Similarly, nothing is known of the ramifications of terminating drainage water reuse. The objective of this study is (i) to monitor the long-term impact on soil chemical properties and thereby the sustainability of drainage water reuse on a marginally productive, saline-sodic, 32.4 ha field located on the west side of California's productive San Joaquin Valley and (ii) to assess spatially what happens to soil when drainage water reuse is terminated. The monitoring and assessment were based on spatial chemical data for soil collected during 10 years of irrigation with drainage water followed by 2 years of no applied irrigation water (only rainfall). Geo-referenced measurements of apparent soil electrical conductivity (EC(a)) were used to direct the soil sampling design to characterize spatial variability of impacted soil properties. Chemical analyses of soil samples were used (i) to characterize the spatial variability of salinity, Na, B, and Mo, which were previously identified as critical to the yield and quality of Bermuda grass (Cynodon dactylon (l.) Pers.) grown for livestock consumption and (ii) to monitor their change during the 12 year study. Soil samples were taken at 0.3 m increments to a depth of 1.2 m at each of 40 sample sites on five occasions: August 1999, April 2002, November 2004, August 2009, and May 2011. Drainage water varying in salinity (1.8-16.3 dS m(-1)), SAR (5.2-52.4), Mo (80-400 μg L(-1)), and B (0.4-15.1 mg L(-1)) was applied from July 2000 to June 2009. Results indicate that salts, Na, Mo, and B were leached from the root zone causing a significant improvement in soil quality from 1999 to 2009. Salinity and SAR

  13. Dissolved organic carbon concentrations and compositions, and trihalomethane formation potentials in waters from agricultural peat soils, Sacramento-San Joaquin Delta, California; implications for drinking-water quality

    USGS Publications Warehouse

    Fujii, Roger; Ranalli, Anthony J.; Aiken, George R.; Bergamaschi, Brian A.

    1998-01-01

    Water exported from the Sacramento-San Joaquin River delta (Delta) is an important drinking-water source for more than 20 million people in California. At times, this water contains elevated concentrations of dissolved organic carbon and bromide, and exceeds the U.S. Environmental Protection Agency's maximum contaminant level for trihalomethanes of 0.100 milligrams per liter if chlorinated for drinking water. About 20 to 50 percent of the trihalomethane precursors to Delta waters originates from drainage water from peat soils on Delta islands. This report elucidates some of the factors and processes controlling and affecting the concentration and quality of dissolved organic carbon released from peat soils and relates the propensity of dissolved organic carbon to form trihalomethanes to its chemical composition.Soil water was sampled from near-surface, oxidized, well-decomposed peat soil (upper soil zone) and deeper, reduced, fibrous peat soil (lower soil zone) from one agricultural field in the west central Delta over 1 year. Concentrations of dissolved organic carbon in the upper soil zone were highly variable, with median concentrations ranging from 46.4 to 83.2 milligrams per liter. Concentrations of dissolved organic carbon in samples from the lower soil zone were much less variable and generally slightly higher than samples from the upper soil zone, with median concentrations ranging from 49.3 to 82.3 milligrams per liter. The dissolved organic carbon from the lower soil zone had significantly higher aromaticity (as measured by specific ultraviolet absorbance) and contained significantly greater amounts of aromatic humic substances (as measured by XAD resin fractionation and carbon-13 nuclear magnetic resonance analysis of XAD isolates) than the dissolved organic carbon from the upper soil zone. These results support the conclusion that more aromatic forms of dissolved organic carbon are produced under anaerobic conditions compared to aerobic conditions

  14. Seasonal changes in concentrations of dissolved pesticides and organic carbon in the Sacramento-San Joaquin delta, California, 1994-1996

    USGS Publications Warehouse

    Orlando, James L.; Kuivila, Kathryn M.

