Spokane Valley-Rathdrum Prairie aquifer, Washington and Idaho

USGS Publications Warehouse

Drost, B.W.; Seitz, Harold R.

1977-01-01

The Spokane Valley-Rathdrum Prairie aquifer is composed of unconsolidated Quaternary glaciofluvial deposits underlying an area of about 350 square miles. Transmissivities in the aquifer range from about 0.13 million to 11 million feet squared per day and ground-water velocities exceed 60 feet per day in some areas. The water-table gradient ranges from about 2 feet per mile to more than 60 feet per mile, and during a year the water table fluctuates on the order of 5 to 10 feet. For most of the aquifer the water table is between 40 and 400 feet below land surface. The aquifer is recharged and discharged at an average rate of about 1,320 cubic feet per second. Water is presently (1976) pumped from the aquifer at an average rate of about 239 cubic feet per second for domestic, industrial, and agricultural uses. Most of this is discharged to the Spokane River, lost to evapotranspiration, or applied to the land surface with little or no change in quality. However, about 34 cubic feet per second becomes waste water generated by domestic and industrial activities and is returned to the aquifer by percolation from cesspools and drain fields. The quality of water in the aquifer is generally good. Less than one-half of 1 percent of the 3,300 analyses available exceeded the maximum contaminant levels specified in the National Interim Primary (or Proposed Secondary) Drinking Water Regulations (U.S. Environmental Protection Agency, 1975) for constituents which may be hazardous to health. Of the 6,300 analyses for constituents considered detrimental to the esthetic quality of water, about 1.4 percent have yielded values which exceeded the recommended levels. Alternative water sources for the area supplied by the aquifer are the Spokane and Little Spokane Rivers, lakes adjacent to the aquifer, and other aquifers. All of these potential sources are less desirable than the Spokane Valley-Rathdrum Prairie aquifer because of insufficient supplies, poor water quality, and (or

The quality of our Nation's waters: water quality in the Mississippi embayment-Texas coastal uplands aquifer system and Mississippi River Valley alluvial aquifer, south-central United States, 1994-2008

USGS Publications Warehouse

Kingsbury, James A.; Barlow, Jeannie R.; Katz, Brian G.; Welch, Heather L.; Tollett, Roland W.; Fahlquist, Lynne S.

2015-01-01

About 8 million people rely on groundwater from the Mississippi embayment—Texas coastal uplands aquifer system for drinking water. The Mississippi River Valley alluvial aquifer also provides drinking water for domestic use in rural areas but is of primary importance to the region as a source of water for irrigation. Irrigation withdrawals from this aquifer are among the largest in the Nation and play a key role in the economy of the area, where annual crop sales total more than $7 billion. The reliance of the region on both aquifers for drinking water and irrigation highlights the importance of long-term management to sustain the availability and quality of these resources.

Geohydrology of the Valley-Fill Aquifers between the Village of Greene, Chenango County and Chenango Valley State Park, Broome County, New York

USGS Publications Warehouse

Hetcher-Aguila, Kari K.; Miller, Todd S.

2005-01-01

The confined aquifer is widely used by people living and working in the Chenango River valley. The confined aquifer consists of ice-contact sand and gravel, typically overlies bedrock, and underlies a confining unit consisting of lacustrine fine sand, silt, and clay. The confining unit is typically more than 100 feet thick in the central parts of the valley between Greene Landing Field and along the northern edge of the Chenango Valley State Park. The thickness of the confined aquifer is more than 40 feet near the Greene Landing Field.

Lateral groundwater inflows into alluvial aquifers of main alpine valleys

NASA Astrophysics Data System (ADS)

Burger, Ulrich

2015-04-01

In alpine regions the topography is mainly characterised by deep incised valleys, mountain slopes and ridges. Usually the main valleys contain aquifers in alluvial soft rock. Lateral these aquifers are confined by mountainous hard rock slopes covered by heterogeneous sediments with different thickness. The slopes can be incised by lateral valleys. Numerical models for the main alluvial aquifers ask for lateral hydrogeological boundaries. Usually no flow boundaries or Constant head Boundaries are used, even if the lateral inflows to the main aquifers are rarely known. In this example a data set for a detailed investigated and monitored area is studied to give an answer on the location and the quantification of these lateral subsurface inflows. The study area is a typical main alpine valley with a thick alluvial aquifer (appr. 120m thick), lateral confined by granite, covered at the base of the steep slopes by quaternary sediments (Burger at al. 2012). The study consists of several steps 1.) Analytical calculation of the inflows on the base of investigated and monitored 2d profiles along fault zones (Perello et al 2013) which pinch out in the main valley 2.) Analytical models along typical W-dipping slopes with monitored slope springs 3.) Evaluating temperature and electrical conductivity profiles measured in approx. 30 groundwater wells in the alluvial aquifers and along the slopes to locate main lateral subsurface inflows 4.) Output of a regional model used for the hydrogeological back analyses of the excavation of a tunnel (Baietto et al. 2014) 5.) Output of a local numerical model calibrated with a monitoring dataset and results of a pumping test of big scale (450l/s for 10days) Results of these analyses are shown to locate and quantify the lateral groundwater inflows in the main alluvial aquifer. References Baietto A., Burger U., Perello P. (2014): Hydrogeological modelling applications in tunnel excavations: examples from tunnel excavations in granitic rocks

A plan to study the aquifer system of the Central Valley of California

USGS Publications Warehouse

Bertoldi, Gilbert L.

1979-01-01

Unconsolidated Quaternary alluvial deposits comprise a large complex aquifer system in the Central Valley of California. Millions of acre-feet of water is pumped from the system annually to support a large and expanding agribusiness industry. Since the 1950's, water levels have been steadily declining in many areas of the valley and concern has been expressed about the ability of the entire ground-water system to support agribusiness at current levels, not to mention its ability to function at projected expansion levels. At current levels of ground-water use, an estimated 1.5 to 2 million acre-feet is withdrawn from storage each year; that is, 1.5 to 2 million acre-feet of water is pumped annually in excess of annual replenishment. The U.S. Geological Survey has initiated a 4-year study to develop geologic, hydrologic, and hydraulic information and to establish a valleywide ground-water data base that will be used to build computer models of the ground-water flow system. Subsequently, these models may be used to evaluate the system response to various ground-water management alternatives. This report describes current problems, objectives of the study, and outlines the general work to be accomplished in the study area. A bibliography of about 600 references is included. (Kosco-USGS)

Hydrology of the Little Androscoggin River Valley aquifer, Oxford County, Maine

USGS Publications Warehouse

Morrissey, D.J.

1983-01-01

The Little Androscoggin River valley aquifer, a 15-square-mile sand and gravel valley-fill aquifer in southwestern Maine, is the source of water for the towns of Norway, Oxford, and South Paris. Estimated inflows to the aquifer during the 1981 water year were 16.4 cubic feet per second from precipitation directly on the aquifer, 11.2 cubic feet per second from till covered uplands adjacent to the aquifer, and 1.4 cubic feet per second from surface-water leakage. Outflows from the aquifer were 26.7 cubic feet per second to surface water and 2.3 cubic feet per second to wells. A finite-difference ground-water flow model was used to simulate conditions observed in the aquifer during 1981. Model conditions observed in the aquifer during 1981. Model simulations indicate that a 50 percent reduction of average 1981 recharge to the aquifer would cause water level declines of up to 20 feet in some areas. Model simulations of increased pumping at a high yield well in the northern part of the aquifer indicate that resulting changes in the water table will not be sufficient to intercept groundwater contaminated by a sludge disposal site. Water in the aquifer is low in dissolved solids (average for 38 samples was 67 mg/L), slightly acidic and soft. Ground-water contamination has occurred near a sludge-disposal site and in the vicinity of a sanitary landfill. Dissolved solids in ground water near the sludge disposal site were as much as ten times greater than average background values for the aquifer. (USGS)

Nitrate Contamination of Deep Aquifers in the Salinas Valley, California

NASA Astrophysics Data System (ADS)

Moran, J. E.; Esser, B. K.; Hillegonds, D. J.; Holtz, M.; Roberts, S. K.; Singleton, M. J.; Visser, A.; Kulongoski, J. T.; Belitz, K.

2011-12-01

The Salinas Valley, known as 'the salad bowl of the world', has been an agricultural center for more than 100 years. Irrigated row crops such as lettuce and strawberries dominate both land use and water use. Groundwater is the exclusive supply for both irrigation and drinking water. Some irrigation wells and most public water supply wells in the Salinas Valley are constructed to draw water from deep portions of the aquifer system, where contamination by nitrate is less likely than in the shallow portions of the aquifer system. However, a number of wells with top perforations greater than 75 m deep, screened below confining or semi-confining units, have nitrate concentrations greater than the Maximum Contaminant Limit (MCL) of 45 mg/L as NO3-. This study uses nitrate concentrations from several hundred irrigation, drinking water, and monitoring wells (Monterey County Water Resources Agency, 1997), along with tritium-helium groundwater ages acquired at Lawrence Livermore National Laboratory through the State of California Groundwater Monitoring and Assessment (GAMA) program (reported in Kulongoski et al., 2007 and in Moran et al., in press), to identify nitrate 'hot spots' in the deep aquifer and to examine possible modes of nitrate transport to the deep aquifer. In addition, observed apparent groundwater ages are compared with the results of transport simulations that use particle tracking and a stochastic-geostatistical framework to incorporate aquifer heterogeneity to determine the distribution of travel times from the water table to each well (Fogg et al., 1999). The combined evidence from nitrate, tritium, tritiogenic 3He, and radiogenic 4He concentrations, reveals complex recharge and flow to the capture zone of the deep drinking water wells. Widespread groundwater pumping for irrigation accelerates vertical groundwater flow such that high nitrate groundwater reaches some deep drinking water wells. Deeper portions of the wells often draw in water that recharged

Santa Clara Valley water district multi-aquifer monitoring-well site, Coyote Creek Outdoor Classroom, San Jose, California

USGS Publications Warehouse

Hanson, R.T.; Newhouse, M.W.; Wentworth, C.M.; Williams, C.F.; Noce, T.E.; Bennett, M.J.

2002-01-01

The U.S. Geological Survey (USGS), in cooperation with the Santa Clara Valley Water District (SCVWD), has completed the first of several multiple-aquifer monitoring-well sites in the Santa Clara Valley. This site monitors ground-water levels and chemistry in the one of the major historic subsidence regions south of San Jose, California, at the Coyote Creek Outdoor Classroom (CCOC) (fig. 1) and provides additional basic information about the geology, hydrology, geochemistry, and subsidence potential of the upper- and lower-aquifer systems that is a major source of public water supply in the Santa Clara Valley. The site also serves as a science education exhibit at the outdoor classroom operated by SCVWD.

Detection of aquifer system compaction and land subsidence using interferometric synthetic aperture radar, Antelope Valley, Mojave Desert, California

USGS Publications Warehouse

Galloway, D.L.; Hudnut, K.W.; Ingebritsen, S.E.; Phillips, S.P.; Peltzer, G.; Rogez, F.; Rosen, P.A.

1998-01-01

Interferometric synthetic aperture radar (InSAR) has great potential to detect and quantify land subsidence caused by aquifer system compaction. InSAR maps with high spatial detail and resolution of range displacement (±10 mm in change of land surface elevation) were developed for a groundwater basin (∼103 km2) in Antelope Valley, California, using radar data collected from the ERS-1 satellite. These data allow comprehensive comparison between recent (1993–1995) subsidence patterns and those detected historically (1926–1992) by more traditional methods. The changed subsidence patterns are generally compatible with recent shifts in land and water use. The InSAR-detected patterns are generally consistent with predictions based on a coupled model of groundwater flow and aquifer system compaction. The minor inconsistencies may reflect our imperfect knowledge of the distribution and properties of compressible sediments. When used in conjunction with coincident measurements of groundwater levels and other geologic information, InSAR data may be useful for constraining parameter estimates in simulations of aquifer system compaction.

Quantifying large scale deformation and aquifer properties over Central Valley, California using a combination of InSAR, GPS and hydraulic head level data

NASA Astrophysics Data System (ADS)

Ojha, C.; Shirzaei, M.; Werth, S.; Argus, D. F.

2016-12-01

California's Central Valley is one of the largest productive agricultural regions in the world, which heavily relies on the underground water supply. As a result of pumping and recharge processes, the aquifer systems compact and expand, which is manifested in quasi-cyclic changes in the surface elevation and observations of hydraulic head levels. On the other hand, over last century, due to overdrafting of aquifer systems the volume of groundwater has substantially reduced, which causes irreversible decline in surface elevation. The aquifer storativity, characterizing the capacity of an aquifer to release groundwater, is affected by the excess vertical strain and permanent deformation. To quantify the capacity of the Central Valley aquifer systems to release fresh water, a valley-wide estimate of the storativity is required. Hence, we performed a joint analysis of large set of interferometric SAR and GPS data sets in conjunction with well data across the valley. In this context, we used L-band set of 420 ALOS-PALSAR SAR images. The data has been processed to generate 1604 SAR interferograms, using a pixel dimension of about 100 m x 100 m and imposing a maximum spatial and temporal baseline threshold of 2000 meter and 1500 days, respectively. In this study we rigorously integrate >500 permanent GPS stations and InSAR data to determine a time series of line of sight changes in a reference frame fixed to (CM) the center of mass of solid Earth. The result highlights an overall map of surface deformation over the entire Central valley region, due to interseismic strain accumulation along San Andreas fault system and compaction of aquifer systems. In the southern part of Central Valley i.e., San Joaquin Valley, which includes the San Joaquin and Tulare Basins, has experienced large changes in groundwater storage during the drought period. As a result, total land subsidence of 0.30-0.50 m has observed [Farr and Liu 2015], adjacent to creeping rate of 20-30 mm/year along

Hydrogeology of the stratified-drift aquifers in the Cayuta Creek and Catatonk Creek valleys in parts of Tompkins, Schuyler, Chemung, and Tioga Counties, New York

USGS Publications Warehouse

Miller, Todd S.; Pitman, Lacey M.

2012-01-01

The surficial deposits, areal extent of aquifers, and the water-table configurations of the stratified-drift aquifer systems in the Cayuta Creek and Catatonk Creek valleys and their large tributary valleys in Tompkins, Schuyler, Chemung, and Tioga Counties, New York were mapped in 2009, in cooperation with the New York State Department of Environmental Conservation. Well and test-boring records, surficial deposit maps, Light Detection and Ranging (LIDAR) data, soils maps, and horizontal-to-vertical ambient-noise seismic surveys were used to map the extent of the aquifers, construct geologic sections, and determine the depth to bedrock (thickness of valley-fill deposits) at selected locations. Geologic materials in the study area include sedimentary bedrock, unstratified drift (till), stratified drift (glaciolacustrine and glaciofluvial deposits), and recent alluvium. Stratified drift consisting of glaciofluvial sand and gravel is the major component of the valley fill in this study area. The deposits are present in sufficient amounts in most places to form extensive unconfined aquifers throughout the study area and, in some places, confined aquifers. Stratified drift consisting of glaciolacustrine fine sand, silt, and clay are present locally in valleys underlying the surficial sand and gravel deposits in the southern part of the Catatonk Creek valley. These unconfined and confined aquifers are the source of water for most residents, farms, and businesses in the valleys. A generalized depiction of the water table in the unconfined aquifer was constructed using water-level measurements made from the 1950s through 2010, as well as LIDAR data that were used to determine the altitudes of perennial streams at 10-foot contour intervals and water surfaces of ponds and wetlands that are hydraulically connected to the unconfined aquifer. The configuration of the water-table contours indicate that the general direction of groundwater flow within Cayuta Creek and Catatonk

Hydrogeology and water quality of the Shell Valley Aquifer, Rolette County, North Dakota

USGS Publications Warehouse

Strobel, M.L.

1997-01-01

The Shell Valley aquifer is the sole source of water for the city of Belcourt and the primary source of water for most of the Turtle Mountain Indian Reservation. The Turtle Mountain Band of Chippewa Indians is concerned about the quantity and quality of water in the Shell Valley aquifer, which underlies about 56 square miles in central Rolette County and has an average saturated thickness of about 35 feet. Water levels across most of the Shell Valley aquifer fluctuate with variations in precipitation but generally are stable. Withdrawals from the north well field decreased slightly during 1976-95, but withdrawals from the south well field increased during 1983-95. Water levels in the south well field declined as withdrawals increased. The average decline during the last 8 years was about 1.75 feet per year. The water level has reached the well screen in at least one of the production wells. Most of the water in the aquifer is a bicarbonate type and has dissolved-solids concentrations ranging from 479 to 1,510 milligrams per liter. None of the samples analyzed had detectable concentrations of pesticides, but hydrocarbons were detected in both ground- and surfacewater samples. Polycyclic aromatic hydrocarbons (PAH) were the most frequently detected hydrocarbons. Benzene, toluene, ethylbenzene, and xylene (BTEX), polychlorinated biphenyls (PCB), and pentachlorophenol (PCP) also were detected.Generally, the Shell Valley aquifer is an adequate source of water for current needs, but evaluation of withdrawals in relation to a knowledge of aquifer hydrology would be important in quantifying sustainable water supplies. Water quality in the aquifer generally is good; the Turtle Mountain Band of Chippewa Indians filters the water to reduce concentrations of dissolved constituents. Hydrocarbons, although present in the aquifer, have not been quantified and may not pose a general health risk. Further analysis of the quantity and distribution of the hydrocarbons would be useful

Linking groundwater use and stress to specific crops using the groundwater footprint in the Central Valley and High Plains aquifer systems, U.S.

NASA Astrophysics Data System (ADS)

Esnault, Laurent; Gleeson, Tom; Wada, Yoshihide; Heinke, Jens; Gerten, Dieter; Flanary, Elizabeth; Bierkens, Marc F. P.; van Beek, Ludovicus P. H.

2014-06-01

A number of aquifers worldwide are being depleted, mainly by agricultural activities, yet groundwater stress has not been explicitly linked to specific agricultural crops. Using the newly developed concept of the groundwater footprint (the area required to sustain groundwater use and groundwater-dependent ecosystem services), we develop a methodology to derive crop-specific groundwater footprints. We illustrate this method by calculating high-resolution groundwater footprint estimates of crops in two heavily used aquifer systems: the Central Valley and High Plains, U.S. In both aquifer systems, hay and haylage, corn, and cotton have the largest groundwater footprints, which highlights that most of the groundwater stress is induced by crops meant for cattle feed. Our results are coherent with other studies in the High Plains but suggest lower groundwater stress in the Central Valley, likely due to artificial recharge from surface water diversions which were not taken into account in previous estimates. Uncertainties of recharge and irrigation application efficiency contribute the most to the total relative uncertainty of the groundwater footprint to aquifer area ratios. Our results and methodology will be useful for hydrologists, water resource managers, and policy makers concerned with which crops are causing the well-documented groundwater stress in semiarid to arid agricultural regions around the world.

Linking Groundwater Use and Stress to Specific Crops Using the Groundwater Footprint in the Central Valley and High Plains Aquifer Systems, U.S.

NASA Astrophysics Data System (ADS)

Wada, Y.; Esnault, L.; Gleeson, T.; Heinke, J.; Gerten, D.; Flanary, E.; Bierkens, M. F.; Van Beek, L. P.

2014-12-01

A number of aquifers worldwide are being depleted, mainly by agricultural activities, yet groundwater stress has not been explicitly linked to specific agricultural crops. Using the newly-developed concept of the groundwater footprint (the area required to sustain groundwater use and groundwater-dependent ecosystem services), we develop a methodology to derive crop-specific groundwater footprints. We illustrate this method by calculating high resolution groundwater footprint estimates of crops in two heavily used aquifer systems: the Central Valley and High Plains, U.S. In both aquifer systems, hay and haylage, corn and cotton have the largest groundwater footprints, which highlights that most of the groundwater stress is induced by crops meant for cattle feed. Our results are coherent with other studies in the High Plains but suggest lower groundwater stress in the Central Valley, likely due to artificial recharge from surface water diversions which were not taken into account in previous estimates. Uncertainties of recharge and irrigation application efficiency contribute the most to the total relative uncertainty of the groundwater footprint to aquifer area ratios. Our results and methodology will be useful for hydrologists, water resource managers, and policy makers concerned with which crops are causing the well-documented groundwater stress in semiarid to arid agricultural regions around the world.

Hydrogeology of the Ramapo River-Woodbury Creek valley-fill aquifer system and adjacent areas in eastern Orange County, New York

USGS Publications Warehouse

Heisig, Paul M.

2015-01-01

Valley-fill aquifers are modest resources within the area, as indicated by the common practice of completing supply wells in the underlying bedrock rather than the overlying glacial deposits. Groundwater turbidity problems curtail use of the resource. However, additional groundwater resources have been identified by test drilling, and there are remaining untested areas. New groundwater supplies that stress localized aquifer areas will alter the groundwater flow system. Considerations include potential water-quality degradation from nearby land use(s) and, where withdrawals induce infiltration of surface-water, balancing withdrawals with flow requirements for downstream users or for maintenance of stream ecological health.

Geohydrology, water quality, and simulation of groundwater flow in the stratified-drift aquifer system in Virgil Creek and Dryden Lake Valleys, Town of Dryden, Tompkins County, New York

USGS Publications Warehouse

Miller, Todd S.; Bugliosi, Edward F.

2013-01-01

In 2002, the U.S. Geological Survey, in cooperation with the Tompkins County Planning Department and the Town of Dryden, New York, began a study of the stratified-drift aquifer system in the Virgil Creek and Dryden Lake Valleys in the Town of Dryden, Tompkins County. The study provided geohydrologic data needed by the town and county to develop a strategy to manage and protect their water resources. In this study area, three extensive confined sand and gravel aquifers (the upper, middle, and lower confined aquifers) compose the stratified-drift aquifer system. The Dryden Lake Valley is a glaciated valley oriented parallel to the direction of ice movement. Erosion by ice extensively widened and deepened the valley, truncated bedrock hillsides, and formed a nearly straight, U-shaped bedrock trough. The maximum thickness of the valley fill in the central part of the valley is about 400 feet (ft). The Virgil Creek Valley in the east part of the study area underwent less severe erosion by ice than the Dryden Lake Valley, and hence, it has a bedrock floor that is several hundred feet higher in altitude than that in the Dryden Lake Valley. The sources and amounts of recharge were difficult to identify in most areas because the confined aquifers are overlain by confining units. However, in the vicinity of the Virgil Creek Dam, the upper confined aquifer crops out at land surface in the floodplain of a gorge eroded by Virgil Creek, and this is where the aquifer receives large amounts of recharge from precipitation that directly falls over the aquifer and from seepage losses from Virgil Creek. The results of streamflow measurements made in Virgil Creek where it flows through the gorge indicated that the stream lost 1.2 cubic feet per second (ft3/s) or 0.78 million gallons per day (Mgal/d) of water in the reach extending from 220 ft downstream from the dam to 1,200 ft upstream from the dam. In the southern part of the study area, large amounts of recharge also replenish the

Preliminary study of the aquifers of the lower Mesilla Valley in Texas and New Mexico by model simulation

USGS Publications Warehouse

Gates, J.S.; White, D.E.; Leggat, E.R.

1984-01-01

Because the salinity of water in all three aquifers south of Canutillo is greater than elsewhere in the study area, there is potential for movement of this water northward toward the Canutillo well field if the cone of depression reaches that part of the aquifer system. This potential should be evaluated in future geohydrologic studies of the lower Mesilla Valley.

Potential for aquifer compaction, land subsidence, and earth fissures in Avra Valley, Pima and Pinal counties, Arizona

USGS Publications Warehouse

Anderson, S.R.

1987-01-01

Avra Valley is a large north-trending alluvial basin about 15 mi west of Tucson in Pima and Pinal Counties, Arizona. The climate of Avra Valley is semiarid, and the average annual precipitation ranges from 8 to 12 in. Two major ephemeral streams, the Santa Cruz River and Brawley Wash, drain the area. These streams and their tributaries provide a source of recharge to an extensive alluvial aquifer that underlies the valley floor. The aquifer consists of interbedded gravel, sand, silt, and clay and contains a vast quantity of groundwater. The physiography, fertile soil, and mild climate of Avra Valley make it an ideal environment for agriculture and urban development. Although the aquifer is replenished by natural recharge and underflow, rates of recharge and underflow have not kept pace with the rate of pumping. Pumping has exceeded recharge for several decades, resulting in a lowering of groundwater levels throughout most of the valley. In places, water level declines have resulted in small amounts of aquifer compaction and land subsidence. Earth fissures, some of which may be the result of localized differential subsidence, also have been observed in the valley. Geohydrologic characteristics of Avra Valley that may contribute to potential aquifer compaction, land subsidence, and earth fissures are described. The quantitative evaluation of potential land subsidence in this report is presented as an interim land- and water-use planning tool pending acquisition and study of additional data. Because of data limitations, the evaluation is made on the assumption that future rates of compaction and subsidence in Avra Valley will be similar to those in the Eloy-Picacho area. The evaluation also assumes that water level declines in the aquifer will continue. Several factors that may reduce groundwater withdrawals, and thus the potential for compaction and subsidence in Avra Valley, were not evaluated. These factors include the enactment of the 1980 Arizona Ground

Groundwater quality in the Santa Clara River Valley, California

USGS Publications Warehouse

Burton, Carmen A.; Landon, Matthew K.; Belitz, Kenneth

2011-01-01

The Santa Clara River Valley (SCRV) study unit is located in Los Angeles and Ventura Counties, California, and is bounded by the Santa Monica, San Gabriel, Topatopa, and Santa Ynez Mountains, and the Pacific Ocean. The 460-square-mile study unit includes eight groundwater basins: Ojai Valley, Upper Ojai Valley, Ventura River Valley, Santa Clara River Valley, Pleasant Valley, Arroyo Santa Rosa Valley, Las Posas Valley, and Simi Valley (California Department of Water Resources, 2003; Montrella and Belitz, 2009). The SCRV study unit has hot, dry summers and cool, moist winters. Average annual rainfall ranges from 12 to 28 inches. The study unit is drained by the Ventura and Santa Clara Rivers, and Calleguas Creek. The primary aquifer system in the Ventura River Valley, Ojai Valley, Upper Ojai Valley, and Simi Valley basins is largely unconfined alluvium. The primary aquifer system in the remaining groundwater basins mainly consists of unconfined sands and gravels in the upper portion and partially confined marine and nonmarine deposits in the lower portion. The primary aquifer system in the SCRV study unit is defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health (CDPH) database. Public-supply wells typically are completed in the primary aquifer system to depths of 200 to 1,100 feet below land surface (bls). The wells contain solid casing reaching from the land surface to a depth of about 60-700 feet, and are perforated below the solid casing to allow water into the well. Water quality in the primary aquifer system may differ from the water in the shallower and deeper parts of the aquifer. Land use in the study unit is approximately 40 percent (%) natural (primarily shrubs, grassland, and wetlands), 37% agricultural, and 23% urban. The primary crops are citrus, avocados, alfalfa, pasture, strawberries, and dry beans. The largest urban areas in the study unit are the cities of

Hydrogeologic Appraisal of the Valley-Fill Aquifer in the Port Jervis Trough, Sullivan and Ulster Counties, New York

USGS Publications Warehouse

Reynolds, Richard J.

2007-01-01

The nature and extent of valley-fill aquifers in the Port Jervis Trough was evaluated for a 16 mile section of this valley from the Orange-Sullivan County line near Westbrookville to the village of Napanoch in Ulster County as part of the U.S. Geological Survey's Detailed Aquifer Mapping Program in New York State. The principal aquifer in the Port Jervis Trough is a 50 feet thick outwash aquifer that extends from the Phillipsport Moraine near Summitville, southward through the study area to Port Jervis, N.Y. Previous studies had estimated as much as 500 feet of saturated drift in parts of the Trough, but new well data show that much of the valley fill consists of fine-grained lacustrine sediments. Drillers' logs show that the outwash aquifer south of Summitville is underlain by as much as 275 feet of lacustrine silt and clay. North of the Phillipsport Moraine, three large glaciolacustrine deltas that were built into Glacial Lake Wawarsing provide some local and discontinuous confined aquifers through their coarser bottomset beds. Elsewhere in the Trough, collapsed and buried portions of kame deltas and terraces provide local confined aquifers. The outwash aquifer appears to be very transmissive, as evidenced by the high specific capacity of 130 gallons per minute per foot [(gal/min)/ft] of a commercial test well screened in the aquifer.

Ground water recharge to the aquifers of northern San Luis Valley, Colorado: A remote sensing investigation

NASA Technical Reports Server (NTRS)

Lee, K. (Principal Investigator); Huntley, D.

1976-01-01

The author has identified the following significant results. Ground water recharge to the aquifers of San Luis Valley west of San Luis Creek was primarily from ground water flow in the volcanic aquifers of the San Juan Mountains. The high permeability and anisotropic nature of the volcanic rocks resulted in very little contrast in flow conditions between the San Juan Mountains and San Luis Valley. Ground water recharge to aquifers of eastern San Luis Valley was primarily from stream seepage into the upper reaches of the alluvial fans at the base of the Sangre de Cristo Mountains. The use of photography and thermal infrared imagery resulted in a savings of time and increase in accuracy in regional hydrogeologic studies. Volcanic rocks exhibited the same spectral reflectance curve as sedimentary rocks, with only the absolute magnitude of reflectance varying. Both saline soils and vegetation were used to estimate general ground water depths.

Hydrogeologic Framework and Ground-Water Budget of the Spokane Valley-Rathdrum Prairie Aquifer, Spokane County, Washington, and Bonner and Kootenai Counties, Idaho

USGS Publications Warehouse

Kahle, Sue C.; Bartolino, James R.

2007-01-01

to more than 135 feet. The altitude of the base of the aquifer ranges from less than 1,800 feet near Lake Pend Oreille to less than 1,200 feet near the aquifer's outlet near Long Lake. The thickness of the aquifer is more than 800 feet in the northwestern part of the northern Rathdrum Prairie, through the West Channel area, and through the west-central part of the Rathdrum Prairie. In Washington, the areas of greatest thickness, more than 600 feet, are mapped in the central parts of the Spokane Valley, Spokane, and the Hillyard Trough. Recharge or inflow to the SVRP aquifer occurs from six main sources: the Spokane River, lakes, infiltration from precipitation over the aquifer, tributaries, infiltration from landscape irrigation and septic systems, and subsurface inflow. Discharge or outflow from the SVRP aquifer occurs from five main sources: the Spokane River, the Little Spokane River, pumpage, subsurface discharge to Long Lake, and infiltration of ground water to sewers. Total estimated mean annual inflow to and outflow from the SVRP aquifer is about 1,470 cubic feet per second. Several data needs were identified during this investigation that would improve the definition of the hydrogeologic framework and ground-water budget components for the SVRP aquifer study area. Deep drilling along the axis of the aquifer could determine the depth to the bottom of the aquifer where data are currently unavailable as well as identify the presence of fine-grained layers and their thickness. A more detailed analysis of the geologic and hydrologic setting near the southern ends of Spirit and Hoodoo Valleys could help determine the location of the ground-water divide between the two valleys and the Rathdrum Prairie. Better estimates of seepage into the aquifer from Coeur d'Alene Lake and Lake Pend Oreille and underflow from the aquifer to Long Lake would strengthen the recharge and discharge estimates of the aquifer. A hydrochemical study incorporating analyses of envi

Hydrogeologic Heterogeneity Enhances the Transfer of Salt Toward the High-Quality Deep Aquifers of the Western San Joaquin Valley (CA, USA)

NASA Astrophysics Data System (ADS)

Henri, C. V.; Harter, T.; Zhang, H.

2016-12-01

Increasing anthropogenic and drought stresses lead salinity to be of serious concern within regard to with the sustainability of regional groundwater quality. Agricultural basins of the Central Valley, CA (USA) are, and will continue to be, impacted by salinity issues in the coming future decades and or centuries. The aquifer system below the Western San Joaquin Valley is characterized by a shallow unconfined aquifer with high salinity overlying high quality semi-confined and deeper confined aquifers. A key challenge in the area is to predict if, when and how water traveling from the the low-quality shallow groundwater will reach and degrade the deeper semi-confined and confined aquifers. Previous studies, accounting for a simplified description of the aquifer hydraulic properties in their flow model, concluded that saline shallow groundwater would need 200-400 years to reach the semi-confined aquifer and 250-600 years to impact the deeper confined aquifer. However, well known heterogeneities in aquifer hydraulic properties significantly impact contaminant transport due to preferential flow paths and increased dispersion. Our study aims to (1) better understand the impact of heterogeneous hydraulic properties on the distribution of travel times from non-point source contamination, and (2) reassess the temporal scale of salt transfer into the deeper aquifers of the Western San Joaquin Valley. A detailed non-stationary geostatistical model was developed to describe the spatial variability of hydrofacies in great detail at the basin scale. The hydraulic properties corresponding to each hydrofacies are then calibrated in order to reproduce water fluxes previously modeled and calibrated. Subsequently, we use the random-walk particle tracking method to simulate the advective-dispersive transport of salt throughout the study area from a non-point source zone represented by the entire top layer of the model. The flux concentrations of solute crossing a series of monitoring

Geohydrology of the Valley-Fill Aquifer in the Norwich-Oxford-Brisben Area, Chenango County, New York

USGS Publications Warehouse

Hetcher, Kari K.; Miller, Todd S.; Garry, James D.; Reynolds, Richard J.

2003-01-01

This set of maps and geohydrologic sections depicts the geology and hydrology of aquifers in the 21.9-square-mile reach of the Chenango River valley between Brisben and North Norwich, N.Y. This report depicts the principal geographic features of the study area; locations of domestic, commercial, and municipal wells from which data were obtained to construct water-table and saturated-thickness maps and five geohydrologic sections; surficial geology; water-table altitude; generalized saturated thickness of the unconfined (water-table) aquifer; generalized thickness of the discontinuous series of confined aquifers; and five geohydrologic sections, all of which are in the northern part of the study area.The unconsolidated material in the Chenango River valley consists primarily of three types of deposits: (1) glaciofluvial material consisting of stratified coarse-grained sediment (sand and gravel) that was deposited by meltwater streams flowing above, below, or next to a glacier; (2) glaciolacustrine material consisting of stratified fine-grained sediment (very fine sand, silt, and clay) that was deposited in lakes that formed at the front of a glacier; and (3) recent alluvial material consisting of stratified fine-to-medium grained sediment (fine-to-medium sand and silt) that was deposited on flood plains.The water-table map was compiled from water-level data obtained from wells completed in the unconfined aquifer, and from altitudes of stream and river surfaces indicated on 1:24,000-scale topographic maps. Depth to the water table ranged from less than 5 feet below land surface near major streams to more than 75 feet on some of the kame terraces along the valley walls. Saturated thickness of the unconfined aquifer ranged from less than 1 foot near Norwich to more than 200 feet at a kame delta north of Oxford.A discontinuous series of confined aquifers is present throughout much of the Chenango River valley north of Oxford. These aquifers consist of kame deposits

Hydrogeologic implications of increased septic-tank-soil-absorption system density, Ogden Valley, Weber County, Utah

USGS Publications Warehouse

Lowe, Mike; Miner, Michael L.; ,

1990-01-01

Ground water in Ogden Valley occurs in perched, confined, and unconfined aquifers in the valley fill to depths of 600 feet and more. The confined aquifer, which underlies only the western portion of the valley, is overlain by cleyey silt lacustrine sediments probably deposited during the Bonneville Basin's Little Valley lake cycle sometime between 90,000 and 150,000 years ago. The top of this cleyey silt confining layer is generally 25 to 60 feet below the ground surface. Unconfined conditions occur above and beyond the outer margin of the confining layer. The sediments overlying the confining layer are primarily Lake Bonneville deposits. Water samples from springs, streams, and wells around Pineview Reservoir, and from the reservoir itself, were collected and analyzed. These samples indicate that water quality in Ogden Valley is presently good. Average nitrate concentrations in the shallow unconfined aquifer increase toward the center of Ogden Valley. This trend was not observed in the confined aquifer. There is no evidence, however, of significant water-quality deterioration, even in the vicinity of Huntsville, a town that has been densely developed using septic-tank-soil-absorption systems for much of the time since it was founded in 1860.

Hydrogeology and water quality of the stratified-drift aquifer in the Pony Hollow Creek Valley, Tompkins County, New York

USGS Publications Warehouse

Bugliosi, Edward F.; Miller, Todd S.; Reynolds, Richard J.

2014-01-01

The lithology, areal extent, and the water-table configuration in stratified-drift aquifers in the northern part of the Pony Hollow Creek valley in the Town of Newfield, New York, were mapped as part of an ongoing aquifer mapping program in Tompkins County. Surficial geologic and soil maps, well and test-boring records, light detection and ranging (lidar) data, water-level measurements, and passive-seismic surveys were used to map the aquifer geometry, construct geologic sections, and determine the depth to bedrock at selected locations throughout the valley. Additionally, water-quality samples were collected from selected streams and wells to characterize the quality of surface and groundwater in the study area. Sedimentary bedrock underlies the study area and is overlain by unstratified drift (till), stratified drift (glaciolacustrine and glaciofluvial deposits), and recent post glacial alluvium. The major type of unconsolidated, water-yielding material in the study area is stratified drift, which consists of glaciofluvial sand and gravel, and is present in sufficient amounts in most places to form an extensive unconfined aquifer throughout the study area, which is the source of water for most residents, farms, and businesses in the valleys. A map of the water table in the unconfined aquifer was constructed by using (1) measurements made between the mid-1960s through 2010, (2) control on the altitudes of perennial streams at 10-foot contour intervals from lidar data collected by Tompkins County, and (3) water surfaces of ponds and wetlands that are hydraulically connected to the unconfined aquifer. Water-table contours indicate that the direction of groundwater flow within the stratified-drift aquifer is predominantly from the valley walls toward the streams and ponds in the central part of the valley where groundwater then flows southwestward (down valley) toward the confluence with the Cayuta Creek valley. Locally, the direction of groundwater flow is radially

Hydrogeologic data update for the stratified-drift aquifer in the Sprout and Fishkill Creek valleys, Dutchess County, New York

USGS Publications Warehouse

Reynolds, Richard J.; Calef, F.J.

2011-01-01

The hydrogeology of the stratified-drift aquifer in the Sprout Creek and Fishkill Creek valleys in southern Dutchess County, New York, previously investigated by the U.S. Geological Survey (USGS) in 1982, was updated through the use of new well data made available through the New York State Department of Environmental Conservation's Water Well Program. Additional well data related to U.S. Environmental Protection Agency (USEPA) remedial investigations of two groundwater contamination sites near the villages of Hopewell Junction and Shenandoah, New York, were also used in this study. The boundary of the stratified-drift aquifer described in a previous USGS report was extended slightly eastward and southward to include adjacent tributary valleys and the USEPA groundwater contamination site at Shenandoah, New York. The updated report consists of maps showing well locations, surficial geology, altitude of the water table, and saturated thickness of the aquifer. Geographic information system coverages of these four maps were created as part of the update process.

Ground-water quality in the southeastern Sacramento Valley aquifer, California, 1996

USGS Publications Warehouse

Milby Dawson, Barbara J.

2001-01-01

processes and human activities are affecting ground-water quality in the upper part of the southeastern Sacramento Valley aquifer. The factors identified as having an influence on ground-water quality were redox condition in the aquifer, depth within the aquifer, and land use overlying the aquifer. Nitrate concentra-tions showed a statistical correlation with each of these factors. Detections of pesticides and volatile organic compounds were too few to compare concentrations with the various factors, but the types of synthetic compounds detected were consistent with the sur-rounding land use. Sixty-one percent of the wells sampled in this study showed the effect of human activities on ground-water quality in the form of a nitrate concentration over 3 milligrams per liter or a detection of a pesticide or volatile organic compound. In general, the water quality in the southeastern Sacramento Valley aquifer was found suitable for most uses.

Ground-Water Flow Model for the Spokane Valley-Rathdrum Prairie Aquifer, Spokane County, Washington, and Bonner and Kootenai Counties, Idaho

USGS Publications Warehouse

Hsieh, Paul A.; Barber, Michael E.; Contor, Bryce A.; Hossain, Md. Akram; Johnson, Gary S.; Jones, Joseph L.; Wylie, Allan H.

2007-01-01

approximately 326 square miles. For the most part, the model extent coincides with the 2005 revised extent of the Spokane Valley-Rathdrum Prairie aquifer as defined in a previous report. However, the model excludes Spirit and Hoodoo Valleys because of uncertainties about the ground-water flow directions in those valleys and the degree of hydraulic connection between the valleys and northern Rathdrum Prairie. The SVRP aquifer is considered to be a single hydrogeologic unit except in Hillyard Trough and the Little Spokane River Arm. In those areas, a continuous clay layer divides the aquifer into an upper, unconfined unit and a lower, confined unit. The model includes all known components of inflows to and outflows from the aquifer. Inflows to the SVRP aquifer include (1) recharge from precipitation, (2) inflows from tributary basins and adjacent uplands, (3) subsurface seepage and surface overflows from lakes that border the aquifer, (4) flow from losing segments of the Spokane River to the aquifer, (5) return percolation from irrigation, and (6) effluent from septic systems. Outflows from the SVRP aquifer include (1) ground-water withdrawals from wells, (2) flow from the aquifer to gaining segments of the Spokane River, (3) aquifer discharge to the Little Spokane River, and (4) subsurface outflow from the lower unit at the western limit of the model area near Long Lake. These inflow and outflow components are represented in the model by using MODFLOW-2000 packages. The parameter-estimation program PEST was used to calibrate the SVRP aquifer model. PEST implements a nonlinear least-squares regression method to estimate model parameters so that the differences between measured and simulated quantities are minimized with respect to an optimal criterion. Calibration data include 1,573 measurements of water levels and 313 measurements of streamflow gains and losses along segments of the Spokane and Little Spokane Rivers. Model parameters estimated during calib

Estimation of the recharge area contributing water to a pumped well in a glacial-drift, river-valley aquifer

USGS Publications Warehouse

Morrissey, Daniel J.

1989-01-01

The highly permeable, unconfined, glacial-drift aquifers that occupy most New England river valleys constitute the principal source of drinking water for many of the communities that obtain part or all of their public water supply from ground water. Recent events have shown that these aquifers are highly susceptible to contamination that results from a number of sources, such as seepage from wastewater lagoons, leaking petroleum-product storage tanks, and road salting. To protect the quality of water pumped from supply wells in these aquifers, it is necessary to ensure that potentially harmful contaminants do not enter the ground in the area that contributes water to the well. A high degree of protection can be achieved through the application of appropriate land-use controls within the contributing area. However, the contributing areas for most supply wells are not known. This report describes the factors that affect the size and shape of contributing areas to public supply wells and evaluates several methods that may be used to delineate contributing areas of wells in glacial-drift, river-valley aquifers. Analytical, two-dimensional numerical, and three-dimensional numerical models were used to delineate contributing areas. These methods of analysis were compared by applying them to a hypothetical aquifer having the dimensions and geometry of a typical glacial-drift, river-valley aquifer. In the model analyses, factors that control the size and shape of a contributing area were varied over ranges of values common to glacial-drift aquifers in New England. The controlling factors include the rate of well discharge, rate of recharge to the aquifer from precipitation and from adjacent till and bedrock uplands, distance of a pumping well from a stream or other potential source of induced recharge, degree of hydraulic connection of the aquifer with a stream, horizontal hydraulic conductivity of the aquifer, ratio of horizontal to vertical hydraulic conductivity, and

A Study of the Connection Among Basin-Fill Aquifers, Carbonate-Rock Aquifers, and Surface-Water Resources in Southern Snake Valley, Nevada

USGS Publications Warehouse

,

2008-01-01

The Secretary of the Interior through the Southern Nevada Public Lands Management Act approved funding for research to improve understanding of hydrologic systems that sustain numerous water-dependent ecosystems on Federal lands in Snake Valley, Nevada. Some of the streams and spring-discharge areas in and adjacent to Great Basin National Park have been identified as susceptible to ground-water withdrawals (Elliott and others, 2006) and research has shown a high potential for ground-water flow from southern Spring Valley into southern Snake Valley through carbonate rocks that outcrop along a low topographic divide known as the Limestone Hills (Welch and others, 2007). Comprehensive geologic, hydrologic, and chemical information will be collected and analyzed to assess the hydraulic connection between basin-fill aquifers and surface-water resources, water-dependent ecological features, and the regional carbonate-rock aquifer, the known source of many high-discharge springs. Understanding these connections is important because proposed projects to pump and export ground water from Spring and Snake Valleys in Nevada may result in unintended capture of water currently supplying springs, streams, wetlands, limestone caves, and other biologically sensitive areas (fig. 1). The methods that will be used in this study may be transferable to other areas in the Great Basin. The National Park Service, Bureau of Land Management, U.S. Fish and Wildlife Service, and U.S. Forest Service submitted the proposal for funding this research to facilitate science-based land management. Scientists from the U.S. Geological Survey (USGS) Water Resources and Geologic Disciplines, and the University of Nevada, Reno, will accomplish four research elements through comprehensive data collection and analysis that are concentrated in two distinct areas on the eastern and southern flanks of the Snake Range (fig. 2). The projected time line for this research is from July 2008 through September 2011.

Conditions of Fissuring in a Pumped-Faulted Aquifer System

NASA Astrophysics Data System (ADS)

Hernandez-Marin, M.; Burbey, T. J.

2007-12-01

Earth fissuring associated with subsidence from groundwater pumping is problematic in many arid-zone heavily pumped basins such as Las Vegas Valley. Long-term pumping at rates considerably greater than the natural recharge rate has stressed the heterogeneous aquifer system resulting in a complex stress-strain regime. A rigorous artificial recharge program coupled with increased surface-water importation has allowed water levels to appreciably recover, which has led to surface rebound in some localities. Nonetheless, new fissures continue to appear, particularly near basin-fill faults that behave as barriers to subsidence bowls. The purpose of this research is to develop a series of computational models to better understand the influence that structure (faults), pumping, and hydrostratigraphy has in the generation and propagation of fissures. The hydrostratigraphy of Las Vegas Valley consists of aquifers, aquitards and a relatively dry vadoze zone that may be as thick as 100m in much of the valley. Quaternary faults are typically depicted as scarps resulting from pre- pumping extensional tectonic events and are probably not responsible for the observed strain. The models developed to simulate the stress-strain and deformation processes in a faulted pumped aquifer-aquitard system of Las Vegas use the ABAQUS CAE (Complete ABAQUS Environment) software system. ABAQUS is a sophisticated engineering industry finite-element modeling package capable of simulating the complex fault- fissure system described here. A brittle failure criteria based on the tensile strength of the materials and the acting stresses (from previous models) are being used to understand how and where fissures are likely to form. , Hypothetical simulations include the role that faults and the vadose zone may play in fissure formation

Geology and water resources of Owens Valley, California

USGS Publications Warehouse

Hollett, Kenneth J.; Danskin, Wesley R.; McCaffrey, William F.; Walti, Caryl L.

1991-01-01

Owens Valley, a long, narrow valley located along the east flank of the Sierra Nevada in east-central California, is the main source of water for the city of Los Angeles. The city diverts most of the surface water in the valley into the Owens River-Los Angeles Aqueduct system, which transports the water more than 200 miles south to areas of distribution and use. Additionally, ground water is pumped or flows from wells to supplement the surface-water diversions to the river-aqueduct system. Pumpage from wells needed to supplement water export has increased since 1970, when a second aqueduct was put into service, and local concerns have been expressed that the increased pumpage may have had a detrimental effect on the environment and the indigenous alkaline scrub and meadow plant communities in the valley. The scrub and meadow communities depend on soil moisture derived from precipitation and the unconfined part of a multilayered aquifer system. This report, which describes the hydrogeology of the aquifer system and the water resources of the valley, is one in a series designed to (1) evaluate the effects that groundwater pumping has on scrub and meadow communities and (2) appraise alternative strategies to mitigate any adverse effects caused by, pumping. Two principal topographic features are the surface expression of the geologic framework--the high, prominent mountains on the east and west sides of the valley and the long, narrow intermountain valley floor. The mountains are composed of sedimentary, granitic, and metamorphic rocks, mantled in part by volcanic rocks as well as by glacial, talus, and fluvial deposits. The valley floor is underlain by valley fill that consists of unconsolidated to moderately consolidated alluvial fan, transition-zone, glacial and talus, and fluvial and lacustrine deposits. The valley fill also includes interlayered recent volcanic flows and pyroclastic rocks. The bedrock surface beneath the valley fill is a narrow, steep-sided graben

Land Subsidence and Aquifer-System Compaction in the Tucson Active Management Area, South-Central Arizona, 1987-2005

USGS Publications Warehouse

Carruth, Rob; Flynn, Pool; Donald, R.; Anderson, Carl E.

2007-01-01

The U.S. Geological Survey monitors land subsidence and aquifer-system compaction caused by ground-water depletion in Tucson Basin and Avra Valley - two of the three alluvial basins within the Tucson Active Management Area. In spring 1987, the Global Positioning System was used to measure horizontal and vertical positions for bench marks at 43 sites to establish a network for monitoring land subsidence in Tucson Basin and Avra Valley. Between 1987 and 2005, the original number of subsidence monitoring stations was gradually increased to more than 100 stations to meet the need for information in the growing metropolitan area. Data from approximately 60 stations common to the Global Positioning System surveys done after an initial survey in 1987 are used to document land subsidence. For the periods of comparison, average land-surface deformation generally is less than the maximum subsidence at an individual station and takes into account land-surface recovery from elastic aquifer-system compaction. Between 1987 and 1998, as much as 3.2 inches of subsidence occurred in Tucson Basin and as much as 4 inches of subsidence occurred in Avra Valley. For the 31 stations that are common to both the 1987 and 1998 Global Positioning System surveys, the average subsidence during the 11-year period was about 0.5 inch in Tucson Basin and about 1.2 inches in Avra Valley. For the approximately 60 stations that are common to both the 1998 and 2002 Global Positioning System surveys, the data indicate that as much as 3.5 inches of subsidence occurred in Tucson Basin and as much as 1.1 inches of subsidence occurred in Avra Valley. The average subsidence for the 4-year period is about 0.4 inch in Tucson Basin and 0.6 inch in Avra Valley. Between the 2002 and the 2005 Global Positioning System surveys, the data indicate that as much as 0.2 inch of subsidence occurred in Tucson Basin and as much as 2.2 inches of subsidence occurred in Avra Valley. The average subsidence for the 3-year

InSAR to support sustainable urbanization over compacting aquifers: The case of Toluca Valley, Mexico

NASA Astrophysics Data System (ADS)

Castellazzi, Pascal; Garfias, Jaime; Martel, Richard; Brouard, Charles; Rivera, Alfonso

2017-12-01

This paper illustrates how InSAR alone can be used to delineate potential ground fractures related to aquifer system compaction. An InSAR-derived ground fracturing map of the Toluca Valley, Mexico, is produced and validated through a field campaign. The results are of great interest to support sustainable urbanization and show that InSAR processing of open-access Synthetic Aperture Radar (SAR) data from the Sentinel-1 satellites can lead to reliable and cost-effective products directly usable by cities to help decision-making. The Toluca Valley Aquifer (TVA) sustains the water needs of two million inhabitants living within the valley, a growing industry, an intensively irrigated agricultural area, and 38% of the water needs of the megalopolis of Mexico City, located 40 km east of the valley. Ensuring water sustainability, infrastructure integrity, along with supporting the important economic and demographic growth of the region, is a major challenge for water managers and urban developers. This paper presents a long-term analysis of ground fracturing by interpreting 13 years of InSAR-derived ground displacement measurements. Small Baseline Subset (SBAS) and Persistent Scatterer Interferometry (PSI) techniques are applied over three SAR datasets totalling 93 acquisitions from Envisat, Radarsat-2, and Sentinel-1A satellites and covering the period from 2003 to 2016. From 2003 to 2016, groundwater level declines of up to 1.6 m/yr, land subsidence up to 77 mm/yr, and major infrastructure damages are observed. Groundwater level data show highly variable seasonal responses according to their connectivity to recharge areas. However, the trend of groundwater levels consistently range from -0.5 to -1.5 m/yr regardless of the well location and depth. By analysing the horizontal gradients of vertical land subsidence, we provide a potential ground fracture map to assist in future urban development planning in the Toluca Valley.

Numerical simulation of groundwater artificial recharge in a semiarid-climate basin of northwest Mexico, case study the Guadalupe Valley Aquifer, Baja California

NASA Astrophysics Data System (ADS)

Campos-Gaytan, J. R.; Herrera-Oliva, C. S.

2013-05-01

In this study was analyzed through a regional groundwater flow model the effects on groundwater levels caused by the application of different future groundwater management scenarios (2007-2025) at the Guadalupe Valley, in Baja California, Mexico. Among these studied alternatives are those scenarios designed in order to evaluate the possible effects generated for the groundwater artificial recharge in order to satisfy a future water demand with an extraction volume considered as sustainable. The State of Baja California has been subject to an increment of the agricultural, urban and industrials activities, implicating a growing water-demand. However, the State is characterized by its semiarid-climate with low surface water availability; therefore, has resulted in an extensive use of groundwater in local aquifer. Water level measurements indicate there has been a decline in water levels in the Guadalupe Valley for the past 30 years. The Guadalupe Valley aquifer represents one the major sources of water supply in Ensenada region. It supplies about 25% of the water distributed by the public water supplier at the city of Ensenada and in addition constitutes the main water resource for the local wine industries. Artificially recharging the groundwater system is one water resource option available to the study zone, in response to increasing water demand. The existing water supply system for the Guadalupe Valley and the city of Ensenada is limited since water use demand periods in 5 to 10 years or less will require the construction of additional facilities. To prepare for this short-term demand, one option available to water managers is to bring up to approximately 3.0 Mm3/year of treated water of the city of Ensenada into the valley during the low-demand winter months, artificially recharge the groundwater system, and withdraw the water to meet the summer demands. A 2- Dimensional groundwater flow was used to evaluate the effects of the groundwater artificial recharge

Geohydrology of the valley-fill aquifer in the Bath area, Lower Cohocton River, Steuben County, New York

USGS Publications Warehouse

Pagano, Timothy S.; Terry, D.B.; Shaw, M.L.; Ingram, A.W.

1984-01-01

The Bath valley-fill aquifer, southern New York, composed of outwash, ice-contact, and ice-disintegration sand and gravel, is highly productive and is in many areas in hydraulic contact with the Cohocton River. Potential well yields range 50 to more than 1,000 gallons per minute. Most of the aquifer is under shallow water-table conditions and vulnerable to surface contamination. Thickness ranges from 20 to 40 feet. Buried aquifers are present locally. The aquifer system underlies an area containing only a few small communities and therefore is not heavily pumped. Geohydrologic data are compiled on six maps at 1:24,000 scale and on a sheet of geologic sections. The maps depict surficial geology, soil-infiltration capacity, potentiometric surface, aquifer thickness, well yields, and land use. This map report set is one in a series of four that depict selected aquifers in Wester New York. It supplements a series that is being done by the U.S. Geological Survey in cooperation with State agencies. The maps are based largely on published reports, data filled in several State agencies, and some additional field data collection. (USGS)

Hydrology of the Ferron sandstone aquifer and effects of proposed surface-coal mining in Castle Valley, Utah, with sections on stratigraphy and leaching of overburden

USGS Publications Warehouse

Lines, Gregory C.; Morrissey, Daniel J.; Ryer, Thomas A.; Fuller, Richard H.

1983-01-01

Coal in the Ferron Sandstone Member of the Mancos Shale of Cretaceous age has traditionally been mined by underground techniques in the Emery Coal Field in the southern end of Castle Valley in east-central Utah. However, approximately 99 million tons are recoverable by surface mining. Ground water in the Ferron is the sole source of supply for the town of Emery, but the aquifer is essentially untapped outside the Emery area.The Ferron Sandstone Member crops out along the eastern edge of Castle Valley and generally dips 2 ? to 10 ? to the northwest. Sandstones in the Ferron are enclosed between relatively impermeable shale in the Tununk and Blue Gate Members of the Mancos Shale. Along the outcrop, the Ferron ranges in thickness from about 80 feet in the northern part of Castle Valley to 850 feet in the southern part. The Ferron also generally thickens in the subsurface downdip from the outcrop. Records from wells and test holes indicate that the full thickness of the Ferron is saturated with water in most areas downdip from the outcrop area.Tests in the Emery area indicate that transmissivity of the Ferron sandstone aquifer ranges from about 200 to 700 feet squared per day where the Ferron is fully saturated. Aquifer transmissivity is greatest near the Paradise Valley-Joes Valley fault system where permeability has been increased by fracturing. Storage coefficient ranges from about 10 .6 to 10 -3 where the Ferron sandstone aquifer is confined and probably averages 5 x 10-2 where it is unconfined.

Conjunctive-management models for sustained yield of stream-aquifer systems

USGS Publications Warehouse

Barlow, P.M.; Ahlfeld, D.P.; Dickerman, D.C.

2003-01-01

Conjunctive-management models that couple numerical simulation with linear optimization were developed to evaluate trade-offs between groundwater withdrawals and streamflow depletions for alluvial-valley stream-aquifer systems representative of those of the northeastern United States. A conjunctive-management model developed for a hypothetical stream-aquifer system was used to assess the effect of interannual hydrologic variability on minimum monthly streamflow requirements. The conjunctive-management model was applied to the Hunt-Annaquatucket-Pettaquamscutt stream-aquifer system of central Rhode Island. Results show that it is possible to increase the amount of current withdrawal from the aquifer by as much as 50% by modifying current withdrawal schedules, modifying the number and configuration of wells in the supply-well network, or allowing increased streamflow depletion in the Annaquatucket and Pettaquamscutt rivers. Alternatively, it is possible to reduce current rates of streamflow depletion in the Hunt River by as much as 35% during the summer, but such reductions would result increases in groundwater withdrawals.

Hydrogeology and ground-water flow of the drift and Platteville aquifer system, St Louis Park, Minnesota

USGS Publications Warehouse

Lindgren, R.J.

1995-01-01

Model simulations indicate that vertical ground-water flow from the drift aquifers and from the Platteville aquifer to underlying bedrock aquifers is greatest through bedrock valleys. The convergence of flow paths near bedrock valleys and the greater volume of water moving through the valleys would likely result in both increased concentrations and greater vertical movement of contaminants in areas underlain by bedrock valleys as compared to areas not underlain by bedrock valleys. Model results also indicate that field measurements of hydraulic head might not help locate discontinuities in confining units and additional test drilling to locate discontinuities might be necessary.

Hydrogeologic Framework and Ground Water in Basin-Fill Deposits of the Diamond Valley Flow System, Central Nevada

USGS Publications Warehouse

Tumbusch, Mary L.; Plume, Russell W.

2006-01-01

The Diamond Valley flow system, an area of about 3,120 square miles in central Nevada, consists of five hydrographic areas: Monitor, Antelope, Kobeh, and Diamond Valleys and Stevens Basin. Although these five areas are in a remote part of Nevada, local government officials and citizens are concerned that the water resources of the flow system eventually could be further developed for irrigation or mining purposes or potentially for municipal use outside the study area. In order to better understand the flow system, the U.S. Geological Survey in cooperation with Eureka, Lander, and Nye Counties and the Nevada Division of Water Resources, is conducting a multi-phase study of the flow system. The principal aquifers of the Diamond Valley flow system are in basin-fill deposits that occupy structural basins comprised of carbonate rocks, siliciclastic sedimentary rocks, igneous intrusive rocks, and volcanic rocks. Carbonate rocks also function as aquifers, but their extent and interconnections with basin-fill aquifers are poorly understood. Ground-water flow in southern Monitor Valley is from the valley margins toward the valley axis and then northward to a large area of discharge by evapotranspiration (ET) that is formed south of a group of unnamed hills near the center of the valley. Ground-water flow from northern Monitor Valley, Antelope Valley, and northern and western parts of Kobeh Valley converges to an area of ground-water discharge by ET in central and eastern Kobeh Valley. Prior to irrigation development in the 1960s, ground-water flow in Diamond Valley was from valley margins toward the valley axis and then northward to a large discharge area at the north end of the valley. Stevens Basin is a small upland basin with internal drainage and is not connected with other parts of the flow system. After 40 years of irrigation pumping, a large area of ground-water decline has developed in southern Diamond Valley around the irrigated area. In this part of Diamond

Hydrogeologic framework of the Santa Clara Valley, California

USGS Publications Warehouse

Hanson, Randall T.

2015-01-01

The hydrologic framework of the Santa Clara Valley in northern California was redefined on the basis of new data and a new hydrologic model. The regional groundwater flow systems can be subdivided into upper-aquifer and lower-aquifer systems that form a convergent flow system within a basin bounded by mountains and hills on three sides and discharge to pumping wells and the southern San Francisco Bay. Faults also control the flow of groundwater within the Santa Clara Valley and subdivide the aquifer system into three subregions.After decades of development and groundwater depletion that resulted in substantial land subsidence, Santa Clara Valley Water District (SCVWD) and the local water purveyors have refilled the basin through conservation and importation of water for direct use and artificial recharge. The natural flow system has been altered by extensive development with flow paths toward major well fields. Climate has not only affected the cycles of sedimentation during the glacial periods over the past million years, but interannual to interdecadal climate cycles also have affected the supply and demand components of the natural and anthropogenic inflows and outflows of water in the valley. Streamflow has been affected by development of the aquifer system and regulated flow from reservoirs, as well as conjunctive use of groundwater and surface water. Interaquifer flow through water-supply wells screened across multiple aquifers is an important component to the flow of groundwater and recapture of artificial recharge in the Santa Clara Valley. Wellbore flow and depth-dependent chemical and isotopic data indicate that flow into wells from multiple aquifers, as well as capture of artificial recharge by pumping of water-supply wells, predominantly is occurring in the upper 500 ft (152 m) of the aquifer system. Artificial recharge represents about one-half of the inflow of water into the valley for the period 1970–1999. Most subsidence is occurring below 250 ft

Aquifer-System Compaction and Land Subsidence: Measurements, Analyses, and Simulations-the Holly Site, Edwards Air Force Base, Antelope Valley, California

USGS Publications Warehouse

Sneed, Michelle; Galloway, Devin L.

2000-01-01

Land subsidence resulting from ground-water-level declines has long been recognized as a problem in Antelope Valley, California. At Edwards Air Force Base (EAFB), ground-water extractions have caused more than 150 feet of water-level decline, resulting in nearly 4 feet of subsidence. Differential land subsidence has caused sinklike depressions and earth fissures and has accelerated erosion of the playa lakebed surface of Rogers Lake at EAFB, adversely affecting the runways on the lakebed which are used for landing aircraft such as the space shuttles. Since 1990, about 0.4 foot of aquifer-system compaction has been measured at a deep (840 feet) borehole extensometer (Holly site) at EAFB. More than 7 years of paired ground-water-level and aquifer-system compaction measurements made at the Holly site were analyzed for this study. Annually, seasonal water-level fluctuations correspond to steplike variations in aquifer-system compaction; summer water-level drawdowns are associated with larger rates of compaction, and winter water-level recoveries are associated with smaller rates of compaction. The absence of aquifer-system expansion during recovery is consistent with the delayed drainage and resultant delayed, or residual, compaction of thick aquitards. A numerical one-dimensional MODFLOW model of aquitard drainage was used to refine estimates of aquifer-system hydraulic parameters that control compaction and to predict potential future compaction at the Holly site. The analyses and simulations of aquifer-system compaction are based on established theories of aquitard drainage. Historical ground-water-level and land-subsidence data collected near the Holly site were used to constrain simulations of aquifer-system compaction and land subsidence at the site for the period 1908?90, and ground-water-level and aquifer- system compaction measurements collected at the Holly site were used to constrain the model for the period 1990?97. Model results indicate that two thick

Empirical analysis of the stress-strain relationship between hydraulic head and subsidence in the San Joaquin Valley Aquifer

NASA Astrophysics Data System (ADS)

Neff, K. L.; Farr, T.

2016-12-01

Aquifer subsidence due to groundwater abstraction poses a significant threat to aquifer sustainability and infrastructure. The need to prevent permanent compaction to preserve aquifer storage capacity and protect infrastructure begs a better understanding of how compaction is related to groundwater abstraction and aquifer hydrogeology. The stress-strain relationship between hydraulic head changes and aquifer compaction has previously been observed to be hysteretic in both empirical and modeling studies. Here, subsidence data for central California's San Joaquin Valley derived from interferometric synthetic aperture radar (InSAR) for the period 2007-2016 is examined relative to hydraulic head levels in monitoring and production wells collected by the California Department of Water Resources. Such a large and long-term data set is available for empirical analysis for the first time thanks to advances in InSAR data collection and geospatial data management. The California Department of Water Resources (DWR) funded this work to provide the background and an update on subsidence in the Central Valley to support future policy. Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA.

Aquifer-test compilation for the San Joaquin Valley, California

USGS Publications Warehouse

McClelland, E.J.

1962-01-01

This report is the first of a series the purpose of which is to make available in standard tabular form the results of aquifer tests that have been made by various private and public agencies in California. The scope of the compilation is to describe systematically, in a form agreed upon by the California Department of Water Resources and the Geological Survey, the (1) test location, (2) pumping data, (3) well data, and (4) summary of results. The results of these tests sometimes have been published but most frequently have been used only as a step in obtaining other information, consequently the results and even the location of aquifer tests have not been readily available.This report has been prepared by the Geological Survey under the immediate supervision of Fred Kunkel, district geologist for California, in cooperation with the California Department of Water Resources, and tabulates through October 1962 all tests analyzed by the Geological Survey for the San Joaquin Valley. The report is designed to be expanded when additional tests are analyzed or new tests are made.

Hydrochemistry of the Mahomet Bedrock Valley Aquifer, East-Central Illinois: indicators of recharge and ground-water flow

USGS Publications Warehouse

Panno, S.V.; Hackley, Keith C.; Cartwright, K.; Liu, Chao-Li

1994-01-01

A conceptual model of the ground-water flow and recharge to the Mahomet Bedrock Valley Aquifer (MVA), east-central Illinois, was developed using major ion chemistry and isotope geochemistry. The MVA is a 'basal' fill in the east-west trending buried bedrock valley composed of clean, permeable sand and gravel to thicknesses of up to 61 m. It is covered by a thick sequence of glacial till containing thinner bodies of interbedded sand and gravel. Ground water from the MVA was found to be characterized by clearly defined geochemical regions with three distinct ground-water types. A fourth ground-water type was found at the confluence of the MVA and the Mackinaw Bedrock Valley Aquifer (MAK) to the west. Ground water in the Onarga Valley, a northeastern tributary of the MVA, is of two types, a mixed cation-SO42- type and a mixed cation-HCO3- type. The ground water is enriched in Na+, Ca2+, Mg2+, and SO42- which appears to be the result of an upward hydraulic gradient and interaction of deeper ground water with oxidized pyritic coals and shale. We suggest that recharge to the Onarga Valley and overlying aquifers is 100% from bedrock (leakage) and lateral flow from the MVA to the south. The central MVA (south of the Onarga Valley) is composed of relatively dilute ground water of a mixed cation-HCO3- type, with low total dissolved solids, and very low concentrations of Cl- and SO42-. Stratigraphic relationships of overlying aquifers and ground-water chemistry of these and the MVA suggest recharge to this region of the MVA (predominantly in Champaign County) is relatively rapid and primarily from the surface. Midway along the westerly flow path of the MVA (western MVA), ground water is a mixed cation-HCO3- type with relatively high Cl-, where Cl- increases abruptly by one to ??? two orders of magnitude. Data suggest that the increase in Cl- is the result of leakage of saline ground water from bedrock into the MVA. Mass-balance calculations indicate that approximately 9.5% of

Subsidence Modeling of the Over-exploited Granular Aquifer System in Aguascalientes, Mexico

NASA Astrophysics Data System (ADS)

Solano Rojas, D. E.; Pacheco, J.; Wdowinski, S.; Minderhoud, P. S. J.; Cabral-Cano, E.; Albino, F.

2017-12-01

The valley of Aguascalientes in central Mexico experiences subsidence rates of up to 100 [mm/yr] due to overexploitation of its aquifer system, as revealed from satellite-based geodetic observations. The spatial pattern of the subsidence over the valley is inhomogeneous and affected by shallow faulting. The understanding of the subsoil mechanics is still limited. A better understanding of the subsidence process in Aguascalientes is needed to provide insights for future subsidence in the valley. We present here a displacement-constrained finite-element subsidence model, based on the USGS MODFLOW software. The construction of our model relies on 3 main inputs: (1) groundwater level time series obtained from extraction wells' hydrographs, (2) subsurface lithostratigraphy interpreted from well drilling logs, and (3) hydrogeological parameters obtained from field pumping tests. The groundwater level measurements were converted to pore pressure in our model's layers, and used in Terzaghi's equation for calculating effective stress. We then used the effective stress along with the displacement obtained from geodetic observations to constrain and optimize five geo-mechanical parameters: compression ratio, reloading ratio, secondary compression index, over consolidation ratio, and consolidation coefficient. Finally, we use the NEN-Bjerrum linear stress model formulation for settlements to determine elastic and visco-plastic strain, accounting for the aquifer system units' aging effect. Preliminary results show higher compaction response in clay-saturated intervals (i.e. aquitards) of the aquifer system, as reflected in the spatial pattern of the surface deformation. The forecasted subsidence for our proposed scenarios show a much more pronounced deformation when we consider higher groundwater extraction regimes.

Summary of ground-water hydrology of the Cambrian-Ordovician aquifer system in the northern Midwest, United States: A in Regional aquifer system analysis

USGS Publications Warehouse

Young, H.L.

1992-01-01

Development of the aquifer system began in various parts of the northern Midwest in the 1860's and 1870's with the drilling of deep, generally flowing artesian wells near Lake Michigan in eastern Wisconsin and northeastern Illinois and along the valleys of the Mississippi River and its tributaries. Initial heads of 186 and 130 feet above Lake Michigan at Milwaukee and Chicago, respectively, have been reported. Large-scale pumping has produced cones of depression in these two areas, with respective head declines of as much as 375 and 900 feet. Other major pumping centers generally have had much smaller declines. The largest withdrawals from the aquifer system were about 180 million gallons per day in each of the major metropolitan areas of Chicago and Minneapolis-St. Paul (Twin Cities). However, the total decline in head in the St. Peter-Prairie du Chien-Jordan aquifer in the Twin Cities by 1980 was only 90 feet because the aquifer is unconfined. Most of the eastern two-thirds of Iowa, where the aquifer system is tightly confined, is characterized by more than 50 feet of head decline, with 200 feet or more at Mason City and the Quad Cities. Pumpage from the Cambrian-Ordovician aquifer system throughout the study area averaged 683 million gallons per day for the period 1976-80. Results of a transient-model simulation show that recharge increased over predevelopment recharge by 447 million gallons per day. Natural discharge decreased by 99 million gallons per day, and 137 million gallons per day was released from aquifer storage. Mineralization of ground water in the aquifer system increases from slightly mineralized calcium magnesium bicarbonate water in the northern recharge areas, through more mineralized, mixed water types with increased sodium and sulfate, to highly mineralized sodium chloride brines in the deeper parts of the structural basins.

Boundary of the Eagle River Watershed Valley-Fill Aquifer, Eagle County, North-Central Colorado, 2006-2007

USGS Publications Warehouse

Rupert, Michael G.; Plummer, Niel

2009-01-01

This vector data set delineates the approximate boundary of the Eagle River watershed valley-fill aquifer (ERWVFA). This data set was developed by a cooperative project between the U.S. Geological Survey, Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority. This project was designed to evaluate potential land-development effects on groundwater and surface-water resources so that informed land-use and water management decisions can be made. The boundary of the ERWVFA was developed by combining information from two data sources. The first data source was a 1:250,000-scale geologic map of the Leadville quadrangle developed by Day and others (1999). The location of Quaternary sediments was used as a first approximation of the ERWVFA. The boundary of the ERWVFA was further refined by overlaying the geologic map with Digital Raster Graphic (DRG) scanned images of 1:24,000 topographic maps (U.S. Geological Survey, 2001). Where appropriate, the boundary of the ERWVFA was remapped to correspond with the edge of the valley-fill aquifer marked by an abrupt change in topography at the edge of the valley floor throughout the Eagle River watershed. The boundary of the ERWVFA more closely resembles a hydrogeomorphic region presented by Rupert (2003, p. 8) because it is based upon general geographic extents of geologic materials and not on an actual aquifer location as would be determined through a rigorous hydrogeologic investigation.

Regional potentiometric-surface map of the Great Basin carbonate and alluvial aquifer system in Snake Valley and surrounding areas, Juab, Millard, and Beaver Counties, Utah, and White Pine and Lincoln Counties, Nevada

USGS Publications Warehouse

Gardner, Philip M.; Masbruch, Melissa D.; Plume, Russell W.; Buto, Susan G.

2011-01-01

Water-level measurements from 190 wells were used to develop a potentiometric-surface map of the east-central portion of the regional Great Basin carbonate and alluvial aquifer system in and around Snake Valley, eastern Nevada and western Utah. The map area covers approximately 9,000 square miles in Juab, Millard, and Beaver Counties, Utah, and White Pine and Lincoln Counties, Nevada. Recent (2007-2010) drilling by the Utah Geological Survey and U.S. Geological Survey has provided new data for areas where water-level measurements were previously unavailable. New water-level data were used to refine mapping of the pathways of intrabasin and interbasin groundwater flow. At 20 of these locations, nested observation wells provide vertical hydraulic gradient data and information related to the degree of connection between basin-fill aquifers and consolidated-rock aquifers. Multiple-year water-level hydrographs are also presented for 32 wells to illustrate the aquifer system's response to interannual climate variations and well withdrawals.

Preliminary evaluation of the hydrogeologic system in Owens Valley, California

USGS Publications Warehouse

Danskin, W.R.

1988-01-01

A preliminary, two-layer, steady-state, groundwater flow model was used to evaluate present data and hydrologic concepts of Owens Valley, California. Simulations of the groundwater system indicate that areas where water levels are most affected by changes in recharge and discharge are near toes of alluvial fans and along the edge of permeable volcanic deposits. Sensitivity analysis for each model parameter shows that steady state simulations are most sensitive to uncertainties in evapotranspiration rates. Tungsten Hills, Poverty Hills, and Alabama Hills were found to act as virtually impermeable barriers to groundwater flow. Accurate simulation of the groundwater system between Bishop and Lone Pine appears to be possible without simulating the groundwater system in Round Valley, near Owens Lake, or in aquifer materials more than 1,000 ft below land surface. Although vast amounts of geologic and hydrologic data have been collected for Owens Valley, many parts of the hydrogeologic system have not been defined with sufficient detail to answer present water management questions. Location and extent of geologic materials that impede the vertical movement of water are poorly documented. The likely range of aquifer characteristics, except vertical hydraulic conductivity, is well known, but spatial distribution of these characteristics is not well documented. A set of consistent water budgets is needed, including one for surface water, groundwater, and the entire valley. The largest component of previous water budgets (evapotranspiration) is largely unverified. More definitive estimates of local gains and losses for Owens River are needed. Although groundwater pumpage from each well is measured, the quantity of withdrawal from different zones of permeable material has not been defined. (USGS)

Data for ground-water test hole near Nicolaus, Central Valley aquifer project, California

USGS Publications Warehouse

French, James J.; Page, R.W.; Bertoldi, Gilbert L.

1983-01-01

Preliminary data are provided for the third of seven test holes drilled as a part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 NE 1/4 sec. 2, T.12N., R.3E., Sutter County, California, about 1 1/2 miles northwest of the town of Nicolaus. Drilled to a depth of 1,150 feet below land surface, the hole is cased to a depth of 100 feet and equipped with three piezometer tubes to depths of 311, 711, and 1,071 feet. A 5-foot well screen is set in sand at the bottom of each piezometer. Each screened interval has a cement plug above and below it to isolate it from other parts of the aquifer, and the well bore is filled between the plugs with sediment. Thirty-one cores and 34 sidewall cores were recovered. Laboratory tests were made for minerology, consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, thermal conductivity, and chemical analysis of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis of the three tapped zones and measured for water level. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

Surface complexation modeling for predicting solid phase arsenic concentrations in the sediments of the Mississippi River Valley alluvial aquifer, Arkansas, USA

USGS Publications Warehouse

Sharif, M.S.U.; Davis, R.K.; Steele, K.F.; Kim, B.; Hays, P.D.; Kresse, T.M.; Fazio, J.A.

2011-01-01

The potential health impact of As in drinking water supply systems in the Mississippi River Valley alluvial aquifer in the state of Arkansas, USA is significant. In this context it is important to understand the occurrence, distribution and mobilization of As in the Mississippi River Valley alluvial aquifer. Application of surface complexation models (SCMs) to predict the sorption behavior of As and hydrous Fe oxides (HFO) in the laboratory has increased in the last decade. However, the application of SCMs to predict the sorption of As in natural sediments has not often been reported, and such applications are greatly constrained by the lack of site-specific model parameters. Attempts have been made to use SCMs considering a component additivity (CA) approach which accounts for relative abundances of pure phases in natural sediments, followed by the addition of SCM parameters individually for each phase. Although few reliable and internally consistent sorption databases related to HFO exist, the use of SCMs using laboratory-derived sorption databases to predict the mobility of As in natural sediments has increased. This study is an attempt to evaluate the ability of the SCMs using the geochemical code PHREEQC to predict solid phase As in the sediments of the Mississippi River Valley alluvial aquifer in Arkansas. The SCM option of the double-layer model (DLM) was simulated using ferrihydrite and goethite as sorbents quantified from chemical extractions, calculated surface-site densities, published surface properties, and published laboratory-derived sorption constants for the sorbents. The model results are satisfactory for shallow wells (10.6. m below ground surface), where the redox condition is relatively oxic or mildly suboxic. However, for the deep alluvial aquifer (21-36.6. m below ground surface) where the redox condition is suboxic to anoxic, the model results are unsatisfactory. ?? 2011 Elsevier Ltd.

Mapping deep aquifer salinity trends in the southern San Joaquin Valley using borehole geophysical data constrained by chemical analyses

NASA Astrophysics Data System (ADS)

Gillespie, J.; Shimabukuro, D.; Stephens, M.; Chang, W. H.; Ball, L. B.; Everett, R.; Metzger, L.; Landon, M. K.

2016-12-01

The California State Water Resources Control Board and the California Division of Oil, Gas and Geothermal Resources are collaborating with the U.S. Geological Survey to map groundwater resources near oil fields and to assess potential interactions between oil and gas development and groundwater resources. Groundwater resources having salinity less than 10,000 mg/L total dissolved solids may be classified as Underground Sources of Drinking Water (USDW) and subject to protection under the federal Safe Drinking Water Act. In this study, we use information from oil well borehole geophysical logs, oilfield produced water and groundwater chemistry data, and three-dimensional geologic surfaces to map the spatial distribution of salinity in aquifers near oil fields. Salinity in the southern San Joaquin Valley is controlled primarily by depth and location. The base of protected waters occurs at very shallow depths, often < 300 meters, in the western part of the valley where aquifer recharge is low in the rain shadow of the Coast Ranges. The base of protected water is much deeper, often >1,500 meters, in the eastern part of the San Joaquin Valley where higher runoff from the western slopes of the Sierra Nevada provide relatively abundant aquifer recharge. Stratigraphy acts as a secondary control on salinity within these broader areas. Formations deposited in non-marine environments are generally fresher than marine deposits. Layers isolated vertically between confining beds and cut off from recharge sources may be more saline than underlying aquifers that outcrop in upland areas on the edge of the valley with more direct connection to regional recharge areas. The role of faulting is more ambiguous. In some areas, abrupt changes in salinity may be fault controlled but, more commonly, the faults serve as traps separating oil-bearing strata that are exempt from USDW regulations, from water-bearing strata that are not exempt.

Preliminary evaluation of the Highland Rim aquifer system in Tennessee for receiving injected wastes

USGS Publications Warehouse

Bradley, M.W.

1986-01-01

The EPA has authority under the Safe Drinking Water Act to protect underground sources of drinking water from contamination by deep well injection. An aquifer, however, may be exempted from protection and used for injected wastes where the aquifer meets criteria established in the Agency 's Underground Injection Control program. The Highland Rim aquifer system in Tennessee consists of Mississippian age carbonate rocks and occurs from the Valley and Ridge of East Tennessee to west of the Tennessee River. This aquifer contains potable water and is an important source of drinking water for municipal and domestic supplies on the Highland Rim. The Highland Rim aquifer system under parts of the Cumberland Plateau is not currently used as a source of drinking water and is not expected to be used in the future. These areas meet parts of the EPA 's Underground Injection Control criteria for exempting aquifers to receive injected waste. (Author 's abstract)

Subsidence Modeling of the Over-exploited Granular Aquifer System in Aguascalientes, Mexico

NASA Astrophysics Data System (ADS)

Solano Rojas, D. E.; Wdowinski, S.; Minderhoud, P. P. S.; Pacheco, J.; Cabral, E.

2016-12-01

The valley of Aguascalientes in central Mexico experiences subsidence rates of up to 100 [mm/yr] due to overexploitation of its aquifer system, as revealed from satellite-based geodetic observations. The spatial pattern of the subsidence over the valley is inhomogeneous and affected by shallow faulting. The understanding of the subsoil mechanics is still limited. A better understanding of the subsidence process in Aguascalientes is needed to provide insights for future subsidence in the valley. We present here a displacement-constrained finite-element subsidence model using Deltares iMOD (interactive MODeling), based on the USGS MODFLOW software. The construction of our model relies on 3 main inputs: (1) groundwater level time series obtained from extraction wells' hydrographs, (2) subsurface lithostratigraphy interpreted from well drilling logs, and (3) hydrogeological parameters obtained from field pumping tests. The groundwater level measurements were converted to pore pressure in our model's layers, and used in Terzaghi's equation for calculating effective stress. We then used the effective stresse along with the displacement obtained from geodetic observations to constrain and optimize five geo-mechanical parameters: compression ratio, reloading ratio, secondary compression index, over consolidation ratio, and consolidation coefficient. Finally, we use the NEN-Bjerrum linear stress model formulation for settlements to determine elastic and visco-plastic strain, accounting for the aquifer system units' aging effect. Preliminary results show higher compaction response in clay-saturated intervals (i.e. aquitards) of the aquifer system, as reflected in the spatial pattern of the surface deformation. The forecasted subsidence for our proposed scenarios show a much more pronounced deformation when we consider higher groundwater extraction regimes.

Sulphur and oxygen isotopic characters of dissolved sulphate in groundwater from the Pleistocene aquifer in the southern Jordan Valley (Jericho area, Palestine).

PubMed

Khayat, Saed; Hötzl, Heinz; Geyer, Stefan; Ali, Wasim; Knöller, Kay; Strauch, Gerhard

2006-09-01

Sulphate and chloride concentrations in the shallow Pleistocene aquifer systems in the lower Jordan valley area indicate a general trend of increasing salinity eastward and southward. This study was conducted in one of the important sub-basins feeding the Pleo-Pleistocene aquifer in the Jericho area in the southern part of the valley using S and O isotopes of dissolved sulphate. The results show that sulphate has mainly two contributions to the groundwater. One is the surface seepage, which is present as a salty leachate form with the positive delta34Ssulphate values of primary gypsum in Lisan and Samara formations, and the second is the upwelling saline water which was in contact with a deep secondary gypsum, aragonites and salty rocks and rose up under heavy abstraction with depleted 34S in sulphate and relatively high sulphate and chloride content. The latest was clearly shown in the Arab Project wells to the east that is undergoing a continuous heavy abstraction. The isotopic signatures of S and O in these wells to the east show that this depleted 34S and highly concentrated sulphate might also indicate a dissolved sulphate originating from pyrite oxidation that results from the interaction with a pyrite-rich aquifer, which can well up with salty water under heavy abstraction and is oxidised in the upper aerobic shallow aquifer.

Ground water in Dale Valley, New York

USGS Publications Warehouse

Randall, Allan D.

1979-01-01

Dale Valley is a broad valley segment, enlarged by glacial erosion, at the headwaters of Little Tonawanda Creek near Warsaw , New York. A thin, shallow alluvial aquifer immediately underlies the valley floor but is little used. A deeper gravel aquifer, buried beneath many feet of lake deposits, is tapped by several industrial wells. A finite-difference digital model treated the deep aquifer as two-dimensional with recharge and discharge through a confining layer. It was calibrated by simulating (1) natural conditions, (2) an 18-day aquifer test, and (3) 91 days of well-field operation. Streamflow records and model simulations suggest that in moderately wet years such as 1974, a demand of 750 gallons per minute could be met by withdrawal from the creek and from the aquifer without excessive drawdown at production wells or existing domestic wells. With reasonable but unverified model adjustments to simulate an unusually dry year, the model predicts that a demand of 600 gallons per minute could be met from the same sources. Water high in chloride has migrated from bedrock into parts of the deep aquifer. Industrial pumpage, faults in the bedrock, and the natural flow system may be responsible. (Woodard-USGS)

Evaluation of the hydrologic system and selected water-management alternatives in the Owens Valley, California

USGS Publications Warehouse

Danskin, Wesley R.

1998-01-01

The Owens Valley, a long, narrow valley along the east side of the Sierra Nevada in eastcentral California, is the main source of water for the city of Los Angeles. The city diverts most of the surface water in the valley into the Owens River?Los Angeles Aqueduct system, which transports the water more than 200 miles south to areas of distribution and use. Additionally, ground water is pumped or flows from wells to supplement the surface-water diversions to the river? aqueduct system. Pumpage from wells needed to supplement water export has increased since 1970, when a second aqueduct was put into service, and local residents have expressed concerns that the increased pumping may have a detrimental effect on the environment and the native vegetation (indigenous alkaline scrub and meadow plant communities) in the valley. Native vegetation on the valley floor depends on soil moisture derived from precipitation and from the unconfined part of a multilayered ground-water system. This report, which describes the evaluation of the hydrologic system and selected water-management alternatives, is one in a series designed to identify the effects that ground-water pumping has on native vegetation and evaluate alternative strategies to mitigate any adverse effects caused by pumping. The hydrologic system of the Owens Valley can be conceptualized as having three parts: (1) an unsaturated zone affected by precipitation and evapotranspiration; (2) a surface-water system composed of the Owens River, the Los Angeles Aqueduct, tributary streams, canals, ditches, and ponds; and (3) a saturated ground-water system contained in the valley fill. Analysis of the hydrologic system was aided by development of a ground-water flow model of the ?aquifer system,? which is defined as the most active part of the ground-water system and which includes nearly all of the Owens Valley except for the area surrounding the Owens Lake. The model was calibrated and verified for water years 1963?88 and

Future groundwater extraction scenarios for an aquifer in a semiarid environment: case study of Guadalupe Valley Aquifer, Baja California, Northwest Mexico.

PubMed

Campos-Gaytan, Jose Ruben; Kretzschmar, Thomas; Herrera-Oliva, Claudia Soledad

2014-11-01

Semiarid northwestern Mexico presents a growing water demand produced by agricultural and domestic requirements during the last two decades. The community of Guadalupe Valley and the city of Ensenada rely on groundwater pumping from the local aquifer as its sole source of water supply. This dependency has resulted in an imbalance between groundwater pumpage and natural recharge. A two-dimensional groundwater flow model was applied to the Guadalupe Valley Aquifer, which was calibrated and validated for the period 1984-2005. The model analysis verified that groundwater levels in the region are subject to steep declines due to decades of intensive groundwater exploitation for agricultural and domestic purposes. The calibrated model was used to assess the effects of different water management scenarios for the period 2007-2025. If the base case (status quo) scenario continues, groundwater levels are in a continuous drawdown trend. Some wells would run dry by August 2017, and water demand may not be met without incurring in an overdraft. The optimistic scenario implies the achievement of the mean groundwater recharge and discharge. Groundwater level depletion could be stopped and restored. The sustainable scenario implies the reduction of current extraction (up to about 50 %), when groundwater level depletion could be stopped. A reduction in current extraction mitigates water stress in the aquifer but cannot solely reverse declining water tables across the region. The combination of reduced current extraction and an implemented alternative solution (such as groundwater artificial recharge), provides the most effective measure to stabilize and reverse declining groundwater levels while meeting water demands in the region.

Time Series Analysis of Subsidence and Water-Level Data for Aquifer System Characterization

NASA Astrophysics Data System (ADS)

Burbey, T. J.

2012-12-01

The accessibility of high resolution surface displacement data in the form of InSAR, PS-InSAR, GPS, and extensometer data in heavily pumped basins provides diagnostic information that can be used in powerful ways to characterize the hydraulic properties of both confining units and aquifers that water-level data alone cannot accomplish. Land surface deformation signals reflect the elastic and inelastic properties of the heterogeneous aquifer system. These deformation signals can be quite complex and coupled with water level data often exhibit temporal signals at daily, seasonal, and decadal scales resulting from accompanying cyclical pumping patterns. In Las Vegas Valley, for example, cyclical seasonal and daily water-level fluctuations are superimposed on long-term water-level declines. The resulting changes in effective stress have resulted in decades of inelastic land surface lowering with superimposed seasonal elastic deformation signals. In this investigation signal processing of both water level and deformation data was done to filter separate signals at daily, seasonal, and decadal time scales that can be individually evaluated to more accurately estimate the hydraulic properties of the principle aquifer system in the valley that consists of multiple aquifers and confining units. Both elastic and inelastic skeletal specific storage, the horizontal hydraulic conductivity of the aquifers, and the vertical hydraulic conductivity of the confining units can be readily evaluated in this manner. The results compare favorably with the parameters calculated from a complex one-dimensional numerical compaction model. The advantage of the time series approach is that a more thorough description of the system can be made and the analytical approach is far simpler than constructing and calibrating a numerical model.

Data for ground-water test hole near Zamora, Central Valley Aquifer Project, California

USGS Publications Warehouse

French, J.J.; Page, R.W.; Bertoldi, G.L.

1982-01-01

Preliminary data are presented for the first of seven test holes drilled as a part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 SE 1/4 sec. 34, T. 12 N. , R. 1 E., Yolo County, California, about 3 miles northeast of the town of Zamora. Drilled to a depth of 2,500 feet below land surface, the hole is cased to a depth of 190 feet and equipped with three piezometer tubes to depths of 947, 1,401, and 2,125 feet. A 5-foot well screen is at the bottom of each piezometer. Eighteen cores and 68 sidewall cores were recovered. Laboratory tests were made for mineralogy, hydraulic conductivity, porosity , consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, diatom identification, thermal conductivity, and chemical analysis of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis and measured for water level in the three tapped zones. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

Estimates of hydraulic properties from a one-dimensional numerical model of vertical aquifer-system deformation, Lorenzi site, Las Vegas, Nevada

USGS Publications Warehouse

Pavelko, Michael T.

2004-01-01

Land subsidence related to aquifer-system compaction and ground-water withdrawals has been occurring in Las Vegas Valley, Nevada, since the 1930's, and by the late 1980's some areas in the valley had subsided more than 5 feet. Since the late 1980's, seasonal artificial-recharge programs have lessened the effects of summertime pumping on aquifer-system compaction, but the long-term trend of compaction continues in places. Since 1994, the U.S. Geological Survey has continuously monitored water-level changes in three piezometers and vertical aquifer-system deformation with a borehole extensometer at the Lorenzi site in Las Vegas, Nevada. A one-dimensional, numerical, ground-water flow model of the aquifer system below the Lorenzi site was developed for the period 1901-2000, to estimate aquitard vertical hydraulic conductivity, aquitard inelastic skeletal specific storage, and aquitard and aquifer elastic skeletal specific storage. Aquifer water-level data were used in the model as the aquifer-system stresses that controlled simulated vertical aquifer-system deformation. Nonlinear-regression methods were used to calibrate the model, utilizing estimated and measured aquifer-system deformation data to minimize a weighted least-squares objective function, and estimate optimal property values. Model results indicate that at the Lorenzi site, aquitard vertical hydraulic conductivity is 3 x 10-6 feet per day, aquitard inelastic skeletal specific storage is 4 x 10-5 per foot, aquitard elastic skeletal specific storage is 5 x 10-6 per foot, and aquifer elastic skeletal specific storage is 3 x 10-7 per foot. Regression statistics indicate that the model and data provided sufficient information to estimate the target properties, the model adequately simulated observed data, and the estimated property values are accurate and unique.

Use of 3H/3He Ages to evaluate and improve groundwater flow models in a complex buried-valley aquifer

USGS Publications Warehouse

Sheets, Rodney A.; Bair, E. Scott; Rowe, Gary L.

1998-01-01

Combined use of the tritium/helium 3 (3H/3He) dating technique and particle-tracking analysis can improve flow-model calibration. As shown at two sites in the Great Miami buried-valley aquifer in southwestern Ohio, the combined use of 3H/3He age dating and particle tracking led to a lower mean absolute error between measured heads and simulated heads than in the original calibrated models and/or between simulated travel times and 3H/3He ages. Apparent groundwater ages were obtained for water samples collected from 44 wells at two locations where previously constructed finite difference models of groundwater flow were available (Mound Plant and Wright-Patterson Air Force Base (WPAFB)). The two-layer Mound Plant model covers 11 km2 within the buried-valley aquifer. The WPAFB model has three layers and covers 262 km2 within the buried-valley aquifer and adjacent bedrock uplands. Sampled wells were chosen along flow paths determined from potentiometric maps or particle-tracking analyses. Water samples were collected at various depths within the aquifer. In the Mound Plant area, samples used for comparison of 3H/3He ages with simulated travel times were from wells completed in the uppermost model layer. Simulated travel times agreed well with 3H/3He ages. The mean absolute error (MAE) was 3.5 years. Agreement in ages at WPAFB decreased with increasing depth in the system. The MAEs were 1.63, 17.2, and 255 years for model layers 1, 2, and 3, respectively. Discrepancies between the simulated travel times and 3H/3He ages were assumed to be due to improper conceptualization or incorrect parameterization of the flow models. Selected conceptual and parameter modifications to the models resulted in improved agreement between 3H/3He ages and simulated travel times and between measured and simulated heads and flows.

Hydrogeology of, and simulation of ground-water flow in a mantled carbonate-rock system, Cumberland Valley, Pennsylvania

USGS Publications Warehouse

Chichester, D.C.

1996-01-01

The U.S. Geological Survey conducted a study in a highly productive and complex regolith-mantled carbonate valley in the northeastern part of the Cumberland Valley, Pa., as part of its Appalachian Valleys and Piedmont Regional Aquifer-system Analysis program. The study was designed to quantify the hydrogeologic characteristics and understand the ground-water flow system of a highly productive and complex thickly mantled carbonate valley. The Cumberland Valley is characterized by complexly folded and faulted carbonate bedrock in the valley bottom, by shale and graywacke to the north, and by red-sedimentary and diabase rocks in the east-southeast. Near the southern valley hillslope, the carbonate rock is overlain by wedge-shaped deposit of regolith, up to 450 feet thick, that is composed of residual material, alluvium, and colluvium. Locally, saturated regolith is greater than 200 feet thick. Seepage-run data indicate that stream reaches, near valley walls, are losing water from the stream, through the regolith, to the ground-water system. Results of hydrograph-separation analyses indicate that base flow in stream basins dominated by regolith-mantled carbonate rock, carbonate rock, and carbonate rock and shale are 81.6, 93.0, and 67.7 percent of total streamflow, respectively. The relative high percentage for the regolith-mantled carbonate-rock basin indicates that the regolith stores precipitation and slowly, steadily releases this water to the carbonate-rock aquifer and to streams as base flow. Anomalies in water-table gradients and configuration are a result of topography and differences in the character and distribution of overburden material, permeability, rock type, and geologic structure. Most ground-water flow is local, and ground water discharges to nearby springs and streams. Regional flow is northeastward to the Susquehanna River. Average-annual water budgets were calculated for the period of record from two continuous streamflow-gaging stations. Average

Nitrate concentrations, 1936-99, and pesticide concentrations, 1990-99, in the unconfined aquifer in the San Luis Valley, Colorado

USGS Publications Warehouse

Stogner, Sr., Robert W.

2001-01-01

ineffective in evaluating variations in the amount of nitrate leaching associated with differences in application rates. It was concluded that irrigation practices have the greatest effect on leaching of nitrate to the aquifer. Management tools, such as irrigation scheduling, center-pivot sprinkler systems, soil and ground-water nitrogen credits, and cultivation of cover and winter crops, are being used to help maintain crop quality and yields while minimizing the potential of leaching and reducing residual nitrogen left in the soil. Review of available data from previous studies indicates that most of the sampled wells with elevated nitrate concentrations are located in the intensively cultivated area north of the Rio Grande. This area represents about 10 percent of the San Luis Valley and approximately 35 percent of the crop and pasture land in the valley. The area where nitrate concentrations exceed the U.S. Environmental Protection Agency drinking water maximum contaminant level represents about 150 square miles or 5 percent of the valley. Aquifer vulnerability to and contamination by pesticides was not evaluated until the 1990's. Risk analyses indicated that selected pesticides can pose a contamination threat to an unconfined aquifer in areas consisting primarily of sandy loam soil; sandy loam soils are common in the San Luis Valley. Water-quality samples collected from some wells during 1990 and 1993 indicated trace- to low-level pesticide contamination. The occurrence of pesticides was infrequent and isolated.