    2006-01-01

    The Sacramento-San Joaquin Delta (Delta) of California is an ecologically rich and hydrologically complex region that receives runoff from nearly one-quarter of the state. Water-quality studies of surface water in the region have found dissolved pesticides in winter storm runoff at concentrations toxic to some aquatic invertebrates. However, scientists have little information on pesticide concentrations in the Delta on a seasonal timescale or the importance of pesticide contributions from within-Delta sources. Consequently, the U.S. Geological Survey conducted a study from 1994 to 1996 during which water samples were collected seasonally from 31 sites located within the Delta and on major tributaries to the Delta. Water samples were analyzed for 20 current-use pesticides and dissolved organic carbon. During the study, 11 current-use pesticides were detected; maximum concentrations ranging from 17 ng/L (for trifluralin) to 1,160 ng/L (for metolachlor). The highest concentrations of five pesticides (carbaryl, carbofuran, metolachlor, molinate, and simazine) were greater than 900 ng/L. The greatest number of pesticides was detected in the summer of 1994, whereas the least number were detected in the winter of 1994. The herbicides metolachlor and simazine were the most frequently detected pesticides and were detected in five of the six sampling seasons. The herbicides molinate and EPTC were detected only during the three summer sampling seasons. A comparison of pesticides detected during the spring and summer of 1995 showed some seasonal variability. Comparison of the three summer seasons sampled showed that a larger number of pesticides were detected, and with generally higher maximum concentrations, in 1994 than in 1995 or 1996. Dissolved organic carbon (DOC) concentrations ranged, over the course of the study, from 1.4 mg/L to 10.4 mg/L, and had a median concentration of 3.8 mg/L. On a seasonal basis, the lowest maximum DOC concentrations occurred during the summer

  15. Re-establishing marshes can return carbon sink functions to a current carbon source in the Sacramento-San Joaquin Delta of California, USA

    USGS Publications Warehouse

    Miller, Robin L.; Fujii, Roger; Schmidt, Paul E.

    2011-01-01

    The Sacramento-San Joaquin Delta in California was an historic, vast inland freshwater wetland, where organic soils almost 20 meters deep formed over the last several millennia as the land surface elevation of marshes kept pace with sea level rise. A system of levees and pumps were installed in the late 1800s and early 1900s to drain the land for agricultural use. Since then, land surface has subsided more than 7 meters below sea level in some areas as organic soils have been lost to aerobic decomposition. As land surface elevations decrease, costs for levee maintenance and repair increase, as do the risks of flooding. Wetland restoration can be a way to mitigate subsidence by re-creating the environment in which the organic soils developed. A preliminary study of the effect of hydrologic regime on carbon cycling conducted on Twitchell Island during the mid-1990s showed that continuous, shallow flooding allowing for the growth of emergent marsh vegetation re-created a wetland environment where carbon preservation occurred. Under these conditions annual plant biomass carbon inputs were high, and microbial decomposition was reduced. Based on this preliminary study, the U.S. Geological Survey re-established permanently flooded wetlands in fall 1997, with shallow water depths of 25 and 55 centimeters, to investigate the potential to reverse subsidence of delta islands by preserving and accumulating organic substrates over time. Ten years after flooding, elevation gains from organic matter accumulation in areas of emergent marsh vegetation ranged from almost 30 to 60 centimeters, with average annual carbon storage rates approximating 1 kg/m2, while areas without emergent vegetation cover showed no significant change in elevation. Differences in accretion rates within areas of emergent marsh vegetation appeared to result from temporal and spatial variability in hydrologic factors and decomposition rates in the wetlands rather than variability in primary production

  16. Pleistocene hydrovolcanism in the Tule Lake Basin, N. E. California

    SciTech Connect

    Lavine, A. . Geology Dept.)

    1993-04-01

    The Prisoners Rock and The Peninsula tuff cones and the North Crater tuff ring, located in the Tule Lake Basin of northeastern California formed along a north-trending fissure approximately 270 ka when basaltic magma interacted with abundant groundwater or shallow lake water, resulting in phreatomagmatic eruptions. Diatomite inclusions in the tuff ring and correlations with the corresponding depth and diatoms in a drill core taken in the center of the basin, 2.5 km to the west of the cones, indicate shallow, marshy or shallow, alkaline-open conditions at Tule Lake around 270 ka. Deposits at Prisoners Rock and The Peninsula indicate subaerial emplacement, which allowed the deposits to lithify with little erosion by the lake. Subsequent wave erosion caused undercutting and breaking off of large blocks along mainly north-trending fractures forming vertical cliff faces on the east and west sides of the cones. The cones are elongated north-south with a greater thickness of deposits on the north and northeast, probably due to prevailing southwesterly winds at the time of eruptions. Deposits of the tuff cones at Prisoners Rock and The Peninsula resulted from deep explosions caused by water-magma ratios of around 3:1. The deposits are mainly inversely graded planar surge beds, ranging in thickness from 5 to 30 cm, and grading from very fine ash to 2 cm-diameter accretionary lapilli. Emplacement by highly steam-saturated, poorly inflated pyroclastic surges is indicated by the abundance of accretionary lapilli, vesiculated tuffs, soft-sediment deformation structures, steep bedding angles (20 to 40 degrees) lack of structures beneath country rock inclusions, massive bedding, and cementation of the deposits by alteration of basaltic glass to calcite, zeolites, clays, and chlorite.