Data for ground-water test hole near Butte City, Central Valley aquifer project, California

USGS Publications Warehouse

French, James J.; Page, R.W.; Bertoldi, G.L.

1983-01-01

This report provides preliminary data for the third of seven test holes drilled as part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 NE 1/4 sec. 32, T. 19 N., R. 1 W., Glenn County, California, about one-half mile south of the town of Butte City. Drilled to a depth of 1,432 feet below land surface, the hole is cased to a depth of 82 feet and equipped with three piezometer tubes to depths of 592 feet, 968 feet, and 1,330 feet. A 5-foot well screen is at the bottom of each piezometer. Each screened interval has a cement plug above and below it to isolate it from other parts of the aquifer , and the well bore is filled between the plugs with sediment. Nine cores and 49 sidewall cores were recovered. Laboratory tests were made for mineralogy, hydraulic conductivity, porosity , consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, and chemical quality of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis and measured for water level in the three tapped zones. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

Hydrologic effects of stress-relief fracturing in an Appalachian Valley

USGS Publications Warehouse

Wyrick, Granville G.; Borchers, James W.

1981-01-01

A hydrologic study at Twin Falls State Park, Wyoming County, West Virginia, was made to determine how fracture systems affect the occurrence and movement of ground water in a typical valley of the Appalachian Plateaus Physiographic Province. Twin Falls was selected because it is generally unaffected by factors that would complicate an analysis of the data. The study area was the Black Fork Valley at Twin Falls. The valley is about 3 miles long and 400 to 600 feet wide and is cut into massive sandstone units interbedded with thin coal and shale beds. The study was made to determine how aquifer characteristics were related to fracture systems in this valley, so that the relation could be applied to studies of other valleys. Two sites were selected for test drilling, pumping tests, and geophysical studies. One site is in the upper part of the valley, and the second is near the lower central part. At both sites, ground water occurs mainly in horizontal bedding-plane fractures under the valley floor and in nearly vertical and horizontal slump fractures along the valley wall. The aquifer is under confined conditions under the valley floor and unconfined conditions along the valley wall. The fractures pinch out under the valley walls, which form impermeable barriers. Tests of wells near the valley center indicated a change in storage coefficient as the cone of depression caused by pumping reached the confined-unconfined boundaries; the tests also indicated barrier-image effects when the cone reached the impermeable boundaries. Drawdown from pumping near the center of the valley affected water levels at both sites, indicating a hydraulic connection from the upper to the lower end of the valley. Stream gain-and-loss studies show that ground water discharges to the stream from horizontal fractures beneath Black Fork Falls, near the mouth of Black Fork. The fracture systems that constitute most of the transmissive part of the aquifer at Twin Falls are like those described as

Groundwater quality in the shallow aquifers of the Monterey Bay, Salinas Valley, and adjacent highland areas, California

USGS Publications Warehouse

Burton, Carmen

2018-05-30

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 shallow aquifers of the groundwater basins around Monterey Bay, the Salinas Valley, and the highlands adjacent to the Salinas Valley constitute one of the study units.

Hydrology of Northern Utah Valley, Utah County, Utah, 1975-2005

USGS Publications Warehouse

Cederberg, Jay R.; Gardner, Philip M.; Thiros, Susan A.

2009-01-01

The ground-water resources of northern Utah Valley, Utah, were assessed during 2003-05 to describe and quantify components of the hydrologic system, determine a hydrologic budget for the basin-fill aquifer, and evaluate changes to the system relative to previous studies. Northern Utah Valley is a horst and graben structure with ground water occurring in both the mountain-block uplands surrounding the valley and in the unconsolidated basin-fill sediments. The principal aquifer in northern Utah Valley occurs in the unconsolidated basin-fill deposits where a deeper unconfined aquifer occurs near the mountain front and laterally grades into multiple confined aquifers near the center of the valley. Sources of water to the basin-fill aquifers occur predominantly as either infiltration of streamflow at or near the interface of the mountain front and valley or as subsurface inflow from the adjacent mountain blocks. Sources of water to the basin-fill aquifers were estimated to average 153,000 (+/- 31,500) acre-feet annually during 1975-2004 with subsurface inflow and infiltration of streamflow being the predominant sources. Discharge from the basin-fill aquifers occurs in the valley lowlands as flow to waterways, drains, ditches, springs, as diffuse seepage, and as discharge from flowing and pumping wells. Ground-water discharge from the basin-fill aquifers during 1975-2004 was estimated to average 166,700 (+/- 25,900) acre-feet/year where discharge to wells for consumptive use and discharge to waterways, drains, ditches, and springs were the principal sources. Measured water levels in wells in northern Utah Valley declined an average of 22 feet from 1981 to 2004. Water-level declines are consistent with a severe regional drought beginning in 1999 and continuing through 2004. Water samples were collected from 36 wells and springs throughout the study area along expected flowpaths. Water samples collected from 34 wells were analyzed for dissolved major ions, nutrients, and

Groundwater-level analysis of selected wells in the Hoosic River Valley near Hoosick Falls, New York, for aquifer framework and properties

USGS Publications Warehouse

Williams, John H.; Heisig, Paul M.

2018-03-05

The U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, analyzed groundwater levels, drilling record logs, and field water-quality data from selected wells, and the surficial geology in the Hoosic River valley south of the village of Hoosick Falls, New York, to provide information about the framework and properties of a confined aquifer. The aquifer, which consists of ice-contact sand and gravel overlain by lacustrine clay and silt, was evaluated by the New York State Department of Environmental Conservation as part of their investigation of alternate water supplies for the village whose wellfield has been affected by perfluorooctanoic acid. Wells inventoried in the study area were classified as confined, water table, or transitional between the two aquifer conditions. Groundwater levels in three confined-aquifer wells and a transitional-aquifer well responded to pumping of a test production well finished in the confined aquifer. Groundwater levels in a water-table well showed no detectable water-level change in response to test-well pumping. Analysis of drawdown and recovery data from the three confined-aquifer wells and a transitional-aquifer well through the application of the Theis type-curve method provided estimates of aquifer properties. Representation of a constant-head boundary in the analysis where an unnamed pond and fluvial-terrace deposits abut the valley wall resulted in satisfactory matches of the Theis type curves with the observed water-level responses. Aquifer transmissivity estimates ranged from 1,160 to 1,370 feet squared per day. Aquifer storativity estimates ranged from 5.2×10–5 to 1.1×10–3 and were consistent with the inferred degree of confinement and distance from the represented recharge boundary.

Chuckwalla Valley multiple-well monitoring site, Chuckwalla Valley, Riverside County

USGS Publications Warehouse

Everett, Rhett

2013-01-01

The U.S. Geological Survey (USGS), in cooperation with the Bureau of Land Management, is evaluating the geohydrology and water availability of the Chuckwalla Valley, California. As part of this evaluation, the USGS installed the Chuckwalla Valley multiple-well monitoring site (CWV1) in the southeastern portion of the Chuckwalla Basin. Data collected at this site provide information about the geology, hydrology, geophysics, and geochemistry of the local aquifer system, thus enhancing the understanding of the geohydrologic framework of the Chuckwalla Valley. This report presents construction information for the CWV1 multiple-well monitoring site and initial geohydrologic data collected from the site.

Ground-water conditions in southern Utah Valley and Goshen Valley, Utah

USGS Publications Warehouse

Cordova, R.M.

1970-01-01

The investigation of ground-water conditions in southern Utah Valley and Goshen Valley, Utah, was made by the U. S. Geological Survey as part of a cooperative program with the Utah Department of Natural Resources, Division of Water Rights, to investigate the water resources of the State. The purposes of the investigation were to (1) determine the occurrence, recharge, discharge, movement, storage, chemical quality, and availability of ground water; (2) appraise the effects of increased withdrawal of water from wells; and (3) evaluate the effect of the Central Utah Project on the ground-water reservoir and the water supply of Utah Lake.This report presents a description of the aquifer system in the two valleys, a detailed description of the ground-water resources, and conclusions about potential development and its effect on the hydrologic conditions in the valleys. Two supplementary reports are products of the investigation. A basic-data release (Cordova, 1969) contains most of the basic data collected for the investigation, including well characteristics, drillers' logs, water levels, pumpage from wells, chemical analyses of ground and surface waters, and discharge of selected springs, drains, and streams. An interpretive report (Cordova and Mower, 1967) contains the results of a large-scale aquifer test in southern Utah Valley.

Effects of ground-water withdrawals on flow in the Sauk River Valley Aquifer and on streamflow in the Cold Spring area, Minnesota

USGS Publications Warehouse

Lindgren, R.J.

2001-01-01

The simulated contributing areas for selected watersupply wells in the Cold Spring area generally extend to and possibly beyond the model boundaries to the north and to the southeast. The contributing areas for the Gold'n Plump Poultry Processing Plant supply wells extend: (1) to the Sauk River, (2) to the north to and possibly beyond to the northern model boundary, and (3) to the southeast to and possibly beyond the southeastern model boundary. The primary effects of projected increased ground-water withdrawals of 0.23 cubic feet per second (7.5 percent increase) were to: (1) decrease outflow from the Sauk River Valley aquifer through constant-head boundaries and (2) decrease leakage from the valley unit of the Sauk River Valley aquifer to the streams. No appreciable differences were discernible between the simulated steady-state contributing areas to wells with 1998 pumpage and those with the projected pumpage.

Radiogenic 4He as a conservative tracer in buried‐valley aquifers

USGS Publications Warehouse

Van der Hoven, Stephen J.; Wright, R. Erik; Carstens, David A.; Hackley, Keith C.

2005-01-01

The accumulation of 4He in groundwater can be a powerful tool in hydrogeologic investigations. However, the use of 4He often suffers from disagreement or uncertainty related to in situ and external sources of 4He. In situ sources are quantified by several methods, while external sources are often treated as calibration parameters in modeling. We present data from direct laboratory measurements of 4He release from sediments and field data of dissolved 4He in the Mahomet Aquifer, a well‐studied buried‐valley aquifer in central Illinois. The laboratory‐derived accumulation rates (0.13–0.91 μcm3 STP kgwater−1 yr−1) are 1–2 orders of magnitude greater than the accumulation rates based on the U and Th concentrations of the sediments (0.004–0.009 μcm3 STP kgwater−1 yr−1). The direct measurement of accumulation rates are more consistent with dissolved concentrations of 4He in the groundwater. We suggest that the direct measurement method is applicable in a variety of hydrogeologic settings. The patterns of accumulation of 4He are consistent with the conceptual model of flow in the aquifer based on hydraulic and geochemical evidence and show areas where in situ production and external sources of 4He are dominant. In the southwestern part of the study area, Ne concentrations are less than atmospheric solubility, indicating gases have been lost from the groundwater. Available evidence indicates that the gases are lost as groundwater passes by pockets of CH4 in glacial deposits overlying the aquifer. However, the external flux from the underlying bedrock appears to dominate the accumulation of radiogenic 4He in the aquifer in the southwestern part of the study area, and the loss or gain of helium as groundwater passes through the overlying sediments is minor in comparison.

Investigation of aquifer-system compaction in the Hueco basin, El Paso, Texas, USA

USGS Publications Warehouse

Heywood, Charles

1995-01-01

The Pleistocene geologic history of the Rio Grande valley in the Hueco basin included a cycle of sediment erosion and re-aggradation, resulting in unconformable stratification of sediment of contrasting compressibility and stress history. Since the 1950s large groundwater withdrawals have resulted in significant water-level declines and associated land subsidence. Knowledge of the magnitude and variation of specific storage is needed for developing predictive models of subsidence and groundwater flow simulations. Analyses of piezometric and extensometric data in the form of stress-strain diagrams from a 16 month period yield in situ measurements of aquifer-system compressibility across two discrete aquifer intervals. The linear elastic behaviour of the deeper interval indicates over-consolidation of basin deposits, probably resulting from deeper burial depth before the middle Pleistocene. By contrast, the shallow aquifer system displays an inelastic component, suggesting pre-consolidation stress not significantly greater than current effective stress levels for a sequence of late Pleistocene clay. Harmonic analyses of the piezometric response to earth tides in two water-level piezometers provide an independent estimate of specific storage of aquifer sands.

The role of alpine rockfall aquifer systems in baseflow maintenance and flood attenuation

NASA Astrophysics Data System (ADS)

Lauber, Ute; Kotyla, Patrick; Morche, David; Goldscheider, Nico

2015-04-01

Rockfall masses are frequent in alpine valleys. Huge rockfalls (millions to billions m³) precipitated after the end of the last glaciation, but many large events (thousand to millions m³) have occurred in historical time, and increasingly during the past decades, as a result of glacier retreat and thawing of permafrost. Most hydrological research focuses on water as a cause or trigger of rockfalls, while much less research has been done on the hydrogeological properties and functions of rockfall masses in alpine valleys. We have studied a series of rockfall and alluvial aquifer systems in the Reintal valley, German Alps, where all surface water infiltrates underground and reemerges downgradient from the rockfall masses. The goal of the study was to characterize the role of this rockfall aquifer in baseflow maintenance and flood attenuation. Employed methods include geomorphological and hydrogeological mapping, tracer tests, and continuous flow measurements. Field observations have revealed that both the infiltration and exfiltration locations vary as a function of the hydrologic conditions. Underground flow path length range from 500 m during high flows to 2 km during low flows; measured groundwater flow velocities range between 13 and 30 m/h; lag times between upstream and downstream flood peaks are 5 to 101 hours. Flood peaks were dampened by a factor of 1.5 and the maximum discharge ratio (22) and peak recession coefficient (0.2/d) downstream are very low compared with other alpine catchments. These results indicate that rockfall aquifers can play an important role in the flow regime and flood attenuation in alpine regions.

Simulation of an urban ground-water-flow system in the Menomonee Valley, Milwaukee, Wisconsin using analytic element modeling

USGS Publications Warehouse

Dunning, C.P.; Feinstein, D.T.

2004-01-01

A single-layer, steady-state analytic element model was constructed to simulate shallow ground-water flow in the Menomonee Valley, an old industrial center southwest of downtown Milwaukee, Wisconsin. Project objectives were to develop an understanding of the shallow ground-water flow system and identify primary receptors of recharge to the valley. The analytic element model simulates flow in a 18.3 m (60 ft) thick layer of estuarine and alluvial sediments and man-made fill that comprises the shallow aquifer across the valley. The thin, laterally extensive nature of the shallow aquifer suggests horizontal-flow predominates, thus the system can appropriately be modeled with the Dupuit-Forchheimer approximation in an analytic element model. The model was calibrated to the measured baseflow increase between two USGS gages on the Menomonee River, 90 head measurements taken in and around the valley during December 1999, and vertical gradients measured at five locations under the river and estuary in the valley. Recent construction of the Milwaukee Metropolitan Sewer District Inline Storage System (ISS) in the Silurian dolomite under the Menomonee Valley has locally lowered heads in the dolomite appreciably, below levels caused by historic pumping. The ISS is a regional hydraulic sink which removes water from the bedrock even during dry weather. The potential effect on flow directions in the shallow aquifer of dry-weather infiltration to the ISS was evaluated by adjusting the resistance of the line-sink strings representing the ISS in the model to allow infiltration from 0 to 100% of the reported 9,500 m3/d. The best fit to calibration targets was found between 60% (5,700 m3/d) and 80% (7,600 m3/d) of the reported dry-weather infiltration. At 60% infiltration, 65% of the recharge falling on the valley terminates at the ISS and 35% at the Menomonee River and estuary. At 80% infiltration, 73% of the recharge terminates at the ISS, and 27% at the river and estuary. Model

Virtual groundwater transfers from overexploited aquifers in the United States.

PubMed

Marston, Landon; Konar, Megan; Cai, Ximing; Troy, Tara J

2015-07-14

The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km(3), 9.18 km(3), and 6.81 km(3), respectively, which is comparable to the capacity of Lake Mead (35.7 km(3)), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use.

California's Central Valley Groundwater Study: A Powerful New Tool to Assess Water Resources in California's Central Valley

USGS Publications Warehouse

Faunt, Claudia C.; Hanson, Randall T.; Belitz, Kenneth; Rogers, Laurel

2009-01-01

Competition for water resources is growing throughout California, particularly in the Central Valley. Since 1980, the Central Valley's population has nearly doubled to 3.8 million people. It is expected to increase to 6 million by 2020. Statewide population growth, anticipated reductions in Colorado River water deliveries, drought, and the ecological crisis in the Sacramento-San Joaquin Delta have created an intense demand for water. Tools and information can be used to help manage the Central Valley aquifer system, an important State and national resource.

Geohydrology of the stratified-drift aquifer system in the lower Sixmile Creek and Willseyville Creek trough, Tompkins County, New York

USGS Publications Warehouse

Miller, Todd S.; Karig, Daniel E.

2010-01-01

In 2002, the U.S. Geological Survey, in cooperation with the Tompkins County Planning Department began a series of studies of the stratified-drift aquifers in Tompkins County to provide geohydrologic data for planners to develop a strategy to manage and protect their water resources. This aquifer study in lower Sixmile Creek and Willseyville Creek trough is the second in a series of aquifer studies in Tompkins County. The study area is within the northern area of the Appalachian Plateau and extends about 9 miles from the boundary between Tompkins County and Tioga County in the south to just south of the City of Ithaca in the north. In lower Sixmile Creek and Willseyville Creek trough, confined sand and gravel aquifers comprise the major water-bearing units while less extensive unconfined units form minor aquifers. About 600 people who live in lower Sixmile Creek and Willseyville Creek trough rely on groundwater from the stratified-drift aquifer system. In addition, water is used by non-permanent residents such as staff at commercial facilities. The estimated total groundwater withdrawn for domestic use is about 45,000 gallons per day (gal/d) or 0.07 cubic foot per second (ft3/s) based on an average water use of 75 gal/d per person for self-supplied water systems in New York. Scouring of bedrock in the preglacial lower Sixmile Creek and Willseyville Creek valleys by glaciers and subglacial meltwaters truncated hillside spurs, formed U-shaped, transverse valley profiles, smoothed valley walls, and deepened the valleys by as much as 300 feet (ft), forming a continuous trough. The unconsolidated deposits in the study area consist mostly of glacial drift, both unstratified drift (till) and stratified drift (laminated lake, deltaic, and glaciofluvial sediments), as well as some post-glacial stratified sediments (lake-bottom sediments that were deposited in reservoirs, peat and muck that were deposited in wetlands, and alluvium deposited by streams). Multiple advances and

Impacts of urbanization on groundwater hydrodynamics and hydrochemistry of the Toluca Valley aquifer (Mexico).

PubMed

Martín Del Campo, M A; Esteller, M V; Expósito, J L; Hirata, R

2014-05-01

The Toluca Valley is located on the high plains of Mexico, where there are significant industrial zones and large populations. Water needs are almost exclusively met by groundwater, which has brought about intense exploitation of the aquifer and indication of some contamination. The present study investigates the effect of urbanization, related to industrialization of the region, on groundwater in the central portion of the Toluca Valley aquifer--a zone with high population density and where the largest industrial park is located. A general decline in the groundwater level has been found over the years, at a rate of as much as 2.5 m/year. The appearance of a large drawdown cone was identified, indicating changes in the direction of groundwater flow. Also identified was the presence of several ground fissures, the location of which coincided with the drawdown cone. In hydrochemical terms, the water type is sodium-magnesium bicarbonate and this characteristic has not changed over time, although it has been possible to detect the presence of larger quantities of sulfates (up to 117 mg/L) and nitrates (up to 47 mg/L) in recent years, likely associated with contamination from industrial and urban wastewater. Factor analysis made it possible to identify ions that would characterize natural processes involving the acquisition of salts (HCO3 (-), Na(+), Mg(2+), and Si), as well as anthropic activities (SO4 (2-), NO3 (-), Cl(-), Ca(2+), and K(+)).

Impact of Elevated CO2 on Trace Element Release from Aquifer Sediments of the San Joaquin Valley, CA

NASA Astrophysics Data System (ADS)

Fox, P. M.; Nico, P. S.; Davis, J. A.; Spycher, N.

2014-12-01

Carbon capture and storage (CCS) is a promising technique for mitigating climate change by storing large volumes of carbon dioxide in deep saline aquifers. In California, the thick marine sediments of the Central and Salinas Valleys have been identified as prime targets for future CO2 storage. However, the potential impacts on water quality of overlying drinking-water aquifers must be studied before CCS can be implemented. In this study, we compare trace element release from San Joaquin Valley aquifer sediments with a wide range of textural and redox properties. Kinetic batch experiments were performed with artificial groundwater continuously equilibrated under CO2-saturated (at 1 atm) and background CO2 (0.002-0.006 atm) conditions, resulting in a shift of nearly 3 pH units. In addition, the reversibility of trace element release was studied by sequentially lowering the CO2 from 1.0 atm to 0.5 atm to background concentrations (0.002-0.006 atm) for CO2-saturated systems in order to mimic the dissipation of a CO2 plume in the aquifer. During exposure to high CO2, a number of elements displayed enhanced release compared to background CO2 experiments (Ca, Mg, Li, Si, B, As, Sr, Ni, Fe, Mn, V, Ti, and Co) with concentrations of As, Fe, and Mn exceeding EPA maximum contaminant levels in some cases. On the other hand, Mo and U showed suppressed release. Most intriguing, many of the elements showing enhanced release displayed at least some degree of irreversibility when CO2 concentrations were decreased to background levels. In fact, in some cases (i.e., for V), an element showed further release when CO2 concentrations were decreased. These results suggest that there may be longer-term effects on groundwater quality that persist even after the CO2 plume has dissipated. Several different mechanisms of trace element release including ion exchange, desorption, and carbonate mineral dissolution are explored. Preliminary modeling results suggest that carbonate mineral

Regional aquifer systems

NASA Astrophysics Data System (ADS)

The fifth in the American Water Resources Association (AWRA) Monograph series “Regional Aquifer Systems of the United States” has just been published as Monograph Series No. 13, “Aquifers of the Midwestern Area,” edited by L. A. Swain and A. Ivan Johnson. The 238-page publication is available for $18 to AWRA members and $21 for nonmembers.Each AWRA Annual Conference since 1985 has sponsored special seminars describing hydrologic, geochemical, and geologic characteristics of the Regional Aquifer System Analysis (RASA) studies carried out by the U.S. Geological Survey

Estimated withdrawals from principal aquifers in the United States, 2000

USGS Publications Warehouse

Maupin, Molly A.; Barber, Nancy L.

2005-01-01

Fresh ground-water withdrawals from 66 principal aquifers in the United States were estimated for irrigation, public-supply, and self-supplied industrial water uses for the year 2000. Total ground-water withdrawals were 76,500 million gallons per day, or 85,800 thousand acre-feet per year for these three uses. Irrigation used the largest amount of ground water, 56,900 million gallons per day, followed by public supply with 16,000 million gallons per day, and self-supplied industrial with 3,570 million gallons per day. These three water uses represented 92 percent of the fresh groundwater withdrawals for all uses in the United States, the remaining 8 percent included self-supplied domestic, aquaculture, livestock, mining, and thermoelectric power uses. Aquifer withdrawals were categorized by five lithologic groups: unconsolidated and semiconsolidated sand and gravel aquifers, carbonate-rock aquifers, igneous and metamorphic-rock aquifers, sandstone aquifers, and sandstone and carbonate-rock aquifers. Withdrawals from aquifers that were not included in one of the 66 principal aquifers were reported in an “Other” aquifers group. The largest withdrawals in the United States were from unconsolidated and semiconsolidated sand and gravel aquifers, which accounted for 80 percent of total withdrawals from all aquifers. Carbonate-rock aquifers provided 8 percent of the withdrawals, and igneous and metamorphic-rock aquifers, 6 percent. Withdrawals from sandstone aquifers, from sandstone and carbonate-rock aquifers, and from the “Other” aquifers category each constituted about 2 percent of the total withdrawals reported.Fifty-five percent of the total withdrawals for irrigation, public-supply, and self-supplied industrial water uses were provided by the High Plains aquifer, California Central Valley aquifer system, the Mississippi River Valley alluvial aquifer, and the Basin and Range basin-fill aquifers. These aquifers provided most of the withdrawals for irrigation

Assessing the Vulnerability of Public-Supply Wells to Contamination: Central Valley Aquifer System near Modesto, California

USGS Publications Warehouse

Jagucki, Martha L.; Jurgens, Bryant C.; Burow, Karen R.; Eberts, Sandra M.

2009-01-01

This fact sheet highlights findings from the vulnerability study of a public-supply well in Modesto, California. The well selected for study pumps on average about 1,600 gallons per minute from the Central Valley aquifer system during peak summer demand. Water samples were collected at the public-supply well and at monitoring wells installed in the Modesto vicinity. Samples from the public-supply wellhead contained the undesirable constituents uranium, nitrate, arsenic, volatile organic compounds (VOCs), and pesticides, although none were present at concentrations exceeding drinking-water standards. Of these contaminants, uranium and nitrate pose the most significant water-quality risk to the public-supply well because human activities have caused concentrations in groundwater to increase over time. Overall, study findings point to four primary factors that affect the movement and (or) fate of contaminants and the vulnerability of the public-supply well in Modesto: (1) groundwater age (how long ago water entered, or recharged, the aquifer); (2) irrigation and agricultural and municipal pumping that drives contaminants downward into the primary production zone of the aquifer; (3) short-circuiting of contaminated water down the public-supply well during the low-pumping season; and (4) natural geochemical conditions of the aquifer. A local-scale computer model of groundwater flow and transport to the public-supply well was constructed to simulate long-term nitrate and uranium concentrations reaching the well. With regard to nitrate, two conflicting processes influence concentrations in the area contributing recharge to the well: (1) Beneath land that is being farmed or has recently been farmed (within the last 10 to 20 years), downward-moving irrigation waters contain elevated nitrate concentrations; yet (2) the proportion of agricultural land has decreased and the proportion of urban land has increased since 1960. Urban land use is associated with low nitrate

Evaluation of areas of contribution and water quality at receptors related to TCE plumes in a valley fill aquifer system

NASA Astrophysics Data System (ADS)

Lefebvre, R.; Ouellon, T.; Blais, V.; Ballard, J.; Brunet, P.

2009-05-01

The Val-Belair sector is located within Quebec City, about 20 km from downtown. Potential source zones and TCE plumes in groundwater are found at the western limit of the sector. At the center of the sector, four municipal water supply wells pump groundwater from an aquifer in surficial sediments where dissolved TCE is found. Private residential wells are also found in the sector. The Nelson River and its tributaries drain the sector and flows from west to east. New characterization results and available data were used to develop a numerical model of groundwater flow and mass transport to 1) define geological and hydrogeological contexts, 2) delineate the distribution of TCE and identify its migration paths and 3) evaluate the effect of TCE on the water quality of receptors (Nelson River, municipal and residential wells). In the sector, 30 to 40 m of sediments filling a buried valley form two aquifers separated by an aquitard: an unconfined deltaic aquifer at surface, an underlying silty prodeltaic aquitard and a semi-confined aquifer of deltaic sands and diamictons. Groundwater exchanges between the aquifers are generally downward through the aquitard, but near the Nelson River there is upward flow. Monitoring has led to sparse TCE detections in the Nelson River, regular detections at a mean value of 0.62 μg/L at one municipal well, occasional detections at another well and no detection at the other two wells. No TCE was detected in private wells, which are located outside the migration paths of TCE plumes. The context and numerical modeling with particle tracking and mass transport show the relationships between the two source zones, three TCE plumes and three receptors. Municipal wells pump in the semi-confined aquifer at a level appearing sustainable, but use most of the recharge in the sub-watershed. Areas of contribution to the wells thus cover almost all the study area with a complex pattern. These wells compete with the effect of the Nelson River to drain

The hydrogeochemistry of a heavily used aquifer in the Mexican wine-producing Guadalupe Valley, Baja California

NASA Astrophysics Data System (ADS)

Daesslé, L. W.; Mendoza-Espinosa, L. G.; Camacho-Ibar, V. F.; Rozier, W.; Morton, O.; van Dorst, L.; Lugo-Ibarra, K. C.; Quintanilla-Montoya, A. L.; Rodríguez-Pinal, A.

2006-10-01

The Guadalupe Valley aquifer is the only water source for one of the most important wine industries in Mexico, and also the main public water supply for the nearby city of Ensenada. This groundwater is monitored for major ion, N-NO3, P-PO4, Fe, As, Se, Mo, Cd, Cu, Pb, Zn and Sb concentrations, as well as TDS, pH, dissolved oxygen and temperature. High concentrations of N-NO3 (26 mg l-1), Se (70 μg l-1), Mo (18 μg l-1) and Cu (4.3 μg l-1) suggest that groundwater is being polluted by the use of fertilizers only in the western section of the aquifer, known as El Porvenir graben. Unlike the sites located near the main recharge area to the East of the aquifer, the water in El Porvenir graben has low tritium concentrations (<1.9 TU), indicating a pre-modern age, and thus longer water residence time. No significant variations in water quality (generally <10%) were detected throughout 2001-2002 in the aquifer, suggesting that reduced rainfall and recharge during this dry period did not significantly affect water quality. However, the wells nearest to the main recharge area in the Eastern aquifer show a slight but constant increase in TDS with time, probably as a result of the high (˜200 L S-1) uninterrupted extraction of water at this specific recharge site. Relatively high As concentrations for the aquifer (10.5 μg l-1) are only found near the northern limit of the basin associated with a geological fault.

Virtual groundwater transfers from overexploited aquifers in the United States

PubMed Central

Marston, Landon; Konar, Megan; Cai, Ximing; Troy, Tara J.

2015-01-01

The High Plains, Mississippi Embayment, and Central Valley aquifer systems within the United States are currently being overexploited for irrigation water supplies. The unsustainable use of groundwater resources in all three aquifer systems intensified from 2000 to 2008, making it imperative that we understand the consumptive processes and forces of demand that are driving their depletion. To this end, we quantify and track agricultural virtual groundwater transfers from these overexploited aquifer systems to their final destination. Specifically, we determine which US metropolitan areas, US states, and international export destinations are currently the largest consumers of these critical aquifers. We draw upon US government data on agricultural production, irrigation, and domestic food flows, as well as modeled estimates of agricultural virtual water contents to quantify domestic transfers. Additionally, we use US port-level trade data to trace international exports from these aquifers. In 2007, virtual groundwater transfers from the High Plains, Mississippi Embayment, and Central Valley aquifer systems totaled 17.93 km3, 9.18 km3, and 6.81 km3, respectively, which is comparable to the capacity of Lake Mead (35.7 km3), the largest surface reservoir in the United States. The vast majority (91%) of virtual groundwater transfers remains within the United States. Importantly, the cereals produced by these overexploited aquifers are critical to US food security (contributing 18.5% to domestic cereal supply). Notably, Japan relies upon cereals produced by these overexploited aquifers for 9.2% of its domestic cereal supply. These results highlight the need to understand the teleconnections between distant food demands and local agricultural water use. PMID:26124137

Data network, collection, and analysis in the Diamond Valley flow system, central Nevada

USGS Publications Warehouse

Knochenmus, Lari A.; Berger, David L.; Moreo, Michael T.; Smith, J. LaRue

2011-01-01

Future groundwater development and its effect on future municipal, irrigation, and alternative energy uses in the Diamond Valley flow system are of concern for officials in Eureka County, Nevada. To provide a better understanding of the groundwater resources, the U.S. Geological Survey, in cooperation with Eureka County, commenced a multi-phase study of the Diamond Valley flow system in 2005. Groundwater development primarily in southern Diamond Valley has resulted in water-level declines since the 1960s ranging from less than 5 to 100 feet. Groundwater resources in the Diamond Valley flow system outside of southern Diamond Valley have been relatively undeveloped. Data collected during phase 2 of the study (2006-09) included micrometeorological data at 4 evapotranspiration stations, 3 located in natural vegetation and 1 located in an agricultural field; groundwater levels in 95 wells; water-quality constituents in aquifers and springs at 21 locations; lithologic information from 7 recently drilled wells; and geophysical logs from 3 well sites. This report describes what was accomplished during phase 2 of the study, provides the data collected, and presents the approaches to strengthen relations between evapotranspiration rates measured at micrometeorological stations and spatially distributed groundwater discharge. This report also presents the approach to improve delineation of areas of groundwater discharge and describes the current methodology used to improve the accuracy of spatially distributed groundwater discharge rates in the Diamond Valley flow system.

Hydrology of the Ferron sandstone aquifer and effects of proposed surface-coal mining in Castle Valley, Utah

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lines, G.C.; Morrissey, D.J.

Coal in the Ferron Sandstone Member of the Mancos Shale of Cretaceous age has traditionally been mined by underground techniques in the Emery Coal Field in the southern end of Castle Valley in east-central Utah. However, approximately 99 million tons are recoverable by surface mining. Ground water in the Ferron is the sole source of supply for the town of Emery, but the aquifer is essentially untapped outside the Emery area. A three-dimensional digital-computer model was used to simulate ground-water flow in the Ferron sandstone aquifer in the Emery area. The model also was used to predict the effects ofmore » dewatering of a proposed surface mine on aquifer potentiometric surfaces and the base flow of streams. Discharge from the proposed surface mine is predicted to average about 0.3 cubic foot per second during the 15 years of mine operation. Dewatering of the mine would affect the potentiometric surface of all sections of the Ferron sanstone aquifer, but the greatest effects would be in the upper section. Modeling results indicate that, except for Christiansen Wash, the dewatering of the proposed surface mine would not affect the base flow of streams.« less

Groundwater quality in the shallow aquifers of the Monterey Bay, Salinas Valley, and adjacent highland areas, Southern Coast Ranges, California

USGS Publications Warehouse

Burton, Carmen

2018-05-30

The Monterey-Salinas Shallow Aquifer study unit covers approximately 7,820 square kilometers (km2) in Santa Cruz, Monterey, and San Luis Obispo Counties in the Central Coast Hydrologic Region of California. The study unit was divided into four study areas—Santa Cruz, Pajaro Valley, Salinas Valley, and Highlands. More than 75 percent of the water used for drinking-water supply in the Central Coast Hydrologic Region of California is groundwater, and there are more than 8,000 well driller’s logs for domestic wells (California Department of Water Resources, 2013).

Groundwater Quality in the Shallow Aquifers of the Monterey Bay, Salinas Valley, and Adjacent Highland Areas, Southern Coast Ranges, California

USGS Publications Warehouse

Burton, Carmen

2018-05-30

The Monterey-Salinas Shallow Aquifer study unit covers approximately 7,820 square kilometers (km2) in Santa Cruz, Monterey, and San Luis Obispo Counties in the Central Coast Hydrologic Region of California. The study unit was divided into four study areas—Santa Cruz, Pajaro Valley, Salinas Valley, and Highlands. More than 75 percent of the water used for drinking-water supply in the Central Coast Hydrologic Region of California is groundwater, and there are more than 8,000 well driller’s logs for domestic wells (California Department of Water Resources, 2013).

Use of environmental tracers to evaluate ground-water age and water-quality trends in a buried-valley aquifer, Dayton area, southwestern, Ohio

USGS Publications Warehouse

Rowe, Gary L.; Shapiro, Stephanie Dunkle; Schlosser, Peter

1999-01-01

Chlorofluorocarbons (CFC method) and tritium and helium isotopes (3H-3He method) were used as environmental tracers to estimate ground-water age in conjunction with efforts to develop a regional ground-water flow model of the buried-valley aquifer in the Dayton area, southwestern Ohio. This report describes results of CFC and water-quality sampling, summarizes relevant aspects of previously published work, and describes the use of 3H-3He ages to characterize temporal trends in ground-water quality of the buried-valley aquifer near Dayton, Ohio. Results of CFC sampling indicate that approximately 25 percent of the 137 sampled wells were contaminated with excess CFC's that rendered the ground water unsuitable for age dating. Evaluation of CFC ages obtained for the remaining samples indicated that the CFC compounds used for dating were being affected by microbial degradation. The degradation occurred under anoxic conditions that are found in most parts of the buried-valley aquifer. As a result, ground-water ages derived by the CFC method were too old and were inconsistent with measured tritium concentrations and independently derived 3H-3He ages. Limited data indicate that dissolved methane may play an important role in the degradation of the CFC's. In contrast, the 3H-3He technique was found to yield ground-water ages that were chemically and hydrologically reasonable. Ground-water ages derived by the 3H-3He technique were compared to values for selected water- quality characteristics to evaluate temporal trends in ground-water quality in the buried- valley aquifer. Distinct temporal trends were not identified for pH, alkalinity, or calcium and magnesium because of rapid equilibration of ground-water with calcite and dolomite in aquifer sediments. Temporal trends in which the amount of scatter and the number of outlier concentrations increased as ground-water age decreased were noted for sodium, potassium, boron, bromide, chloride, ammonia, nitrate, phosphate

Fuzzy-based assessment of groundwater intrinsic vulnerability of a volcanic aquifer in the Chilean Andean Valley.

PubMed

Duhalde, Denisse J; Arumí, José L; Oyarzún, Ricardo A; Rivera, Diego A

2018-06-11

A fuzzy logic approach has been proposed to face the uncertainty caused by sparse data in the assessment of the intrinsic vulnerability of a groundwater system with parametric methods in Las Trancas Valley, Andean Mountain, south-central Chile, a popular touristic place in Chile, but lacking of a centralized drinking and sewage water public systems; this situation is a potentially source of groundwater pollution. Based on DRASTIC, GOD, and EKv and the expert knowledge of the study area, the Mamdani fuzzy approach was generated and the spatial data were processed by ArcGIS. The groundwater system exhibited areas with high, medium, and low intrinsic vulnerability indices. The fuzzy approach results were compared with traditional methods results, which, in general, have shown a good spatial agreement even though significant changes were also identified in the spatial distribution of the indices. The Mamdani logic approach has shown to be a useful and practical tool to assess the intrinsic vulnerability of an aquifer under sparse data conditions.

Seasonal subsidence and rebound in Las Vegas Valley, Nevada, observed by Synthetic Aperture Radar Interferometry

USGS Publications Warehouse

Hoffmann, Jörn; Zebker, Howard A.; Galloway, Devin L.; Amelung, Falk

2001-01-01

Analyses of areal variations in the subsidence and rebound occurring over stressed aquifer systems, in conjunction with measurements of the hydraulic head fluctuations causing these displacements, can yield valuable information about the compressibility and storage properties of the aquifer system. Historically, stress‐strain relationships have been derived from paired extensometer/piezometer installations, which provide only point source data. Because of the general unavailability of spatially detailed deformation data, areal stress‐strain relations and their variability are not commonly considered in constraining conceptual and numerical models of aquifer systems. Interferometric synthetic aperture radar (InSAR) techniques can map ground displacements at a spatial scale of tens of meters over 100 km wide swaths. InSAR has been used previously to characterize larger magnitude, generally permanent aquifer system compaction and land subsidence at yearly and longer timescales, caused by sustained drawdown of groundwater levels that produces intergranular stresses consistently greater than the maximum historical stress. We present InSAR measurements of the typically small‐magnitude, generally recoverable deformations of the Las Vegas Valley aquifer system occurring at seasonal timescales. From these we derive estimates of the elastic storage coefficient for the aquifer system at several locations in Las Vegas Valley. These high‐resolution measurements offer great potential for future investigations into the mechanics of aquifer systems and the spatial heterogeneity of aquifer system structure and material properties as well as for monitoring ongoing aquifer system compaction and land subsidence.

Aquifer systems in the Great Basin region of Nevada, Utah, and adjacent states: A study plan

USGS Publications Warehouse

Harrill, James R.; Welch, Alan H.; Prudic, David E.; Thomas, James M.; Carman, Rita L.; Plume, Russell W.; Gates, Joseph S.; Mason, James L.

1983-01-01

The Great Basin Regional Aquifer Study includes about 140,000 square miles in parts of Nevada, Utah, California, Idaho, Oregon, and Arizona. Within that area, 240 hydrographic areas occupy structural depressions formed primarily by basin-and-range faulting. The principal aquifers are in basin- fill deposits; however, permeable carbonate rocks underlie valleys in much of eastern Nevada and western Utah and are significant regional aquifers. Anticipated future water needs require a better understanding of the resource so that wise management will be possible. In October 1980, the U.S Geological Survey started a 4-year study to (1) describe the ground-water systems as they existed under natural conditions and as they exist today, (2) analyze the changes that have led to the systems' present condition, (3) tie the results of this and previous studies together in a regional analysis, and (4) provide means by which effects of future ground-water development can be estimated.A plan of work is presented that describes the general approach to be taken in this study. It defines (1) the major task necessary to meet objectives and (2) constraints on the scope of work. The approach has been strongly influenced by the diverse nature of ground-water flow systems and the large number of basins. A detailed appraisal of 240 individual areas would require more resources than are available. Consequently, the general approach is to study selected "typical" areas and key hydrologic processes. Effort during the first 3 years will be directed toward describing the regional hydrology, conducting detailed studies of "type" areas, and studying selected hydrologic processes. Effort during the final year will be directed toward developing a regional analyses of results.Special studies that will address hydrologic processes, key components of the ground-water system, and improved use of technology include evaluations of regional geochemistry, regional hydrogeology, recharge, ground

Delineation and description of the regional aquifer systems of Tennessee; Cumberland Plateau aquifer system

USGS Publications Warehouse

Brahana, J.V.; Macy, J.A.; Mulderink, Dolores; Zemo, Dawn

1986-01-01

The Cumberland Plateau aquifer system consists of Pennsylvanian sandstones, conglomerates, shales, and coals which underlie the Cumberland Plateau in Tennessee. Major water-bearing zones occur within the sandstones and conglomerates in interconnected fractures. The water-bearing formations are separated by shale and siltstone that retard the vertical circulation of ground water, The Pennington Formation serves as the base of this aquifer system and is an effective confining unit, The Cumberland Plateau aquifer system is an important water source for the Cumberland Plateau, wells and springs from the aquifer system supply most of the rural domestic and public drinking-water supplies, water from wells drilled into the Cumberland Plateau aquifer system is generally of good to excellent quality. Of the 32 water-quality analyses on file from this aquifer. only 2 had dissolved-solids concentrations greater than 500 milligrams per liter, and about three-fourths had less than 200 milligrams per liter dissolved solids, However, no samples from depths greater than 300 feet below land surface have been recorded. Ground water from locations where the sandstones are buried deeply, such as the Wartburg basin, may contain dissolved-solids concentrations greater than 1,000 milligrams per liter.

Evidence for Upward Flow of Saline Water from Depth into the Mississippi River Valley Alluvial Aquifer in Southeastern Arkansas

NASA Astrophysics Data System (ADS)

Larsen, D.; Paul, J.

2017-12-01

Groundwater salinization is occurring in the Mississippi River Valley Alluvial (MRVA) aquifer in southeastern Arkansas (SE AR). Water samples from the MRVA aquifer in Chicot and Desha counties have yielded elevated Cl-concentrations with some as high as 1,639 mg/L. Considering that the MRVA aquifer is the principle source of irrigation water for the agricultural economy of SE AR, salinization needs to be addressed to ensure the sustainability of crop, groundwater, and soil resources in the area. The origin of elevated salinity in MRVA aquifer was investigated using spatial and factor analysis of historical water quality data, and sampling and tracer analysis of groundwater from irrigation, municipal, and flowing industrial wells in SE AR. Spatial analysis of Cl- data in relation to soil type, geomorphic features and sand-blow density indicate that the Cl- anomalies are more closely related to the sand-blow density than soil data, suggesting an underlying tectonic control for the distribution of salinity. Factor analysis of historical geochemical data from the MRVA and underlying Sparta aquifer shows dilute and saline groups, with saline groups weighted positively with Cl- or Na+ and Cl-. Tracer data suggest a component of evaporatively evolved crustal water of pre-modern age has mixed with younger, fresher meteoric sources in SE AR to create the saline conditions in the MRVA aquifer. Stable hydrogen and oxygen values of waters sampled from the Tertiary Sparta and MRVA aquifers deviate from the global and local meteoric water lines along an evaporative trend (slope=4.4) and mixing line with Eocene Wilcox Group groundwaters. Ca2+ and Cl- contents vary with Br- along mixing trends between dilute MRVA water and Jurassic Smackover Formation pore fluids in southern AR. Increasing Cl- content with C-14 age in MRVA aquifer groundwater suggests that the older waters are more saline. Helium isotope ratios decrease with He gas content for more saline water, consistent with

Characteristics of Southern California coastal aquifer systems

USGS Publications Warehouse

Edwards, B.D.; Hanson, R.T.; Reichard, E.G.; Johnson, T.A.

2009-01-01

Most groundwater produced within coastal Southern California occurs within three main types of siliciclastic basins: (1) deep (>600 m), elongate basins of the Transverse Ranges Physiographic Province, where basin axes and related fluvial systems strike parallel to tectonic structure, (2) deep (>6000 m), broad basins of the Los Angeles and Orange County coastal plains in the northern part of the Peninsular Ranges Physiographic Province, where fluvial systems cut across tectonic structure at high angles, and (3) shallow (75-350 m), relatively narrow fluvial valleys of the generally mountainous southern part of the Peninsular Ranges Physiographic Province in San Diego County. Groundwater pumped for agricultural, industrial, municipal, and private use from coastal aquifers within these basins increased with population growth since the mid-1850s. Despite a significant influx of imported water into the region in recent times, groundwater, although reduced as a component of total consumption, still constitutes a significant component of water supply. Historically, overdraft from the aquifers has caused land surface subsidence, flow between water basins with related migration of groundwater contaminants, as well as seawater intrusion into many shallow coastal aquifers. Although these effects have impacted water quality, most basins, particularly those with deeper aquifer systems, meet or exceed state and national primary and secondary drinking water standards. Municipalities, academicians, and local water and governmental agencies have studied the stratigraphy of these basins intensely since the early 1900s with the goals of understanding and better managing the important groundwater resource. Lack of a coordinated effort, due in part to jurisdictional issues, combined with the application of lithostratigraphic correlation techniques (based primarily on well cuttings coupled with limited borehole geophysics) have produced an often confusing, and occasionally conflicting

Hydrogeology of a drift-filled bedrock valley near Lino Lakes, Anoka County, Minnesota

USGS Publications Warehouse

Winter, T.C.; Pfannkuch, H.O.

1976-01-01

The bedrock surface of east-central Minnesota is dissected by an intricate network of valleys. Outside the bedrock valley at site B, 3 mi (4. 8 km) from site A, 100 ft (30 m) of drift overlies the bedrock surface. Observation wells were installed at the two sites to determine the vertical ground-water movement between the various aquifer units and the lateral movement between the two sites. An aquifer test of the lowest valley-fill aquifer at site A showed that the observation well completed in the same aquifer as the pumping well responded immediately; whereas a lag of about 100 min occurred between the lower valley fill and uppermost body of sand and gravel. This indicates that the hydraulic connection between these two layers is poor at the immediate site. Test results show that the lower sand-and-gravel aquifer has a transmissivity between 14,000 and 27,000 ft2/d (1,300 and 2,500 m2/d). Although the hydraulic gradient is vertically downward in the valley, much of the drift fill is poorly permeable. This suggests that the quantity of downward-percolating water reaching the lowest valley-fill aquifer is relatively small at the test site. Because valley cut through a number of bedrock aquifers in the region, they could potentially be an important avenue of contamination from land-surface waste. In addition, the vast network of bedrock valleys in the Twin Cities area might cause contaminants to disseminate rather rapidly throughout a large area.

Application of water quality index to evaluate groundwater quality (temporal and spatial variation) of an intensively exploited aquifer (Puebla valley, Mexico).