  17. Environmental sensor networks and continuous data quality assurance to manage salinity within a highly regulated river basin

    SciTech Connect

    Quinn, N.W.T.; Ortega, R.; Holm, L.

    2010-01-05

    This paper describes a new approach to environmental decision support for salinity management in the San Joaquin Basin of California that focuses on web-based data sharing using YSI Econet technology and continuous data quality management using a novel software tool, Aquarius.

  18. 76 FR 17347 - Revision to the California State Implementation Plan, Great Basin Unified Air Pollution Control...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-29

    ...) * * * (D) Great Basin Unified Air Pollution Control District (1) Rule 201, ``Exemptions,'' adopted on... AGENCY 40 CFR Part 52 Revision to the California State Implementation Plan, Great Basin Unified Air Pollution Control District CFR Correction In Title 40 of the Code of Federal Regulations, Part 52 (Sec....

  19. San Joaquin-Tulare Conjunctive Use Model: Detailed model description

    SciTech Connect

    Quinn, N.W.T.

    1992-03-01

    The San Joaquin - Tulare Conjunctive Use Model (SANTUCM) was originally developed for the San Joaquin Valley Drainage Program to evaluate possible scenarios for long-term management of drainage and drainage - related problems in the western San Joaquin Valley of California. A unique aspect of this model is its coupling of a surface water delivery and reservoir operations model with a regional groundwater model. The model also performs salinity balances along the tributaries and along the main stem of the San Joaquin River to allow assessment of compliance with State Water Resources Control Board water quality objectives for the San Joaquin River. This document is a detailed description of the various subroutines, variables and parameters used in the model.

  20. Characterization of VOC Emissions from Various Components of Dairy Farming and their effect on San Joaquin Valley Air Quality

    NASA Astrophysics Data System (ADS)

    Yang, M. M.; Meinardi, S.; Krauter, C.; Blake, D.

    2008-12-01

    The San Joaquin Valley Air Basin in Central California is classified by the U.S. Environmental Protection Agency (EPA) as a serious non-attainment area for health-based eight-hour federal ozone (smog) standard (1). In August 2005, the San Joaquin Valley Air Pollution Control District issued a report identifying dairies as a main source of Volatile Organic Compounds (VOCs) and fine particulate matter in the valley (2). Among these compounds, we have found that ethanol, methanol, acetone and acetaldehyde are produced in major quantities throughout the San Joaquin valley as by-products of yeast fermentation of silage and photochemical oxidation. These oxygenates, especially ethanol, play an important role in ozone (O3) formation within the valley. Three different types of sampling protocols were employed in order to determine the degree of enhancement of the four oxygenates in the valley air shed, as well as to determine their sources, emission profiles and emission rates. An assessment of the emissions of these oxygenates in the valley was achieved using data obtained on low altitude flights through the valley and from ground level samples collected thoughout the valley. The photochemical production of ozone was calculated for each of the four oxygenates and approximately one hundred other quantified VOCs. Based on the Maximum Incremental Reactivity (MIR) scale and concentrations of each oxygenate in the atmosphere, as much as 20% of O3 production in the valley is from ethanol and its photochemical by-product acetaldehyde. Our findings suggest that improvement to the valley air quality may be obtained by focusing on instituting new silage containment practices and regulations. 1. Lindberg, J. "Analysis of the San Joaquin Valley 2007 Ozone Plan." State of California Air Resources Board. Final Draft Staff Report. 5/30/2007. 2. Crow, D., executive director/APCO. "Air Pollution Control Officer's Determination of VOC Emisison Factors for Dairies." San Joaquin Valley Air

  1. Potential of BLM lands in western Fresno and eastern San Benito and Monterey Counties, California, as critical habitats for the endangered San Joaquin kit fox, Vulpes macrotis mutica, and blunt-nosed leopard lizard, Crotaphytus silus

    SciTech Connect

    O'Farrell, T.P.; McCue, P.; Kato, T.