PubMed

Salcedo-Sánchez, Edith R; Garrido Hoyos, Sofía E; Esteller Alberich, Ma Vicenta; Martínez Morales, Manuel

2016-10-01

The spatial and temporal variation of water quality in the urban area of the Puebla Valley aquifer was evaluated using historical and present data obtained during this investigation. The current study assessed water quality based on the Water Quality Index developed by the Canadian Council of Ministers of the Environment (CCME-WQI), which provides a mathematical framework to evaluate the quality of water in combination with a set of conditions representing quality criteria, or limits. This index is flexible regarding the type and number of variables used by the evaluation given that the variables of interest are selected according to the characteristics and objectives of development, conservation and compliance with regulations. The CCME-WQI was calculated using several variables that assess the main use of the wells in the urban area that is public supply, according to criteria for human use and consumption established by Mexican law and international standards proposed by the World Health Organization. The assessment of the index shows a gradual deterioration in the quality of the aquifer over time, as the amount of wells with excellent quality have decreased and those with lower index values (poor quality) have increased throughout the urban area of the Puebla Valley aquifer. The parameters affecting groundwater quality are: total dissolved solids, sulfate, calcium, magnesium and total hardness.

Aquifers In Nirgal Vallis

NASA Astrophysics Data System (ADS)

Reiss, D.; Jaumann, R.

The topographic information provided by the Mars Orbiter Laser Altimeter has been used in combination with the Mars Observer Camera imagery to estimate the topo- graphic position of sapping pits and gully heads on the rim of Nirgal Vallis. Hence Nirgal Vallis is understood to be formed by groundwater sapping (1, 2, 3, 4) an aquifer is proposed as water supply. Gullies in the northern rim of Nirgal Vallis as discovered in Mars Observer Camera (MOC) images (5, 6) proof the existence of such an aquifer. Further evidence for sapping in Nirgal Vallis is demonstrated by short hanging tribu- taries with amphitheater-like heads. The basis of these sapping pits defines the con- tact of aquifer to aquiclude during the valley formation. The gully heads are much deeper under the local surface and the correlation of their topographic position with the valley depth indicate the subsidence of the groundwater level following the ver- tical erosion of the valley. This implies the existence of different groundwater tables over time confined by impermeable layers, whereas the gully head level is the most recent groundwater table which still may be erosional active under the conditions of increasing water pressure and ice barrier failure (5). The occurrence of more than one tilted sapping level at different topographic positions which are time-correlated with the erosional notching of the valley, either indicates different aquifers with litholog- ical aquicludes or a climate controlled subsidence of the permafrost layer acting as confining layer. References: (1) Baker et al., 1992, In: Mars, Univ. of Arizona Press. (2) Carr, 1995, JGR 100, 7479. (3) Malin and Carr, 1999, Icarus, 397, 589. (4) Jaumann and Reiss, 2002, LPSC. (5) Malin and Edgett, 2000, Science, 288, 2330. (6) Malin and Edgett, 2001, JGR 106, 23429.

Groundwater quality in the Valley and Ridge and Piedmont and Blue Ridge carbonate-rock aquifers, eastern United States

USGS Publications Warehouse

Lindsey, Bruce; Belitz, Kenneth

2017-01-19

Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are important sources of drinking water. The Valley and Ridge and Piedmont and Blue Ridge carbonate-rock aquifers constitute two of the important areas being evaluated. One or more inorganic constituents with human-health benchmarks were detected at high concentrations in about 15 percent of the study area and at moderate concentrations in about 17 percent. Organic constituents were not detected at high concentrations in the study area. One or more organic constituents with human-health benchmarks were detected at moderate concentrations in about 2 percent of the study area.

Modelling the effect of buried valleys on groundwater flow: case study in Ventspils vicinity, Latvia

NASA Astrophysics Data System (ADS)

Delina, Aija; Popovs, Konrads; Bikse, Janis; Retike, Inga; Babre, Alise; Kalvane, Gunta

2015-04-01

Buried subglacial valleys are widely distributed in glaciated regions and they can have great influence on groundwater flow and hence on groundwater resources. The aim of this study is to evaluate the effect of the buried valleys on groundwater flow in a confined aquifer (Middle Devonian Eifelian stage Arukila aquifer, D2ar) applying numerical modelling. The study area is located at vicinity of Ventspils Town, near wellfield Ogsils where number of the buried valleys with different depth and filling material are present. Area is located close to the Baltic Sea at Piejūra lowland Rinda plain and regional groundwater flow is towards sea. Territory is covered by thin layer of Quaternary sediments in thicknesses of 10 to 20 meters although Prequaternary sediments are exposed at some places. Buried valleys are characterized as narrow, elongated and deep formations that is be filled with various, mainly Pleistocene glacigene sediments - either till loam of different ages or sand and gravel or interbedding of both above mentioned. The filling material of the valleys influences groundwater flow in the confined aquifers which is intercepted by the valleys. It is supposed that glacial till loam filled valleys serves as a barrier to groundwater flow and as a recharge conduit when filled with sand and gravel deposits. Numerical model was built within MOSYS modelling system (Virbulis et al. 2012) using finite element method in order to investigate buried valley influence on groundwater flow in the study area. Several conceptual models were tested in numerical model depending on buried valley filling material: sand and gravel, till loam or mixture of them. Groundwater flow paths and travel times were studied. Results suggested that valley filled with glacial till is acting as barrier and it causes sharp drop of piezometric head and downward flow. Valley filled with sand and gravel have almost no effect on piezometric head distribution, however it this case buried valleys

Hydrogeologic and geochemical characterization of groundwater resources in Rush Valley, Tooele County, Utah

USGS Publications Warehouse

Gardner, Philip M.; Kirby, Stefan

2011-01-01

The water resources of Rush Valley were assessed during 2008–2010 with an emphasis on refining the understanding of the groundwater-flow system and updating the groundwater budget. Surface-water resources within Rush Valley are limited and are generally used for agriculture. Groundwater is the principal water source for most other uses including supplementing irrigation. Most groundwater withdrawal in Rush Valley is from the unconsolidated basin-fill aquifer where conditions are generally unconfined near the mountain front and confined at lower altitudes near the valley center. Productive aquifers also occur in fractured bedrock along the valley margins and beneath the basin-fill deposits in some areas.Drillers’ logs and geophysical gravity data were compiled and used to delineate seven hydrogeologic units important to basin-wide groundwater movement. The principal basin-fill aquifer includes the unconsolidated Quaternary-age alluvial and lacustrine deposits of (1) the upper basin-fill aquifer unit (UBFAU) and the consolidated and semiconsolidated Tertiary-age lacustrine and alluvial deposits of (2) the lower basin-fill aquifer unit (LBFAU). Bedrock hydrogeologic units include (3) the Tertiary-age volcanic unit (VU), (4) the Pennsylvanian- to Permian-age upper carbonate aquifer unit (UCAU), (5) the upper Mississippian- to lower Pennsylvanian-age upper siliciclastic confining unit (USCU), (6) the Middle Cambrian- to Mississippian-age lower carbonate aquifer unit (LCAU), and (7) the Precambrian- to Lower Cambrian-age noncarbonate confining unit (NCCU). Most productive bedrock wells in the Rush Valley groundwater basin are in the UCAU.Average annual recharge to the Rush Valley groundwater basin is estimated to be about 39,000 acre-feet. Nearly all recharge occurs as direct infiltration of snowmelt and rainfall within the mountains with smaller amounts occurring as infiltration of streamflow and unconsumed irrigation water at or near the mountain front. Groundwater

Status and understanding of groundwater quality in the Santa Clara River Valley, 2007-California GAMA Priority Basin Project

USGS Publications Warehouse

Burton, Carmen A.; Montrella, Joseph; Landon, Matthew K.; Belitz, Kenneth

2011-01-01

Groundwater quality in the approximately 460-square-mile Santa Clara River Valley study unit was investigated from April through June 2007 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. The Santa Clara River Valley study unit contains eight groundwater basins located in Ventura and Los Angeles Counties and is within the Transverse and Selected Peninsular Ranges hydrogeologic province. The Santa Clara River Valley study unit was designed to provide a spatially unbiased assessment of the quality of untreated (raw) groundwater in the primary aquifer system. The assessment is based on water-quality and ancillary data collected in 2007 by the USGS from 42 wells on a spatially distributed grid, and on water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer system was defined as that part of the aquifer system corresponding to the perforation intervals of wells listed in the CDPH database for the Santa Clara River Valley study unit. The quality of groundwater in the primary aquifer system may differ from that in shallow or deep water-bearing zones; for example, shallow groundwater may be more vulnerable to surficial contamination. Eleven additional wells were sampled by the USGS to improve understanding of factors affecting water quality.The status assessment of the quality of the groundwater 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 in the primary aquifers of the Santa Clara River Valley study unit

Hydrogeologic framework and occurrence, movement, and chemical characterization of groundwater in Dixie Valley, west-central Nevada

USGS Publications Warehouse

Huntington, Jena M.; Garcia, C. Amanda; Rosen, Michael R.

2014-01-01

Dixie Valley, a primarily undeveloped basin in west-central Nevada, is being considered for groundwater exportation. Proposed pumping would occur from the basin-fill aquifer. In response to proposed exportation, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation and Churchill County, conducted a study to improve the understanding of groundwater resources in Dixie Valley. The objective of this report is to characterize the hydrogeologic framework, the occurrence and movement of groundwater, the general water quality of the basin-fill aquifer, and the potential mixing between basin-fill and geothermal aquifers in Dixie Valley. Various types of geologic, hydrologic, and geochemical data were compiled from previous studies and collected in support of this study. Hydrogeologic units in Dixie Valley were defined to characterize rocks and sediments with similar lithologies and hydraulic properties influencing groundwater flow. Hydraulic properties of the basin-fill deposits were characterized by transmissivity estimated from aquifer tests and specific-capacity tests. Groundwater-level measurements and hydrogeologic-unit data were combined to create a potentiometric surface map and to characterize groundwater occurrence and movement. Subsurface inflow from adjacent valleys into Dixie Valley through the basin-fill aquifer was evaluated using hydraulic gradients and Darcy flux computations. The chemical signature and groundwater quality of the Dixie Valley basin-fill aquifer, and potential mixing between basin-fill and geothermal aquifers, were evaluated using chemical data collected from wells and springs during the current study and from previous investigations. Dixie Valley is the terminus of the Dixie Valley flow system, which includes Pleasant, Jersey, Fairview, Stingaree, Cowkick, and Eastgate Valleys. The freshwater aquifer in the study area is composed of unconsolidated basin-fill deposits of Quaternary age. The basin-fill hydrogeologic unit

Aquifer-test results, direction of ground-water flow, and 1984-90 annual ground-water pumpage for irrigation, lower Big Lost River Valley, Idaho

USGS Publications Warehouse

Bassick, M.D.; Jones, M.L.

1992-01-01

The study area (see index map of Idaho), part of the Big Lost River drainage basin, is at the northern side of the eastern Snake River Plain. The lower Big Lost River Valley extends from the confluence of Antelope Creek and the Big Lost River to about 4 mi south of Arco and encompasses about 145 mi2 (see map showing water-level contours). The study area is about 18 mi long and, at its narrowest, 4 mi wide. Arco, Butte City, and Moore, with populations of 1,016, 59, and 190, respectively, in 1990, are the only incorporated towns. The entire study area, except the extreme northwestern part, is in Butte City. The study area boundary is where alluvium and colluvium pinch out and abut against the White Knob Mountains (chiefly undifferentiated sedimentary rock with lesser amounts of volcanic rock) on the west and the Lost River Range (chiefly sedimentary rock) on the east. Gravel and sand in the valley fill compose the main aquifer. The southern boundary is approximately where Big Lost River valley fill intercalates with or abuts against basalt of the Snake River Group. Spring ground-water levels and flow in the Big Lost River depend primarily on temperature and the amount and timing of precipitation within the entire drainage basin. Periods of abundant water supply and water shortages are, therefore, related to the amount of annual precipitation. Surface reservoir capacity in the valley (Mackay Reservoir, about 20 mi northwest of Moore) is only 20 percent of the average annual flow of the Big Lost River (Crosthwaite and others, 1970, p. 3). Stored surface water is generally unavailable for carryover from years of abundant water supply to help relieve drought conditions in subsequent years. Many farmers have drilled irrigation wells to supplement surface-water supplies and to increase irrigated acreage. Average annual flow of the Big Lost River below Mackay Reservoir near Mackay (gaging station 13127000, not shown) in water years 1905, 1913-14, and 1920-90 was about 224

Preliminary groundwater flow model of the basin-fill aquifers in Detrital, Hualapai, and Sacramento Valleys, Mohave County, northwestern Arizona

USGS Publications Warehouse

Tillman, Fred D.; Garner, Bradley D.; Truini, Margot

2013-01-01

Preliminary numerical models were developed to simulate groundwater flow in the basin-fill alluvium in Detrital, Hualapai, and Sacramento Valleys in northwestern Arizona. The purpose of this exercise was to gather and evaluate available information and data, to test natural‑recharge concepts, and to indicate directions for improving future regional groundwater models of the study area. Both steady-state and transient models were developed with a single layer incorporating vertically averaged hydraulic properties over the model layer. Boundary conditions for the models were constant-head cells along the northern and western edges of the study area, corresponding to the location of the Colorado River, and no-flow boundaries along the bedrock ridges that bound the rest of the study area, except for specified flow where Truxton Wash enters the southern end of Hualapai Valley. Steady-state conditions were simulated for the pre-1935 period, before the construction of Hoover Dam in the northwestern part of the model area. Two recharge scenarios were investigated using the steady-state model—one in which natural aquifer recharge occurs directly in places where water is available from precipitation, and another in which natural aquifer recharge from precipitation occurs in the basin-fill alluvium that drains areas of available water. A transient model with 31 stress periods was constructed to simulate groundwater flow for the period 1935–2010. The transient model incorporates changing Colorado River, Lake Mead, and Lake Mohave water levels and includes time-varying groundwater withdrawals and aquifer recharge. Both the steady-state and transient models were calibrated to available water-level observations in basin-fill alluvium, and simulations approximate observed water-level trends throughout most of the study area.

Detection and Measurement of Land Subsidence Using Global Positioning System and Interferometric Synthetic Aperture Radar, Coachella Valley, California, 1998-2000

USGS Publications Warehouse

Sneed, Michelle; Stork, Sylvia V.; Ikehara, Marti E.

2002-01-01

Land subsidence associated with ground-water-level declines has been recognized as a potential problem in Coachella Valley, California. Since the early 1920s, ground water has been a major source of agricultural, municipal, and domestic supply in the valley. Pumping of ground water resulted in water-level declines as large as 15 meters (50 feet) through the late 1940s. In 1949, the importation of Colorado River water to the lower Coachella Valley began, resulting in a reduction in ground-water pumping and a recovery of water levels during the 1950s through the 1970s. Since the late 1970s, demand for water in the valley has exceeded deliveries of imported surface water, resulting in increased pumping and associated ground-water-level declines and, consequently, an increase in the potential for land subsidence caused by aquifer-system compaction. The location, extent, and magnitude of the vertical land-surface changes in Coachella Valley between 1998 and 2000 were determined using Global Positioning System (GPS) and interferometric synthetic aperture radar (InSAR) methods. GPS measurements made at 15 geodetic monuments in the lower Coachella Valley indicate that -34 to +60 millimeters ? 45 millimeters (-0.11 to +0.20 foot ? 0.15 foot) of vertical change in the land surface occurred during the 2-year period. Changes at three of the monuments exceeded the maximum uncertainty of ? 45 millimeters (? 0.15 foot) at the 95-percent confidence level, which indicates that small amounts of uplift occurred at these monuments between October 1998 and August 2000. Water-level measurements made at wells near the three uplifted monuments during this 2-year period indicate that the water levels fluctuate seasonally; water-level measurements made at these wells in September 1998 and September 2000 indicate that the water levels rose slightly near two monuments and declined slightly near the third. The relation between the seasonally fluctuating, but fairly stable, water levels between

Geohydrologic systems in Kansas, geohydrology of the upper aquifer unit in the western interior plains aquifer system

USGS Publications Warehouse

Kenny, J.F.; Wolf, R.J.; Hansen, Cristi V.

1993-01-01

The purpose of the investigation is to provide a description of the principal geohydrologic systems in Upper Cambrian through Lower Cretaceous rocks in Kansas. This investigation was made as part of the Central Midwest Regional Aquifer-System Analysis (CMRASA). The CMRASA is one of several major investigations by the U.S. Geological Survey of regional aquifer systems in the United States. These regional investigations are designed to increase knowledge of the flow regime and hydrologic properties of major aquifer systems and to provide quantitative information for the assessment, development, and management of water supplies. The CMRASA study area includes all or parts of 10 Central Midwestern States (Jorgensen and Signor, 1981), as shown of the envelope cover,This Hydrologic Investigations Atlas, which consists of a series of chapters, presents a description of the physical framework and geohydrology of principal aquifers and confining systems in Kansas. Chapter H presents the geohydrology of the upper aquifer unit in the Western Interior Plains aquifer system. The physical framework of the aquifer system in relation to other systems is described by maps and sections showing areal extent and the thickness of rocks that compose the unit. The physical framework of the upper aquifer unit is described in detail in chapter D of the atlas (Hansen and others, in press). The hydrology of the system in relation to that of other systems is described in this chapter by maps showing the altitude of fluid levels and the direction of water movement within the unit. The chemical composition of water in the system is described by maps that show the distribution of dissolved-solids concentrations and the differences in water types on the basis of principal chemical constituents. Chapter A of this atlas series (Wolf and others, 1990) describes the relation of principal geohydrologic systems in Kansas and presents a more detailed discussion of the methods and data used to prepare

Factors affecting groundwater quality in the Valley and Ridge aquifers, eastern United States, 1993-2002

USGS Publications Warehouse

Johnson, Gregory C.; Zimmerman, Tammy M.; Lindsey, Bruce D.; Gross, Eliza L.

2011-01-01

Chemical and microbiological analyses of water from 230 wells and 35 springs in the Valley and Ridge Physiographic Province, sampled between 1993 and 2002, indicated that bedrock type (carbonate or siliciclastic rock) and land use were dominant factors influencing groundwater quality across a region extending from northwestern Georgia to New Jersey. The analyses included naturally occurring compounds (major mineral ions and radon) and anthropogenic contaminants [pesticides and volatile organic compounds (VOCs)], and contaminants, such as nitrate and bacteria, which commonly increase as a result of human activities. Natural factors, such as topographic position and the mineral composition of underlying geology, act to produce basic physical and geochemical conditions in groundwater that are reflected in physical properties, such as pH, temperature, specific conductance, and alkalinity, and in chemical concentrations of dissolved oxygen, radon, and major mineral ions. Anthropogenic contaminants were most commonly found in water from wells and springs in carbonate-rock aquifers. Nitrate concentrations exceeded U.S. Environmental Protection Agency maximum contaminant levels in 12 percent of samples, most of which were from carbonate-rock aquifers. Escherichia coli (E. coli), pesticide, and VOC detection frequencies were significantly higher in samples from sites in carbonate-rock aquifers. Naturally occurring elements, such as radon, iron, and manganese, were found in higher concentrations in siliciclastic-rock aquifers. Radon levels exceeded the proposed maximum contaminant level of 300 picocuries per liter in 74 percent of the samples, which were evenly distributed between carbonate- and siliciclastic-rock aquifers. The land use in areas surrounding wells and springs was another significant explanatory variable for the occurrence of anthropogenic compounds. Nitrate and pesticide concentrations were highest in samples collected from sites in agricultural areas and

Documentation of the Santa Clara Valley regional ground-water/surface-water flow model, Santa Clara Valley, California

USGS Publications Warehouse

Hanson, R.T.; Li, Zhen; Faunt, C.C.

2004-01-01

The Santa Clara Valley is a long, narrow trough extending about 35 miles southeast from the southern end of San Francisco Bay where the regional alluvial-aquifer system has been a major source of water. Intensive agricultural and urban development throughout the 20th century and related ground-water development resulted in ground-water-level declines of more than 200 feet and land subsidence of as much as 12.7 feet between the early 1900s and the mid-1960s. Since the 1960s, Santa Clara Valley Water District has imported surface water to meet growing demands and reduce dependence on ground-water supplies. This importation of water has resulted in a sustained recovery of the ground-water flow system. To help support effective management of the ground-water resources, a regional ground-water/surface-water flow model was developed. This model simulates the flow of ground water and surface water, changes in ground-water storage, and related effects such as land subsidence. A numerical ground-water/surface-water flow model of the Santa Clara Valley subbasin of the Santa Clara Valley was developed as part of a cooperative investigation with the Santa Clara Valley Water District. The model better defines the geohydrologic framework of the regional flow system and better delineates the supply and demand components that affect the inflows to and outflows from the regional ground-water flow system. Development of the model includes revisions to the previous ground-water flow model that upgraded the temporal and spatial discretization, added source-specific inflows and outflows, simulated additional flow features such as land subsidence and multi-aquifer wellbore flow, and extended the period of simulation through September 1999. The transient-state model was calibrated to historical surface-water and ground-water data for the period 197099 and to historical subsidence for the period 198399. The regional ground-water flow system consists of multiple aquifers that are grouped

Geohydrologic systems in Kansas physical framework of the upper aquifer unit in the western interior plains aquifer system

USGS Publications Warehouse

Hansen, Cristi V.; Spinazola, Joseph M.; Underwood, E.J.; Wolf, R.J.

1992-01-01

The purpose of this Hydrologic Investigations Atlas is to provide a description of the principal geohydrologic systems in Upper Cambrian through Lower Cretaceous rocks in Kansas. This investigation was made as part of the Central Midwest Regional Aquifer-System Analysis (CMRASA). The CMRASA is one of several major investigations by the U.S. Geological Survey of regional aquifer systems in the United States. These regional investigations are designed to increase knowledge of the flow regime and hydrologic properties of major aquifer systems and to provide quantitative information for the assessment, development, and management water supplies. The CMRASA study area includes all or parts of 10 Central Midwestern States (Jorgensen and Signor, 1981), as shown on the envelope cover.This Hydrologic Investigations Atlas, which consists of a series of nine chapters, presents a description of the physical framework and the geohydrology of principal aquifers and confining systems in Kansas. Chapter D presents maps that show the areal extent, altitude and configuration of the top, and thickness of Mississippian rocks that compose the upper aquifer unit of the Western Interior Plains aquifer system in Kansas, The chapter is limited to the presentation of the physical framework of the upper aquifer unit. The interpretation of the physical framework of the upper aquifer unit is based on selected geophysical and lithologic logs and published maps of stratigraphically equivalent units. Maps indicating the thickness and the altitude and configuration of the top of the upper aquifer unit in the Western Interior Plains aquifer system have been prepared as part of a series of interrelated maps that describe the stratigraphic interval from the Precambrian basement through Lower Cretaceous rocks. A concerted effort was made to ensure that maps of each geohydrologic unit are consistent with the maps of underlying and overlying units. Chapter A of this atlas series (Wolf and others, 1990

Hazard connected to tunnel construction in Mt Stena karstic area (Rosandra Valley, Classical Karst)

NASA Astrophysics Data System (ADS)

Cucchi, F.; Boschin, W.; Visintin, L.; Zini, L.

2009-04-01

Rosandra Valley -a unique geomorphological environment- is located in the western side of the Classical Karst plateau. This deep limestone gorge is crossed by a stream that is fed by a large basin located in Slovenia. Rosandra Valley is the only example of Classical Karst river valley with surface hydrography; the torrent digs a deep gully into the rock, rich in rapids, swirl holes, small waterfalls, enclosed meanders and basins; here, the first seepage phenomena occur, and part of the water feeds the underground aquifer. Rosandra Valley is theatre to complex structural situation; the NE slope culminates in the structure of Mt Stena, a limestone tectonic scale located between two faults and firmly rooted in the karst platform. Tectonics is quite important for the development of deep karst in this area; Mt Stena, in particular, hosts a comprehensive net of articulated and diversely shaped caves, basically organised on several levels, which stretches over a total of 9,000 metres, bearing testimony to ancient geological and hydrogeological origins. The deepest areas of the system reach a suspended aquifer that is probably sustained by an overthrust and placed about 100 meters above Rosandra torrent underground aquifer. During feasibility studies about Trieste-Divača high velocity railway link, interaction between project and karst features was examined; in fact the proximity of proposal project and Mt Stena karst system suggest to improve the knowledge related to karst and hydrogeological aspects of the massif. Compatibly with the project requirements, risk of voids intersection and water contamination were analyzed. In fact the Mt Stena suspended aquifer partially feeds Rosandra torrent which flows in a protected natural area. Karst features were represented in a 3D model in order to better understand the spatial relationship between railway project and karst system.

Hydrogeology of an alpine rockfall aquifer system and its role in flood attenuation and maintaining baseflow

NASA Astrophysics Data System (ADS)

Lauber, U.; Kotyla, P.; Morche, D.; Goldscheider, N.

2014-06-01

The frequency and intensity of extreme hydrological events in alpine regions is projected to increase with climate change. The goal of this study was to better understand the functioning of aquifers composed of complex alluvial and rockfall deposits in alpine valleys and to quantify the role of these natural storage spaces in flood attenuation and baseflow maintenance. Geomorphological and hydrogeological mapping, tracer tests, and continuous flow measurements were conducted in the Reintal valley (German Alps), where runoff from a karst spring infiltrates into a series of postglacial alluvial/rockfall aquifers. During high-flow conditions, groundwater velocities of 30 m h-1 were determined along 500 m; hydrograph analyses revealed short lag times (5 h) between discharge peaks upstream and downstream from the aquifer series; the maximum discharge ratio downstream (22) and the peak recession coefficient (0.196 d-1) are low compared with other alpine catchments. During low-flow conditions, the underground flow path length increased to 2 km and groundwater velocities decreased to 13 m h-1. Downstream hydrographs revealed a delayed discharge response after 101 h and peaks dampened by a factor of 1.5. These results indicate that alluvial/rockfall aquifers might play an important role in the flow regime and attenuation of floods in alpine regions.

Environmental effects of aquifer overexploitation: a case study in the highlands of Mexico.

PubMed

Esteller, Maria Vicenta; Diaz-Delgado, Carlos

2002-02-01

There are several environmental processes occurring under aquifer overexploitation conditions. These processes include groundwater table decline, subsidence, attenuation and drying of springs, decrease of river flow, and increased pollution vulnerability, among others processes. Some of these effects have been observed on the Upper Basin of the Lerma River. The Lerma River begins in the SE of the Valley of Toluca at 2,600 m asl, in the wetland known as Lagoons of Almoloya del Río. This wetland is made up of a group of lagoons, which are an important aquatic system from an environmental point of view. The water inflow of this wetland is a discharge of springs, which occur between the fractured volcanic material of the mountain range and granular volcanic-continental deposits of the Valley of Toluca aquifer. The intensive exploitation of the Valley of Toluca aquifer to supply urban and industrial water to Mexico City and Toluca began in 1950 and is responsible for a steady decline of piezometric levels of 1-3.5 m/yr. Other effects of this exploitation--the drying of the wetland, the decrease of river flow and the land subsidence--caused serious ecological and social impacts. The authorities declared this aquifer as overexploited in order to reduce the exploitation and preserve the availability of water resources in this important region.

Groundwater quality in the Monterey Bay and Salinas Valley groundwater basins, California

USGS Publications Warehouse

Kulongoski, Justin T.; Belitz, Kenneth

2011-01-01

The Monterey-Salinas study unit is nearly 1,000 square miles and consists of the Santa Cruz Purisima Formation Highlands, Felton Area, Scotts Valley, Soquel Valley, West Santa Cruz Terrace, Salinas Valley, Pajaro Valley, and Carmel Valley groundwater basins (California Department of Water Resources, 2003; Kulongski and Belitz, 2011). These basins were grouped into four study areas based primarily on geography. Groundwater basins in the north were grouped into the Santa Cruz study area, and those to the south were grouped into the Monterey Bay, the Salinas Valley, and the Paso Robles study areas (Kulongoski and others, 2007). The study unit has warm, dry summers and cool, moist winters. Average annual rainfall ranges from 31 inches in Santa Cruz in the north to 13 inches in Paso Robles in the south. The study areas are drained by several rivers and their principal tributaries: the Salinas, Pajaro, and Carmel Rivers, and San Lorenzo Creek. The Salinas Valley is a large intermontane valley that extends southeastward from Monterey Bay to Paso Robles. It has been filled, up to a thickness of 2,000 feet, with Tertiary and Quaternary marine and terrestrial sediments that overlie granitic basement. The Miocene-age Monterey Formation and Pliocene- to Pleistocene-age Paso Robles Formation, and Pleistocene to Holocene-age alluvium contain freshwater used for supply. The primary aquifers in the study unit 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 are typically drilled to depths of 200 to 650 feet, consist of solid casing from the land surface to depths of about 175 to 500 feet, and are perforated below the solid casing. Water quality in the primary aquifers may differ from that in the shallower and deeper parts of the aquifer system. Groundwater movement is generally from the southern part of the Salinas Valley north towards the Monterey Bay

Preliminary delineation and description of the regional aquifers of Tennessee : Cumberland Plateau aquifer system

USGS Publications Warehouse

Brahana, J.V.; Macy, Jo Ann; Mulderink, Dolores; Zemo, Dawn

1986-01-01

The Cumberland Plateau aquifer system consists of Pennsylvanian sandstones, conglomerates, shales, and coals which underlie the Cumberland Plateau in Tennessee. Major water-bearing zones occur within the sandstones and conglomerates in interconnected fractures. The water-bearing formations are separated by shale and siltstone that retard the vertical circulation of ground water. The Pennington Formation serves as the base of this aquifer system and is an effective confining unit. The Cumberland Plateau aquifer system is an important water source for the Cumberland Plateau. Wells and springs from the aquifer system supply most of the rural domestic and public drinking-water supplies. Water from wells drilled into the Cumberland Plateau aquifer system is generally of good to excellent quality. Of the 32 water-quality analyses on file from this aquifer, only 2 had dissolved-solids concentrations greater than 500 milligrams per liter, and about three-fourths had less than 200 milligrams per liter dissolved solids. However, no samples from depths greater than 300 feet below land surface have been recorded. Ground water from locations where the sandstones are buried deeply, such as the Wartburg basin, may contain dissolved-solids concentrations greater than 1,000 milligrams per liter.

Water resources of Parowan Valley, Iron County, Utah

USGS Publications Warehouse

Marston, Thomas M.

2017-08-29

Parowan Valley, in Iron County, Utah, covers about 160 square miles west of the Red Cliffs and includes the towns of Parowan, Paragonah, and Summit. The valley is a structural depression formed by northwest-trending faults and is, essentially, a closed surface-water basin although a small part of the valley at the southwestern end drains into the adjacent Cedar Valley. Groundwater occurs in and has been developed mainly from the unconsolidated basin-fill aquifer. Long-term downward trends in groundwater levels have been documented by the U.S. Geological Survey (USGS) since the mid-1950s. The water resources of Parowan Valley were assessed during 2012 to 2014 with an emphasis on refining the understanding of the groundwater and surface-water systems and updating the groundwater budget.Surface-water discharge of five perennial mountain streams that enter Parowan Valley was measured from 2013 to 2014. The total annual surface-water discharge of the five streams during 2013 to 2014 was about 18,000 acre-feet (acre-ft) compared to the average annual streamflow of about 22,000 acre-ft from USGS streamgages operated on the three largest of these streams from the 1940s to the 1980s. The largest stream, Parowan Creek, contributes more than 50 percent of the annual surface-water discharge to the valley, with smaller amounts contributed by Red, Summit, Little, and Cottonwood Creeks.Average annual recharge to the Parowan Valley groundwater system was estimated to be about 25,000 acre-ft from 1994 to 2013. Nearly all recharge occurs as direct infiltration of snowmelt and rainfall on the Markagunt Plateau east of the valley. Smaller amounts of recharge occur as infiltration of streamflow and unconsumed irrigation water near the east side of the valley on alluvial fans associated with mountain streams at the foot of the Red Cliffs. Subsurface flow from the mountain block to the east of the valley is a significant source of groundwater recharge to the basin-fill aquifer

Confined aquifer head measurements and storage properties in the San Luis Valley, Colorado, from spaceborne InSAR observations

NASA Astrophysics Data System (ADS)

Chen, Jingyi; Knight, Rosemary; Zebker, Howard A.; Schreüder, Willem A.

2016-05-01

Interferometric Synthetic Aperture Radar (InSAR), a remote sensing technique for measuring centimeter-level surface deformation, is used to estimate hydraulic head in the confined aquifer of the San Luis Valley (SLV), Colorado. Reconstructing head measurements from InSAR in agricultural regions can be difficult, as InSAR phase data are often decorrelated due to vegetation growth. Analysis of 17 L-band ALOS PALSAR scenes, acquired between January 2007 and March 2011, demonstrates that comprehensive InSAR deformation measurements can be recovered over the vegetated groundwater basin with an improved processing strategy. Local skeletal storage coefficients and time delays between the head change and deformation are estimated through a joint InSAR-well data analysis. InSAR subsidence estimates are transformed to head changes with finer temporal and spatial resolution than is possible using existing well records alone. Both InSAR and well data suggest that little long-term water-storage loss occurred in the SLV over the study period and that inelastic compaction was negligible. The seasonal head variations derived from InSAR are consistent with the existing well data at most locations where confined aquifer pumping activity dominates. Our results demonstrate the advantages of InSAR measurements for basin-wide characterization of aquifer storage properties and groundwater levels over agricultural regions.

Space geodetic observation of expansion of the San Gabriel Valley, California, aquifer system, during heavy rainfall in winter 2004-2005

USGS Publications Warehouse

King, N.E.; Argus, D.; Langbein, J.; Agnew, D.C.; Bawden, G.; Dollar, R.S.; Liu, Z.; Galloway, D.; Reichard, E.; Yong, A.; Webb, F.H.; Bock, Y.; Stark, K.; Barseghian, D.

2007-01-01

Starting early in 2005, the positions of GPS stations in the San Gabriel valley region of southern California showed statistically significant departures from their previous behavior. Station LONG moved up by about 47 mm, and nearby stations moved away from LONG by about 10 mm. These changes began during an extremely rainy season in southern California and coincided with a 16-m increase in water level at a nearby well in Baldwin Park and a regional uplift detected by interferometric synthetic aperture radar. No equivalent signals were seen in GPS station position time series elsewhere in southern California. Our preferred explanation, supported by the timing and by a hydrologic simulation, is deformation due to recharging of aquifers after near-record rainfall in 2004-2005. We cannot rule out an aseismic slip event, but we consider such an event unlikely because it requires slip on multiple faults and predicts other signals that are not observed. Copyright 2007 by the American Geophysical Union.

Regional groundwater-flow model of the Redwall-Muav, Coconino, and alluvial basin aquifer systems of northern and central Arizona

USGS Publications Warehouse

Pool, D.R.; Blasch, Kyle W.; Callegary, James B.; Leake, Stanley A.; Graser, Leslie F.

2011-01-01

capita water use for exempt wells. Accuracy of the simulated groundwater-flow system was evaluated by using observational control from water levels in wells, estimates of base flow from streamflow records, and estimates of spring discharge. Major results from the simulations include the importance of variations in recharge rates throughout the study area and recharge along ephemeral and losing stream reaches in alluvial basins. Insights about the groundwater-flow systems in individual basins include the hydrologic influence of geologic structures in some areas and that stream-aquifer interactions along the lower part of the Little Colorado River are an effective control on water level distributions throughout the Little Colorado River Plateau basin. Better information on several aspects of the groundwater flow system are needed to reduce uncertainty of the simulated system. Many areas lack documentation of the response of the groundwater system to changes in withdrawals and recharge. Data needed to define groundwater flow between vertically adjacent water-bearing units is lacking in many areas. Distributions of recharge along losing stream reaches are poorly defined. Extents of aquifers and alluvial lithologies are poorly defined in parts of the Big Chino and Verde Valley sub-basins. Aquifer storage properties are poorly defined throughout most of the study area. Little data exist to define the hydrologic importance of geologic structures such as faults and fractures. Discharge of regional groundwater flow to the Verde River is difficult to identify in the Verde Valley sub-basin because of unknown contributions from deep percolation of excess surface water irrigation.

Questa Baseline and Pre-Mining Ground-Water Quality Investigation. 17. Geomorphology of the Red River Valley, Taos County, New Mexico, and Influence on Ground-Water Flow in the Shallow Alluvial Aquifer

USGS Publications Warehouse

Vincent, Kirk R.

2008-01-01

In April 2001, the U.S. Geological Survey (USGS) and the New Mexico Environment Department (NMED) began a cooperative study to infer the pre-mining ground-water chemistry at the Molycorp molybdenum mine site in the Red River Valley of north-central New Mexico. This report is one in a series of reports that can be used to determine pre-mining ground-water conditions at the mine site. Molycorp?s Questa molybdenum mine in the Red River Valley, northern New Mexico, is located near the margin of the Questa caldera in a highly mineralized region. The bedrock of the Taos Range surrounding the Red River is composed of Proterozoic rocks of various types, which are intruded and overlain by Oligocene volcanic rocks associated with the Questa caldera. Locally, these rocks were altered by hydrothermal activity. The alteration zones that contain sulfide minerals are particularly important because they constitute the commercial ore bodies of the region and, where exposed to weathering, form sites of rapid erosion referred to as alteration scars. Over the past thousand years, if not over the entire Holocene, erosion rates were spatially variable. Forested hillslopes eroded at about 0.04 millimeter per year, whereas alteration scars eroded at about 2.7 millimeters per year. The erosion rate of the alteration scars is unusually rapid for naturally occurring sites that have not been disturbed by humans. Watersheds containing large alteration scars delivered more sediment to the Red River Valley than the Red River could remove. Consequently, large debris fans, as much as 80 meters thick, developed within the valley. The geomorphology of the Red River Valley has had several large influences on the hydrology of the shallow alluvial aquifer, and those influences were in effect before the onset of mining within the watershed. Several reaches where alluvial ground water emerges to become Red River streamflow were observed by a tracer dilution study conducted in 2001. The aquifer narrows

Compilation of geologic, hydrologic, and ground-water flow modeling information for the Spokane Valley-Rathdrum Prairie aquifer, Spokane County, Washington, and Bonner and Kootenai Counties, Idaho

USGS Publications Warehouse

Kahle, Sue C.; Caldwell, Rodney R.; Bartolino, James R.

2005-01-01

The U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources and Washington Department of Ecology compiled and described geologic, hydrologic, and ground-water flow modeling information about the Spokane Valley-Rathdrum Prairie (SVRP) aquifer in northern Idaho and northeastern Washington. Descriptions of the hydrogeologic framework, water-budget components, ground- and surface-water interactions, computer flow models, and further data needs are provided. The SVRP aquifer, which covers about 370 square miles including the Rathdrum Prairie, Idaho and the Spokane valley and Hillyard Trough, Washington, was designated a Sole Source Aquifer by the U.S. Environmental Protection Agency in 1978. Continued growth, water management issues, and potential effects on water availability and water quality in the aquifer and in the Spokane and Little Spokane Rivers have illustrated the need to better understand and manage the region's water resources. The SVRP aquifer is composed of sand, gravel, cobbles, and boulders primarily deposited by a series of catastrophic glacial outburst floods from ancient Glacial Lake Missoula. The material deposited in this high-energy environment is coarser-grained than is typical for most basin-fill deposits, resulting in an unusually productive aquifer with well yields as high as 40,000 gallons per minute. In most places, the aquifer is bounded laterally by bedrock composed of granite, metasedimentary rocks, or basalt. The lower boundary of the aquifer is largely unknown except along the margins or in shallower parts of the aquifer where wells have penetrated its entire thickness and reached bedrock or silt and clay deposits. Based on surface geophysics, the thickness of the aquifer is about 500 ft near the Washington-Idaho state line, but more than 600 feet within the Rathdrum Prairie and more than 700 feet in the Hillyard trough based on drilling records. Depth to water in the aquifer is greatest in the northern

Occurrence, Distribution, Sources, and Trends of Elevated Chloride Concentrations in the Mississippi River Valley Alluvial Aquifer in Southeastern Arkansas

USGS Publications Warehouse

Kresse, Timothy M.; Clark, Brian R.

2008-01-01

Water-quality data from approximately 2,500 sites were used to investigate the distribution of chloride concentrations in the Mississippi River Valley alluvial aquifer in southeastern Arkansas. The large volume and areal distribution of the data used for the investigation proved useful in delineating areas of elevated (greater than 100 milligrams per liter) chloride concentrations, assessing potential sources of saline water, and evaluating trends in chloride distribution and concentration over time. Irrigation water containing elevated chloride concentrations is associated with negative effects to rice and soybeans, two of the major crops in Arkansas, and a groundwater chloride concentration of 100 milligrams per liter is recommended as the upper limit for use on rice. As such, accurately delineating areas with high salinity ground water, defining potential sources of chloride, and documenting trends over time is important in assisting the agricultural community in water management. The distribution and range of chloride concentrations in the study area revealed distinct areas of elevated chloride concentrations. Area I includes an elongated, generally northwest-southeast trending band of moderately elevated chloride concentrations in the northern part of the study area. This band of elevated chloride concentrations is approximately 40 miles in length and varies from approximately 2 to 9 miles in width, with a maximum chloride concentration of 360 milligrams per liter. Area II is a narrow, north-south trending band of elevated chloride concentrations in the southern part of the study area, with a maximum chloride concentration of 1,639 milligrams per liter. A zone of chloride concentrations exceeding 200 milligrams per liter is approximately 25 miles in length and 5 to 6 miles in width. In Area I, low chloride concentrations in samples from wells completed in the alluvial aquifer next to the Arkansas River and in samples from the upper Claiborne aquifer, which

Summary of the Snake River plain Regional Aquifer-System Analysis in Idaho and eastern Oregon

USGS Publications Warehouse

Lindholm, G.F.

1993-01-01

The 15,600 sq mi Snake River Plain in southern Idaho and eastern Oregon was studied as part of the U.S. Geological Survey's Regional Aquifer-System Analysis program. Quaternary basalt of the Snake River Group underlies most of the 10,800 square mile eastern plain and constitutes the most productive aquifers. Transmissivity of the upper 200 feet of the basalt aquifer commonly ranges from 100,000 to 1,000,000 square feet per day. Vertical hydraulic conductivity is several orders of magnitude lower than horizontal hydraulic conductivity and is related to the degree of jointing. Alluvial sand and gravel in the Boise River valley constitutes the most productive aquifers in the 4,800 square mile western plain. Along much of its length, the Snake River gains groundwater. Between Milner and King Hill, the river gained 4.7 million acre-ft in 1980, most as spring flow from the north side. The chemical composition of groundwater in the plain is essentially the same as that in streams and ground- water from tributary drainage basins. The use of surface water for irrigation for 100 years has caused major changes in the hydrologic system on the plain. During that time, recharge on the main part of the eastern plain increased about 70 percent, discharge about 80 percent. In 1980, about 8.9 million acre-ft of Snake River water was diverted and 2.3 million acre-ft of groundwater was pumped from 5,300 wells for irrigation.

Mexicali aquifer and its relation with the Colorado river and the Cerro Prieto geothermal reservoir

NASA Astrophysics Data System (ADS)

Ramirez-Hernandez, J.; Reyes-Lopez, J. A.; Carreon-Diazconti, C.; Lazaro-Mancilla, O.

2008-05-01

Until some years ago the Colorado River has been the main recharge source of the Mexicali and the Imperial Valley aquifers. River discharge interruption after the constructions of dams upstream (i.e. Parker, Davis and Hoover) and the creation of great irrigation systems in both Valleys have modified their dynamics. Currently, the distribution of water recharge is the network of irrigation and drainage channels that distribute water to more than 500.000 ha. The chemical quality of the recharge water also has changed because the irrigation run-off water has become more mineralized. On the other hand, the intense steam exploitation of the Cerro Prieto geothermal reservoir has inverted the flow direction from the Volcano Lagoon area that until the 60s constituted the discharge zone of the aquifer and the geothermal reservoir. In this work, changes in the aquifer water recharge regime, the phreatic level and the water chemical quality are analyzed. It was found that after the reduction of the annual water extraction from aquifer up to 750X106 m3, the static levels have reached a dynamic balance that could be altered if water seepage from the irrigation channels, specially from the All American Channel, is reduced. The total dissolved solids (TDS) concentration has increased from 1000 ppm in 1970 to 1800 ppm in 2005. The water of recent infiltration, the gradual cooling of the shallowest strata of the geothermal reservoir, and the almost total disappearance of the hydrothermal surface manifestations are evidences of groundwater flow inversion. The new source of groundwater recharge due to seepage of evaporation disposal geothermal brine pond is documented. This pond incorporates water with a very different chemical composition to the groundwater system. Therefore, mineralization of the shallow aquifer layers and the soil contamination process are identified. It was concluded that the aquifer hydrodynamics in the Valley of Mexicali depends on the irrigation system more

Simulation of ground-water flow and land subsidence in the Antelope Valley ground-water basin, California

USGS Publications Warehouse

Leighton, David A.; Phillips, Steven P.

2003-01-01

Antelope Valley, California, is a topographically closed basin in the western part of the Mojave Desert, about 50 miles northeast of Los Angeles. The Antelope Valley ground-water basin is about 940 square miles and is separated from the northern part of Antelope Valley by faults and low-lying hills. Prior to 1972, ground water provided more than 90 percent of the total water supply in the valley; since 1972, it has provided between 50 and 90 percent. Most ground-water pumping in the valley occurs in the Antelope Valley ground-water basin, which includes the rapidly growing cities of Lancaster and Palmdale. Ground-water-level declines of more than 200 feet in some parts of the ground-water basin have resulted in an increase in pumping lifts, reduced well efficiency, and land subsidence of more than 6 feet in some areas. Future urban growth and limits on the supply of imported water may continue to increase reliance on ground water. To better understand the ground-water flow system and to develop a tool to aid in effectively managing the water resources, a numerical model of ground-water flow and land subsidence in the Antelope Valley ground-water basin was developed using old and new geohydrologic information. The ground-water flow system consists of three aquifers: the upper, middle, and lower aquifers. The aquifers, which were identified on the basis of the hydrologic properties, age, and depth of the unconsolidated deposits, consist of gravel, sand, silt, and clay alluvial deposits and clay and silty clay lacustrine deposits. Prior to ground-water development in the valley, recharge was primarily the infiltration of runoff from the surrounding mountains. Ground water flowed from the recharge areas to discharge areas around the playas where it discharged either from the aquifer system as evapotranspiration or from springs. Partial barriers to horizontal ground-water flow, such as faults, have been identified in the ground-water basin. Water-level declines owing to

Ground-water conditions in Avra Valley, Pima and Pinal Counties, Arizona -1985

USGS Publications Warehouse

Cuff, Melinda K.; Anderson, S.R.

1987-01-01

Avra Valley is a north-trending alluvial basin about 15 mi west of Tucson in Pima and Pinal Counties in south-central Arizona. The valley includes about 520 sq mi of which about 100 sq mi is in the San Xavier Indian Reservation. The basin is bounded on the east by the Tortolita, Tucson, and Sierrita Mountains and on the west by the Picacho, Silverbell, and Roskruge Mountains. The climate of the valley is semiarid, the average annual precipitation ranges from 8 to 12 in., and the average annual lake evaporation ranges from 58 to 62 in. Two major ephemeral streams--Santa Cruz River and Brawley Wash--drain the area. Santa Cruz River and Brawley Wash and their tributaries provide a source of recharge to an extensive alluvial aquifer that underlies the valley floor. Since 1940, the amount of groundwater pumped from the aquifer has been greater than the amount of natural recharge from infiltration and underflow. Overdraft of the aquifer resulted in substantial water level declines throughout the valley. Until 1969, use of groundwater in Avra Valley was for irrigation. Since 1969, the city of Tucson has pumped and transported groundwater for municipal use in the adjacent Tucson basin from lands that were purchased and retired from agriculture. The purpose of this report is to describe groundwater conditions in Avra Valley as of 1985. A brief discussion of the geohydrologic setting and history of groundwater development are given to define aquifer characteristics, changes in groundwater levels, and groundwater pumpage since 1940. (Lantz-PTT)

Aquifer susceptibility in Virginia, 1998-2000

USGS Publications Warehouse

Nelms, David L.; Harlow, George E.; Plummer, Niel; Busenberg, Eurybiades

2003-01-01

and springs in the fractured-rock terrains (the Appalachian Plateaus, Valley and Ridge, Blue Ridge, and Piedmont regional aquifer systems) contained concentrations of CFCs and 3H greater than one or both of the thresholds. Because all of the water samples exceeded at least one of the threshold values, young water is present throughout most of these regional aquifer systems; therefore, water supplies developed in these systems are susceptible to contamination from near-surface sources. No relation between well depth and presence of CFCs is evident from samples in the fractured-rock terrains. More than 95 percent of the samples for which the dating methods were applicable contained waters with apparent ages less than 35 years. About 5 percent of these samples, most of which were from the Blue Ridge and Piedmont regional aquifer systems, contained young waters with apparent ages of less than 5 years. Most of the samples from the Valley and Ridge Carbonate, Blue Ridge, and Piedmont regional aquifer systems had young water fractions of more than 50 percent, whereas samples from the Coastal Plain Shallow and Appalachian Plateaus regional aquifer systems contained less than 40 percent young waters. Concentrations of CFCs in excess of air-water equilibrium, which can indicate that nonatmospheric sources (such as sewage effluent) have introduced CFCs into the ground-water system, were measured in 6 and 48 percent of the water samples from the Coastal Plain and fractured-rock regional aquifer systems, respectively. The nitrate (NO3) concentrations greater than the USGS detection level of 0.05 milligrams per liter generally increase as the apparent age of the young water fraction decreases, with the highest NO3 concentrations for samples in which one or more of the CFCs are above modern atmospheric mixing ratios (commonly referred to as 'contaminated' for ground-water dating purposes). Most of the samples in which NO3 was detected w

Groundwater-flow model for the Wood River Valley aquifer system, south-central Idaho

USGS Publications Warehouse

Fisher, Jason C.; Bartolino, James R.; Wylie, Allan H.; Sukow, Jennifer; McVay, Michael

2016-06-27

Subsurface outflow beneath the Big Wood River near Stanton Crossing. Temporal changes in aquifer storage are most affected by areal recharge and groundwater pumping, and also contribute to changes in streamflow gains.