    1981-11-01

    The major objectives were to determine the presence and relative density of the San Joaquin kit fox and blunt-nosed leopard lizard on BLM lands in western Fresno and eastern San Benito and Monterey counties, California, and to determine the potential of these lands as critical habitat for these endangered species. A total of 6220 acres in the Ciervo Hills and 4000 acres near Coalinga were surveyed for both San Joaquin kit fox and blunt-nosed leopard lizards; 810 acres in the Griswold Hills were surveyed for kit fox only; and 2000 acres in the Tumey Hills were surveyed for blunt-nosed leopard lizards only. Eight line transects per mile were used to gather information on: (1) kit fox dens, scats, tracks, and remains of their prey; (2) presence of blunt-nosed leopard lizards; (3) vegetation associations; (4) density of rodent burrows on lands surveyed for leopard lizards; (5) topography; (6) evidence of human activities; (7) presence of other wildlife species; and (8) any additional scientific data related to endangered species. Night spotlight surveys were conducted in the Ciervo Hills, Griswold Hills, and on lands adjacent to Coalinga and San Ardo to document presence of kit fox, their potential prey, and other vertebrates. Of BLM land surveyed in 1981, the Coalinga Land Unit had the highest potential as critical habitat for the San Joaquin kit fox, the Ciervo Hills Land Unit was ranked second,and parcels in the Griswold Hills received the lowest score given since inventories were initiated in 1979. Public lands in the Salinas Valley were too steep to serve as habitat for kit fox. Over 70% of the parcels had only fair to no potential as critical habitat for the blunt-nosed leopard lizard. BLM lands near Coalinga and those in the central plateau of the Tumey Hills visually appeared to have some potential as habitat for the species.

  2. Possible effects of drilling operations in Section 6D, Naval Petroleum Reserve No. 2, Kern County, California on the endangered San Joaquin kit fox, blunt-nosed leopard lizard, and other sensitive species

    SciTech Connect

    O'Farrell, T.P.; Kato, T.

    1982-12-01

    Getty Oil Company requested permission from the US Department of Energy to drill 10 petroleum wells and one water disposal well in Section 6D, Naval Petroleum Reserve No. 2, Kern County, California, which is thought to provide habitat for the endangered San Joaquin kit fox and blunt-nosed leopard lizard, and two sensitive species: the giant kangaroo rat and San Joaquin antelope ground squirrel. The objective of this study was to assess the possible impacts of development drilling on these species and their essential habitats. Most of the proposed wells will be located on or near existing well pads; therefore, only 2 hectares of potential habitat will be disturbed. Although 21 kit fox dens were found, none were closer than 10 m from proposed well pads, and most were more than 40 m away. No evidence of either the blunt-nosed leopard lizard or giant kangaroo rat was gathered. Ten San Joaquin antelope ground squirrels were observed. Although 2 hectares of habitat will be disturbed, there is no evidence to indicate that any of the species has burrows that will be lost during landclearing. Loss of vegetation may have some small, unknown impacts on food supplies for species preyed upon by kit fox and blunt-nosed leopard lizards, but the disturbed vegetation represents a small fraction of the food supplies available in the surrounding habitat. Because the project poses few threats to individuals of the endangered or sensitive species surveyed, it was concluded that completion of the drilling is unlikely to jeopardize the continued existence of any of the species or their essential habitats if: (1) present kit fox dens are protected during construction activities, (2) topsoil removed during land-levelling is used to reclaim past disturbances of the habitat, and (3) artificial kit fox dens are installed to compensate for the possible loss of denning sites.

  3. Biological assessment: possible impacts of exploratory drilling in sections 8B and 18H, Naval Petroleum Reserve No. 2, Kern County, California on the endangered San Joaquin kit fox, blunt-nosed leopard lizard, and other sensitive species

    SciTech Connect

    O'Farrell, T.P.; Sauls, M.L.