Groundwater quality in the Antelope Valley, 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. Antelope Valley is one of the study areas being evaluated. The Antelope study area is approximately 1,600 square miles (4,144 square kilometers) and includes the Antelope Valley groundwater basin (California Department of Water Resources, 2003). Antelope Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lakebeds in the lower parts of the valley. Land use in the study area is approximately 68 percent (%) natural (mostly shrubland and grassland), 24% agricultural, and 8% urban. The primary crops are pasture and hay. The largest urban areas are the cities of Palmdale and Lancaster (2010 populations of 152,000 and 156,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Antelope Valley 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 Antelope Valley are completed to depths between 360 and 700 feet (110 to 213 meters), consist of solid casing from the land surface to a depth of 180 to 350 feet (55 to 107 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation and sewer and septic

Superfund Record of Decision (EPA Region 9): San Fernando Valley Area 2, operable unit 2, Los Angeles County, CA, June 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-06-01

This decision document presents the selected remedial action for the Glendale North Operable Unit, San Fernando Valley Area 2 Superfund site. The remedy involves groundwater extraction and treatment for the shallow aquifer system in the Glendale area of the San Fernando Valley.

Superfund Record of Decision (EPA Region 9): San Fernando Valley Area 2, operable unit 3, Los Angeles County, CA, June 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-06-01

This decision document presents the selected remedial action for the Glendale South Operable Unit, San Fernando Valley Area 2 Superfund site. The remedy involves groundwater extraction and treatment for the shallow aquifer system in the Glendale area of the San Fernando Valley.

Hindcast of water availability in regional aquifer systems using MODFLOW Farm Process

USGS Publications Warehouse

Schmid, Wolfgang; Hanson, Randall T.; Faunt, Claudia C.; Phillips, Steven P.

2015-01-01

Coupled groundwater and surface-water components of the hydrologic cycle can be simulated by the Farm Process for MODFLOW (MF-FMP) in both irrigated and non-irrigated areas and aquifer-storage and recovery systems. MF-FMP is being applied to three productive agricultural regions of different scale in the State of California, USA, to assess the availability of water and the impacts of alternative management decisions. Hindcast simulations are conducted for similar periods from the 1960s to near recent times. Historical groundwater pumpage is mostly unknown in one region (Central Valley) and is estimated by MF-FMP. In another region (Pajaro Valley), recorded pumpage is used to calibrate model-estimated pumpage. Multiple types of observations are used to estimate uncertain parameters, such as hydraulic, land-use, and farm properties. MF-FMP simulates how climate variability and water-import availability affect water demand and supply. MF-FMP can be used to predict water availability based on anticipated changes in anthropogenic or natural water demands. Keywords groundwater; surface-water; irrigation; water availability; response to climate variability/change

Status of groundwater quality in the Southern, Middle, and Northern Sacramento Valley study units, 2005-08: California GAMA Priority Basin Project

USGS Publications Warehouse

Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth

2011-01-01

Groundwater quality in the Southern, Middle, and Northern Sacramento Valley study units was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study units are located in California's Central Valley and include parts of Butte, Colusa, Glenn, Placer, Sacramento, Shasta, Solano, Sutter, Tehama, Yolo, and Yuba Counties. The GAMA Priority Basin Project 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 three study units were designated to provide spatially-unbiased assessments of the quality of untreated groundwater in three parts of the Central Valley hydrogeologic province, as well as to provide a statistically consistent basis for comparing water quality regionally and statewide. Samples were collected in 2005 (Southern Sacramento Valley), 2006 (Middle Sacramento Valley), and 2007-08 (Northern Sacramento Valley). The GAMA studies in the Southern, Middle, and Northern Sacramento Valley were designed to provide statistically robust assessments of the quality of untreated groundwater in the primary aquifer systems that are used for drinking-water supply. The assessments are based on water-quality data collected by the USGS from 235 wells in the three study units in 2005-08, and water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer systems (hereinafter, referred to as primary aquifers) assessed in this study are defined by the depth intervals of the wells in the CDPH 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. The status of the current quality of the groundwater resource was assessed by using data from samples analyzed for volatile organic

Hydrogeology of the surficial aquifer system, Dade County, Florida

USGS Publications Warehouse

Fish, J.E.; Stewart, M.T.

1991-01-01

An investigation of the surficial aquifer system in Dade County, begun in 1983, is part of a regional study of the aquifer system in southeastern Florida. Test drilling for lithologic samples, flow measurements during drilling, aquifer testing, and analyses of earlier data permitted delineation of the hydraulic conductivity distribution (on hydrogeologic sections), the aquifers in the system, the generalized transmissivity distribution, and interpretation of the ground-water flow system. The surficial aquifer system, in which an unconfined ground-water flow system exists, is composed of the sediments from land surface downward to the top of a regionally extensive zone of sediments of low permeability called the intermediate confining unit. The aquifer system units, which vary in composition from clay-size sediments to cavernous limestone, are hydro stratigraphically divided into the Biscayne aquifer at the top; an intervening semiconfining unit that consists principally of clayey sand; a predominantly gray limestone aquifer in the Tamiami Formation in western and west-central Dade County; and sand or clayey sand near the base of the surficial aquifer system. The base of the surficial aquifer system ranges from a depth of about 175 to 210 feet below land surface in westernmost Dade County to greater than 270 feet in northeastern Dade County. Test drilling and aquifer-test data indicate a complex hydraulic conductivity distribution. Hydraulic conductivities of the very highly permeable zone of the Biscayne aquifer commonly exceed 10,000 feet per day; in the gray limestone aquifer, they range from 210 to 780 feet per day. Transmissivities of the surficial aquifer system vary locally but have a recognizable areal trend. Estimated values generally are about 300,000 feet squared per day or greater in nearly all of central and eastern Dade County. Transmissivity is lower to the west, decreasing to less than 75,000 feet squared per day in western Dade County. High

Calibrated models as management tools for stream-aquifer systems: the case of central Kansas, USA

NASA Astrophysics Data System (ADS)

Sophocleous, Marios; Perkins, Samuel P.

1993-12-01

We address the problem of declining streamflows in interconnected stream-aquifer systems and explore possible management options to address the problem for two areas of central Kansas: the Arkansas River valley from Kinsley to Great Bend and the lower Rattlesnake Creek-Quivira National Wildlife Refuge area. The approach we followed implements, calibrates, and partially validates for the study areas a stream-aquifer numerical model combined with a parameter estimation package and sensitivity analysis. Hydrologic budgets for both predevelopment and developed conditions indicate significant differences in the hydrologic components of the study areas resulting from development. The predevelopment water budgets give an estimate of natural ground-water recharge, whereas the budgets for developed conditions give an estimate of induced recharge, indicating that major ground-water development changes the recharge-discharge regime of the model areas with time. Such stream-aquifer models serve to link proposed actions to hydrologic effects, as is clearly demonstrated by the effects of various management alternatives on the streamflows of the Arkansas River and Rattlesnake Creek. Thus we show that a possible means of restoring specified streamflows in the area is to implement protective stream corridors with restricted ground-water extraction.

Calibrated models as management tools for stream-aquifer systems: the case of central Kansas, USA

USGS Publications Warehouse

Sophocleous, M.; Perkins, S.P.

1993-01-01

We address the problem of declining streamflows in interconnected stream-aquifer systems and explore possible management options to address the problem for two areas of central Kansas: the Arkansas River valley from Kinsley to Great Bend and the lower Rattlesnake Creek-Quivira National Wildlife Refuge area. The approach we followed implements, calibrates, and partially validates for the study areas a stream-aquifer numerical model combined with a parameter estimation package and sensitivity analysis. Hydrologic budgets for both predevelopment and developed conditions indicate significant differences in the hydrologic components of the study areas resulting from development. The predevelopment water budgets give an estimate of natural ground-water recharge, whereas the budgets for developed conditions give an estimate of induced recharge, indicating that major ground-water development changes the recharge-discharge regime of the model areas with time. Such stream-aquifer models serve to link proposed actions to hydrologic effects, as is clearly demonstrated by the effects of various management alternatives on the streamflows of the Arkansas River and Rattlesnake Creek. Thus we show that a possible means of restoring specified streamflows in the area is to implement protective stream corridors with restricted ground-water extraction. ?? 1993.

Geohydrology of deep-aquifer system monitoring-well site at Marina, Monterey County, California

USGS Publications Warehouse

Hanson, Randall T.; Everett, Rhett; Newhouse, Mark W.; Crawford, Steven M.; Pimentel, M. Isabel; Smith, Gregory A.

2002-01-01

In 2000, a deep-aquifer system monitoring-well site (DMW1) was completed at Marina, California to provide basic geologic and hydrologic information about the deep-aquifer system in the coastal region of the Salinas Valley. The monitoring-well site contains four wells in a single borehole; one completed from 930 to 950 feet below land surface (bls) in the Paso Robles Formation (DMW1-4); one 1,040 to 1,060 feet below land surface in the upper Purisima Formation (DMW1-3); one from 1,410 to 1,430 feet below land surface in the middle Purisima Formation (DMW1-2); and one from 1,820 to 1,860 feet below land surface in the lower Purisima Formation (DMW1-1). The monitoring site is installed between the coast and several deep-aquifer system supply wells in the Marina Coast Water District, and the completion depths are within the zones screened in those supply wells. Sediments below a depth of 955 feet at DMW1 are Pliocene age, whereas the sediments encountered at the water-supply wells are Pleistocene age at an equivalent depth. Water levels are below sea level in DMW1 and the Marina Water District deep-aquifer system supply wells, which indicate that the potential for seawater intrusion exists in the deep-aquifer system. If the aquifers at DMW1 are hydraulically connected with the submarine outcrops in Monterey Bay, then the water levels at the DMW1 site are 8 to 27 feet below the level necessary to prevent seawater intrusion. Numerous thick fine-grained interbeds and confining units in the aquifer systems retard the vertical movement of fresh and saline ground water between aquifers and restrict the movement of seawater to narrow water-bearing zones in the upper-aquifer system.Hydraulic testing of the DMW1 and the Marina Water District supply wells indicates that the tested zones within the deep-aquifer system are transmissive water-bearing units with hydraulic conductivities ranging from 2 to 14.5 feet per day. The hydraulic properties of the supply wells and monitoring

Characterizing Sources of Recharge and Groundwater Quality in Sacramento Aquifers Following California's Historic Drought

NASA Astrophysics Data System (ADS)

Robertson, C. A.; Paukert Vankeuren, A. N.; Wagner, A. J.; Blackburn, C.; Druecker, D.

2016-12-01

Characterizing recharge will be critical for sustainable groundwater use, particularly following California's historic five-year drought . Groundwater is of great importance to Sacramento, which is a high priority basin as determined by the Sustainable Groundwater Management Act of 2014. The California State University, Sacramento (CSUS) campus has 18 monitoring wells, making it an ideal laboratory for examination of recharge sources and water quality in confined and unconfined aquifers in the Central Valley aquifer system. Historically, CSUS aquifers appear to have been recharged by water from the Western Sierra Nevada. The campus is bounded by the Lower American River, and some of its wells are in hydraulic connection with the river1. Lower than average river stage during the drought may have affected recharge to the aquifers from the river. Additionally, low impact development (LID) stormwater-management ponds have recently been installed on campus in an effort to increase infiltration and to help mitigate contamination of the aquifers and American River from campus runoff. The recently installed LID ponds on campus may have increased infiltration of local precipitation into the unconfined aquifer. Data collected from the monitoring wells allow for the examination of differences between the confined and unconfined aquifer systems in the Central Valley. To identify recharge sources, stable isotope and major ion analyses for samples collected from both campus aquifers are compared to samples from local precipitation and rivers in the Western Sierra Nevada feeding the American River. These results are used to assess current water quality and compared to historic datasets collected by the USGS to reveal changes that have occurred as a result of the recent drought. These data are the first in a dataset developed by CSUS Geology students for long-term monitoring of local groundwater quality. 1Moran et al., 2004. LLNL, UCR-203258.

Conjunctive-use optimization model of the Mississippi River Valley alluvial aquifer of northeastern Arkansas

USGS Publications Warehouse

Czarnecki, John B.; Clark, Brian R.; Reed, Thomas B.

2003-01-01

The Mississippi River Valley alluvial aquifer is a water-bearing assemblage of gravels and sands that underlies about 32,000 square miles of Missouri, Kentucky, Tennessee, Mississippi, Louisiana, and Arkansas. Because of the heavy demands placed on the aquifer, several large cones of depression over 100 feet deep have formed in the potentiometric surface, resulting in lower well yields and degraded water quality in some areas. A ground-water flow model of the alluvial aquifer was previously developed for an area covering 14,104 square miles, extending northeast from the Arkansas River into the northeast corner of Arkansas and parts of southeastern Missouri. The flow model showed that continued ground-water withdrawals at rates commensurate with those of 1997 could not be sustained indefinitely without causing water levels to decline below half the original saturated thickness of the aquifer. To develop estimates of withdrawal rates that could be sustained in compliance with the constraints of critical ground-water area designation, conjunctive-use optimization modeling was applied to the flow model of the alluvial aquifer in northeastern Arkansas. Ground-water withdrawal rates form the basis for estimates of sustainable yield from the alluvial aquifer and from rivers specified within the alluvial aquifer model. A management problem was formulated as one of maximizing the sustainable yield from all ground-water and surface-water withdrawal cells within limits imposed by plausible withdrawal rates, and within specified constraints involving hydraulic head and streamflow. Steady-state flow conditions were selected because the maximized withdrawals are intended to represent sustainable yield of the system (a rate that can be maintained indefinitely). Within the optimization model, 11 rivers are specified. Surface-water diversion rates that occurred in 2000 were subtracted from specified overland flow at the appropriate river cells. Included in these diversions were the

Conjunctive-use optimization model of the Mississippi River Valley alluvial aquifer of Southeastern Arkansas

USGS Publications Warehouse

Czarnecki, John B.; Clark, Brian R.; Stanton, Gregory P.

2003-01-01

The Mississippi River Valley alluvial aquifer is a water-bearing assemblage of gravels and sands that underlies about 32,000 square miles of Missouri, Kentucky, Tennessee, Mississippi, Louisiana, and Arkansas. Because of the heavy demands placed on the aquifer, several large cones of depression have formed in the potentiometric surface, resulting in lower well yields and degraded water quality in some areas. A ground-water flow model of the alluvial aquifer was previously developed for an area covering 3,826 square miles, extending south from the Arkansas River into the southeastern corner of Arkansas, parts of northeastern Louisiana, and western Mississippi. The flow-model results indicated that continued ground-water withdrawals at rates commensurate with those of 1997 could not be sustained indefinitely without causing water levels to decline below half the original saturated thickness of the aquifer. Conjunctive-use optimization modeling was applied to the flow model of the alluvial aquifer to develop withdrawal rates that could be sustained relative to the constraints of critical ground-water area designation. These withdrawal rates form the basis for estimates of sustainable yield from the alluvial aquifer and from rivers specified within the alluvial aquifer model. A management problem was formulated as one of maximizing the sustainable yield from all ground-water and surface-water withdrawal cells within limits imposed by plausible withdrawal rates, and within specified constraints involving hydraulic head and streamflow. Steady-state conditions were selected because the maximized withdrawals are intended to represent sustainable yield of the system (a rate that can be maintained indefinitely).One point along the Arkansas River and one point along Bayou Bartholomew were specified for obtaining surface-water sustainable-yield estimates within the optimization model. Streamflow constraints were specified at two river cells based on average 7-day low flows

A General Solution for Groundwater Flow in Estuarine Leaky Aquifer System with Considering Aquifer Anisotropy

NASA Astrophysics Data System (ADS)

Chen, Po-Chia; Chuang, Mo-Hsiung; Tan, Yih-Chi

2014-05-01

In recent years the urban and industrial developments near the coastal area are rapid and therefore the associated population grows dramatically. More and more water demand for human activities, agriculture irrigation, and aquaculture relies on heavy pumping in coastal area. The decline of groundwater table may result in the problems of seawater intrusion and/or land subsidence. Since the 1950s, numerous studies focused on the effect of tidal fluctuation on the groundwater flow in the coastal area. Many studies concentrated on the developments of one-dimensional (1D) and two-dimensional (2D) analytical solutions describing the tide-induced head fluctuations. For example, Jacob (1950) derived an analytical solution of 1D groundwater flow in a confined aquifer with a boundary condition subject to sinusoidal oscillation. Jiao and Tang (1999) derived a 1D analytical solution of a leaky confined aquifer by considered a constant groundwater head in the overlying unconfined aquifer. Jeng et al. (2002) studied the tidal propagation in a coupled unconfined and confined costal aquifer system. Sun (1997) presented a 2D solution for groundwater response to tidal loading in an estuary. Tang and Jiao (2001) derived a 2D analytical solution in a leaky confined aquifer system near open tidal water. This study aims at developing a general analytical solution describing the head fluctuations in a 2D estuarine aquifer system consisted of an unconfined aquifer, a confined aquifer, and an aquitard between them. Both the confined and unconfined aquifers are considered to be anisotropic. The predicted head fluctuations from this solution will compare with the simulation results from the MODFLOW program. In addition, the solutions mentioned above will be shown to be special cases of the present solution. Some hypothetical cases regarding the head fluctuation in costal aquifers will be made to investigate the dynamic effects of water table fluctuation, hydrogeological conditions, and

Sustainable Capture: Concepts for Managing Stream-Aquifer Systems.

PubMed

Davids, Jeffrey C; Mehl, Steffen W

2015-01-01

Most surface water bodies (i.e., streams, lakes, etc.) are connected to the groundwater system to some degree so that changes to surface water bodies (either diversions or importations) can change flows in aquifer systems, and pumping from an aquifer can reduce discharge to, or induce additional recharge from streams, springs, and lakes. The timescales of these interactions are often very long (decades), making sustainable management of these systems difficult if relying only on observations of system responses. Instead, management scenarios are often analyzed based on numerical modeling. In this paper we propose a framework and metrics that can be used to relate the Theis concepts of capture to sustainable measures of stream-aquifer systems. We introduce four concepts: Sustainable Capture Fractions, Sustainable Capture Thresholds, Capture Efficiency, and Sustainable Groundwater Storage that can be used as the basis for developing metrics for sustainable management of stream-aquifer systems. We demonstrate their utility on a hypothetical stream-aquifer system where pumping captures both streamflow and discharge to phreatophytes at different amounts based on pumping location. In particular, Capture Efficiency (CE) can be easily understood by both scientists and non-scientist alike, and readily identifies vulnerabilities to sustainable stream-aquifer management when its value exceeds 100%. © 2014, National Ground Water Association.

Simulation of a long-term aquifer test conducted near the Rio Grande, Albuquerque, New Mexico

USGS Publications Warehouse

McAda, Douglas P.

2001-01-01

A long-term aquifer test was conducted near the Rio Grande in Albuquerque during January and February 1995 using 22 wells and piezometers at nine sites, with the City of Albuquerque Griegos 1 production well as the pumped well. Griegos 1 discharge averaged about 2,330 gallons per minute for 54.4 days. A three-dimensional finite-difference ground-water-flow model was used to estimate aquifer properties in the vicinity of the Griegos well field and the amount of infiltration induced into the aquifer system from the Rio Grande and riverside drains as a result of pumping during the test. The model was initially calibrated by trial-and-error adjustments of the aquifer properties. The model was recalibrated using a nonlinear least-squares regression technique. The aquifer system in the area includes the middle Tertiary to Quaternary Santa Fe Group and post-Santa Fe Group valley- and basin-fill deposits of the Albuquerque Basin. The Rio Grande and adjacent riverside drains are in hydraulic connection with the aquifer system. The hydraulic-conductivity values of the upper part of the Santa Fe Group resulting from the model calibrated by trial and error varied by zone in the model and ranged from 12 to 33 feet per day. The hydraulic conductivity of the inner-valley alluvium was 45 feet per day. The vertical to horizontal anisotropy ratio was 1:140. Specific storage was 4 x 10-6 per foot of aquifer thickness, and specific yield was 0.15 (dimensionless). The sum of squared errors between the observed and simulated drawdowns was 130 feet squared. Not all aquifer properties could be estimated using nonlinear regression because of model insensitivity to some aquifer properties at observation locations. Hydraulic conductivity of the inner-valley alluvium, middle part of the Santa Fe Group, and riverbed and riverside-drain bed and specific yield had low sensitivity values and therefore could not be estimated. Of the properties estimated, hydraulic conductivity of the upper part of

Simulation of ground-water flow in the Coastal Plain aquifer system of North Carolina

USGS Publications Warehouse

Giese, G.I.; Eimers, J.L.; Coble, R.W.

1997-01-01

areas. Hydrologic analysis of the flow system using the calibrated model indicated that, because of ground-water withdrawals, areas of ground-water recharge have expanded and encroached upon some major stream valleys and into coastal area. Simulations of pumping conditions indicate that by 1980 large parts of the former coastal discharge areas had become areas of potential or actual recharge. Declines of ground-water level, which are the result of water taken from storage, are extensive in some areas and minimal in others. Hydraulic head declines of more than 135 feet have occurred in the northern Coastal Plain since 1940 primarily due to withdrawals in the Franklin area in Virginia. Declines of ground-water levels greater than 110 feet have occurred in aquifers in the central Coastal Plain due to combined effects of pumpage for public and industrial water supplies. Water-level declines exceeding 100 feet have occurred in the Beaufort County area because of withdrawals for a mining operation and water supplies for a chemical plant. Head declines have been less than 10 feet in the shallow surficial and Yorktown aquifers and in the updip parts of the major confined aquifers distant from areas of major withdrawals. In 1980, contribution from aquifer storage was 14 cubic feet per second, which is about 4.8 percent of pumpage and about 0.05 percent of ground-water recharge. A water-budget analysis using the model simulations indicates that much of the water removed from the ground-water system by pumping ultimately is made up by a reduction in water leaving the aquifer system, which discharges to streams as base flow. The reduction in stream base flow was 294 cubic feet per second in 1980 and represents about 1.1 percent of the ground-water recharge. The net reduction to streamflow is not large, however, because most pumped ground water is eventually discharged to streams. In places, such as at rock quarries in Onslow and Craven Counties, water is lost from st

Simulated ground-water flow and sources of water in the Killbuck Creek Valley near Wooster, Wayne County, Ohio

USGS Publications Warehouse

Breen, K.J.; Kontis, A.L.; Rowe, G.L.; Haefner, R.J.

1995-01-01

The stratified-drift aquifer in the 3,000-ft (feet)-wide and 100-ft-deep buried valley of Killbuck Creek near Wooster in northeastern Ohio was studied. The stratified drift with adjacent sandstone and shale bedrock produce a system of ground-water flow representative of the western part of the glaciated north-eastern United States. The stratified-drift aquifer is an excellent source of water for municipal and industrial wells. The aquifer is recharged locally by water from precipitation on the valley floor and uplands, by infiltration from streams, and by lateral flow to the valley from the uplands. As a result, the aquifer is vulnerable to surface or subsurface spills of contaminants in the valley or the adjacent uplands. Quality of water in the stratified drift is affected by influx of water from bedrock lateral to or beneath the valley. This influx is controlled, in part, by the pumping stress placed on the stratified-drift aquifer. Hydrogeologic and aqueous-geochemical data were analyzed to establish the framework necessary for stead-state and transient simulations of ground-water flow in stratified drift and bedrock with a three-layer ground-water-flow model. A new model routine, the Variable-Recharge procedure, was developed to simulate areal recharge and the contribution of the uplands to the drift system. This procedure allows for water applied to land surface to infiltrate or to be rejected. Rejected recharge and ground water discharged when the water table is at land surface form surface runoff-this excess upland water can be redirected as runoff to other parts of the model. Infiltration of streamwater, areal recharge to uplands and valley, and lateral subsurface flow from the uplands to the valley are sources of water to the stratufued0druft aquifer. Water is removed from the stratified-drift aquifer at Wooster primarily by production wells pumping at a rate of approximately 8.5 ft3/s (cubic feet per second). The ground-water budget resulting from two

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

USGS Regional Groundwater Availability Studies: Quantifying Aquifer Response

NASA Astrophysics Data System (ADS)

Reeves, H. W.

2017-12-01

The U.S. Geological Survey (USGS) identified six challenges in determining groundwater availability: 1) limited direct measurement, 2) varying response times for different systems, 3) varying spatial scales for different availability questions and aquifer systems, 4) varying tolerance to changes in water levels or outflows, 5) redistribution of stresses and potential return-flow of water pumped from the system, and 6) varying chemical quality of groundwater and the role of quality in determining suitability for different uses. USGS Regional groundwater availability studies are designed to address these challenges. USGS regional groundwater availability studies focus on quantifying the groundwater budget for principal aquifers and determining how this budget has changed in response to pumping or variations in climate. This focus requires relating limited measurements to a quantitative understanding of the temporal and spatial response of regional aquifers. For most principal aquifer studies, aquifer response is quantified using regional groundwater flow models, and USGS regional groundwater availability studies have provided test cases for the development and application of advanced modeling techniques and methods. Results from regional studies from the Lake Michigan Basin and Northern Atlantic Coastal Plain illustrate how different parts of these systems respond differently to pumping with some areas showing large drawdowns and others having much less drawdown but greater capture of discharge. The Central Valley and Mississippi Embayment studies show how extensive pumping and transfer of water have resulted in much more groundwater moving through the aquifer system under current conditions compared to pre-development. These and other results from regional studies will be explored to illustrate how regional groundwater availability and related studies address the six challenges to determining groundwater availability.

How to Recharge a Confined Aquifer: An Exploration of Geologic Controls on Groundwater Storage.

NASA Astrophysics Data System (ADS)

Maples, S.; Fogg, G. E.; Maxwell, R. M.; Liu, Y.

2017-12-01

Decreased snowpack storage and groundwater overdraft in California has increased interest in managed aquifer recharge (MAR) of excess winter runoff to the Central Valley aquifer system, which has unused storage capacity that far exceeds the state's surface reservoirs. Recharge to the productive, confined aquifer system remains a challenge due to the presence of nearly-ubiquitous, multiple silt and clay confining units that limit recharge pathways. However, previous studies have identified interconnected networks of sand and gravel deposits that bypass the confining units and accommodate rapid, high-volume recharge to the confined aquifer system in select locations. We use the variably-saturated, fully-integrated groundwater/surface-water flow code, ParFlow, in combination with a high-resolution, transition probability Markov-chain geostatistical model of the subsurface geologic heterogeneity of the east side of the Sacramento Valley, CA, to characterize recharge potential across a landscape that includes these geologic features. Multiple 180-day MAR simulations show that recharge potential is highly dependent on subsurface geologic structure, with a several order-of-magnitude range of recharge rates and volumes across the landscape. Where there are recharge pathways to the productive confined-aquifer system, pressure propagation in the confined system is widespread and rapid, with multi-kilometer lateral pressure propagation. Although widespread pressure propagation occurs in the confined system, only a small fraction of recharge volume is accommodated there. Instead, the majority of recharge occurs by filling unsaturated pore spaces. Where they outcrop at land surface, high-K recharge pathways fill rapidly, accommodating the majority of recharge during early time. However, these features become saturated quickly, and somewhat counterintuitively, the low-K silt and clay facies accommodate the majority of recharge volume during most of the simulation. These findings

Recharge sources and geochemical evolution of groundwater in the Quaternary aquifer at Atfih area, the northeastern Nile Valley, Egypt

NASA Astrophysics Data System (ADS)

El-Sayed, Salah Abdelwahab; Morsy, Samah M.; Zakaria, Khalid M.

2018-06-01

This study addresses the topic of recharge sources and evolution of groundwater in the Atfih area situated in the northeastern part of the Nile Valley, Egypt. Inventory of water wells and collection of groundwater and surface water samples have been achieved. Water samples are analyzed for major ions according to the American Society for Testing and Materials and for the environmental isotopes analysis (oxygen-18 and deuterium) by using a Triple Liquid Isotopic Water Analyzer (Los Gatos). The groundwater is available from the Quaternary aquifer formed mainly of graded sand and gravel interbedded with clay lenses. The hydrogeologic, hydrogeochemical and isotopic investigations indicate the hydrodynamic nature of the aquifer, where different flow paths, recharge sources and evolution mechanisms are distinguished. The directions of groundwater flow are from E, W and S directions suggesting the contribution from Nile River, the Eocene aquifer and the Nile basin, respectively. The groundwater altitudes range from 13 m (MSL) to 44 m (MSL). The hydraulic gradient varies between 0.025 and 0.0015. The groundwater is alkaline (pH > 7) and has salinity ranging from fresh to brackish water (TDS between 528 mg/l and 6070 mg/l). The observed wide range in the ionic composition and water types reflects the effect of different environmental and geological conditions through which the water has flowed. The isotopic compositions of groundwater samples vary between -14.13‰ and +23.56 for δD and between - 2.91‰ and +3.10 for δ18O. The isotopic data indicates that the Quaternary aquifer receive recharge from different sources including the Recent Nile water, surplus irrigation water, old Nile water before the construction of Aswan High Dam, surface runoff of local rains and Eocene aquifer. Evaporation, water rock interaction and mixing between different types of waters are the main processes in the groundwater evolution. Major suggestions are presented to develop the aquifer

Data for four geologic test holes in the Sacramento Valley, California

USGS Publications Warehouse

Berkstresser, C.F.; French, J.J.; Schaal, M.E.

1985-01-01

The report provides geological and geophysical data for four of seven test holes drilled as a part of the Central Valley Aquifer Project, which is part of the Regional Aquifer Systems Analysis. The holes were drilled with a rotary well drilling machine to depths of 900 feet in the southwestern part of the Sacramento Valley in Solano and Yolo Counties. Geologic data for each well include lithology, texture, color, character of the contact, sorting, rounding, and cementation, determined from cuttings, cores, and sidewall covers. Fifty cores, 3 feet long, were obtained from each hole, and from eight to fourteen sidewall cores were collected. Geophysical data include a dual-induction log, spherically focused log (SFL), compensated neutron-formation density log, gamma-ray log, and a caliper log. These data are presented in four tables and on four plates. (USGS)

Regional flow in a complex coastal aquifer system: Combining voxel geological modelling with regularized calibration

NASA Astrophysics Data System (ADS)

Meyer, Rena; Engesgaard, Peter; Høyer, Anne-Sophie; Jørgensen, Flemming; Vignoli, Giulio; Sonnenborg, Torben O.

2018-07-01

Low-lying coastal regions are often highly populated, constitute sensitive habitats and are at the same time exposed to challenging hydrological environments due to surface flooding from storm events and saltwater intrusion, which both may affect drinking water supply from shallow and deeper aquifers. Near the Wadden Sea at the border of Southern Denmark and Northern Germany, the hydraulic system (connecting groundwater, river water, and the sea) was altered over centuries (until the 19th century) by e.g. the construction of dikes and drains to prevent flooding and allow agricultural use. Today, massive saltwater intrusions extend up to 20 km inland. In order to understand the regional flow, a methodological approach was developed that combined: (1) a highly-resolved voxel geological model, (2) a ∼1 million node groundwater model with 46 hydrofacies coupled to rivers, drains and the sea, (3) Tikhonov regularization calibration using hydraulic heads and average stream discharges as targets and (4) parameter uncertainty analysis. It is relatively new to use voxel models for constructing geological models that often have been simplified to stacked, pseudo-3D layer geology. The study is therefore one of the first to combine a voxel geological model with state-of-the-art flow calibration techniques. The results show that voxel geological modelling, where lithofacies information are transferred to each volumetric element, is a useful method to preserve 3D geological heterogeneity on a local scale, which is important when distinct geological features such as buried valleys are abundant. Furthermore, it is demonstrated that simpler geological models and simpler calibration methods do not perform as well. The proposed approach is applicable to many other systems, because it combines advanced and flexible geological modelling and flow calibration techniques. This has led to new insights in the regional flow patterns and especially about water cycling in the marsh area near

Potentiometric surface of the intermediate aquifer system, west- central Florida, May 1987

USGS Publications Warehouse

Lewelling, B.R.

1988-01-01

The intermediate aquifer system within the Southwest Florida Water Management District underlies a 5,000 sq mi area of De Soto, Sarasota, Hardee, Manatee, and parts of Charlotte, Hillsborough, Highlands, and Polk Counties. The intermediate aquifer system occurs between the overlying surficial aquifer system and the underlying Floridan aquifer system, and consists of layers of sand, shell, clay, marl, limestone, and dolom of the Tamiami, Hawthorn, and Tampa Formations of late Tertiary age. The intermediate aquifer system contains one or more water-bearing units separated by discontinuous confining units. This aquifer system is the principal source of potable water in the southwestern part of the study area and is widely used as a source of water in other parts where wells are open to the intermediate aquifer system or to both the intermediate and Floridan aquifer systems. Yields of individual wells open to the intermediate aquifer system range from a few gallons to several hundred gallons per minute. The volume of water withdrawn from the intermediate aquifer system is considerably less than that withdrawn from the Floridan aquifer system in the study area. The surface was mapped by determining the altitude of water levels in a network of wells and is represented on maps by contours that connect points of equal altitude. The compos potentiometric surface of all water-bearing units within the intermediate aquifer system is shown. In areas where multiple aquifers exist, wells open to all aquifers were selected for water level measurements whenever possible. In the southwestern and lower coastal region of the study area, two aquifers and confining units are described for the intermediate aquifer system: the Tamiami-upper Hawthorn aquifer and the underlying lower Hawthorn-upper Tampa aquifer. The potentiometric surface of the Tamiami-upper Hawthorn aquifer is also shown. Water levels are from wells drilled and open exclusively to that aquifer. The exact boundary for the

Ground-water resources of the Caguas-Juncos Valley, Puerto Rico

USGS Publications Warehouse

Puig, J.C.; Rodriguez, J.M.

1993-01-01

?The Caguas-Juncos valley, which occupies an area of 35 square miles in east-central Puerto Rico, is underlain by the largely unconfined alluvial aquifer. Withdrawals from this aquifer for public water supply and for agricultural, industrial, and domestic water uses totalled about 3.0 million gallons per day in 1988. Some wells in the valley yield as much as 310 gallons per minute from the alluvial deposits along Rio Gurabo near Gurabo and near Juncos. Wells used at dairy farms in the area commonly yield about 30 gallons per minute. The potentiometric surface of the alluvial aquifer varies seasonally and generally is highest near the end of December and lowest in April. Transmissivity of the alluvial aquifer, estimated from specific capacity and slug test data, ranges from 65 to 4,800 feet squared per day. The estimated specific yield of the water-table is about 10 to 15 percent. The amount of water stored in the aquifer is estimated to be about 122,000 acre-feet. Analyses of ground-water samples revealed the presence of two distinct problems-- high natural concentrations of iron and manganese, and localized areas of human- related contamination scattered throughout the valley. The ground water is a calcium-bicarbonate type and typically has dissolved solids concentrations of less than 500 milligrams per liter.

Hydrologic conditions in the Bill Williams River National Wildlife Refuge and Planet Valley, Arizona, 2000

USGS Publications Warehouse

Wilson, Richard P.; Owen-Joyce, Sandra J.

2002-01-01

During a period of sustained base-flow conditions in the Bill Williams River below Alamo Dam in west central Arizona from March to July 2000, the channel of the river through Planet Valley was dry, and the water table sloped almost due west parallel to the main slope of the flood plain. Water from the river infiltrated into the channel bottom at the head of Planet Valley, moved downgradient in the subsurface, and reappeared in the channel about 0.3 mile downstream from the east boundary of the Bill Williams River National Wildlife Refuge. A river aquifer in hydraulic connection with the Bill Williams River was mapped from a point 6.3 miles upstream from Highway 95 to the upstream end of Planet Valley. Formations that make up the river aquifer in Planet Valley are younger alluvium, older alluviums, and fanglomerate. Total thickness of the river aquifer probably is less than 200 feet in the bedrock canyons to as much as 1,035 feet in Planet Valley. The purpose of this study was to investigate the current hydrologic conditions along the Bill Williams River, which included an inventory of wells within the river aquifer of the Colorado River and in Planet Valley, and to determine the configuration of the water table. A map shows the elevation and configuration of the water table from the east end of Planet Valley to the confluence of the Bill Williams River with Lake Havasu.

Groundwater quality in Coachella Valley, 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. Coachella Valley is one of the study areas being evaluated. The Coachella study area is approximately 820 square miles (2,124 square kilometers) and includes the Coachella Valley groundwater basin (California Department of Water Resources, 2003). Coachella Valley has an arid climate, with average annual rainfall of about 6 inches (15 centimeters). The runoff from the surrounding mountains drains to rivers that flow east and south out of the study area to the Salton Sea. Land use in the study area is approximately 67 percent (%) natural, 21% agricultural, and 12% urban. The primary natural land cover is shrubland. The largest urban areas are the cities of Indio and Palm Springs (2010 populations of 76,000 and 44,000, respectively). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. The primary aquifers in Coachella Valley 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 Coachella Valley are completed to depths between 490 and 900 feet (149 to 274 meters), consist of solid casing from the land surface to a depth of 260 to 510 feet (79 to 155 meters), and are screened or perforated below the solid casing. Recharge to the groundwater system is primarily runoff from the surrounding mountains, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to

Use of sinkhole and specific capacity distributions to assess vertical gradients in a karst aquifer

USGS Publications Warehouse

McCoy, K.J.; Kozar, M.D.

2008-01-01

The carbonate-rock aquifer in the Great Valley, West Virginia, USA, was evaluated using a database of 687 sinkholes and 350 specific capacity tests to assess structural, lithologic, and topographic influences on the groundwater flow system. The enhanced permeability of the aquifer is characterized in part by the many sinkholes, springs, and solutionally enlarged fractures throughout the valley. Yet, vertical components of subsurface flow in this highly heterogeneous aquifer are currently not well understood. To address this problem, this study examines the apparent relation between geologic features of the aquifer and two spatial indices of enhanced permeability attributed to aquifer karstification: (1) the distribution of sinkholes and (2) the occurrence of wells with relatively high specific capacity. Statistical results indicate that sinkholes (funnel and collapse) occur primarily along cleavage and bedding planes parallel to subparallel to strike where lateral or downward vertical gradients are highest. Conversely, high specific capacity values are common along prominent joints perpendicular or oblique to strike. The similarity of the latter distribution to that of springs suggests these fractures are areas of upward-convergent flow. These differences between sinkhole and high specific capacity distributions suggest vertical flow components are primarily controlled by the orientation of geologic structure and associated subsurface fracturing. ?? 2007 Springer-Verlag.

Transient well flow in leaky multiple-aquifer systems

NASA Astrophysics Data System (ADS)

Hemker, C. J.

1985-10-01

A previously developed eigenvalue analysis approach to groundwater flow in leaky multiple aquifers is used to derive exact solutions for transient well flow problems in leaky and confined systems comprising any number of aquifers. Equations are presented for the drawdown distribution in systems of infinite extent, caused by wells penetrating one or more of the aquifers completely and discharging each layer at a constant rate. Since the solution obtained may be regarded as a combined analytical-numerical technique, a type of one-dimensional modelling can be applied to find approximate solutions for several complicating conditions. Numerical evaluations are presented as time-drawdown curves and include effects of storage in the aquitard, unconfined conditions, partially penetrating wells and stratified aquifers. The outcome of calculations for relatively simple systems compares very well with published corresponding results. The proposed multilayer solution can be a valuable tool in aquifer test evaluation, as it provides the analytical expression required to enable the application of existing computer methods to the determination of aquifer characteristics.

Groundwater model of the Great Basin carbonate and alluvial aquifer system version 3.0: Incorporating revisions in southwestern Utah and east central Nevada

USGS Publications Warehouse

Brooks, Lynette E.

2017-12-01

The groundwater model described in this report is a new version of previously published steady-state numerical groundwater flow models of the Great Basin carbonate and alluvial aquifer system, and was developed in conjunction with U.S. Geological Survey studies in Parowan, Pine, and Wah Wah Valleys, Utah. This version of the model is GBCAAS v. 3.0 and supersedes previous versions. The objectives of the model for Parowan Valley were to simulate revised conceptual estimates of recharge and discharge, to estimate simulated aquifer storage properties and the amount of reduction in storage as a result of historical groundwater withdrawals, and to assess reduction in groundwater withdrawals necessary to mitigate groundwater-level declines in the basin. The objectives of the model for the area near Pine and Wah Wah Valleys were to recalibrate the model using new observations of groundwater levels and evapotranspiration of groundwater; to provide new estimates of simulated recharge, hydraulic conductivity, and interbasin flow; and to simulate the effects of proposed groundwater withdrawals on the regional flow system. Meeting these objectives required the addition of 15 transient calibration stress periods and 14 projection stress periods, aquifer storage properties, historical withdrawals in Parowan Valley, and observations of water-level changes in Parowan Valley. Recharge in Parowan Valley and withdrawal from wells in Parowan Valley and two nearby wells in Cedar City Valley vary for each calibration stress period representing conditions from March 1940 to November 2013. Stresses, including recharge, are the same in each stress period as in the steady-state stress period for all areas outside of Parowan Valley. The model was calibrated to transient conditions only in Parowan Valley. Simulated storage properties outside of Parowan Valley were set the same as the Parowan Valley properties and are not considered calibrated. Model observations in GBCAAS v. 3.0 are

Summary of the Oahu, Hawaii, Regional Aquifer-System Analysis

USGS Publications Warehouse

Nichols, William D.; Shade, Patricia J.; Hunt, Charles D.

1996-01-01

Oahu, the third largest of the Hawaiian islands, is formed by the eroded remnants of two elongated shield volcanoes with broad, low profiles. Weathering and erosion have modified the original domed surfaces of the volcanoes, leaving a landscape of deep valleys and steep interfluvial ridges in the interior highlands. The Koolau Range in eastern Oahu and the Waianae Range in western Oahu are the eroded remnants of the Koolau and Waianae Volcanoes. The origin, mode of emplacement, texture, and composition of the rocks of Oahu affect their ability to store and transmit water. The volcanic rocks are divided into four groups: (1) lava flows, (2) dikes, (3) pyroclastic deposits, and (4) saprolite and weathered basalt. Stratified sequences of thin-bedded lava flows form the most productive aquifers in Hawaii. Dikes are near-vertical sheets of massive intrusive rock that typically contain only fracture permeability. Pyroclastic deposits include ash, cinder, and spatter; they are essentially granular, with porosity and permeability similar to those of granular sediments. Weathering of basaltic rocks in the humid, subtropical climate of Oahu alters igneous minerals to clays and oxides, reducing the permeability of the parent rock. Saprolite is weathered material that has retained textural features of the parent rock. Estimates of hydraulic conductivity along the plane of dike-free lava flows tend to fall within about one order of magnitude, from about 500 to about 5,000 feet per day. Estimates of specific yield range from about 1 to 20 percent; most of the values lie within a narrow range of about 5 to 10 percent. The occurrence of ground water on Oahu is determined by the type and character of the rocks and by the presence of geohydrologic barriers. The primary modes of freshwater occurrence on Oahu are as a basal lens of fresh ground water floating on saltwater, as dike-impounded ground water, and as perched ground water. Saltwater occurs at depth throughout much of the

Potentiometric surfaces of the intermediate aquifer system, west-central Florida, September 2000

USGS Publications Warehouse

Duerr, A.D.

2001-01-01

The intermediate aquifer system underlies a 5,000-square-mile area within the Southwest Florida Water Management District including De Soto, Sarasota, Hardee, Manatee, and parts of Charlotte, Hillsborough, Highlands, Polk, and Lee Counties.  The intermediate aquifer system is overlain by the surficial aquifer system and is underlain by the Floridan aquifer system.  The intermediate aquifer system consists of layers of sand, shell, clay, calcareous clay, limestone, and dolomite of the Tamiami Formation and Hawthorn Group of Oligocene to Pleistocene age (Wingard and others, 1995).  The intermediate aquifer system contains one or more water-bearing units separated by discontinuous confining units.  The intermediate aquifer system is the principal source of potable water in the southwestern part of the study area and is widely used as a source of water where wells are open to the intermediate aquifer system or to both the intermediate and Floridan aquifer systems.  Yields of individual wells open to the intermediate aquifer system vary from a few gallons to several hundred gallons per minute.  The volume of water withdrawn from the intermediate aquifer system is considerably less than that withdrawn from the Floridan aquifer system in the study area (Duerr and others, 1988).

Hydrogeologic framework of the North Carolina Coastal Plain aquifer system

USGS Publications Warehouse

Winner, M.D.; Coble, R.W.

1989-01-01

The hydrogeologic framework of the North Carolina Coastal Plain aquifer system consists of ten aquifers separated by nine confining units. From top to bottom the aquifers are: the surficial aquifer, Yorktown aquifer, Pungo River aquifer, Castle Hayne aquifer, Beaufort aquifer, Peedee aquifer, Black Creek aquifer, upper Cape Fear aquifer, lower Cape Fear aquifer, and the Lower Cretaceous aquifer. The uppermost aquifer (the surficial aquifer in most places) is a water-table aquifer and the bottom of the system is underlain by crystalline bedrock. The sedimentary deposits forming the aquifers are of Holocene to Cretaceous age and are composed mostly of sand with lesser amounts of gravel and limestone. Confining units between aquifers are composed primarily of clay and silt. The thickness of the aquifers ranges from zero along the Fall Line to more than 10,000 feet at Cape Hatteras. Prominent structural features are the increasing easterly homoclinal dip of the sediments and the Cape Fear arch, the axis of which trends in a southeast direction. The stratigraphic continuity is determined from correlations of 161 geophysical logs along with data from drillers' and geologists' logs. Aquifers were defined by means of these logs plus water-level and water-quality data and evidence of the continuity of pumping effects. Eighteen hydrogeologic sections depict the correlation of these aquifers throughout the Coastal Plain.

Stream seepage and groundwater levels, Wood River Valley, south-central Idaho, 2012-13

USGS Publications Warehouse

Bartolino, James R.

2014-01-01

Stream discharge and water levels in wells were measured at multiple sites in the Wood River Valley, south-central Idaho, in August 2012, October 2012, and March 2013, as a component of data collection for a groundwater-flow model of the Wood River Valley aquifer system. This model is a cooperative and collaborative effort between the U.S. Geological Survey and the Idaho Department of Water Resources. Stream-discharge measurements for determination of seepage were made during several days on three occasions: August 27–28, 2012, October 22–24, 2012, and March 27–28, 2013. Discharge measurements were made at 49 sites in August and October, and 51 sites in March, on the Big Wood River, Silver Creek, their tributaries, and nearby canals. The Big Wood River generally gains flow between the Big Wood River near Ketchum streamgage (13135500) and the Big Wood River at Hailey streamgage (13139510), and loses flow between the Hailey streamgage and the Big Wood River at Stanton Crossing near Bellevue streamgage (13140800). Shorter reaches within these segments may differ in the direction or magnitude of seepage or may be indeterminate because of measurement uncertainty. Additional reaches were measured on Silver Creek, the North Fork Big Wood River, Warm Springs Creek, Trail Creek, and the East Fork Big Wood River. Discharge measurements also were made on the Hiawatha, Cove, District 45, Glendale, and Bypass Canals, and smaller tributaries to the Big Wood River and Silver Creek. Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established by the U.S. Geological Survey in 2006. Maps of the October 2012 water-table altitude in the unconfined aquifer and the potentiometric-surface altitude of the confined aquifer have similar topology to those on maps of October 2006 conditions. Between October 2006 and October 2012, water-table altitude in the unconfined aquifer rose by

Hydrogeology and groundwater quality of the glaciated valleys of Bradford, Tioga, and Potter Counties, Pennsylvania

USGS Publications Warehouse

Williams, John H.; Taylor, Larry E.; Low, Dennis J.

1998-01-01

The most important sources of groundwater in Bradford, Tioga, and Potter Counties are the stratified-drift aquifers. Saturated sand and gravel primarily of outwash origin forms extensive unconfined aquifers in the valleys. Outwash is underlain in most major valleys by silt, clay, and very fine sand of lacustrine origin that comprise extensive confining units. The lacustrine confining units locally exceed 100 feet in thickness. Confined aquifers of ice-contact sand and gravel are buried locally beneath the lacustrine deposits. Bedrock and till are the basal confining units of the stratifies-drift aquifer systems. Recharge to the stratified-drift aquifers if by direct infiltration of precipitation, tributary-stream infiltration, infiltration of unchanneled runoff at the valley walls, and groundwater inflow from the bedrock and till uplands. Valley areas underlain by superficial sand and gravel contribute about 1 million gallons per day per square mile of water from precipitation to the aquifers. Tributary streams provide recharge of nearly 590 gallons per day per foot of stream reach. Water is added at the rate of 1 million gallons per day per square mile of bordering uplands not drained by tributary streams to the stratified-drift aquifers from unchanneled runoff and groundwater inflow. Induced infiltration can be a major source of recharge to well fields completed in unconfined stratified-drift aquifers that are in good hydraulic connection with surface water. The well fields of an industrial site in North Towanda, a public-water supplier at Tioga Point, and the U.S. Fish and Wildlife Service at Asaph accounted for 75 percent of the 10.8 million gallons per day pf groundwater withdrawn by public suppliers and other selected users in 1985. The well fields tap stratified-drift aquifers that are substantially recharged by induced infiltration or tributary-stream infiltration. Specific-capacity data from 95 wells indicate that most wells completed in stratified

Stochastic modeling of a lava-flow aquifer system

USGS Publications Warehouse

Cronkite-Ratcliff, Collin; Phelps, Geoffrey A.

2014-01-01

This report describes preliminary three-dimensional geostatistical modeling of a lava-flow aquifer system using a multiple-point geostatistical model. The purpose of this study is to provide a proof-of-concept for this modeling approach. An example of the method is demonstrated using a subset of borehole geologic data and aquifer test data from a portion of the Calico Hills Formation, a lava-flow aquifer system that partially underlies Pahute Mesa, Nevada. Groundwater movement in this aquifer system is assumed to be controlled by the spatial distribution of two geologic units—rhyolite lava flows and zeolitized tuffs. The configuration of subsurface lava flows and tuffs is largely unknown because of limited data. The spatial configuration of the lava flows and tuffs is modeled by using a multiple-point geostatistical simulation algorithm that generates a large number of alternative realizations, each honoring the available geologic data and drawn from a geologic conceptual model of the lava-flow aquifer system as represented by a training image. In order to demonstrate how results from the geostatistical model could be analyzed in terms of available hydrologic data, a numerical simulation of part of an aquifer test was applied to the realizations of the geostatistical model.

The Central Valley Hydrologic Model

NASA Astrophysics Data System (ADS)

Faunt, C.; Belitz, K.; Hanson, R. T.

2009-12-01

Historically, California’s Central Valley has been one of the most productive agricultural regions in the world. The Central Valley also is rapidly becoming an important area for California’s expanding urban population. In response to this competition for water, a number of water-related issues have gained prominence: conjunctive use, artificial recharge, hydrologic implications of land-use change, subsidence, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS made a detailed assessment of the Central Valley aquifer system that includes the present status of water resources and how these resources have changed over time. The principal product of this assessment is a tool, referred to as the Central Valley Hydrologic Model (CVHM), that simulates surface-water flows, groundwater flows, and land subsidence in response to stresses from human uses and from climate variability throughout the entire Central Valley. The CVHM utilizes MODFLOW combined with a new tool called “Farm Process” to simulate groundwater and surface-water flow, irrigated agriculture, land subsidence, and other key processes in the Central Valley on a monthly basis. This model was discretized horizontally into 20,000 1-mi2 cells and vertically into 10 layers ranging in thickness from 50 feet at the land surface to 750 feet at depth. A texture model constructed by using data from more than 8,500 drillers’ logs was used to estimate hydraulic properties. Unmetered pumpage and surface-water deliveries for 21 water-balance regions were simulated with the Farm Process. Model results indicate that human activities, predominately surface-water deliveries and groundwater pumping for irrigated agriculture, have dramatically influenced the hydrology of the Central Valley. These human activities have increased flow though the aquifer system by about a factor of six compared to pre-development conditions. The simulated hydrology reflects spatial

Water availability and land subsidence in the Central Valley, California, USA

NASA Astrophysics Data System (ADS)

Faunt, Claudia C.; Sneed, Michelle; Traum, Jon; Brandt, Justin T.

2016-05-01

The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007-2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

Accounting System for Water Use by Vegetation in the Lower Colorado River Valley

USGS Publications Warehouse

Owen-Joyce, Sandra J.

1992-01-01

The Colorado River is the principal source of water in the valley of the Colorado River between Hoover Dam and the international boundary with Mexico (fig. 1). Agricultural, domestic, municipal, industrial, hydroelectric-power genera-tion, and recreation are the primary uses of river water in the valley. Most of the consumptive use of water from the river occurs downstream from Davis Dam, where water is diverted to irrigate crops along the river or is exported to interior regions of California and Arizona. Most of the agricultural areas are on the alluvium of the flood plain; in a few areas, land on the alluvial terraces has been cultivated. River water is consumed mainly by vegetation (crops and phreatophytes) on the flood plain. Crops were grown on 70.3 percent of the vegetated area classified by using 1984 digital image satellite data. Phreatophytes, natural vege-tation that obtain water from the alluvial aquifer, covered the remaining vegetated areas on the uncultivated flood plain. Most of the water used for irrigation is diverted or pumped from the river. In some areas, water is pumped from wells completed in the alluvial aquifer, which is hydraulically connected to the river.

New insight on the water management in Ica Valley-Peru

NASA Astrophysics Data System (ADS)

Guttman, Joseph; Berger, Diego

2014-05-01

The Andes divide Peru into three natural drainage basins: Pacific basin, Atlantic basin and Lake Titicaca basin. According to the National Water Authority (ANA), the Pacific basin is the driest basin. The bulk of water that feed the local aquifers in the coastal Pacific region is coming from rivers that flow west from the Andes. One of them is the Ica River- source of the Ica Aquifer and the Pampas de Villacuri Aquifer. The Ica River flows in a graben that was created by a series of faults. The graben is filled with sand and gravel with interbeded and lenses of clay. The aquifer thickness varies between 25 meters to more than 200 meters. The Ica Valley has an extension of 7700 km2 and belongs to the Province of Ica, the second larger economic center in Peru. The Valley is located in the hyperarid region of the Southern Coastal area of Peru with a few millimeters of precipitation per year. The direct recharge is almost zero. The recharge into the Ica Valley aquifer is comes indirectly by infiltration of storm water through the riverbed generates in the Andes, through irrigation canals and by irrigation return flow. In this hyperarid region, local aquifers like the Ica Valley are extremely valuable resources to local populations and are the key sources of groundwater for agriculture and population needs. Therefore, these aquifers play a crucial role in providing people with water and intense attention should be given to manage the water sector properly and to keep the aquifer sustainable for future generations. The total pumping (from rough estimations) is much greater than the direct and indirect recharge. The deficit in the water balance is reflected in large water level decline, out of operation of shallow wells and the ascending of saline water from deeper layers. The change from flood irrigation that contributes about 35-40% of the water to the aquifer, to drip irrigation dramatically reduces the amount of water that infiltrates into the sub-surface from the

Discovering complex groundwater dynamics of a multiple aquifer system on the base of stable and radio-isotope patterns

NASA Astrophysics Data System (ADS)

Wilske, Cornelia; Rödiger, Tino; Suckow, Axel; Geyer, Stefan; Weise, Stephan; Merchel, Silke; Rugel, Georg; Pavetich, Stefan; Merkel, Broder; Siebert, Christian

2017-04-01

The water supply in semi-arid Israel and Palestine, predominantly relies on groundwater as freshwater resource, stressed by increasing demand and low recharge rates. Sustainable management of such resources requires a sound understanding of its groundwater migration through space and time, particularly in structurally complex multi-aquifer systems as the Eastern Mountain Aquifer, affected by salting. To differentiate between the flow paths of the different water bodies and their respective residence times, a multi-tracer approach, combining age dating isotopes (36Cl/Cl; 3H) with rock specific isotopes like 87Sr/86Sr and δ34S-SO4 was applied. As a result, the investigated groundwaters from the two Cretaceous aquifers and their respective flow paths are differentiable by e.g. their 87Sr/86Sr signatures, resembling the intensity of the rock-water interaction and hence indirectly residence times. In the discharge areas within the Jordan Valley and along the Dead Sea shore, δ34S-SO4 ratios reveal the different sources of salinity (ascending brines, interstitial brines and dissolved salts). Based on 36Cl and 3H and the atmospheric input functions, very heterogeneous infiltration times and effective flow velocities, respectively, indicate an at least dual porosity system, resulting in distinctly different regimes of matrix and pipe flow.

Airborne electromagnetics (EM) as a three-dimensional aquifer-mapping tool

USGS Publications Warehouse

Wynn, Jeff; Pool, Don; Bultman, Mark; Gettings, Mark; Lemieux, Jean

2000-01-01

The San Pedro River in southeastern Arizona hosts a major migratory bird flyway, and was declared a Riparian Conservation Area by Congress in 1988. Recharge of the adjacent Upper San Pedro Valley aquifer was thought to come primarily from the Huachuca Mountains, but the U. S. Army Garrison of Fort Huachuca and neighboring city of Sierra Vista have been tapping this aquifer for many decades, giving rise to claims that they jointly threatened the integrity of the Riparian Conservation Area. For this reason, the U. S. Army funded two airborne geophysical surveys over the Upper San Pedro Valley (see figure 1), and these have provided us valuable information on the aquifer and the complex basement structure underlying the modern San Pedro Valley. Euler deconvolution performed on the airborne magnetic data has provided a depth-to-basement map that is substantially more complex than a map obtained earlier from gravity data, as would be expected from the higher-resolution magnetic data. However, we found the output of the Euler deconvolution to have "geologic noise" in certain areas, interpreted to be post-Basin-and-Range Tertiary volcanic flows in the sedimentary column above the basement but below the ground surface.

[Nitrate storage and transport within a typical karst aquifer system in the paralleled ridge-valley of east Sichuan].

PubMed

Yang, Ping-Heng; Yuan, Dao-Xian; Ren, You-Rong; Xie, Shi-You; He, Qiu-Fang; Hu, Xiao-Feng

2012-09-01

In order to investigate the nitrate storage and transport in the karst aquifer system, the hydrochemical dynamics of Qingmuguan underground river system was monitored online by achieving high-resolution data during storm events and monthly data in normal weather. The principal component analysis was employed to analyze the karst water geochemistry. Results showed that nitrate in Jiangjia spring did not share the same source with soluble iron, manganese and aluminum, and exhibited different geochemical behaviors. Nitrate was derived from land surface and infiltrated together with soil water, which was mainly stored in fissure, pore and solution crack of karst unsaturated zone, whereas soluble iron, manganese and aluminum were derived from soil erosion and directly recharged the underground river through sinkholes and shafts. Nitrate transport in the karst aquifer system could be ideally divided into three phases, including input storage, fast output and re-inputting storage. Under similar external conditions, the karstification intensity of vadose zone was the key factor to determine the dynamics of nitrate concentrations in the groundwater during storm events. Nitrate stored in the karst vadose zone was easily released, which would impair the aquatic ecosystem and pose seriously threats to the local health. Thus, to strengthen the management of ecological system, changing the land-use patterns and scientifically applying fertilizer could effectively make a contribution to controlling mass nutrient input from the surface.

Relation of Chlorofluorocarbon Ground-Water Age Dates to Water Quality in Aquifers of West Virginia

USGS Publications Warehouse

,; Kurt, J.; Kozar, Mark D.

2007-01-01

The average apparent age of ground water in fractured-bedrock aquifers in West Virginia was determined using chlorofluorocarbon (CFC) dating methods. Since the introduction of CFC gases as refrigerants in the late 1930s, atmospheric concentrations have increased until production ceased in the mid-1990s. CFC dating methods are based on production records that date to the early 1940s, and the preservation of atmospheric CFC concentrations in ground water at the time of recharge. As part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) and Ambient Ground-Water Monitoring Network (AGN) programs in West Virginia from 1997 to 2005, 80 samples from the Appalachian Plateaus Physiographic Province, 27 samples from the Valley and Ridge Physiographic Province, and 5 samples from the Ohio River alluvial aquifers were collected to estimate ground-water ages in aquifers of West Virginia. Apparent CFC ages of water samples from West Virginia aquifers ranged from 5.8 to 56 years. In the Appalachian Plateaus, topographically driven ground-water flow is evident from apparent ages of water samples from hilltop, hillside, and valley settings (median apparent ages of 12, 14, and 25 years, respectively). Topographic setting was the only factor that was found to be related to apparent ground-water age in the Plateaus at the scale of this study. Similar relations were not found in Valley and Ridge aquifers, indicating that other factors such as bedding or geologic structure may serve larger roles in controlling ground-water flow in that physiographic province. Degradation of CFCs was common in samples collected from methanogenic/anoxic aquifers in the Appalachian Plateaus and suboxic to anoxic aquifers in the Valley and Ridge. CFC contamination was most common in Ohio River alluvial aquifers and carbonate units of the Valley and Ridge, indicating that these highly transmissive surficial aquifers are the most vulnerable to water-quality degradation and may

Depth to water, 1991, in the Rathdrum Prairie, Idaho; Spokane River valley, Washington; Moscow-Lewiston-Grangeville area, Idaho; and selected intermontane valleys, east-central Idaho

USGS Publications Warehouse

Berenbrock, Charles E.; Bassick, M.D.; Rogers, T.L.; Garcia, S.P.

1995-01-01

This map report illustrates digitally generated depth-to-water zones for the Rathdrum Prairie in Idaho; part of the Spokane River Valley in eastern Washington; and the intermontane valleys of the upper Big Wood, Big Lost, Pahsimeroi, Little Lost, and Lemhi Rivers and Birch Creek in Idaho. Depth to water is 400 to 500 feet below land surface in the northern part of Rathdrum Prairie, 100 to 200 feet below land surface at the Idaho-Washington State line, and 0 to 250 feet below land surface in the Spokane area. Depth to water in the intermontane valleys in east-central Idaho is least (usually less than 50 feet) near streams and increases toward valley margins where mountain-front alluvial fans have formed. Depths to water shown in the Moscow-Lewiston-Grangeville area in Idaho are limited to point data at individual wells because most of the water levels measured were not representative of levels in the uppermost aquifer but of levels in deeper aquifers.

Lithology, hydrologic characteristics, and water quality of the Arkansas River Valley alluvial aquifer in the vicinity of Van Buren, Arkansas

USGS Publications Warehouse

Kresse, Timothy M.; Westerman, Drew A.; Hart, Rheannon M.

2015-01-01

The hydrologic and geochemical data gathered for this study provide a qualitative assessment of the potential of the Arkansas River Valley alluvial aquifer as a source of public water supply in the Van Buren area. Results indicate minimal influx of water from the Arkansas River, and recharge to the aquifer appears to be dominantly by infiltration of precipitation through overlying alluvium. If vertical wells are used as a source of public water supply, then several wells will have to be used in combination at relatively low pumping rates and placed in areas with a greater percent sand. Use of a horizontal well configuration near the river to increase production may depend on infiltration of river water to supplement water removed from storage, especially where areas of lower permeability sediments might be encountered within the surrounding alluvium. If a poor hydraulic connection exists between the river and the alluvium, as indicated by this study, then production will depend on ample precipitation and recharge throughout the year and groundwater storage sufficient to prevent declining water levels where pumping rates exceed recharge.

Hydrogeology and water quality of the Nanticoke Creek stratified-drift aquifer, near Endicott, New York

USGS Publications Warehouse

Kreitinger, Elizabeth A.; Kappel, William M.

2014-01-01

The Village of Endicott, New York, is seeking an alternate source of public drinking water with the potential to supplement their current supply, which requires treatment due to legacy contamination. The southerly-draining Nanticoke Creek valley, located north of the village, was identified as a potential water source and the local stratified-drift (valley fill) aquifer was investigated to determine its hydrogeologic and water-quality characteristics. Nanticoke Creek and its aquifer extend from the hamlet of Glen Aubrey, N.Y., to the village of Endicott, a distance of about 15 miles, where it joins the Susquehanna River and its aquifer. The glacial sediments that comprise the stratified-drift aquifer vary in thickness and are generally underlain by glacial till over Devonian-aged shale and siltstone. Groundwater is more plentiful in the northern part of the aquifer where sand and gravel deposits are generally more permeable than in the southern part of the aquifer where less-permeable unconsolidated deposits are found. Generally there is enough groundwater to supply most homeowner wells and in some cases, supply small public-water systems such as schools, mobile-home parks, and small commercial/industrial facilities. The aquifer is recharged by precipitation, runoff, and tributary streams. Most tributary streams flowing across alluvial deposits lose water to the aquifer as they flow off of their bedrock-lined channels and into the more permeable alluvial deposits at the edges of the valley. The quality of both surface water and groundwater is generally good. Some water wells do have water-quality issues related to natural constituents (manganese and iron) and several homeowners noted either the smell and (or) taste of hydrogen sulfide in their drinking water. Dissolved methane concentrations from five drinking-water wells were well below the potentially explosive value of 28 milligrams per liter. Samples from surface and groundwater met nearly all State and Federal

Ground-water hydrology of the upper Sevier River Basin, south-central Utah, and simulation of ground-water flow in the valley-fill in Panguitch Valley.

USGS Publications Warehouse

Thiros, Susan A.; Brothers, William C.

1993-01-01

The ground-water hydrology of the upper Sevier River basin, primarily of the unconsolidated valley-fill aquifers, was studied from 1988 to 1989. Recharge to the valley-fill aquifers is mostly by seepage from surface-water sources. Changes in soil-moisture content am water levels were measured in Panguitch Valley both at a flood-irrigated and at a sprinkler-irrigated alfalfa field to quantify seepage from unconsumed irrigation water. Lag time between irrigation and water-level response decreased from 6 to 2 days in the flood-irrigated field as the soil-moisture content increased. Water levels measured in the sprinkler-irrigated field did not respond to irrigation. Discharge from the valley-fill aquifer to the Sevier River in Panguitch Valley is about 53,570 acre-feet per year.Water levels measured in wells from 1951 to 1989 tend to fluctuate with the quantity of precipitation falling at higher elevations. Ground-water discharge to the Sevier River in Panguitch Valley causes a general increase in the specific conductance of the river in a downstream direction.A three-layered ground-water-flow model was used to simulate the effects of changes in irrigation practices am increased ground-water withdrawals in Panguitch Valley. The establishment of initial conditions consisted of comparing simulated water levels and simulated gains and losses from the Sevier River and selected canals with values measured during the 1988 irrigation season. The model was calibrated by comparing water-level changes measured from 1961 to 1963 to simulated changes. A simulated change from flood to sprinkler irrigation resulted in a maximum decline in water level of 0.9 feet after the first year of change. Simulating additional discharge from wells resulted in drawdowns of about 20 feet after the first year of pumping.

Hydrogeological Characterization of the Middle Magdalena Valley - Colombia

NASA Astrophysics Data System (ADS)

Arenas, Maria Cristina; Riva, Monica; Donado, Leonardo David; Guadagnini, Alberto

2017-04-01

We provide a detailed hydrogeological characterization of the complex aquifer system of the Middle Magdalena Valley, Colombia. The latter is comprised by 3 sub-basins within which 7 blocks have been identified for active exploration and potential production of oil and gas. As such, there is a critical need to establish modern water resources management practices in the area to accommodate the variety of social, environmental and industrial needs. We do so by starting from a detailed hydrogeological characterization of the system and focus on: (a) a detailed hydrogeological reconnaissance of the area leading to the definition of the main hydrogeological units; (b) the collection, organization and analysis of daily climatic data from 39 stations available in the region; and (c) the assessment of the groundwater flow circulation through the formulation of a conceptual and a mathematical model of the subsurface system. Groundwater flow is simulated in the SAM 1.1 aquifer located in the Middle Magdalena Valley with the objective of showing and evaluating alternative conceptual hydrogeological modeling alternatives. We focus here on modeling results at system equilibrium (i.e., under steady-state conditions) and assess the value of available information in the context of the candidate modeling strategies we consider. Results of our modeling effort are conducive to the characterization of the distributed hydrogeological budget and the assessment of critical areas as a function of the conceptualization of the system functioning and data avilability.

Effect of natural gas exsolution on specific storage in a confined aquifer undergoing water level decline.

PubMed

Yager, R M; Fountain, J C

2001-01-01

The specific storage of a porous medium, a function of the compressibility of the aquifer material and the fluid within it, is essentially constant under normal hydrologic conditions. Gases dissolved in ground water can increase the effective specific storage of a confined aquifer, however, during water level declines. This causes a reduction in pore pressure that lowers the gas solubility and results in exsolution. The exsolved gas then displaces water from storage, and the specific storage increases because gas compressibility is typically much greater than that of water or aquifer material. This work describes the effective specific storage of a confined aquifer exsolving dissolved gas as a function of hydraulic head and the dimensionless Henry's law constant for the gas. This relation is applied in a transient simulation of ground water discharge from a confined aquifer system to a collapsed salt mine in the Genesee Valley in western New York. Results indicate that exsolution of gas significantly increased the effective specific storage in the aquifer system, thereby decreasing the water level drawdown.

Effect of natural gas exsolution on specific storage in a confined aquifer undergoing water level decline

USGS Publications Warehouse

Yager, R.M.; Fountain, J.C.

2001-01-01

The specific storage of a porous medium, a function of the compressibility of the aquifer material and the fluid within it, is essentially constant under normal hydrologic conditions. Gases dissolved in ground water can increase the effective specific storage of a confined aquifer, however, during water level declines. This causes a reduction in pore pressure that lowers the gas solubility and results in exsolution. The exsolved gas then displaces water from storage, and the specific storage increases because gas compressibility is typically much greater than that of water or aquifer material. This work describes the effective specific storage of a confined aquifer exsolving dissolved gas as a function of hydraulic head and the dimensionless Henry's law constant for the gas. This relation is applied in a transient simulation of ground water discharge from a confined aquifer system to a collapsed salt mine in the Genesee Valley in western New York. Results indicate that exsolution of gas significantly increased the effective specific storage in the aquifer system, thereby decreasing the water level drawdown.

Hydrogeology of the surficial and intermediate aquifer systems in Sarasota and adjacent counties, Florida

USGS Publications Warehouse

Barr, G.L.

1996-01-01

From 1991 to 1995, the hydrogeology of the surficial aquifer system and the major permeable zones and confining units of the intermediate aquifer system in southwest Florida was studied. The study area is a 1,400-square-mile area that includes Sarasota County and parts of Manatee, De Soto, Charlotte, and Lee Counties. Lithologic, geophysical, hydraulic property, and water-level data were used to correlate the hydrogeology and map the extent of the aquifer systems. Water chemistry was evaluated in southwest Sarasota County to determine salinity of the surficial and intermediate aquifer systems. The surficial aquifer is an unconfined aquifer system that overlies the intermediate aquifer system and ranges from a few feet to over 60 feet in thickness in the study area. Hydraulic properties of the surficial aquifer system determined from aquifer and laboratory tests, and model simulations vary considerably across the study area. The intermediate aquifer system, a confined aquifer system that lies between the surficial and the Upper Floridan aquifers, is composed of alternating confining units and permeable zones. The intermediate aquifer system has three major permeable zones that exhibit a wide range of hydraulic properties. Horizontal flow in the intermediate aquifer system is northeast to southwest. Most of the study area is in a discharge area of the intermediate aquifer system. Water ranges naturally from fresh in the surficial aquifer system and upper permeable zones of the intermediate aquifer system to moderately saline in the lower permeable zone. Water-quality data collected in coastal southwest Sarasota County indicate that ground-water withdrawals from major pumping centers have resulted in lateral seawater intrusion and upconing into the surficial and intermediate aquifer systems.

Origin and Evolution of Li-rich Brines at Clayton Valley, Nevada, USA

NASA Astrophysics Data System (ADS)

Munk, L. A.; Bradley, D. C.; Hynek, S. A.; Chamberlain, C. P.

2011-12-01

Lithium is the key component in Li-ion batteries which are the primary energy storage for electric/hybrid cars and most electronics. Lithium is also an element of major importance on a global scale because of interest in increasing reliance on alternative energy sources. Lithium brines and pegmatites are the primary and secondary sources, respectively of all produced Li. The only Li-brine in the USA that is currently in production exists in Clayton Valley, NV. The groundwater brines at Clayton Valley are located in a closed basin with an average evaporation rate of 142 cm/yr. The brines are pumped from six aquifer units that are composed of varying amounts of volcanic ash, gravel, salt, tufa, and fine-grained sediments. Samples collected include spring water, fresh groundwater, groundwater brine, and meteoric water (snow). The brines are classified as Na-Cl waters and the springs and fresh groundwater have a mixed composition and are more dilute than the brines. The Li content of the waters in Clayton Valley ranges from less than 1 μg/L (snow) up to 406.9 mg/L in the lower ash aquifer system (one of six aquifers in the basin). The cold springs surrounding Clayton Valley have Li concentrations of about 1 mg/L. A hot spring located just east of Clayton Valley contains 1.6 mg/L Li. The Li concentration of the fresh groundwater is less than 1 mg/L. Hot groundwater collected in the basin contain 30-40 mg/L Li. Water collected from a geothermal drilling north of Silver Peak, NV, had water with 4.9 mg/L Li at a depth of >1000m. The δD and δ18O isotopic signatures of fresh groundwater and brine form an evaporation path that extends from the global meteoric water line toward the brine from the salt aquifer system (the most isotopically enriched brine with ave. δD = -3.5, ave. δ18O = -67.0). This suggests that mixing of inflow water with the salt aquifer brine could have played an important role in the evolution of the brines. Along with mixing, evaporation appears to

Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

USGS Publications Warehouse

Scanlon, Bridget R.; Faunt, Claudia; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

2012-01-01

Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ∼50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ∼7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.

Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

USGS Publications Warehouse

Scanlon, Bridget R.; Faunt, Claudia C.; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

2012-01-01

Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ~50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ~7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.

Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

PubMed Central

Scanlon, Bridget R.; Faunt, Claudia C.; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

2012-01-01

Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ∼50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ∼7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley. PMID:22645352

Water availability and land subsidence in the Central Valley, California, USA

USGS Publications Warehouse

Faunt, Claudia; Sneed, Michelle; Traum, Jonathan A.; Brandt, Justin

2016-01-01

The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007–2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

Groundwater quality in the Indian Wells Valley, 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. Indian Wells Valley is one of the study areas being evaluated. The Indian Wells study area is approximately 600 square miles (1,554 square kilometers) and includes the Indian Wells Valley groundwater basin (California Department of Water Resources, 2003). Indian Wells Valley has an arid climate and is part of the Mojave Desert. Average annual rainfall is about 6 inches (15 centimeters). The study area has internal drainage, with runoff from the surrounding mountains draining towards dry lake beds in the lower parts of the valley. Land use in the study area is approximately 97.0 percent (%) natural, 0.4% agricultural, and 2.6% urban. The primary natural land cover is shrubland. The largest urban area is the city of Ridgecrest (2010 population of 28,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from the Sierra Nevada to the west and from the other surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada and to the west and from the other surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada and direct infiltration from irrigation and septic systems. The primary sources of discharge are pumping wells and evapotranspiration near the dry lakebeds. The primary aquifers in the Indian Wells 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

Groundwater quality in the shallow aquifers of the Tulare, Kaweah, and Tule Groundwater Basins and adjacent highlands areas, Southern San Joaquin Valley, California

USGS Publications Warehouse

Fram, Miranda S.

2017-01-18

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 shallow aquifers of the Tulare, Kaweah, and Tule groundwater basins and adjacent highlands areas of the southern San Joaquin Valley constitute one of the study units being evaluated.

The Spokane aquifer, Washington: its geologic origin and water-bearing and water-quality characteristics

USGS Publications Warehouse

Molenaar, Dee

1988-01-01

The Spokane aquifer is an unconfined aquifer consisting of coarse sand, gravel, cobbles, and boulders deposited during several catastrophic glacial outburst floods--known as the Spokane Floods---of Pleistocene time. The aquifer is one of the most productive in the United States, and, as the only significant source of good-quality water supply in the Spokane Valley, it has been designated as a 'Sole Source Aquifer' by the U.S. Environmental Protection Agency. The Spokane aquifer underlies an area of about 135 square miles in the Spokane Valley and varies in saturated thickness from a few feet to 500 feet or more. The aquifer is recharged by ground-water underflow from the Rathdrum Prairie aquifer in Idaho on the east, by ground-water underflow and surface-water seepage from small drainage areas along the Spokane Valley margins, and by percolation from various sources--from rainfall and snowmelt, from some reaches of the Spokane and Little Spokane Rivers, and from septic-tank drain fields, cesspools, and irrigation water. Discharge from the aquifer occurs by ground-water underflow from the lowermost end of the valley, by leakage to the Spokane and the Little Spokane Rivers, by evapotranspiration, and by ground-water withdrawal by pumping. The transmissivity of the aquifer ranges from less than 0.05 to 70 feet squared per second, and its specific yield ranges from less than 5 to 20 percent of the aquifer volume. Seasonal water-level fluctuations in wells tapping the aquifer are generally less than 10 feet. The annual pumpage from the aquifer in 1977 was about 164,000 acre-feet, of which about 70 percent was for municipal supplies, which included some industrial and commercial supplies. Land use over the aquifer includes predominantly agricultural activities in the eastern one-third of the valley and urban and residential developments in most of the remaining area. Potential sources of contamination of the aquifer include percolation from cesspools, septic-tank drain

Territorial approach to increased energy consumption of water extraction from depletion of a highlands Mexican aquifer.

PubMed

Fonseca, Carlos Roberto; Esteller, María Vicenta; Díaz-Delgado, Carlos

2013-10-15

This work proposes a method to estimate increased energy consumption of pumping caused by a drawdown of groundwater level and the equivalent energy consumption of the motor-pump system in an aquifer under intensive exploitation. This method has been applied to the Valley of Toluca aquifer, located in the Mexican highlands, whose intensive exploitation is reflected in a decline in the groundwater level of between 0.10 and 1.6 m/year. Results provide a summary of energy consumption and a map of energy consumption isopleths showing the areas that are most susceptible to increases in energy consumption due to pumping. The proposed method can be used to estimate the effect of the intensive exploitation of the Valley of Toluca aquifer on the energy consumption of groundwater extraction. Finding reveals that, for the year 2006, groundwater extraction in the urban zone required 2.39 times more energy than the conditions observed 38 years earlier. In monetary terms, this reflects an increase of USD$ 3 million annually, according to 2005 energy production costs. Copyright © 2013 Elsevier Ltd. All rights reserved.

Drought, Land-Use Change, and Water Availability in California's Central Valley

NASA Astrophysics Data System (ADS)

Faunt, C. C.; Sneed, M.; Traum, J.

2015-12-01

The Central Valley is a broad alluvial-filled structural trough that covers about 52,000 square kilometers and is one of the most productive agricultural regions in the world. Because the valley is semi-arid and the availability of surface water varies substantially from year to year, season to season, and from north to south, agriculture developed a reliance on groundwater for irrigation. During recent drought periods (2007-09 and 2012-present), groundwater pumping has increased due to a combination of factors including drought and land-use changes. In response, groundwater levels have declined to levels approaching or below historical low levels. In the San Joaquin Valley, the southern two thirds of the Central Valley, the extensive groundwater pumpage has caused aquifer system compaction, resulting in land subsidence and permanent loss of groundwater storage capacity. The magnitude and rate of subsidence varies based on geologic materials, consolidation history, and historical water levels. Spatially-variable subsidence has changed the land-surface slope, causing operational, maintenance, and construction-design problems for surface-water infrastructure. It is important for water agencies to plan for the effects of continued water-level declines, storage losses, and/or land subsidence. To combat these effects, excess surface water, when available, is artificially recharged. As surface-water availability, land use, and artificial recharge continue to vary, long-term groundwater-level and land-subsidence monitoring and modelling are critical to understanding the dynamics of the aquifer system. Modeling tools, such as the Central Valley Hydrologic Model, can be used in the analysis and evaluation of management strategies to mitigate adverse impacts due to subsidence, while also optimizing water availability. These analyses will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

Ground-water quality in east-central Idaho valleys

USGS Publications Warehouse

Parliman, D.J.

1982-01-01

From May through November 1978, water quality, geologic, and hydrologic data were collected for 108 wells in the Lemhi, Pahsimeroi, Salman River (Stanley to Salmon), Big Lost River, and Little Lost River valleys in east-central Idaho. Data were assembled to define, on a reconnaissance level, water-quality conditions in major aquifers and to develop an understanding of factors that affected conditions in 1978 and could affect future ground-water quality. Water-quality characteristics determined include specific conductance, pH, water temperature, major dissolved cations, major dissolved anions, and coliform bacteria. Concentrations of hardness, nitrite plus nitrate, coliform bacteria, dissolved solids, sulfate, chloride, fluoride , iron, calcium, magnesium, sodium, potassium or bicarbonate exceed public drinking water regulation limits or were anomalously high in some water samples. Highly mineralized ground water probably is due to the natural composition of the aquifers and not to surface contamination. Concentrations of coliform bacteria that exceed public drinking water limits and anomalously high dissolved nitrite-plus-nitrite concentrations are from 15- to 20-year old irrigation wells in heavily irrigated or more densely populated areas of the valleys. Ground-water quality and quantity in most of the study area are sufficient to meet current (1978) population and economic demands. Ground water in all valleys is characterized by significant concentrations of calcium, magnesium, and bicarbonate plus carbonate ions. Variations in the general trend of ground-water composition (especially in the Lemhi Valley) probably are most directly related to variability in aquifer lithology and proximity of sampling site to source of recharge. (USGS)

Plan of study for the northern Midwest regional aquifer-system analysis

USGS Publications Warehouse

Steinhilber, W.L.; Young, H.L.

1979-01-01

Sedimentary rocks of Cambrian and Ordovician age form a major aquifer system in most of Wisconsin and Iowa, northern Illinois, northwestern Indiana, southeastern Minnesota, and northern Missouri. Many metropolitan areas depend on the aquifer for all or part of their water supplies. Declines in potentiometric head have been large in the most heavily pumped areas, most notably Chicago, Milwaukee-Waukesha, Minneapolis-St. Paul, and Des Moines. A thorough understanding of the aquifer system is needed for sound management decisions. Thus, a 4-year study of the aquifer, beginning in October 1978, is included in the U.S. Geological Survey 's program of Regional Aquifer-System Analysis. The study will evaluate the aquifer 's water-supply potential, describe its water quality, and, through computer models of the ground-water flow system, provide the means to evaluate regional aquifer response to different patterns of ground-water development. This report describes the objectives, work plan, and organization of this study. (Woodard-USGS)

Considerations for monitoring water quality of the Schenectady aquifer, Schenectady County, New York

USGS Publications Warehouse

Allen, R.V.; Waller, Roger Milton

1981-01-01

Six public water-supply systems in Schenectady County, N.Y., obtain water from sand and gravel units that form a more or less continuous aquifer system contiguous to the Mohawk River. The aquifer is under water-table conditions and in hydraulic contact with the river, so that pumping wells induces recharge from the river. Direct recharge to the aquifer from precipitation and runoff occurs throughout the valley floor. Chemical analyses since 1972 have indicated no water-quality deterioration from toxic substances, including pesticides. Geohydrologic conditions at each of the six well fields were evaluated to determine the feasibility of a monitoring system to provide warning of contamination before it reaches a pumping center. Potential contamination sources in the area are landfills, gravel pits, industrial sites, and transportation corridors. Only two of the well fields have wells that could be used for monitoring; at most sites, two or more wells would need to be installed to provide minimal means of detecting contaminants migrating toward a pumping center. (USGS)

Nitrate in aquifers beneath agricultural systems

USGS Publications Warehouse

Burkart, M.R.; Stoner, J.D.; ,

2007-01-01

Research from several regions of the world provides spatially anecdotal evidence to hypothesize which hydrologic and agricultural factors contribute to groundwater vulnerability to nitrate contamination. Analysis of nationally consistent measurements from the U.S. Geological Survey's NAWQA program confirms these hypotheses for a substantial range of agricultural systems. Shallow unconfined aquifers are most susceptible to nitrate contamination associated with agricultural systems. Alluvial and other unconsolidated aquifers are the most vulnerable and also shallow carbonate aquifers that provide a substantial but smaller contamination risk. Where any of these aquifers are overlain by permeable soils the risk of contamination is larger. Irrigated systems can compound this vulnerability by increasing leaching facilitated by additional recharge and additional nutrient applications. The system of corn, soybean, and hogs produced significantly larger concentrations of groundwater nitrate than all other agricultural systems because this system imports the largest amount of N-fertilizer per unit production area. Mean nitrate under dairy, poultry, horticulture, and cattle and grains systems were similar. If trends in the relation between increased fertilizer use and groundwater nitrate in the United States are repeated in other regions of the world, Asia may experience increasing problems because of recent increases in fertilizer use. Groundwater monitoring in Western and Eastern Europe as well as Russia over the next decade may provide data to determine if the trend in increased nitrate contamination can be reversed. If the concentrated livestock trend in the United States is global, it may be accompanied by increasing nitrogen contamination in groundwater. Concentrated livestock provide both point sources in the confinement area and intense non-point sources as fields close to facilities are used for manure disposal. Regions where irrigated cropland is expanding, such as

Regional Aquifer-System Analysis Program of the US Geological Survey; bibliography, 1978-86

USGS Publications Warehouse

Weeks, J.B.; Sun, Ren Jen

1987-01-01

The Regional Aquifer-System Analysis Program of the U.S. Geological Survey was initiated in 1978. The purpose of this program is to define the regional geohydrology and establish a framework of background information on geology, hydrology, and geochemistry of the Nation 's important aquifer systems. This information is needed to develop an understanding of the Nation 's major groundwater flow systems and to support better groundwater resources management. As of 1986, investigations of 28 regional aquifer systems were planned, investigations of 9 regional aquifer systems were completed, and 11 regional aquifer systems were being studied. This report is a bibliography of reports completed under the Regional Aquifer-System Analysis Program from 1978 through 1986. The reports resulting from each regional aquifer-system study are listed after an introduction to the study. During 1978-86, 488 reports were completed under the Regional Aquifer-System Analysis Program, and 168 reports which were partially funded by the Regional Aquifer-System Analysis Program were completed under the National Research Program. (Author 's abstract)

Simulation of dispersion in layered coastal aquifer systems

USGS Publications Warehouse

Reilly, T.E.

1990-01-01

A density-dependent solute-transport formulation is used to examine ground-water flow in layered coastal aquifers. The numerical experiments indicate that although the transition zone may be thought of as an impermeable 'sharp' interface with freshwater flow parallel to the transition zone in homogeneous aquifers, this is not the case for layered systems. Freshwater can discharge through the transition zone in the confining units. Further, for the best simulation of layered coastal aquifer systems, either a flow-direction-dependent dispersion formulation is required, or the dispersivities must change spatially to reflect the tight thin confining unit. ?? 1990.

The removal of microorganisms and organic micropollutants from wastewater during infiltration to aquifers after irrigation of farmland in the Tula Valley, Mexico.

PubMed

Chávez, Alma; Maya, Catalina; Gibson, Richard; Jiménez, Blanca

2011-05-01

The Tula Valley receives untreated wastewater from Mexico City for agricultural irrigation, half of which infiltrates to aquifers from where drinking water is extracted. Samples of wastewater and infiltrated water from three areas of the valley were analyzed for microorganisms, organic micropollutants, and some basic parameters. Concentrations of microorganisms in the infiltrated water were generally very low but the incidence of fecal coliforms (present in 68% of samples), somatic bacteriophages (36%), Giardia spp. (14%), and helminth eggs (8%) suggested a health risk. Organic micropollutants, often present at high concentrations in the wastewater, were generally absent from the infiltrated water except carbamazepine which was in 55% of samples (up to 193 ng/L). There was no correlation between carbamazepine concentrations and the presence of microorganisms but highest concentrations of carbamazepine and boron coincided. A treatment such as nanofiltration would be necessary for the infiltrated water to be a safe potable supply. Copyright © 2011 Elsevier Ltd. All rights reserved.

Ground-water quality of the surficial aquifer system and the upper Floridan Aquifer, Ocala National Forest and Lake County, Florida, 1990-99

USGS Publications Warehouse

Adamski, J.C.; Knowles, Leel

2001-01-01

Data from 217 ground-water samples were statistically analyzed to assess the water quality of the surficial aquifer system and Upper Floridan aquifer in the Ocala National Forest and Lake County, Florida. Samples were collected from 49 wells tapping the surficial aquifer system, 141 wells tapping the Upper Floridan aquifer, and from 27 springs that discharge water from the Upper Floridan aquifer. A total of 136 samples was collected by the U.S. Geological Survey from 1995 through 1999. These data were supplemented with 81 samples collected by the St. Johns River Water Management District and Lake County Water Resources Management from 1990 through 1998. In general, the surficial aquifer system has low concentrations of total dissolved solids (median was 41 milligrams per liter) and major ions. Water quality of the surficial aquifer system, however, is not homogeneous throughout the study area. Concentrations of total dissolved solids, many major ions, and nutrients are greater in samples from Lake County outside the Ocala National Forest than in samples from within the Forest. These results indicate that the surficial aquifer system in Lake County outside the Ocala National Forest probably is being affected by agricultural and (or) urban land-use practices. High concentrations of dissolved oxygen (less than 0.1 to 8.2 milligrams per liter) in the surficial aquifer system underlying the Ocala National Forest indicate that the aquifer is readily recharged by precipitation and is susceptible to surface contamination. Concentrations of total dissolved solids were significantly greater in the Upper Floridan aquifer (median was 182 milligrams per liter) than in the surficial aquifer system. In general, water quality of the Upper Floridan aquifer was homogeneous, primarily being a calcium or calciummagnesium- bicarbonate water type. Near the St. Johns River, the water type of the Upper Floridan aquifer is sodium-chloride, corresponding to an increase in total dissolved

Age and quality of ground water and sources of nitrogen in the aquifers in Pumpkin Creek Valley, western Nebraska, 2000

USGS Publications Warehouse

Steele, G.V.; Cannia, J.C.; Sibray, S.S.; McGuire, V.L.

2005-01-01

Ground water is the source of drinking water for the residents of Pumpkin Creek Valley, western Nebraska. In this largely agricultural area, shallow aquifers potentially are susceptible to nitrate contamination. During the last 10 years, ground-water levels in the North Platte Natural Resources District have declined and contamination has become a major problem for the district. In 2000, the U.S. Geological Survey and the North Platte Natural Resources District began a cooperative study to determine the age and quality of the ground water and the sources of nitrogen in the aquifers in Pumpkin Creek Valley. Water samples were collected from 8 surface-water sites, 2 springs, and 88 ground-water sites during May, July, and August 2000. These samples were analyzed for physical properties, nutrients or nitrate, and hydrogen and oxygen isotopes. In addition, a subset of samples was analyzed for any combination of chlorofluorocarbons, tritium, tritium/helium, sulfur-hexafluoride, carbon-14, and nitrogen-15. The apparent age of ground water in the alluvial aquifer typically varied from about 1980 to modern, whereas ground water in the fractured Brule Formation had a median value in the 1970s. The Brule Formation typically contained ground water that ranged from the 1940s to the 1990s, but low-yield wells had apparent ages of 5,000 to 10,000 years before present. Data for oxygen-18 and deuterium indicated that lake-water samples showed the greatest effects from evaporation. Ground-water data showed no substantial evaporative effects and some ground water became isotopically heavier as the water moved downgradient. In addition, the physical and chemical ground-water data indicate that Pumpkin Creek is a gaining stream because little, if any, of its water is lost to the ground-water system. The water-quality type changed from a sodium calcium bicarbonate type near Pumpkin Creek's headwaters to a calcium sodium bicarbonate type near its mouth. Nitrate concentrations were

Nitrate in aquifers beneath agricultural systems

USGS Publications Warehouse

Burkart, M.R.; Stoner, J.D.

2002-01-01

Research from several regions of the world provides spatially anecdotal evidence to hypothesize which hydrologic and agricultural factors contribute to groundwater vulnerability to nitrate contamination. Analysis of nationally consistent measurements from the U.S. Geological Survey's NAWOA program confirms these hypotheses for a substantial range of agricultural systems. Shallow unconfined aquifers are most susceptible to nitrate contamination associated with agricultural systems. Alluvial and other unconsolidated aquifers are the most vulnerable and shallow carbonate aquifers provide a substantial but smaller contamination risk. Where any of these aquifers are overlain by permeable soils the risk of contamination is larger. Irrigated systems can compound this vulnerability by increasing leaching facilitated by additional recharge and additional nutrient applications. The agricultural system of corn, soybeans, and hogs produced significantly larger concentrations of groundwater nitrate than all other agricultural systems, although mean nitrate concentrations in counties with dairy, poultry, cattle and grains, and horticulture systems were similar. If trends in the relation between increased fertilizer use and groundwater nitrate in the United States are repeated in other regions of the world, Asia may experience increasing problems because of recent increases in fertilizer use. Groundwater monitoring in Western and Eastern Europe as well as Russia over the next decade may provide data to determine if the trend in increased nitrate contamination can be reversed. If the concentrated livestock trend in the United States is global, it may be accompanied by increasing nitrogen contamination in groundwater. Concentrated livestock provide both point sources in the confinement area and intense non-point sources as fields close to facilities are used for manure disposal. Regions where irrigated cropland is expanding, such as in Asia, may experience the greatest impact of

Potential development and recharge of ground water in Mill Creek Valley, Butler and Hamilton Counties, Ohio, based on analog model analysis

USGS Publications Warehouse

Fidler, Richard E.

1971-01-01

Mill Creek valley is part of the greater Cincinnati industrial area in southwestern Ohio. In 1964, nearly 30 percent of the water supply in the study area of about 27 square miles was obtained from wells in the glacial-outwash aquifer underlying the valley. Ground-water demand has increased steadily since the late 1800's, and excessive pumpage during the years of World War II caused water levels to decline to critical levels. Natural recharge to the aquifer, from precipitation, is about 8.5 mgd (million gallons per day). In 1964, the total water use was about 30 mgd, of which 8.1 mgd was obtained from wells in Mill Creek valley, and the remainder was imported from outside the basin. With rapid industrial expansion and population growth, demand for ground water is continuing to increase. By the year 2000 ground-water pumpage is expected to exceed 25 mgd. At a public hearing before the Ohio Water Commission in 1961, artificial recharge of the aquifer through injection wells was proposed as a possible solution to the Mill Creek valley water-supply problem. The present study attempts to determine the feasibility of injection-well recharge systems in the Mill Creek valley. Although basically simple, the hydrologic system in Mill Creek valley is complex in detail and is difficult to evaluate using conventional quantitative methods. Because of this complexity, an electric analog model was used to test specific development plans. Three hypothetical pumping plans were developed by projecting past pumpage data to the years 1980 and 2000. Various combinations of injection wells were tested on the model under different hypothetical conditions of pumpage. Based on analog model analysis, from three to eight inject-ion wells, with an approximate input of 2 mgd each, would reverse the trend in declining groundwater levels and provide adequate water to meet anticipated future demands.

Bedrock mapping of buried valley networks using seismic reflection and airborne electromagnetic data

NASA Astrophysics Data System (ADS)

Oldenborger, G. A.; Logan, C. E.; Hinton, M. J.; Pugin, A. J.-M.; Sapia, V.; Sharpe, D. R.; Russell, H. A. J.