    1982-07-01

    The U.S. Department of Energy proposes to drill exploratory wells on two sections, 8B and 18H, within Naval Petroleum Reserve No. 2 in western Kern County, California. The proposed sites are thought to provide habitat for the endangered San Joaquin kit fox and blunt-nosed leopard lizard, as well as two sensitive species: the giant kangaroo rat and San Joaquin antelope ground squirrel. The objective was to assess the possible impacts of the exploratory drilling on these species and their essential habitats. Although 23 potential San Joaquin kit fox den sites were found during surveys of a total of 512 ha (1280 acres) surrounding both well sites, no burrows were closer than 30 m from proposed disturbance, and most were over 200 m away. Two blunt-nosed leopard lizards were observed on private land within 8B, one was observed on private land in 18H, and two were seen on DOE portions of 18H. No evidence of blunt-nosed leopard lizards was gathered in the immediate vicinity of either proposed well site. Although 5 ha of habitat will be disturbed, there is no evidence to indicate any of the species has burrows on-site that will be lost during land clearing. Loss of habitat will be mitigated during the cleanup and restoration phases when disturbed areas will be revegetated. Increased traffic, human activities, noise and ground vibration levels, as well as illumination throughout the night, may disturb the fauna. However, these species have adapted to intensive human disturbances on Elk Hills without obvious negative effects. The short duration of the project should allow any displaced animals to return to the sites after drilling ceases.

  4. Dissolved Organic Carbon Export from Sacramento and San Joaquin River Watersheds as Impacted by Precipitation and Agricultural Land Use

    NASA Astrophysics Data System (ADS)

    Oh, N.; Pallud, C. E.

    2009-12-01

    Most of the agricultural activities in California occur within the Sacramento and San Joaquin River Basins, where, as a consequence, water quality as well as quantity have been significantly affected over the last century. Dissolved organic carbon (DOC) concentrations and fluxes from the Sacramento and San Joaquin River Basins have received much attention because riverine DOC flux is an important part of the carbon cycle connecting terrestrial and oceanic ecosystems and because DOC concentration can influence public health as a precursor of carcinogenic disinfectant byproducts (DBPs) such as trihalomethanes and haloacetic acids. Studies on the fate of DOC in watersheds and its relationship with land use are crucial to improve drinking water quality. Considering that water yield from a watershed is one of the main factors governing riverine DOC flux, it is essential to understand factors affecting riverine discharge from watersheds such as precipitation variability, wetland surface area, soil moisture content, and irrigation methods. We investigated the role of precipitation, crop species, and agricultural practices including flood irrigation on watershed water budget and DOC export from subwatersheds of the Sacramento and San Joaquin River Basins using GIS analysis. The preliminary results indicate that agricultural practices effect on DOC fluxes may deserve further attention due to its impacts on watershed water budget, which will be critical for watershed management of DBP precursors.

  5. Estimated agricultural ground-water pumpage in parts of Fresno, Kings, and Madera Counties, San Joaquin Valley, California, 1974-77

    USGS Publications Warehouse

    Mitten, Hugh T.

    1978-01-01

    Agricultural ground-water pumpage data are presented for 1974-77 for the area on the west side of the San Joaquin Valley in parts of Fresno, Kings, and Madera Counties, Calif., which has approximately the boundaries of the Westlands Water District. The method of estimating pumpage was based on electric-power consumption at the agricultual wells. (Woodard-USGS)

  6. Origin of Meter-Size Granite Basins in the Southern Sierra Nevada, California

    USGS Publications Warehouse

    Moore, James G.; Gorden, Mary A.; Robinson, Joel E.; Moring, Barry C.

    2008-01-01

    Meter-size granite basins are found in a 180-km belt extending south from the South Fork of the Kings River to Lake Isabella on the west slope of the southern Sierra Nevada, California. Their origin has long been debated. A total of 1,033 basins have been inventoried at 221 sites. The basins occur on bedrock granitic outcrops at a median elevation of 1,950 m. Median basin diameter among 30 of the basin sites varies from 89 to 170 cm, median depth is 12 to 63 cm. Eighty percent of the basin sites also contain smaller bedrock mortars (~1-2 liters in capacity) of the type used by Native Americans (American Indians) to grind acorns. Features that suggest a manmade origin for the basins are: restricted size, shape, and elevation range; common association with Indian middens and grinding mortars; a south- and west-facing aspect; presence of differing shapes in distinct localities; and location in a food-rich belt with pleasant summer weather. Volcanic ash (erupted A.D. 1240+-60) in the bottom of several of the basins indicates that they were used shortly before ~760 years ago but not thereafter. Experiments suggest that campfires built on the granite will weaken the bedrock and expedite excavation of the basins. The primary use of the basins was apparently in preparing food, including acorns and pine nuts. The basins are among the largest and most permanent artifacts remaining from the California Indian civilization.