2016-05-01

In glaciated terrain, buried valleys often host aquifers that are significant groundwater resources. However, given the range of scales, spatial complexity and depth of burial, buried valleys often remain undetected or insufficiently mapped. Accurate and thorough mapping of bedrock topography is a crucial step in detecting and delineating buried valleys and understanding formative valley processes. We develop a bedrock mapping procedure supported by the combination of seismic reflection data and helicopter time-domain electromagnetic data with water well records for the Spiritwood buried valley aquifer system in Manitoba, Canada. The limited spatial density of water well bedrock observations precludes complete depiction of the buried valley bedrock topography and renders the water well records alone inadequate for accurate hydrogeological model building. Instead, we leverage the complementary strengths of seismic reflection and airborne electromagnetic data for accurate local detection of the sediment-bedrock interface and for spatially extensive coverage, respectively. Seismic reflection data are used to define buried valley morphology in cross-section beneath survey lines distributed over a regional area. A 3D model of electrical conductivity is derived from inversion of the airborne electromagnetic data and used to extrapolate buried valley morphology over the entire survey area. A spatially variable assignment of the electrical conductivity at the bedrock surface is applied to different features of the buried valley morphology identified in the seismic cross-sections. Electrical conductivity is then used to guide construction of buried valley shapes between seismic sections. The 3D locus of points defining each morphological valley feature is constructed using a path optimization routine that utilizes deviation from the assigned electrical conductivities as the cost function. Our resulting map represents a bedrock surface of unprecedented detail with more

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

Ground-water quality and geochemistry in Dayton, Stagecoach, and Churchill Valleys, western Nevada

USGS Publications Warehouse

Thomas, James M.; Lawrence, Stephen J.

1994-01-01

The U.S. Geological Survey investigated the quality of ground water in the Dayton, Stagecoach, and Churchill Valleys as part of the Carson River Basin National Water-Quality Assessment (NAWQA) pilot study. Four aquifer systems have been de- lineated in the study area. Principal aquifers are unconsolidated deposits at altitudes of less than 4,900 feet above sea level and more than 50 feet below land surface. Shallow aquifers are at altitudes of less than 4,900 feet and less than 50 feet below land surface. Upland aquifers are above 4,900 feet and provide recharge to the principal aquifers. Thermal aquifers, defined as those having a water temperature greater than 30 degrees Celsius, are also present. Ground water used in Dayton, Stagecoach, and Churchill Valleys is pumped from principal aquifers in unconsolidated basin-fill deposits. Ground water in these aquifers originates as precipitation in the adjacent mountains and is recharged by the Carson River and by underflow from adjacent upstream valleys. Ground-water flow is generally parallel to the direction of surface-water flow in the Carson River. Ground water is discharged by pumping, evapo- transpiration, and underflow into the Carson River. The results of geochemical modeling indicate that as ground water moves from upland aquifers in mountainous recharge areas to principal aquifers in basin-fill deposits, the following processes probably occur: (1) plagioclase feldspar, sodium chloride, gypsum (or pyrite), potassium feldspar, and biotite dissolve; (2) calcite precipitates; (3) kaolinite forms; (4) small amounts of calcium and magnesium in the water exchange for potassium on aquifer minerals; and (5) carbon dioxide is gained or lost. The geochemical models are consistent with (1) phases identified in basin- fill sediments; (2) chemical activity of major cations and silica; (3) saturation indices of calcite and amorphous silica; (4) phase relations for aluminosilicate minerals indicated by activity diagrams; and

Stochastic simulation of soil particle-size curves in heterogeneous aquifer systems through a Bayes space approach

NASA Astrophysics Data System (ADS)

Menafoglio, A.; Guadagnini, A.; Secchi, P.

2016-08-01

We address the problem of stochastic simulation of soil particle-size curves (PSCs) in heterogeneous aquifer systems. Unlike traditional approaches that focus solely on a few selected features of PSCs (e.g., selected quantiles), our approach considers the entire particle-size curves and can optionally include conditioning on available data. We rely on our prior work to model PSCs as cumulative distribution functions and interpret their density functions as functional compositions. We thus approximate the latter through an expansion over an appropriate basis of functions. This enables us to (a) effectively deal with the data dimensionality and constraints and (b) to develop a simulation method for PSCs based upon a suitable and well defined projection procedure. The new theoretical framework allows representing and reproducing the complete information content embedded in PSC data. As a first field application, we demonstrate the quality of unconditional and conditional simulations obtained with our methodology by considering a set of particle-size curves collected within a shallow alluvial aquifer in the Neckar river valley, Germany.

Steady groundwater flow through many cylindrical inhomogeneities in a multi-aquifer system

NASA Astrophysics Data System (ADS)

Bakker, Mark

2003-06-01

A new approach is presented for the simulation of steady-state groundwater flow in multi-aquifer systems that contain many cylindrical inhomogeneities. The hydraulic conductivity of all aquifers and the resistance of all leaky layers may be different inside each cylinder. The approach is based on separation of variables and combines principles of the theory for multi-aquifer flow with principles of the analytic element method. The solution fulfills the governing differential equations exactly everywhere; the head, flow, and leakage between aquifers may be computed analytically at any point in the aquifer system. The boundary conditions along the circumference of the cylinder are satisfied approximately, but may be met at any precision. Two examples are discussed to illustrate the accuracy of the approach and the significance of inhomogeneities in multi-aquifer systems. The first application simulates the vertical and horizontal, advective spreading of a conservative tracer in a homogeneous aquifer that is overlain by an aquifer with cylindrical inclusions of higher permeability. The second application concerns the three-dimensional shape of the capture zone of a well that is screened in the bottom aquifer of a three-aquifer system. The capture zone extends to the top aquifer due to cylindrical holes of lower resistance in the separating clay layers.

Ambient Noise Monitoring of the Santa Clara and San Gabriel Aquifers

NASA Astrophysics Data System (ADS)

Clements, T.; Denolle, M.

2016-12-01

Ambient noise cross-correlation is an effective technique to monitor temporal changes in the properties of the solid earth. The technique has had particular success in monitoring over time scales differing by orders of magnitude, with precursors to volcanic eruptions occurring over days [Brenguier, et al., 2008, Nature] and post-seismic relaxation in fault zones occurring over years [Brenguier, et al., 2008, Science]. Recently, the technique was extended to investigate the interaction of the solid earth and climate via ice sheet melt [Mordret et al.,2016]. In that vein, we use ambient noise cross-correlation to monitor basin-scale aquifers. The technique is amenable to studying aquifers, as it has potential for high spatial resolution, on the scale of a basin and can monitor aquifer recharge/draw down on timescales from large, single-day storms to multi-year droughts. Geodetics studies have previously recorded both long term, in the Santa Clara Valley [Chaussard et al., 2014, Schmidt and Burgmann, 2003], and short-term, in the San Gabriel Valley [King et al. 2007], ground uplift due to aquifer recharge. We use the Moving Window Cross Spectral technique [Clarke et al., 2011] to monitor wave-speed perturbation in the Santa Clara valley over the period 2001-2016 and San Gabriel Basin over the period 1995-2016. Preliminary results, using stations from the Berkeley Digital Seismograph Network and the USGS Northern California Regional Network, show that seismic velocities vary 0.1% intra-annually. We explore the temporal variations, along with correlations in observed ground water data, precipitation and geodesic measurements to deduce the poroelastic properties of the aquifers during the last two El-Nino and recent droughts in California.

Kirschenmann Road multi-well monitoring site, Cuyama Valley, Santa Barbara County, California

USGS Publications Warehouse

Everett, R.R.; Hanson, R.T.; Sweetkind, D.S.

2011-01-01

The U.S. Geological Survey (USGS), in cooperation with the Water Agency Division of the Santa Barbara County Department of Public Works, is evaluating the geohydrology and water availability of the Cuyama Valley, California (fig. 1). As part of this evaluation, the USGS installed the Cuyama Valley Kirschenmann Road multiple-well monitoring site (CVKR) in the South-Main subregion of the Cuyama Valley (fig. 1). The CVKR well site is designed to allow for the collection of depth-specific water-level and water-quality data. Data collected at this site provides information about the geology, hydrology, geophysics, and geochemistry of the local aquifer system, thus, enhancing the understanding of the geohydrologic framework of the Cuyama Valley. This report presents the construction information and initial geohydrologic data collected from the CVKR monitoring site, along with a brief comparison to selected supply and irrigation wells from the major subregions of the Cuyama Valley (fig. 1).

Groundwater quality in the Owens Valley, 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. Owens Valley is one of the study areas being evaluated. The Owens study area is approximately 1,030 square miles (2,668 square kilometers) and includes the Owens Valley groundwater basin (California Department of Water Resources, 2003). Owens Valley has a semiarid to arid climate, with average annual rainfall of about 6 inches (15 centimeters). The study area has internal drainage, with runoff primarily from the Sierra Nevada draining east to the Owens River, which flows south to Owens Lake dry lakebed at the southern end of the valley. Beginning in the early 1900s, the City of Los Angeles began diverting the flow of the Owens River to the Los Angeles Aqueduct, resulting in the evaporation of Owens Lake and the formation of the current Owens Lake dry lakebed. Land use in the study area is approximately 94 percent (%) natural, 5% agricultural, and 1% urban. The primary natural land cover is shrubland. The largest urban area is the city of Bishop (2010 population of 4,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to the Owens Lake dry lakebed. The primary aquifers in Owens Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database

Lithology and base of the surficial aquifer system, Palm Beach County, Florida

USGS Publications Warehouse

Miller, Wesley L.

1987-01-01

The surficial aquifer system is a major source of freshwater in Palm Beach County. In 1982, public supply withdrawals from the aquifer system totaled 33,543 million gallons, 77.5% of total public supply withdrawals. To evaluate the aquifer system and its geologic framework, a cooperative study with Palm Beach County was begun in 1982 by the U.S. Geological Survey. The surficial aquifer system in Palm Beach County is composed primarily of sand, sandstone, shell, silt, calcareous clay (marl), and limestone deposited during the Pleistocene and Pliocene epochs. In the western two-thirds of Palm Beach County, sediments in the aquifer system are poorly consolidated sand, shell, and sandy limestone. Owing to interspersed calcareous clays and silt and very poorly sorted materials, permeabilities in this zone of the aquifer system are relatively low. Two other zones of the aquifer system are found in the eastern one-third of the county where the sediments are appreciably more permeable than in the west due to better sorting and less silt and clay content. The location of more detailed lithologic logs for wells in these sections, along with data from nearby wells, allowed enhanced interpretation and depiction of the lithology which had previously been generalized. The most permeable zone of the aquifer system in this area is characterized by highly developed secondary porosity where infiltrating rainwater and solution by groundwater have removed calcitic-cementing materials from the sediments to produce interconnected cavities. Increased permeability in the aquifer system is generally coincident with the eastern boundary of the overlying organic soils and Lake Flirt Marl. Lithologic logs of wells in Palm Beach County indicate that sediments forming the aquifer system were deposited directly on the erosional surface of the Hawthorn Formation in some areas. In other locations in the county, lithologic logs indicate that the base of the aquifer system was formed by fluvial

Aquifers of Arkansas: protection, management, and hydrologic and geochemical characteristics of groundwater resources in Arkansas

USGS Publications Warehouse

Kresse, Timothy M.; Hays, Phillip D.; Merriman, Katherine R.; Gillip, Jonathan A.; Fugitt, D. Todd; Spellman, Jane L.; Nottmeier, Anna M.; Westerman, Drew A.; Blackstock, Joshua M.; Battreal, James L.

2014-01-01

The Interior Highlands of western Arkansas has less reported groundwater use than other areas of the State, reflecting a combination of factors. These factors include prevalent and increasing use of surface water, less intensive agricultural uses, lower population and industry densities, lesser potential yield of the resource, and lack of detailed reporting. The overall low yields of aquifers of the Interior Highlands result in domestic supply as the dominant use, with minor industrial, public, and commercial-supply use. Where greater volumes are required for growth of population and industry, surface water is the greatest supplier of water needs in the Interior Highlands. The various aquifers of the Interior Highlands generally occur in shallow, fractured, well-indurated, structurally modified bedrock of this mountainous region of the State, as compared to the relatively flat-lying, unconsolidated sediments of the Coastal Plain. In terms of age from youngest to oldest, the aquifers of the Interior Highlands include: the Arkansas River Valley alluvial aquifer, the Ouachita Mountains aquifer, the Western Interior Plains confining system, the Springfield Plateau aquifer, and the Ozark aquifer. Spatial trends in groundwater geochemistry in the Interior Highlands differ greatly from trends noted for aquifers of the Coastal Plain. In the Coastal Plain, the prevalence of long regional flow paths results in regionally predictable and mappable geochemical changes along the flow paths. In the Interior Highlands, short, topographically controlled flow paths (from hilltops to valleys) within small watersheds represent the predominant groundwater-flow system. As such, dense data coverage from numerous wells would be required to effectively characterize these groundwater basins and define small-scale geochemical changes along any given flow path for aquifers of the Interior Highlands. Changes in geochemistry generally were related to rock type and residence time along

Hydrologeology and water quality of the Floridan aquifer system and effect of Lower Floridan aquifer pumping on the Upper Floridan aquifer, Pooler, Chatham County, Georgia, 2011–2012

USGS Publications Warehouse

Gonthier, Gerard

2012-01-01

Two test wells were completed in Pooler, Georgia, in 2011 to investigate the potential of using the Lower Floridan aquifer as a source of water for municipal use. One well was completed in the Lower Floridan aquifer at a depth of 1,120 feet (ft) below land surface; the other well was completed in the Upper Floridan aquifer at a depth of 486 ft below land surface. At the Pooler test site, the U.S. Geological Survey performed flowmeter surveys, packer-isolated slug tests within the Lower Floridan confining unit, slug tests of the entire Floridan aquifer system, and aquifer tests of the Upper and Lower Floridan aquifers. Drill cuttings, geophysical logs, and borehole flowmeter surveys indicate that the Upper Floridan aquifer extends 333 –515 ft below land surface, the Lower Floridan confining unit extends 515–702 ft below land surface, and the Lower Floridan aquifer extends 702–1,040 ft below land surface. Flowmeter surveys indicate that the Upper Floridan aquifer contains two water-bearing zones at depth intervals of 339 –350 and 375–515 ft; the Lower Floridan confining unit contains one zone at a depth interval of 550–620 ft; and the Lower Floridan aquifer contains five zones at depth intervals of 702–745, 745–925, 925–984, 984–1,015, and 1,015–1,040 ft. Flowmeter testing of the test borehole open to the entire Floridan aquifer system indicated that the Upper Floridan aquifer contributed 92.4 percent of the total flow rate of 708 gallons per minute; the Lower Floridan confining unit contributed 3.0 percent; and the Lower Floridan aquifer contributed 4.6 percent. Horizontal hydraulic conductivity of the Lower Floridan confining unit derived from slug tests within three packer-isolated intervals ranged from 0.5 to 10 feet per day (ft/d). Aquifer-test analyses yielded values of transmissivity for the Upper Floridan aquifer, Lower Floridan confining unit, and the Lower Floridan aquifer of 46,000, 700, and 4,000 feet squared per day (ft2/d

Ground-water quality and geochemistry in Carson and Eagle Valleys, western Nevada and eastern California

USGS Publications Warehouse

Welch, Alan H.

1994-01-01

Aquifers in Carson and Eagle Valleys are an important source of water for human consumption and agriculture. Concentrations of major constituents in water from the principal aquifers on the west sides of Carson and Eagle Valleys appear to be a result of natural geochemical reactions with minerals derived primarily from plutonic rocks. In general, water from principal aquifers is acceptable for drinking when compared with current (1993) Nevada State drinking-water maximum contaminant level standards. Water was collected and analyzed for all inorganic constituents for which primary or secondary drinking-water standards have been established. About 3 percent of these sites had con- stituents that exceeded one or more primary or secondary drinking-water standards have been established. About 3 percent of these sites had con- stituents that exceeded one or more primary standards and water at about 10 percent of the sites had at least one constituent that surpassed a secondary standard. Arsenic exceeded the standard in water at less than 1 percent of the principal aquifer sites; nitrate surpassed its standard in water at 3 percent of 93 sites. Water from wells in the principal aquifer with high concentrations of nitrate was in areas where septic systems are used; these concentrations indicate that contamination may be entering the wells. Concentrations of naturally occurring radionuclides in water from the principal aquifers, exceed the proposed Federal standards for some constituents, but were not found t be above current (1993) State standards. The uranium concen- trations exceeded the proposed 20 micrograms per liter Federal standard at 10 percent of the sites. Of the sites analyzed for all of the inorganic constituents with primary standards plus uranium, 15 percent exceed one or more established standards. If the proposed 20 micrograms per liter standard for uranium is applied to the sampled sites, then 23 percent would exceed the standard for uranium or some other

Geospatial compilation of historical water-level changes in the Chicot and Evangeline aquifers 1977-2013 and Jasper aquifer 2000-13, Gulf Coast aquifer system, Houston-Galveston region, Texas

USGS Publications Warehouse

Johnson, Michaela R.; Linard, Joshua I.

2014-01-01

The U.S. Geological Survey (USGS) in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District has produced an annual series of reports that depict water-level changes in the Chicot, Evangeline, and Jasper aquifers of the Gulf Coast aquifer system in the Houston-Galveston region, Texas, from 1977 to 2013. Changes are determined from water-level measurements between December and March of each year from groundwater wells screened in one of the three aquifers. Existing published maps and unpublished geographic information system (GIS) datasets were compiled into a comprehensive geodatabase of all water-level-change maps produced as part of this multiagency effort. Annual water-level-change maps were georeferenced and digitized where existing GIS data were unavailable (1979–99). Existing GIS data available for 2000–13 were included in the geodatabase. The compilation contains 121 datasets showing water-level changes for each primary aquifer of the Gulf Coast aquifer system: 56 for the Chicot aquifer (1977; 1979–2013 and 1990; 1993–2013), 56 for the Evangeline aquifer (1977; 1979–2013 and 1990; 1993–2013), and 9 for the Jasper aquifer (2000; 2005–13).

Status and understanding of groundwater quality in the Monterey-Salinas Shallow Aquifer Study Unit, 2012–13: California GAMA Priority Basin Project

USGS Publications Warehouse

Burton, Carmen; Wright, Michael

2018-05-30

Groundwater quality in the approximately 7,820-square-kilometer (km2) Monterey-Salinas Shallow Aquifer (MS-SA) study unit was investigated from October 2012 to May 2013 as part of the second phase of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is in the central coast region of California in the counties of Santa Cruz, Monterey, and San Luis Obispo. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in cooperation with the U.S. Geological Survey and the Lawrence Livermore National Laboratory.The MS-SA study was designed to provide a statistically robust assessment of untreated-groundwater quality in the shallow aquifer systems. The assessment was based on water-quality samples collected by the U.S. Geological Survey from 100 groundwater sites and 70 household tap sites, along with ancillary data such as land use and well-construction information. The shallow aquifer systems were defined by the depth interval of wells associated with domestic supply. The MS-SA study unit consisted of four study areas—Santa Cruz (210 km2), Pajaro Valley (360 km2), Salinas Valley (2,000 km2), and Highlands (5,250 km2).This study had two primary components: the status assessment and the understanding assessment. The first primary component of this study—the status assessment—assessed the quality of the groundwater resource indicated by data from samples analyzed for volatile organic compounds (VOCs), pesticides, and naturally present inorganic constituents, such as major ions and trace elements. The status assessment is intended to characterize the quality of groundwater resources in the shallow aquifer system of the MS-SA study unit, not the treated drinking water delivered to consumers by water purveyors. As opposed to the public wells, however, water from private wells, which often tap the shallow aquifer, is usually consumed without any treatment. The second

Occurrence, distribution, and concentration of hydrocarbons in and near the Shell Valley Aquifer, North Dakota

USGS Publications Warehouse

Berkas, Wayne R.

2000-01-01

Water samples from 27 wells completed in and near the Shell Valley aquifer were analyzed for benzene, toluene, ethylbenzene, and xylene (BTEX), polynuclear aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), and pentachlorophenol (PCP) using the enzyme-linked immunoassay method. The analyses indicated the presence of PAH, PCB, and PCP in the study area. However, an individual compound at a high concentration or many compounds at low concentrations could cause the detections. Therefore, selected samples were analyzed using the gas chromatography (GC) method, which can detect individual compounds and determine the concentrations of those compounds. Concentrations for all compounds detected using the GC method were less than the minimum reporting levels (MRLs) for each constituent, indicating numerous compounds at low concentrations probably caused the immunoassay detections. The GC method also can detect compounds other than BTEX, PAH, PCB, and PCP. Concentrations for 81 of the additional compounds were determined and were less than the MRLs.Four compounds that could not be quantified accurately using the requested analytical methods also were detected. Acetone was detected in 4 of the 27 wells, 2-butanone was detected in 3 of the 27 wells, prometon was detected in 1 of the 27 wells, and tetrahydrofuran was detected in 9 of the 27 wells. Acetone, 2-butanone, and tetrahydrofuran probably leached from the polyvinyl chloride (PVC) pipe and joint glue and probably are not contaminants from the aquifer. Prometon is a herbicide that controls most annual and many perennial broadleaf weeds and primarily is used on roads and railroad tracks. The one occurrence of prometon could be caused by overspraying for weeds.

Groundwater availability of the Denver Basin aquifer system, Colorado

USGS Publications Warehouse

Paschke, Suzanne

2011-01-01

The Denver Basin aquifer system is a critical water resource for growing municipal, industrial, and domestic uses along the semiarid Front Range urban corridor of Colorado. The confined bedrock aquifer system is located along the eastern edge of the Rocky Mountain Front Range where the mountains meet the Great Plains physiographic province. Continued population growth and the resulting need for additional water supplies in the Denver Basin and throughout the western United States emphasize the need to continually monitor and reassess the availability of groundwater resources. In 2004, the U.S. Geological Survey initiated large-scale regional studies to provide updated groundwater-availability assessments of important principal aquifers across the United States, including the Denver Basin. This study of the Denver Basin aquifer system evaluates the hydrologic effects of continued pumping and documents an updated groundwater flow model useful for appraisal of hydrologic conditions.

MISSISSIPPI EMBAYMENT AQUIFER SYSTEM IN MISSISSIPPI: GEOHYDROLOGIC DATA COMPILATION FOR FLOW MODEL SIMULATION.

USGS Publications Warehouse

Arthur, J.K.; Taylor, R.E.

1986-01-01

As part of the Gulf Coast Regional Aquifer System Analysis (GC RASA) study, data from 184 geophysical well logs were used to define the geohydrologic framework of the Mississippi embayment aquifer system in Mississippi for flow model simulation. Five major aquifers of Eocene and Paleocene age were defined within this aquifer system in Mississippi. A computer data storage system was established to assimilate the information obtained from the geophysical logs. Computer programs were developed to manipulate the data to construct geologic sections and structure maps. Data from the storage system will be input to a five-layer, three-dimensional, finite-difference digital computer model that is used to simulate the flow dynamics in the five major aquifers of the Mississippi embayment aquifer system.

Geology and ground water of the Tualatin Valley, Oregon

USGS Publications Warehouse

Hart, D.H.; Newcomb, R.C.

1965-01-01

The Tualatin Valley proper consists of broad valley plains, ranging in altitude from 100 to 300 feet, and the lower mountain slopes of the drainage basin of the Tualatin River, a tributary of the Willamette River in northwestern Oregon. The valley is almost entirely farmed. Its population is increasing rapidly, partly because of the expansion of metropolitan Portland. Structurally, the bedrock of the basin is a saucer-shaped syncline almost bisected lengthwise by a ridge. The bedrock basin has been partly filled by alluvium, which underlies the valley plains. Ground water occurs in the Columbia River basalt, a lava unit that forms the top several hundred feet of the bedrock, and also in the zones of fine sand in the upper part of the alluvial fill. It occurs under unconfined, confined, and perched conditions. Graphs of the observed water levels in wells show that the ground water is replenished each year by precipitation. The graphs show also that the amount and time of recharge vary in different aquifers and for different modes of ground-water occurrence. The shallower alluvial aquifers are refilled each year to a level where further infiltration recharge is retarded and water drains away as surface runoff. No occurrences of undue depletion of the ground water by pumping are known. The facts indicate that there is a great quantity of additional water available for future development. The ground water is developed for use by some spring works and by thousands of wells, most of which are of small yield. Improvements are now being made in the design of the wells in basalt and in the use of sand or gravel envelopes for wells penetrating the fine-sand aquifers. The ground water in the basalt and the valley fill is in general of good quality, only slightly or moderately hard and of low salinity. Saline and mineralized water is present in the rocks of Tertiary age below the Columbia River basalt. Under certain structural and stratigraphic conditions this water of poor

Determination of land subsidence related to ground-water-level declines using Global Positioning System and leveling surveys in Antelope Valley, Los Angeles and Kern counties, California, 1992

USGS Publications Warehouse

Ikehara, M.E.; Phillips, S.P.

1994-01-01

A large-scale, land-subsidence monitoring network for Antelope Valley, California, was established, and positions and elevations for 85 stations were measured using Global Positioning System geodetic surveying in spring 1992. The 95-percent confidence (2@) level of accuracy for the elevations calculated for a multiple-constraint adjustment generally ranged from +0.010 meter (0.032 foot) to +0.024 meter (0.078 foot). The magnitudes and rates of land subsidence as of 1992 were calculated for several periods for 218 bench marks throughout Antelope Valley. The maximum measured magnitude of land subsidence that occurred between 1926 and 1992 was 6.0 feet (1.83 meters) at BM 474 near Avenue I and Sierra Highway. Measured or estimated subsidence of 2-7 feet (.61-2.l3 meters) had occurred in a 210- square-mile (542-square-kilometer) area of Antelope Valley, generally bounded by Avenue K, Avenue A, 90th Street West, and 120th Street East, during the same period. Land subsidence in Antelope Valley is caused by aquifer-system compaction, which is related to ground-water-level declines and the presence of fine-grained, compressible sediments. Comparison of potentiomethric-surface, water-level decline, and subsidence-rate maps for several periods indicated a general correlation between water-level declines and the distribution and rate of subsidence in the Lancaster ground-water subbasin. A conservative estimate of the amount of the reduction in storage capacity of the aquifer system in the Lancaster subbasin is about 50,000 acre-feet in the area that has been affected by more than one foot (.30 meters) of subsidence as of 1992. Information on the history of ground-water levels and the distribution and thickness of fine-grained compressible sediments can be used to mitigate continued land subsidence. Future monitoring of ground-water levels and land-surface elevations in subsidence-sensitive regions of Antelope Valley may be an effective means to manage land subsidence.

Monitoring technologies for the evaluation of a Soil-Aquifer-Treatment system in coastal aquifer environments.

NASA Astrophysics Data System (ADS)

Kallioras, Andreas; Tsertou, Athanasia; Foglia, Laura; Bumberger, Jan; Vienken, Thomas; Dietrich, Peter; Schüth, Christoph

2014-05-01

Artificial recharge of groundwater has an important role to play in water reuse. Treated sewage effluent can be infiltrated into the ground for recharge of aquifers. As the effluent water moves through the soil and the aquifer, it undergoes significant quality improvements through physical, chemical, and biological processes in the underground environment. Collectively, these processes and the water quality improvement obtained are called soil-aquifer-treatment (SAT) or geopurification. Recharge systems for SAT can be designed as infiltration-recovery systems, where all effluent water is recovered as such from the aquifer, or after blending with native groundwater. SAT typically removes essentially all suspended solids, biochemical oxygen demand (BOD), and pathogens (viruses, bacteria, protozoa, and helminthic eggs). Concentrations of synthetic organic carbon, phosphorous, and heavy metals are greatly reduced. The pilot site of LTCP will involve the employment of infiltration basins, which will be using waters of impaired quality as a recharge source, and hence acting as a Soil-Aquifer-Treatment, SAT, system. T he LTCP site will be employed as a pilot SAT system complemented by new technological developments, which will be providing continuous monitoring of the quantitative and qualitative characteristics of infiltrating groundwater through all hydrologic zones (i.e. surface, unsaturated and saturated zone). This will be achieved through the development and installation of an integrated system of prototype sensors, installed on-site, and offering a continuous evaluation of the performance of the SAT system. An integrated approach of the performance evaluation of any operating SAT system should aim at parallel monitoring of all hydrologic zones, proving the sustainability of all involved water quality treatment processes within unsaturated and saturated zone. Hence a prototype system of Time Domain Reflectometry (TDR) sensors will be developed, in order to achieve

Detection and Measurement of Land Subsidence Using Global Positioning System Surveying and Interferometric Synthetic Aperture Radar, Coachella Valley, California, 1996-2005

USGS Publications Warehouse

Sneed, Michelle; Brandt, Justin T.

2007-01-01

Land subsidence associated with ground-water-level declines has been investigated by the U.S. Geological Survey in the Coachella Valley, California, since 1996. Ground water has been a major source of agricultural, municipal, and domestic supply in the valley since the early 1920s. Pumping of ground water resulted in water-level declines as large as 15 meters (50 feet) through the late 1940s. In 1949, the importation of Colorado River water to the southern Coachella Valley began, resulting in a reduction in ground-water pumping and a recovery of water levels during the 1950s through the 1970s. Since the late 1970s, demand for water in the valley has exceeded deliveries of imported surface water, resulting in increased pumping and associated ground-water-level declines and, consequently, an increase in the potential for land subsidence caused by aquifer-system compaction. Global Positioning System (GPS) surveying and interferometric synthetic aperture radar (InSAR) methods were used to determine the location, extent, and magnitude of the vertical land-surface changes in the southern Coachella Valley. GPS measurements made at 13 geodetic monuments in 1996 and in 2005 in the southern Coachella Valley indicate that the elevation of the land surface had a net decline of 333 to 22 millimeters ?58 millimeters (1.1 to 0.07 foot ?0.19 foot) during the 9-year period. Changes at 10 of the 13 monuments exceeded the maximum uncertainty of ?58 millimeters (?0.19 foot) at the 95-percent confidence level, indicating that subsidence occurred at these monuments between June 1996 and August 2005. GPS measurements made at 20 geodetic monuments in 2000 and in 2005 indicate that the elevation of the land surface changed -312 to +25 millimeters ?42 millimeters (-1.0 to +0.08 foot ?0.14 foot) during the 5-year period. Changes at 14 of the 20 monuments exceeded the maximum uncertainty of ?42 millimeters (?0.14 foot) at the 95-percent confidence level, indicating that subsidence occurred at

Hydrogeology of, and Simulation of Ground-Water Flow In, the Pohatcong Valley, Warren County, New Jersey

USGS Publications Warehouse

Carleton, Glen B.; Gordon, Alison D.

2007-01-01

), chlorofluorocarbon (CFC), and tritium-helium age-dating techniques range from 0 to 27 years, with a median age of 6 years. Land-surface and ground-water water budgets were calculated, yielding an estimated rate of direct recharge tothe surficial aquifer of about 23 in/yr, and an estimated net recharge to the ground-water system within the area underlain by carbonate rock (11.4 mi2) of 29 in/yr (10 in/yr over the entire 33.3 mi2 basin). A finite-difference, numerical model was developed to simulate ground-water flow in the Pohatcong Valley. The four-layer model encompasses the entire carbonate-rock part of the valley. The carbonate-rock aquifer was modeled as horizontally anisotropic, with the direction of maximum transmissivity aligned with the longitudinal axis of the valley. All lateral boundaries are no-flow boundaries. Recharge was applied uniformly to the topmost active layer with additional recharge added near the lateral boundaries to represent infiltration of runoff from adjacent crystalline-rock areas. The model was calibrated to June 2001 water levels in wells completed in the carbonate-rock aquifer, August 2000 stream base-flow measurements, and the approximate ground-water age. The ground-water-flow model was constructed in part to test possible site contamination remediation alternatives. Four previously determined ground-water remediation alternatives (GW1, GW2, GW3, and GW4) were simulated. For GW1, the no-action alternative, simulated pathlines originating in the tetrachloroethene (PCE) and trichloroethene (TCE) source areas within the Ground-Water Contamination Site end at Pohatcong Creek near the confluence with Shabbecong Creek, although some particles went deeper in the aquifer system and ultimately discharge to Pohatcong Creek about 10 miles downvalley in Pohatcong Township. Remediation alternatives GW2, GW3, and GW4 include ground-water withdrawal, treatment, and reinjection. The design for GW2 includes wells in the TCE and PCE source areas that wit

Review: Groundwater flow and transport modeling of karst aquifers, with particular reference to the North Coast Limestone aquifer system of Puerto Rico

PubMed Central

Ghasemizadeh, Reza; Hellweger, Ferdinand; Butscher, Christoph; Padilla, Ingrid; Vesper, Dorothy; Field, Malcolm; Alshawabkeh, Akram

2013-01-01

Karst systems have a high degree of heterogeneity and anisotropy, which makes them behave very differently from other aquifers. Slow seepage through the rock matrix and fast flow through conduits and fractures result in a high variation in spring response to precipitation events. Contaminant storage occurs in the rock matrix and epikarst, but contaminant transport occurs mostly along preferential pathways that are typically inaccessible locations, which makes modeling of karst systems challenging. Computer models for understanding and predicting hydraulics and contaminant transport in aquifers make assumptions about the distribution and hydraulic properties of geologic features that may not always apply to karst aquifers. This paper reviews the basic concepts, mathematical descriptions, and modeling approaches for karst systems. The North Coast Limestone aquifer system of Puerto Rico (USA) is introduced as a case study to illustrate and discuss the application of groundwater models in karst aquifer systems to evaluate aquifer contamination. PMID:23645996

Ground-water resources investigation in the Amran Valley, Yeman Arab Republic

USGS Publications Warehouse

Tibbitts, G. Chase; Aubel, James

1980-01-01

A program of hydrologic studies and exploratory drilling was conducted intermittently between 1974 and 1978 to evaluate the water-bearing properties of the unconsolidated alluvial sediments and associated rocks in the semi-arid Amran Valley basin, an 800-square-kilometer area in north-central Yemen Arab Republic. Inventory data from 395 wells were compiled, observation well and rain-gage networks were established and 16 standard complete chemical analyses were made for samples from selected wells. The water resources of the area were overexploited. The chemical quality of the water is generally good. Four aquifer tests were run to determine transmissivity and storage characteristics. The pumping tests show that groundwater occurs under semi-confined leaky-aquifer conditions in the valley fill. Wells drilled in the alluvial fill of the south-central part of the valley have the highest yields. Wells penetrating the limestone and volcanic rocks generally have little or no yield except in fracture zones. Basalt flows occur interbedded with the wadi alluvium at several depths. Cropping out rocks in the Amran Valley range in age from late Jurassic to Holocene. (USGS)

An evaluation of the bedrock aquifer system in northeastern Wisconsin

USGS Publications Warehouse

Emmons, P.J.

1987-01-01

Model simulations indicate that, by 1914, ground-water withdrawals from the aquifer system had already impacted the study area. Pumping in the Green Bay metropolitan area had lowered the potentiometric heads in aquifer 1 by 69 feet and in aquifer 2 by 55 feet. Model simulations indicate that, by 1981, ground-water withdrawals have caused a cone of depression centered in the city of De Pere area. The influence of the cone affects almost the entire study area and has significantly altered the horizontal and vertical flow regimes in the aquifer system. In 1981, computed drawdowns below the prepumping potentiometric surface of aquifer 1 range from 0 feet on the western side of the study area to 330 feet in the center of the cone of depression. In aquifer 2, the computed drawdown ranges from 0 feet on the western side of the study area to 253 feet in the center of the cone.

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

Evaluation of volatile organic compounds in two Mojave Desert basins-Mojave River and Antelope Valley-in San Bernardino, Los Angeles, and Kern Counties, California, June-October 2002

USGS Publications Warehouse

Densmore, Jill N.; Belitz, Kenneth; Wright, Michael T.; Dawson, Barbara J.; Johnson, Tyler D.

2005-01-01

The California Aquifer Susceptibility Assessment of the Ground-Water Ambient Monitoring and Assessment Program was developed to assess water quality and susceptibility of ground-water resources to contamination from surficial sources. This study focuses on the Mojave River and the Antelope Valley ground-water basins in southern California. Volatile organic compound (VOC) data were evaluated in conjunction with tritium data to determine a potential correlation with aquifer type, depth to top of perforations, and land use to VOC distribution and occurrence in the Mojave River and the Antelope Valley Basins. Detection frequencies for VOCs were compiled and compared to assess the distribution in each area. Explanatory variables were evaluated by comparing detection frequencies for VOCs and tritium and the number of compounds detected. Thirty-three wells were sampled in the Mojave River Basin (9 in the floodplain aquifer, 15 in the regional aquifer, and 9 in the sewered subset of the regional aquifer). Thirty-two wells were sampled in the Antelope Valley Basin. Quality-control samples also were collected to identify, quantify, and document bias and variability in the data. Results show that VOCs generally were detected slightly more often in the Antelope Valley Basin samples than in the Mojave River Basin samples. VOCs were detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Tritium was detected more frequently in the Mojave River Basin samples than in the Antelope Valley Basin samples, and it was detected more frequently in the floodplain aquifer than in the regional aquifer and the sewered subset. Most of the samples collected in both basins for this study contained old water (water recharged prior to 1952). In general, in these desert basins, tritium need not be present for VOCs to be present. When VOCs were detected, young water (water recharge after 1952) was slightly more likely to be contaminated than old water

Hydrogeology, ground-water use, and ground-water levels in the Mill Creek Valley near Evendale, Ohio

USGS Publications Warehouse

Schalk, Charles; Schumann, Thomas

2002-01-01

Withdrawals of ground water in the central Mill Creek Valley near Evendale, Ohio, caused water-level declines of more than 100 feet by the 1950s. Since the 1950s, management practices have changed to reduce the withdrawals of ground water, and recovery of water levels in long-term monitoring wells in the valley has been documented. Changing conditions such as these prompted a survey of water use, streamflow conditions, and water levels in several aquifers in the central Mill Creek Valley, Hamilton and Butler Counties, Ohio. Geohydrologic information, water use, and water levels were compiled from historical records and collected during the regional survey. Data collected during the survey are presented in terms of updated geohydrologic information, water use in the study area, water levels in the aquifers, and interactions between ground water and surface water. Some of the data are concentrated at former Air Force Plant 36 (AFP36), which is collocated with the General Electric Aircraft Engines (GEAE) plant, and these data are used to describe geohydrology and water levels on a more local scale at and near the plant. A comparison of past and current ground-water use and levels indicates that the demand for ground water is decreasing and water levels are rising. Before 1955, most of the major industrial ground-water users had their own wells, ground water was mined from a confined surficial (lower) aquifer, and water levels were more than 100 feet below their predevelopment level. Since 1955, however, these users have been purchasing their water from the city of Cincinnati or a private water purveyor. The cities of Reading and Lockland, both producers of municipal ground-water supplies in the area, shut down their well fields within their city limits. Because the demand for ground-water supplies in the valley has lessened greatly since the 1950s, withdrawals have decreased, and, consequently, water levels in the lower aquifer are 65 to 105 feet higher than they were

Hydrogeology of Valley-Fill Aquifers and Adjacent Areas in Eastern Chemung County, New York

USGS Publications Warehouse

Heisig, Paul M.

2015-10-19

Water-resource potential is greatest within saturated sand and gravel in the Chemung River valley (nearly 1 mile wide), especially where induced infiltration of additional water from the Chemung River is possible. The second most favorable area is the Newtown Creek valley at the confluence of Newtown Creek with North Branch Newtown Creek east of Horseheads, N.Y. Extensive sand and gravel deposits within the Breesport, N.Y., area are largely unsaturated but may have greater saturation along the east side of Jackson Creek immediately north of Breesport. Till deposits confine sand and gravel along Newtown Creek at Erin, N.Y., and along much of the upper reach of North Branch Newtown Creek; this confining unit may limit recharge and potential well yield. The north-south oriented valleys of Baldwin and Wynkoop Creeks end at notched divides that imply input of glacial meltwater and limited sediment from outside of the present watersheds. These two valleys are relatively narrow but contain variably sorted sand and gravel, which, in places, may be capable of supplying modest-size community water systems.

Effects of Proposed Additional Ground-Water Withdrawals from the Mississippi River Valley Alluvial Aquifer on Water Levels in Lonoke County, Arkansas

USGS Publications Warehouse

Czarnecki, John B.

2006-01-01

The Grand Prairie Water Users Association, located in Lonoke County, Arkansas, plans to increase ground-water withdrawals from the Mississippi River Valley alluvial aquifer from their current (2005) rate of about 400 gallons per minute to 1,400 gallons per minute (2,016,000 gallons per day). The effect of pumping from a proposed well was simulated using a digital model of ground-water flow. The proposed additional withdrawals were added to an existing pumping cell specified in the model, with increased pumping beginning in 2005, and specified to pump at a total combined rate of 2,016,000 gallons per day for a period of 46 years. In addition, pumping from wells owned by Cabot Water Works, located about 2 miles from the proposed pumping, was added to the model beginning in 2001 and continuing through to the end of 2049. Simulated pumping causes a cone of depression to occur in the alluvial aquifer with a maximum decline in water level of about 8.5 feet in 46 years in the model cell of the proposed well compared to 1998 withdrawals. However, three new dry model cells occur south of the withdrawal well after 46 years. This total water-level decline takes into account the cumulative effect of all wells pumping in the vicinity, although the specified pumping rate from all other model cells in 2005 is less than for actual conditions in 2005. After 46 years with the additional pumping, the water-level altitude in the pumped model cell was about 177.4 feet, which is 41.7 feet higher than 135.7 feet, the altitude corresponding to half of the original saturated thickness of the alluvial aquifer (a metric used to determine if the aquifer should be designated as a Critical Ground-Water Area (Arkansas Natural Resources Commission, 2006)).

Induced infiltration from the Rockaway River and water chemistry in a stratified-drift aquifer at Dover, New Jersey, with a section on modeling ground-water flow in the Rockaway River Valley

USGS Publications Warehouse

Dysart, Joel E.; Rheaume, Stephen J.; Kontis, Angelo L.

1999-01-01

The vertical hydraulic conductivity per unit thickness (streambed leakance) of unconsolidated sediment immediately beneath the channel of the Rockaway River near a municipal well field at Dover, N.J., is between 0.2 and 0.6 feet per day per foot and is probably near the low end of this range. This estimate is based on evaluation of three lines of evidence: (1) Streamflow measurements, which indicated that induced infiltration of river water near the well field averaged 0.67 cubic feet per second; (2) measurements of the rate of downward propagation of diurnal fluctuations in dissolved oxygen and water temperature at three piezometers, which indicated vertical Darcian flow velocities of 0.6 and 1.5 feet per day, respectively; and (3) chemical mixing models based on stable isotopes of oxygen and hydrogen, which indicated that 30 percent of the water reaching a well near the center of the well field was derived from the river. The estimated streambed-leakance values are compatible with other aquifer properties and with hydraulic stresses observed over a 2-year period, as demonstrated by a set of six alternative groundwater flow models of the Rockaway River valley. Simulated water levels rose 0.5 to 1.7 feet near the well field when simulated streambed leakance was changed from 0.2 to 0.6 feet per day per foot, or when a former reach of the Rockaway River valley that is now blocked by glacial drift was simulated as containing a continuous sand aquifer (rather than impermeable till). Model recalibration to observed water levels could accommodate either of these changes, however, by plausible adjustments in hydraulic conductivity of 35 percent or less.The ground-water flow models incorporate a new procedure for simulating areal recharge, in which water available for recharge in any time interval is accepted as recharge only where the water level in the uppermost model layer is below land surface. Water rejected as recharge on upland hillsides is allowed to recharge

Geology of the surficial aquifer system, Dade County, Florida; lithologic logs

USGS Publications Warehouse

Causaras, C.R.

1986-01-01

The geologic framework of the surficial aquifer system in Dade County, Florida, was investigated as part of a longterm study by the USGS in cooperation with the South Florida Water Management District, to describe the geology, hydrologic characteristics, and groundwater quality of the surficial aquifer system. Thirty-three test wells were drilled completely through the surficial aquifer system and into the underlying, relatively impermeable units of the Tamiami and Hawthorn Formations. Detailed lithologic logs were made from microscopic examination of rock cuttings and cores obtained from these wells. The logs were used to prepare geologic sections that show the lithologic variations, thickness of the lithologic units, and different geologic formations that comprise the aquifers system. (Author 's abstract)

Hydrology of the Texas Gulf Coast aquifer systems

USGS Publications Warehouse

Ryder, Paul D.; Ardis, Ann F.

1991-01-01

A complex, multilayered ground-water flow system exists in the Coastal Plain sediments of Texas. The Tertiary and Quaternary clastic deposits have an areal extent of 114,000 square miles onshore and in the Gulf of Mexico. Two distinct aquifer systems are recognized within the sediments, which range in thickness from a few feet to more than 12,000 feet The older system--the Texas coastal uplands aquifer system-consists of four aquifers and two confining units in the Claiborne and Wilcox Groups. It is underlain by the practically impermeable Midway confining unit or by the top of the geopressured zone. It is overlain by the nearly impermeable Vicksburg-Jackson confining unit, which separates it from the younger coastal lowlands aquifer system. The coastal lowlands aquifer system consists of five permeable zones and two confining units that range in age from Oligocene to Holocene. The hydrogeologic units of both systems are exposed in bands that parallel the coastline. The units dip and thicken toward the Gulf. Quality of water in the aquifer systems is highly variable, with dissolved solids ranging from less than 500 to 150,000 milligrams per liter.Substantial withdrawal from the aquifer systems began in the early 1900's and increased nearly continuously into the 1970's. The increase in withdrawal was relatively rapid from about 1940 to 1970. Adverse hydrologic effects, such as saltwater encroachment in coastal areas, land-surface subsidence in the Houston-Galveston area, and long-term dewatering in the Whiter Garden area, were among some of the factors that caused pumping increases to slow or to cease in the 1970's and 1980's.Ground-water withdrawals in the study area in 1980 were about 1.7 billion gallons per day. Nearly all of the withdrawal was from four units: Permeable zones A, B, and C of Miocene age and younger, and the lower Claiborae-upper Wilcox aquifer. Ground-water levels have declined hundreds of feet in the intensively pumped areas of Houston

The hydrothermal system of Long Valley Caldera, California

USGS Publications Warehouse

Sorey, M.L.; Lewis, Robert Edward; Olmsted, F.H.

1978-01-01

Long Valley caldera, an elliptical depression covering 450 km 2 on the eastern front of the Sierra Nevada in east-central California, contains a hot-water convection system with numerous hot springs and measured and estimated aquifer temperatures at depths of 180?C to 280?C. In this study we have synthesized the results of previous geologic, geophysical, geochemical, and hydrologic investigations of the Long Valley area to develop a generalized conceptual and mathematical model which describes the gross features of heat and fluid flow in the hydrothermal system. Cenozoic volcanism in the Long Valley region began about 3.2 m.y. (million years) ago and has continued intermittently until the present time. The major event that resulted in the formation of the Long Valley caldera took place about 0.7 m.y. ago with the eruption of 600 km 3 or more of Bishop Tuff of Pleistocene age, a rhyolitic ash flow, and subsequent collapse of the roof of the magma chamber along one or more steeply inclined ring fractures. Subsequent intracaldera volcanism and uplift of the west-central part of the caldera floor formed a subcircular resurgent dome about 10 km in diameter surrounded by a moat containing rhyolitic, rhyodacitic, and basaltic rocks ranging in age from 0.5 to 0.05 m.y. On the basis of gravity and seismic studies, we estimate an aver- age thickness of fill of 2.4 km above the precaldera granitic and metamorphic basement rocks. A continuous layer of densely welded Bishop Tuff overlies the basement rocks, with an average thickness of 1.4 km; the fill above the welded Bishop Tuff consists of intercalated volcanic flows and tuffs and fluvial and lacustrine deposits. Assuming the average grain density of the fill is between 2.45 and 2.65 g/cm 3 , we calculate the average bulk porosity of the total fill as from 0.11 to 0.21. Comparison of published values of porosity of the welded Bishop Tuff exposed southeast of the caldera with calculated values indicates average bulk porosity

Grizzly Valley fault system, Sierra Valley, CA

USGS Publications Warehouse

Gold, Ryan; Stephenson, William; Odum, Jack; Briggs, Rich; Crone, Anthony; Angster, Steve

2012-01-01

The Grizzly Valley fault system (GVFS) strikes northwestward across Sierra Valley, California and is part of a network of active, dextral strike-slip faults in the northern Walker Lane (Figure 1). To investigate Quaternary motion across the GVFS, we analyzed high-resolution (0.25 m) airborne LiDAR data (Figure 2) in combination with six, high-resolution, P-wave, seismic-reflection profiles [Gold and others, 2012]. The 0.5- to 2.0-km-long seismic-reflection profiles were sited orthogonal to suspected tectonic lineaments identified from previous mapping and our analysis of airborne LiDAR data. To image the upper 400–700 m of subsurface stratigraphy of Sierra Valley (Figure 3), we used a 230-kg accelerated weight drop source. Geophone spacing ranged from 2 to 5 m and shots were co-located with the geophones. The profiles reveal a highly reflective, deformed basal marker that we interpret to be the top of Tertiary volcanic rocks, overlain by a 120- to 300-m-thick suite of subhorizontal reflectors we interpret as Plio-Pleistocene lacustrine deposits. Three profiles image the principle active trace of the GVFS, which is a steeply dipping fault zone that offsets the volcanic rocks and the basin fill (Figures 4 & 5).