  7. The Basin and Range Province in Utah, Nevada, and California

    USGS Publications Warehouse

    Nolan, Thomas B.

    1943-01-01

    In this report an attempt has been made to summarize and in places to interpret the published information that was available through 1938 on the geology of those parts of Nevada, California, and Utah that are included in the geologic province known as the Basin and Range province. This region includes most of the Great Basin, from which no water flows to the sea, as well as part of the drainage basin of the lower Colorado River. It is characterized by numerous parallel, linear mountain ranges that are separated from one another by wide valleys or topographic basins. All the major divisions of geologic time are represented by the rocks exposed in this region. The oldest are of pre-Cambrian age and crop out chiefly along the eastern and southern borders. They have been carefully studied at only a few localities, and the correlation and extent of the subdivision so far recognized is uncertain. There appear to be at least three series of pre-Cambrian rocks which are probably separated from one another by profound unconformities. Large masses of intrusive igneous rocks have been recognized only in the oldest series. During the Paleozoic era the region was a part of the Cordilleran geosyncline, and sediments were deposited during all of the major and most of the minor subdivisions of the era. There are thick and widespread accumulations of Cambrian and Ordovician strata, the maximum aggregate thickness possibly exceeding 23,000 feet. The eastern and western boundaries of the province were approximately those of the area of rapid subsidence within the geosyncline, though the axes of maximum subsidence oscillated back and forth during the two periods. The Silurian and Devonian seas, on the other hand, extended beyond the province and, possibly as a consequence, are represented by much thinner sections - of the order of 6,000 feet. At the end of the Devonian period the geosyncline was split by the emergence of a geanticline in western Nevada, and Mississippian and

  8. Geology of the Tulare Formation and other continental deposits, Kettleman City area, San Joaquin Valley, California, with a section on ground-water management considerations and use of texture maps

    USGS Publications Warehouse

    Page, R.W.

    1983-01-01

    The Tulare Formation and other continental deposits of Pliocene to Holocene age crop out over most of the area near Kettleman City in the San Joaquin Valley of California. The deposits range in thickness from 0 to more than 4,000 feet and overlie the upper Mya zone of the San Joaquin Formation of Pliocene age. Some features of their base reflect structural deformation during Quaternary time. Many freshwater fossils occur in the Tulare Formation itself, including the largest fossil assemblage of clams and snails known on the Pacific Coast. Sediments in the Tulare Formation and other continental deposits consist mainly of unconsolidated deposits of clay, silt, sand, and gravel. Texture maps of the Tulare Formation and other continental deposits show the distribution, both laterally and vertically, of the coarse- and fine-grained sediment in the area. Such maps can be used by water managers for selecting areas for recharge and discharge operations and by ground-water modelers for assigning relative values of hydraulic conductivity and storage coefficient. (USGS)

  9. Holocene faulting in the western Basin and Range, California

    SciTech Connect

    Bryant, W.A. . Div. of Mines and Geology)

    1993-04-01

    Principal late Quaternary faults in the Basin and Range Geomorphic Province of eastern and northeastern California were evaluated for evidence of Holocene surface fault rupture as part of DMG's Fault Evaluation and Zoning Project. Those faults considered to have been active in Holocene time were zoned for special studies in order to mitigate surface fault rupture hazard as authorized by the Alquist-Priolo Special Studies Zones Act of 1972. Thirty-seven faults or fault zones were evaluated from the southern Sierra Nevada east to Death Valley and north to Surprise Valley. About 70% of these faults have evidence of Holocene displacement. Slip-rates for 20 faults have been determined by others or were estimated during this study. It is difficult to categorize slip-rates in this region because fault zones often are characterized by a complex history of both right-lateral strike-slip (rlss) and normal dip-slip displacement include the Death Valley, Deep Springs, Genoa, Hilton Creek, Honey Lake, Owens Valley, and Panamint Valley faults. All but 2 of these faults (Deep Springs and Genoa) have correspondingly high slip-rates [>=] 2mm/yr. The Death Valley, Honey Lake, Owens Valley, and Panamint Valley faults are characterized primarily by rlss displacement; the other 3 faults have predominantly normal displacement. Most of the faults considered to have primarily vertical displacement are characterized by maximum vertical slip-rates less than 1mm/yr. Range-front faults with maximum vertical slip-ra