Erosional valleys in the Thaumasia region of Mars: Hydrothermal and seismic origins

USGS Publications Warehouse

Tanaka, K.L.; Dohm, J.M.; Lias, J.H.; Hare, T.M.

1998-01-01

Analysis of erosional valleys, geologic materials and features, and topography through time in the Thaumasia region of Mars using co-registered digital spatial data sets reveals significant associations that relate to valley origin. Valleys tend to originate (1) on Noachian to Early Hesperian (stages 1 and 2) large volcanoes, (2) within 50-100 km of stages 1 and 2 rift systems, and (3) within 100 km of Noachian (stage 1) impact craters >50 km in diameter. These geologic preferences explain observations of higher valley-source densities (VSDs) in areas of higher elevations and regional slopes (>1??) because the volcanoes, rifts, and craters form high, steep topography or occur in terrain of high relief. Other stage 1 and stage 2 high, steep terrains, however, do not show high VSDs. The tendency for valleys to concentrate near geologic features and the overall low drainage densities in Thaumasia compared to terrestrial surfaces rule out widespread precipitation as a major factor in valley formation (as is proposed in wann, wet climate scenarios) except perhaps during the Early Noachian, for which much of the geologic record has been obliterated. Instead, volcanoes and rifts may indicate the presence of shallow crustal intrusions that could lead to local hydrothermal circulation, melting of ground ice and snow, and groundwater sapping. However, impact-crater melt would provide a heat source at the surface that might drive away water, forming valleys in the process. Post-stage 1 craters mostly have low nearby VSDs, which, for valleys incised in older rocks, suggests burial by e??jecta and, for . younger valleys, may indicate desiccation of near-surface water and deepening of the cryosphere. Later Hesperian and Amazonian (stages 3 and 4) valleys originate within 100-200 km of three young, large impact craters and near rifts systems at Warrego Valle??s and the southern part of Coprates rise. These valleys likely developed when the cryosphere was a couple kilometers or

Geohydrologic Framework of Recharge and Seawater Intrusion in the Pajaro Valley, Santa Cruz and Monterey Counties, California

USGS Publications Warehouse

Hanson, Randall T.

2003-01-01

Pajaro Valley is a coastal watershed of 160 square miles located along Monterey Bay north of Elkhorn Slough and south of the city of Santa Cruz. The valley has been predominantly developed for agriculture since the late 1800s. In 1984 the Pajaro Valley Water Management Agency (PVWMA) was formed and was delegated with the responsibility of the management of the water resources within the Pajaro Valley by the State of California. About 84 percent of the water is used for agriculture and 16 percent is used for industrial and municipal water supply; almost all of the demand is supplied by ground water. Ground-water pumpage varies with seasonal and climatic periods. The alluvial aquifers are composed of Quaternary- and Tertiary-aged sediments that are layered marine and terrestrial coarse-grained deposits separated by extensive fine-grained deposits that potentially restrict vertical movement of ground water and seawater intrusion in the coastal subareas. The coarse-grained deposits, which persist over large areas, control pumpage and related seawater intrusion. The Aromas Sand crops out throughout the north and central parts of the PVWMA area and offshore on the continental shelf and in Monterey submarine canyon. Because many of the wells in the coastal and inland subregions are screened at depths of 200 to 400 feet below land surface, a direct avenue is provided for seawater intrusion through the coarse-grained deposits of the shallower alluvium and Aromas Sand. Geophysical logs from monitoring wells indicate discrete zones of saline water that are related to pumpage and seawater intrusion in the aquifers of the shallower alluvium and upper Aromas Sand in the upper-aquifer system and to deeper saline waters in the lower Aromas Sand within the lower-aquifer system. The precipitation data indicate that there were at least nine dry and nine wet periods that range from 2 to 19 years during the period of record, 1880?1997. The ground-water pumpage, runoff, streamflow and

Use of a three-dimensional model for the analysis of the ground-water flow system in Parker Valley, Arizona and California

USGS Publications Warehouse

Tucci, Patrick

1982-01-01

A three-dimensional, finite-difference model was used to simulate ground-water flow conditions in Parker Valley. The study evaluated present knowledge and concepts of the ground-water system and the ability of the model to represent the system. Modeling assumptions and generalized physical parameters that were used may have transfer value in the construction and calibration of models of other basins along the lower Colorado River. The aquifer was simulated in two layers to represent the three-dimensional system. Ground-water conditions were simulated for 1940-41, the mid-1960's, and 1980. Overall model results generally compared favorably with available field information. The model results showed that for 1940-41 the Colorado River was a losing stream through out Parker Valley. Infiltration of surface water from the river was the major source of recharge. The dominant mechanism of discharge was evapotranspiration by phreatophytes. Agricultural development between 1941 and the mid-1960 's resulted in significant changes to the ground-water system. Model results for conditions in the mid-1960 's showed that the Colorado River had become a gaining stream in the northern part of the valley as a result of higher water levels. The rise in water levels was caused by infiltration of applied irrigation water. Diminished water-level gradients from the river in the rest of the valley reduced the amount of infiltration of surface water from the river. Models results for conditions in 1980 showed that ground-water level rises of several feet caused further reduction in the amount of surface-water infiltration from the river. (USGS)

Large sedimentary aquifer systems functioning. Constraints by classical isotopic and chemical tools, and REE in the Eocene sand aquifer, SW France

NASA Astrophysics Data System (ADS)

Petelet-Giraud, E.; Negrel, P. J.; Millot, R.; Guerrot, C.; Brenot, A.; Malcuit, E.

2010-12-01

Large sedimentary aquifer systems often constitute strategic water resources for drinking water supply, agriculture irrigation and industry, but can also represent an energetic resource for geothermal power. Large water abstractions can induce complete modification of the natural functioning of such aquifer systems, e.g. with seepage between aquifer layers that can lead to water quality degradation. These large aquifer systems thus require rational water management at the sedimentary basin scale in order to preserve both water quantity and quality. In addition to hydrogeological modelling mainly dealing with water quantity, chemical and isotopic methods were applied to evidence the spatial variability of water characteristics and to turn this into better understanding of hydrosystems functioning. The large Eocene Sand aquifer system of the Adour-Garonne sedimentary basin was studied through various hydrological, chemical and isotopic tools. This system extends over 116,000 km2 (one-fifth of the French territory, located in the South west part). The aquifer being artesian in the west of the district and confined with piezometric levels around 250-m depth in the east. The ‘Eocene Sands’, composed of sandy Tertiary sediments alternating with carbonate deposits, is a multi-layer system with high permeability and a thickness of several tens of metres to a hundred metres..The Eocene Sand aquifer system comprises at least five aquifers: Paleocene, Eocene infra-molassic sands (IMS), early Eocene, middle Eocene, and late Eocene. According to δ18O and δ2H values and estimated 14C ages, both present-day recharge (mainly located in the north of the area) and old recharge (16-35 ky) can be evidenced. High spatial variability was evidenced within a same aquifer layer, with temporal variability over one hydrological cycle limited to a few points located in the recharge areas. These results and especially the very old waters recharged under colder climate combined with the

Geology of the surficial aquifer system, Broward County, Florida; lithologic logs

USGS Publications Warehouse

Causaras, C.R.

1985-01-01

The geologic framework of the surficial aquifer system, of which the Biscayne aquifer is the major component in Broward County, Florida, is presented in eight geologic cross sections. The cross sections are based on detailed lithologic logs of 27 test wells that were drilled, in the summer of 1981, through the sediments overlying the relatively impermeable units of the Hawthorn Formation, of Miocene age. The cross sections show the aquifer system as a wedge-shaped sequence of Cenozoic sediments. The aquifer thickness gradually decreases from more than 400 feet along the coast to about 160 feet in the west and southwest parts of Broward County. The sediments that comprise the aquifer system range in age from Pliocene to Pleistocene and are assigned to the following stratigraphic units from bottom to top: Tamiami Formation, Caloosahatchee Marl, Fort Thompson Formation, Key Largo Limestone, Anastasia Formation, Miami Oolite, and Pamlico Sand. (USGS)

Geohydrology of, and nitrogen and chloride in, the glacial aquifer, Milford-Matamoras area, Pike County, Pennsylvania

USGS Publications Warehouse

Senior, L.A.

1994-01-01

The glacial aquifer that underlies the Routes 209 and 6 corridor between Milford and Matamoras, Pa., is one of the most productive in Pike County. The aquifer is comprised of unconsolidated glacial outwash and kame-terrace deposits that lie within a glacially carved valley now occupied by the Delaware River. Most businesses and residences along this narrow, 7-mile-long corridor rely on individual wells for water supply and septic systems for waste-water disposal. A study of nutrients and chloride in ground water in the glacial aquifer was conducted to determine the effect of these constituents contributed from septic systems and road runoff on ground-water quality. Sources of nutrients and chloride in the recharge zone upgradient of the aquifer include road and parking-lot runoff, septic systems, and precipitation. Nitrate and chloride from these sources can infiltrate and move in the direction of ground-water flow in the saturated zone of the aquifer. A water-table map based on 29 water levels measured in August 1991 indicates that the direction of ground-water flow is from the edges of the valley toward t he Delaware River but is nearly parallel to the Delaware River in the central area of the valley. The average concentrations of nitrogen and chloride in recharge and total annual loads of nitrogen and chloride to ground water were estimated for six areas with different population densities. These estimates assumed a recharge rate to the glacial aquifer of 20 inches per year and a 15 percent loss of chloride and nitrogen in the atmospheric precipitation to surface runoff. The estimated average concentration of nitrogen in recharge ranged from 2.5 to 10 mg/L (milligrams per liter), which corresponds to a total annual load of nitrogen as ammonium released from septic tanks and present in precipitation was oxidized to nitrate as the dominant nitrogen species in ground water. Contributions of nitrogen from septic tanks were greater than contributions from runoff

Distribution of aquifers, liquid-waste impoundments, and municipal water-supply sources, Massachusetts

USGS Publications Warehouse

Delaney, David F.; Maevsky, Anthony

1980-01-01

Impoundments of liquid waste are potential sources of ground-water contamination in Massachusetts. The map report, at a scale of 1 inch equals 4 miles, shows the idstribution of aquifers and the locations of municipal water-supply sources and known liquid-waste impoundments. Ground water, an important source of municipal water supply, is produced from shallow sand and gravel aquifers that are generally unconfined, less than 200 feet thick, and yield less than 2,000 gallons per minute to individual wells. These aquifers commonly occupy lowlands and stream valleys and are most extensive in eastern Massachusetts. Surface impoundments of liquid waste are commonly located over these aquifers. These impoundments may leak and allow waste to infiltrate underlying aquifers and alter their water quality. (USGS)

Hydrogeology of shallow basin-fill deposits in areas of Salt Lake Valley, Salt Lake County, Utah

USGS Publications Warehouse

Thiros, Susan A.

2003-01-01

A study of recently developed residential/commercial areas of Salt Lake Valley, Utah, was done from 1999 to 2001 in areas in which shallow ground water has the potential to move to a deeper aquifer that is used for public supply. Thirty monitoring wells were drilled and sampled in 1999 as part of the study. The ground water was either under unconfined or confined conditions, depending on depth to water and the presence or absence of fine-grained deposits. The wells were completed in the shallowest water-bearing zone capable of supplying water. Monitoring-well depths range from 23 to 154 feet. Lithologic, geophysical, hydraulic-conductivity, transmissivity, water-level, and water-temperature data were obtained for or collected from the wells.Silt and clay layers noted on lithologic logs correlate with increases in electrical conductivity and natural gamma radiation shown on many of the electromagnetic-induction and natural gamma logs. Relatively large increases in electrical conductivity, determined from the electromagnetic-induction logs, with no major changes in natural gamma radiation are likely caused by increased dissolved-solids content in the ground water. Some intervals with high electrical conductivity correspond to areas in which water was present during drilling.Unconfined conditions were present at 7 of 20 monitoring wells on the west side and at 2 of 10 wells on the east side of Salt Lake Valley. Fine-grained deposits confine the ground water. Anthropogenic compounds were detected in water sampled from most of the wells, indicating a connection with the land surface. Data were collected from 20 of the monitoring wells to estimate the hydraulic conductivity and transmissivity of the shallow ground-water system. Hydraulic-conductivity values of the shallow aquifer ranged from 30 to 540 feet per day. Transmissivity values of the shallow aquifer ranged from 3 to 1,070 feet squared per day. There is a close linear relation between transmissivity determined

An Induced Infiltration and Groundwater Transfer Project to Enhance Recharge in the Lower Mississippi River Valley Alluvial Aquifer: Modeling and Analysis

NASA Astrophysics Data System (ADS)

Rigby, J.; Haugh, C. J.; Barlow, J.

2015-12-01

The Lower Mississippi River Basin is one of the major agricultural production regions in the United States producing over two-thirds of the rice, nearly half of sugarcane produced in the U.S., as well as significant amounts of soybeans, corn, and cotton. While the region experiences over 50 inches of precipitation annually, reaching yield potential for crops requires irrigation. Approximately 75% of crop acres in the alluvial valley are irrigated, and the expectation is that all acreage will eventually be irrigated. Currently over 90% of water for crop irrigation is derived from the shallow alluvial aquifer outpacing net recharge by several million acre-feet per year. This has resulted in severe groundwater declines in Arkansas and an increasingly threatening situation in northwestern Mississippi. In Mississippi, direct injection has received increasing attention as a means of artificial recharge, though water quality remains a concern both for the integrity of the aquifer and efficiency of injection. This project considers the use of pumping wells near major rivers known to be in connection with the aquifer to induce additional infiltration of surface water by steepening local gradients. The pumped water would be transferred by pipeline to areas within the regional cone of depression where it is then injected to enhance groundwater recharge. Groundwater flow modeling with zone budget analysis is used to evaluate the potential for net supply gains from induced infiltration at potential sites along major rivers in the region. The groundwater model will further evaluate the impact of the transfer and direct injection on regional water tables.

Groundwater infiltration from alluvial aquifer into karstic aquifer - case study of recharge from river I\\vska to Ižica karstic springs

NASA Astrophysics Data System (ADS)

Meglič, P.; Brenčič, M.

2012-04-01

River I\\vska and Ižica karstic springs are situated in the central part of Slovenia (approximately 20 km south from city Ljubljana) on southern edge of Barje, a tectonic depression field with mostly Holocene and Pleistocene lacustrine and rivers' sediments. Barje is surrounded with hills, which on the southern part consists mostly of Triassic dolomite and Jurassic limestone as well as the basement of Barje in this area. Recharge area of I\\vska River and Ižica karstic springs is covering around 102 km2 of the southern hilly edge of Barje. I\\vska River is a torrent with springs on Blo\\vska planota and flows towards Barje to the north. River formed deep narrow valley that slightly opens at the beginning of I\\vski Vintgar, where flows on a shallow gravel river bed deposited on karstic aquifer. The valley opens on Ljubljansko Barje at village I\\vska vas. Ižica karstic springs are situated on the contact of karst aquifer and Barje intergranular aquifer east of I\\vska valley. After a big flood event on 18th of September 2010 I\\vska River disappeared in the karstic fissures on the river bottom, near bridge in I\\vska village. One day later infiltration point moved 1070 meters upstream. This extreme event caused around 40% higher base flow discharge of Ižica River and total disappearance of I\\vska River for a few days. The analyzed discharge data in the year 2010 of the I\\vska and Ižica River, gave a new understanding of the discharge of I\\vska River and groundwater flow in the area. Before this extreme event discharge of the I\\vska River was measured at different profiles in the channel and reduction of discharge was observed along the course indicating that I\\vska recharges Ižica springs. Analyses presented were performed in the frame of INCOME project and are aimed to improve understanding of hydrogeological conditions in the catchment area of Barje aquifer which is exploited for the public water supply of Ljubljana.

Geochemical and isotopic composition of ground water with emphasis on sources of sulfate in the upper Floridan Aquifer and intermediate aquifer system in southwest Florida

USGS Publications Warehouse

Sacks, Laura A.; Tihansky, Ann B.

1996-01-01

In southwest Florida, sulfate concentrations in water from the Upper Floridan aquifer and overlying intermediate aquifer system are commonly above 250 milligrams per liter (the drinking water standard), particularly in coastal areas. Possible sources of sulfate include dissolution of gypsum from the deeper part of the Upper Floridan aquifer or the middle confining unit, saltwater in the aquifer, and saline waters from the middle confining unit and Lower Floridan aquifer. The sources of sulfate and geochemical processes controlling ground-water composition were evaluated for the Peace and Myakka River Basins and adjacent coastal areas of southwest Florida. Samples were collected from 63 wells and a saline spring, including wells finished at different depth intervals of the Upper Floridan aquifer and intermediate aquifer system at about 25 locations. Sampling focused along three ground-water flow paths (selected based on a predevelopment potentiometric-surface map). Ground water was analyzed for major ions, selected trace constituents, dissolved organic carbon, and stable isotopes (delta deuterium, oxygen-18, carbon-13 of inorganic carbon, and sulfur-34 of sulfate and sulfide); the ratio of strontium-87 to strontium-86 was analyzed for waters along one of the flow paths. Chemical and isotopic data indicate that dedolomitization reactions (gypsum and dolomite dissolution and calcite precipitation) control the chemical composition of water in the Upper Floridan aquifer in inland areas. This is confirmed by mass-balance modeling between wells in the shallowest interval in the aquifer along the flow paths. However, gypsum occurs deeper in the aquifer than these wells. Upwelling of sulfate-rich water that previously dissolved gypsum in deeper parts of the aquifer is a more likely source of sulfate than gypsum dissolution in shallow parts of the aquifer. This deep ground water moves to shallower zones in the aquifer discharge area. Saltwater from the Upper Floridan aquifer

Groundwater vulnerability mapping in Guadalajara aquifers system (Western Mexico)

NASA Astrophysics Data System (ADS)

Rizo-Decelis, L. David; Marín, Ana I.; Andreo, Bartolomé

2016-04-01

Groundwater vulnerability mapping is a practical tool to implement strategies for land-use planning and sustainable socioeconomic development coherent with groundwater protection. The objective of vulnerability mapping is to identify the most vulnerable zones of catchment areas and to provide criteria for protecting the groundwater used for drinking water supply. The delineation of protection zones in fractured aquifers is a challenging task due to the heterogeneity and anisotropy of hydraulic conductivities, which makes difficult prediction of groundwater flow organization and flow velocities. Different methods of intrinsic groundwater vulnerability mapping were applied in the Atemajac-Toluquilla groundwater body, an aquifers system that covers around 1300 km2. The aquifer supplies the 30% of urban water resources of the metropolitan area of Guadalajara (Mexico), where over 4.6 million people reside. Study area is located in a complex neotectonic active volcanic region in the Santiago River Basin (Western Mexico), which influences the aquifer system underneath the city. Previous works have defined the flow dynamics and identified the origin of recharge. In addition, the mixture of fresh groundwater with hydrothermal and polluted waters have been estimated. Two main aquifers compose the multilayer system. The upper aquifer is unconfined and consists of sediments and pyroclastic materials. Recharge of this aquifer comes from rainwater and ascending vertical fluids from the lower aquifer. The lower aquifer consists of fractured basalts of Pliocene age. Formerly, the main water source has been the upper unit, which is a porous and unconsolidated unit, which acts as a semi-isotropic aquifer. Intense groundwater usage has resulted in lowering the water table in the upper aquifer. Therefore, the current groundwater extraction is carried out from the deeper aquifer and underlying bedrock units, where fracture flow predominates. Pollution indicators have been reported in

Hydrogeology and water quality of the Floridan aquifer system and effect of Lower Floridan aquifer withdrawals on the Upper Floridan aquifer at Barbour Pointe Community, Chatham County, Georgia, 2013

USGS Publications Warehouse

Gonthier, Gerard; Clarke, John S.

2016-06-02

Two test wells were completed at the Barbour Pointe community in western Chatham County, near Savannah, Georgia, in 2013 to investigate the potential of using the Lower Floridan aquifer as a source of municipal water supply. One well was completed in the Lower Floridan aquifer at a depth of 1,080 feet (ft) below land surface; the other well was completed in the Upper Floridan aquifer at a depth of 440 ft below land surface. At the Barbour Pointe test site, the U.S. Geological Survey completed electromagnetic (EM) flowmeter surveys, collected and analyzed water samples from discrete depths, and completed a 72-hour aquifer test of the Floridan aquifer system withdrawing from the Lower Floridan aquifer.Based on drill cuttings, geophysical logs, and borehole EM flowmeter surveys collected at the Barbour Pointe test site, the Upper Floridan aquifer extends 369 to 567 ft below land surface, the middle semiconfining unit, separating the two aquifers, extends 567 to 714 ft below land surface, and the Lower Floridan aquifer extends 714 to 1,056 ft below land surface.A borehole EM flowmeter survey indicates that the Upper Floridan and Lower Floridan aquifers each contain four water-bearing zones. The EM flowmeter logs of the test hole open to the entire Floridan aquifer system indicated that the Upper Floridan aquifer contributed 91 percent of the total flow rate of 1,000 gallons per minute; the Lower Floridan aquifer contributed about 8 percent. Based on the transmissivity of the middle semiconfining unit and the Floridan aquifer system, the middle semiconfining unit probably contributed on the order of 1 percent of the total flow.Hydraulic properties of the Upper Floridan and Lower Floridan aquifers were estimated based on results of the EM flowmeter survey and a 72-hour aquifer test completed in Lower Floridan aquifer well 36Q398. The EM flowmeter data were analyzed using an AnalyzeHOLE-generated model to simulate upward borehole flow and determine the transmissivity of

The hydrogeologic framework for the southeastern Coastal Plain aquifer system of the United States

USGS Publications Warehouse

Renken, R.A.

1984-01-01

Tertiary and Cretaceous age sand aquifers of the southeastern United States Coastal Plain constitute a distinct multistate hydrogeologic regime informally defined as the southeastern sand aquifer. Seven regional hydrogeologic units are defined; four regional aquifer units and three regional confining beds. Sand aquifers of this system consist of quartzose, feldspathic, and coarse to fine sand and sandstone and minor limestone; confining beds are composed of clay, shale, chalk, and marl. Three hydrogeologic units of Cretaceous to Holocene age overlie the sand system: the surficial aquifer, upper confining unit, and Floridan aquifer system. These three units are not part of the southeastern sand aquifer, but are an integral element of the total hydrogeologic system, and some act as a source of recharge to, or discharge from the underlying clastic sediments. Low-permeability strata of Paleozoic to early Mesozoic age form the base off the total system. (USGS)

Statistical and simulation analysis of hydraulic-conductivity data for Bear Creek and Melton Valleys, Oak Ridge Reservation, Tennessee

USGS Publications Warehouse

Connell, J.F.; Bailey, Z.C.

1989-01-01

A total of 338 single-well aquifer tests from Bear Creek and Melton Valley, Tennessee were statistically grouped to estimate hydraulic conductivities for the geologic formations in the valleys. A cross-sectional simulation model linked to a regression model was used to further refine the statistical estimates for each of the formations and to improve understanding of ground-water flow in Bear Creek Valley. Median hydraulic-conductivity values were used as initial values in the model. Model-calculated estimates of hydraulic conductivity were generally lower than the statistical estimates. Simulations indicate that (1) the Pumpkin Valley Shale controls groundwater flow between Pine Ridge and Bear Creek; (2) all the recharge on Chestnut Ridge discharges to the Maynardville Limestone; (3) the formations having smaller hydraulic gradients may have a greater tendency for flow along strike; (4) local hydraulic conditions in the Maynardville Limestone cause inaccurate model-calculated estimates of hydraulic conductivity; and (5) the conductivity of deep bedrock neither affects the results of the model nor does it add information on the flow system. Improved model performance would require: (1) more water level data for the Copper Ridge Dolomite; (2) improved estimates of hydraulic conductivity in the Copper Ridge Dolomite and Maynardville Limestone; and (3) more water level data and aquifer tests in deep bedrock. (USGS)

Hydrogeology of an Alpine rockfall aquifer system and its role in flood attenuation and maintaining baseflow

NASA Astrophysics Data System (ADS)

Lauber, U.; Kotyla, P.; Morche, D.; Goldscheider, N.

2014-11-01

The frequency and intensity of extreme hydrological events in Alpine regions is projected to increase with climate change. The goal of this study is to better understand the functioning of aquifers composed of complex alluvial and rockfall deposits in Alpine valleys and to quantify the role of these natural storage spaces in flood attenuation and baseflow maintenance. Geomorphological and hydrogeological mapping, tracer tests, and continuous flow measurements were conducted in the Reintal (German Alps), where runoff from a karst spring infiltrates a series of postglacial alluvial/rockfall aquifers. During high-flow conditions, groundwater velocities of 30 m h-1 were determined along 500 m; hydrograph analyses revealed short lag times (5 h) between discharge peaks upstream and downstream from the aquifer series; the maximum discharge ratio downstream (22) and the peak recession coefficient (0.196 d-1) are low compared with other Alpine catchments. During low-flow conditions, the underground flow path length increased to 2 km and groundwater velocities decreased to 13 m h-1. Downstream hydrographs revealed a delayed discharge response after 101 h and peaks damped by a factor of 1.5. These results indicate that alluvial/rockfall aquifers might play an important role in the flow regime and attenuation of floods in Alpine regions.

Hydrogeochemical investigation of groundwater in Jericho area in the Jordan Valley, West Bank, Palestine

NASA Astrophysics Data System (ADS)

Da'as, Ammar; Walraevens, Kristine

2013-06-01

Water resources in the Middle East, particularly in Palestine, are extremely scarce and costly. The Jordan Valley is a fertile productive region, described as the food basket of Palestine. Groundwater originating from the Quaternary Aquifer System forms the main water resource in the Jordan Valley. However, the quality of this groundwater is threatened mainly by the high chloride concentration. The most representative area of the Jordan Valley is Jericho area, which was chosen to be the study area. The study area (65 km2) is almost a flat area with a gentle decline towards the east. It is the lowest land on earth with ground levels reaching 400 meters below sea level (mbsl) near the Dead Sea shores. The Quaternary Aquifer System in the study area could be divided into an upper alluvial layer with thickness varying from 40 to 150 m and a lower low-permeable Lisan layer, which crops out in the eastern part of the study area with thickness over 200 m. Hydrogeochemical investigation reveals that the water is generally earth alkaline with higher content of earth alkalis and prevailing chloride. According to Stuyfzand (1986) and Piper's (1944) classification systems, water type in the Alluvial Aquifer varies from fresh hard CaMgHCO3 or MgCaHCO3 water in the west and northwest to brackish very-hard MgNaCl or NaMgCl in the middle. In the east, the water becomes brackish-salt extremely-hard MgNaCl or NaCl. Groundwater quality is deteriorating (increase in salinity) spatially towards the east and vertically with increasing depth (when nearing the Lisan Formation). As an indication of groundwater salinity, total dissolved solids show some variability with time over the last 21 years (1983-2004). In short-time scale, there are high seasonal and yearly fluctuations with regard to salinity, specifically in Cl- and SO42- contents. Spring water from the Upper Cenomanian Aquifer (CaHCO3) represents the fresh end member, while Rift Valley Brines (RVB-CaNaCl) and Dead Sea Brines (DSB

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.

Conceptual hydrogeologic framework of the shallow aquifer system at Virginia Beach, Virginia

USGS Publications Warehouse

Smith, Barry S.; Harlow, George E.

2002-01-01

The hydrogeologic framework of the shallow aquifer system at Virginia Beach was revised to provide a better understanding of the distribution of fresh ground water, its potential use, and its susceptibility to contamination. The revised conceptual framework is based primarily on analyses of continuous cores and downhole geophysical logs collected at 7 sites to depths of approximately 200 ft.The shallow aquifer system at Virginia Beach is composed of the Columbia aquifer, the Yorktown confining unit, and the Yorktown-East-over aquifer. The shallow aquifer system is separated from deeper units by the continuous St. Marys confining unit.The Columbia aquifer is defined as the predominantly sandy surficial deposits above the Yorktown confining unit. The Yorktown confining unit is composed of a series of very fine sandy to silty clay units of various colors at or near the top of the Yorktown Formation. The Yorktown confining unit varies in thickness and in composition, but on a regional scale is a leaky confining unit. The Yorktown-Eastover aquifer is defined as the predominantly sandy deposits of the Yorktown Formation and the upper part of the Eastover Formation above the confining clays of the St. Marys Formation. The limited areal extent of highly permeable deposits containing freshwater in the Yorktown-Eastover aquifer precludes the installation of highly productive freshwater wells over most of the city. Some deposits of biofragmental sand or shell hashes in the Yorktown-Eastover aquifer can support high-capacity wells.A water sample was collected from each of 10 wells installed at 5 of the 7 core sites to determine the basic chemistry of the aquifer system. One shallow well and one deep well was installed at each site. Concentrations of chloride were higher in the water from the deeper well at each site. Concentrations of dissolved iron in all of the water samples were higher than the U.S. Environmental Protection Agency Secondary Drinking Water Regulations

Conceptual and numerical modeling approach of the Guarani Aquifer System

NASA Astrophysics Data System (ADS)

Rodríguez, L.; Vives, L.; Gomez, A.

2013-01-01

In large aquifers, relevant for their considerable size, regional groundwater modeling remains challenging given geologic complexity and data scarcity in space and time. Yet, it may be conjectured that regional scale groundwater flow models can help in understanding the flow system functioning and the relative magnitude of water budget components, which are important for aquifer management. The Guaraní Aquifer System is the largest transboundary aquifer in South America. It contains an enormous volume of water; however, it is not well known, being difficult to assess the impact of exploitation currently used to supply over 25 million inhabitants. This is a sensitive issue because the aquifer is shared by four countries. Moreover, an integrated groundwater model, and therefore a global water balance, were not available. In this work, a transient regional scale model for the entire aquifer based upon five simplified, equally plausible conceptual models represented by different hydraulic conductivity parametrizations is used to analyze the flow system and water balance components. Combining an increasing number of hydraulic conductivity zones and an appropriate set of boundary conditions, the hypothesis of a continuous sedimentary unit yielded errors within the calibration target in a regional sense. The magnitude of the water budget terms resulted very similar for all parametrizations. Recharge and stream/aquifer fluxes were the dominant components representing, on average, 84.2% of total inflows and 61.4% of total outflows, respectively. However, leakage was small compared to stream discharges of main rivers. For instance, the simulated average leakage for the Uruguay River was 8 m3 s-1 while the observed absolute minimum discharge was 382 m3 s-1. Streams located in heavily pumped regions switched from a gaining condition in early years to a losing condition over time. Water is discharged through the aquifer boundaries, except at the eastern boundary. On average

Status and understanding of groundwater quality in the Bear Valley and Lake Arrowhead Watershed Study Unit, 2010: California GAMA Priority Basin Project

USGS Publications Warehouse

Mathany, Timothy; Burton, Carmen

2017-06-20

Groundwater quality in the 112-square-mile Bear Valley and Lake Arrowhead Watershed (BEAR) study unit was investigated as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit comprises two study areas (Bear Valley and Lake Arrowhead Watershed) in southern California in San Bernardino County. The GAMA-PBP is conducted by the California State Water Resources Control Board (SWRCB) in cooperation with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory.The GAMA BEAR study was designed to provide a spatially balanced, robust assessment of the quality of untreated (raw) groundwater from the primary aquifer systems in the two study areas of the BEAR study unit. The assessment is based on water-quality collected by the USGS from 38 sites (27 grid and 11 understanding) during 2010 and on water-quality data from the SWRCB-Division of Drinking Water (DDW) database. The primary aquifer system is defined by springs and the perforation intervals of wells listed in the SWRCB-DDW water-quality database for the BEAR study unit.This study included two types of assessments: (1) a status assessment, which characterized the status of the quality of the groundwater resource as of 2010 by using data from samples analyzed for volatile organic compounds, pesticides, and naturally present inorganic constituents, such as major ions and trace elements, and (2) an understanding assessment, which evaluated the natural and human factors potentially affecting the groundwater quality. The assessments were intended to characterize the quality of groundwater resources in the primary aquifer system of the BEAR study unit, not the treated drinking water delivered to consumers. Bear Valley study area and the Lake Arrowhead Watershed study area were also compared statistically on the basis of water-quality results and factors potentially affecting the groundwater quality.Relative concentrations (RCs

An atlas of eleven selected aquifers in New York

USGS Publications Warehouse

Waller, Roger Milton; Finch, Anne J.

1982-01-01

Water from 11 aquifer systems in New York, excluding Long Island , is used by 2.8 million people. Ten are in areas hydraulically connected with the master stream and have a shallow water table, the 11th is a buried valley system on the Lake Ontario Plain. In all systems, till, lake silt and clay, and bedrock knobs are interspersed within sand and gravel. Confining conditions occur locally in all systems and are extensive in some. Each area is partly urbanized, contains industry, and has an extensive transportation network, all of which may be sources of contamination. Well yields for public and industrial supply are commonly several hundred gallons per minute. More than 90 maps depict surficial geology, soil-zone permeability, aquifer dimensions and potential, water levels, and land use; tables of ground-water use, population served, and a summary of contamination potential are also given. Major concern in all areas is the potential for contamination and, in a few areas, adequacy of supply. The areas described are Schenectady, Endicott-Johnson City, Ramapo and Mahwah Rivers, Irondequoit Creek, Jamestown, Elmira-Horseheads-Big Flats, Cortland, Homer-Preble, Sprout and Fishkill Creeks, Fulton, and south Fallsburg-Woodbourne. (USGS)

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.

Integrating borehole logs and aquifer tests in aquifer characterization

USGS Publications Warehouse

Paillet, Frederick L.; Reese, R.S.

2000-01-01

Integration of lithologic logs, geophysical logs, and hydraulic tests is critical in characterizing heterogeneous aquifers. Typically only a limited number of aquifer tests can be performed, and these need to be designed to provide hydraulic properties for the principle aquifers in the system. This study describes the integration of logs and aquifer tests in the development of a hydrostratigraphic model for the surficial aquifer system in and around Big Cypress National Preserve in eastern Collier County, Florida. Borehole flowmeter tests provide qualitative permeability profiles in most of 26 boreholes drilled in the Study area. Flow logs indicate the depth of transmissive units, which are correlated across the study area. Comparison to published studies in adjacent areas indicates that the main limestone aquifer of the 000000Tamiami Formation in the study area corresponds with the gray limestone aquifer in western Dade County and the water table and lower Tamiami Aquifer in western Collier County. Four strategically located, multiwell aquifer tests are used to quantify the qualitative permeability profiles provided by the flowmeter log analysis. The hydrostratigraphic model based on these results defines the main aquifer in the central part of the study area as unconfined to semiconfined with a transmissivity as high as 30,000 m2/day. The aquifer decreases in transmissivity to less than 10,000 m2/day in some parts of western Collier County, and becomes confined to the east and northeast of the study area, where transmissivity decreases to below 5000 m2/day.Integration of lithologic logs, geophysical logs, and hydraulic tests is critical in characterizing heterogeneous aquifers. Typically only a limited number of aquifer tests can be performed, and these need to be designed to provide hydraulic properties for the principle aquifers in the system. This study describes the integration of logs and aquifer tests in the development of a hydrostratigraphic model for the

Ground-water conditions in the Grand County area, Utah, with emphasis on the Mill Creek-Spanish Valley area

USGS Publications Warehouse

Blanchard, Paul J.

1990-01-01

The Grand County area includes all of Grand County, the Mill Creek and Pack Creek drainages in San Juan County, and the area between the Colorado and Green Rivers in San Juan County. The Grand County area includes about 3,980 square miles, and the Mill Creek-Spanish Valley area includes about 44 square miles. The three principal consolidated-rock aquifers in the Grand County area are the Entrada, Navajo, and Wingate aquifers in the Entrada Sandstone, the Navajo Sandstone, and the Wingate Sandstone, and the principal consolidated-rock aquifer in the Mill Creek-Spanish Valley area is the Glen Canyon aquifer in the Glen Canyon Group, comprised of the Navajo Sandstone, the Kayenta Formation, and the Wingate Sandstone.Recharge to the Entrada, Navajo, and Glen Canyon aquifers typically occurs where the formations containing the aquifers crop out or are overlain by unconsolidated sand deposits. Recharge is enhanced where the sand deposits are saturated at a depth of more than about 6 feet below the land surface, and the effects of evaporation begin to decrease rapidly with depth. Recharge to the Wingate aquifer typically occurs by downward movement of water from the Navajo aquifer through the Kayenta Formation, and primarily occurs where the Navajo Sandstone, Kayenta Formation, and the Wingate Sandstone are fractured.

Ground-water hydrology and water quality of the southern high plains aquifer, Melrose Air Force Range, Cannon Air Force Base, Curry and Roosevelt Counties, New Mexico, 2002-03

USGS Publications Warehouse

Langman, Jeff B.; Gebhardt, Fredrick E.; Falk, Sarah E.

2004-01-01

In cooperation with the U.S. Air Force, the U.S. Geological Survey characterized the ground-water hydrology and water quality at Melrose Air Force Range in east-central New Mexico. The purpose of the study was to provide baseline data to Cannon Air Force Base resource managers to make informed decisions concerning actions that may affect the ground-water system. Five periods of water-level measurements and four periods of water-quality sample collection were completed at Melrose Air Force Range during 2002 and 2003. The water-level measurements and water-quality samples were collected from a 29-well monitoring network that included wells in the Impact Area and leased lands of Melrose Air Force Range managed by Cannon Air Force Base personnel. The purpose of this report is to provide a broad overview of ground-water flow and ground-water quality in the Southern High Plains aquifer in the Ogallala Formation at Melrose Air Force Range. Results of the ground-water characterization of the Southern High Plains aquifer indicated a local flow system in the unconfined aquifer flowing northeastward from a topographic high, the Mesa (located in the southwestern part of the Range), toward a regional flow system in the unconfined aquifer that flows southeastward through the Portales Valley. Ground water was less than 55 years old across the Range; ground water was younger (less than 25 years) near the Mesa and ephemeral channels and older (25 years to 55 years) in the Portales Valley. Results of water-quality analysis indicated three areas of different water types: near the Mesa and ephemeral channels, in the Impact Area of the Range, and in the Portales Valley. Within the Southern High Plains aquifer, a sodium/chloride-dominated ground water was found in the center of the Impact Area of the Range with water-quality characteristics similar to ground water from the underlying Chinle Formation. This sodium/chloride-dominated ground water of the unconfined aquifer in the Impact

Predicting arsenic in drinking water wells of the Central Valley, California

USGS Publications Warehouse

Ayotte, Joseph; Nolan, Bernard T.; Gronberg, JoAnn M.

2016-01-01

Probabilities of arsenic in groundwater at depths used for domestic and public supply in the Central Valley of California are predicted using weak-learner ensemble models (boosted regression trees, BRT) and more traditional linear models (logistic regression, LR). Both methods captured major processes that affect arsenic concentrations, such as the chemical evolution of groundwater, redox differences, and the influence of aquifer geochemistry. Inferred flow-path length was the most important variable but near-surface-aquifer geochemical data also were significant. A unique feature of this study was that previously predicted nitrate concentrations in three dimensions were themselves predictive of arsenic and indicated an important redox effect at >10 μg/L, indicating low arsenic where nitrate was high. Additionally, a variable representing three-dimensional aquifer texture from the Central Valley Hydrologic Model was an important predictor, indicating high arsenic associated with fine-grained aquifer sediment. BRT outperformed LR at the 5 μg/L threshold in all five predictive performance measures and at 10 μg/L in four out of five measures. BRT yielded higher prediction sensitivity (39%) than LR (18%) at the 10 μg/L threshold–a useful outcome because a major objective of the modeling was to improve our ability to predict high arsenic areas.

Potentiometric surface of the Catahoula aquifer in central Louisiana, 2013

USGS Publications Warehouse

Fendick, Jr., Robert B.; Carter, Kayla

2015-12-09

The potentiometric surface of the Catahoula aquifer was constructed by using the altitude of water levels measured at 29 wells during the period May through September 2013. The altitude of water levels ranged from 0.02 ft above the National Geodetic Vertical Datum of 1929 (NGVD 29) in well Co-51 to 238 ft above NGVD 29 in well Na-317. Groundwater movement in the Catahoula aquifer is generally to the southeast and towards discharge areas beneath the Sabine, Red, Little, and Tensas River Valleys.

Potentiometric surfaces of the intermediate aquifer system, west-central Florida, May, 1993

USGS Publications Warehouse

Mularoni, R.A.

1994-01-01

The intermediate aquifer system underlies a 5000-sq-mi area including De Soto, Sarasota, Hardee, Manatee, and parts of Charlotte, Hillsborough, Highlands, and Polk Counties, Florida. It is overlain by the surf@cial aquifer system and underlain by the Floridan aquifer system. The potentiometric surface of the intermediate aquifer system was mapped by determining the altitude of water levels in a network of wells and represented on a map by contours that connect points of equal altitude. This map represents water-level conditions near the end of the spring dry season when ground- water withdrawals for agricultural use were high. The cumulative rainfall for the study area was 4.84 inches above normal for the period from June 1992 to May 1993. Hydrographs for selected wells indicated that the annual and seasonal fluctuations of the water levels were generally large (greater than 15 feet) in the central interior region where water demand for irrigation is high during the fall and spring. Seasonal fluctuations were smaller in the northern recharge area where water use is predominantly for public supply. Water levels measured in May 1993 for the composite intermediate aquifer potentiometric surface were lower than those measured in May or September 1992. A cone of depression exists in the potentiometric surface for the composite aquifer system at Warm Mineral Springs, which is a natural discharge point from this system.

Ground-water storage depletion in Pahrump Valley, Nevada-California, 1962-75

USGS Publications Warehouse

Harrill, James R.

1982-01-01

During the 13-year period, February 1962 to February 1975, about 540,000 acre-feet of ground water was pumped from Pahrump Valley. This resulted in significant water-level declines along the base of the Pahrump and Manse fans where pumping was concentrated. Maximum observed net decline was slightly more than 60 feet. Much smaller declines occurred in the central valley, and locally, water levels in some shallow wells rose due to recharge derived from the deep percolation of irrigation water. The pumping resulted in about 219,000 acre-feet of storage depletion. Of this, 155,000 acre-feet was from the draining of unconsolidated material, 46,000 was from compaction of fine-grained sediments, and 18,000 acre-feet was from the elastic response of the aquifer and water. The total storage depletion was equal to about 40 percent of the total pumpage. The remaining pumped water was derived from the capture of natural ground-water discharge and reuse of pumped water that had recirculated back to ground water. Natural recharge to and discharge from the ground-water system is estimated to be 37,000 acre-feet per year. Of this, 18,000 acre-feet per year leaves the area as subsurface outflow through carbonate-rock aquifers which form a multivalley flow system. The extent of this system was not precisely determined by this study. The most probable discharge area for this outflow is along the flood plain of the Amargosa River between the towns of Shoshone and Tecopa. This outflow probably cannot be economically captured by pumping from Pahrump Valley. Consequently, the maximum amount of natural discharge available for capture is 19,000 acre-feet per year. This is larger than the 12,000 acre-feet per year estimated in a previous study; the difference is due to different techniques used in the analysis. As of 1975, pumping was causing an overdraft of 11,000 acre-feet per year on the ground-water system. No new equilibrium is probable in the foreseeable future. Water levels will

Regional Aquifer-System Analysis Program of the U.S. Geological Survey, 1978-1992

USGS Publications Warehouse

Sun, Ren Jen; Johnston, Richard H.

1994-01-01

The major ground-water systems of the United States have been investigated by the U.S. Geological Survey (USGS) through its Regional Aquifer-System Analysis (RASA) Program. During the first 15 years of the program (1978-92), 25 regional aquifer systems, including the most heavily pumped aquifers in the Nation, were intensively studied. As of mid-1992, 18 of the regional aquifer studies are completed or nearly so; 7 of the regional aquifer studies are ongoing, and compilation of a national ground-water atlas is in progress. This report summarizes the status of each RASA study and briefly describes the hydrology of the 25 regional aquifer systems. Important study results and examples of applications of study results are presented for some of the completed RASA investigations. The major contributions of the RASA Program are (1) assembly of data from numerous local studies and long-time data collections into systematic regional data bases; (2) comprehensive descriptions of the geologic, hydrologic, and geochemical characteristics of the regional aquifer systems; and (3) an understanding of how the regional ground-water-flow systems function under natural (predevelopment) and current (developed) conditions. To provide the comprehensive system descriptions, many of the RASA studies present, for the first time, maps depicting the hydrogeologic frameworks, water chemistry, potentiometric surfaces, and other aspects of entire regional aquifer systems. To provide an understanding of how the flow systems function, several of the completed RASA studies provide, for the first time, hydrologic budgets for both predevelopment and developed conditions. The results of the RASA Program are contained in nearly 900 reports published by the USGS, as well as various State and local agencies, and in articles published in scientific journals. A series of U.S. Geological Survey Professional Papers are being published to summarize and synthesize the results of each RASA study.

Groundwater quality in the glacial aquifer system, United States

USGS Publications Warehouse

Stackelberg, Paul E.

2017-12-07

Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are important sources of drinking water (Burow and Belitz, 2014). The glacial aquifer system constitutes one of the important areas being evaluated.

Geohydrology and water quality of the North Platte River alluvial aquifer, Garden County, Western Nebraska

USGS Publications Warehouse

Steele, Gregory V.; Cannia, James C.

1995-01-01

In 1993, a 3-year study was begun to describe the geohydrology and water quality of the North Platte River alluvial aquifer near Oshkosh, Garden County, Nebraska. The study's objectives are to evaluate the geohydrologic characteristics of the alluvial aquifer and to establish a network of observation wells for long-term monitoring of temporal variations and spatial distributions of nitrate and major-ion concentrations. Monitor wells were installed at 11 sites near Oshkosh. The geohydrology of the aquifer was characterized based on water-level measurements and two short-term aquifer tests. Bimonthly water samples were collected and analyzed for pH, specific conductivity, water temperature, dissolved oxygen, and nutrients that included dissolved nitrate. Concentrations of major ions were defined from analyses of semiannual water samples. Analyses of the geohydrologic and water-quality data indicate that the aquifer is vulnerable to nitrate contamination. These data also show that nitrate concentrations in ground water flowing into and out of the study area are less than the U.S. Environmental Protection Agency's Maximum Concentration Level of 10 milligrams per liter for drinking water. Ground water from Lost Creek Valley may be mixing with ground water in the North Platte River Valley, somewhat moderating nitrate concentrations near Oshkosh.

Use of seasonal trend decomposition to understand groundwater behaviour in the Permo-Triassic Sandstone aquifer, Eden Valley, UK

NASA Astrophysics Data System (ADS)

Lafare, Antoine E. A.; Peach, Denis W.; Hughes, Andrew G.

2016-02-01

The daily groundwater level (GWL) response in the Permo-Triassic Sandstone aquifers in the Eden Valley, England (UK), has been studied using the seasonal trend decomposition by LOESS (STL) technique. The hydrographs from 18 boreholes in the Permo-Triassic Sandstone were decomposed into three components: seasonality, general trend and remainder. The decomposition was analysed first visually, then using tools involving a variance ratio, time-series hierarchical clustering and correlation analysis. Differences and similarities in decomposition pattern were explained using the physical and hydrogeological information associated with each borehole. The Penrith Sandstone exhibits vertical and horizontal heterogeneity, whereas the more homogeneous St Bees Sandstone groundwater hydrographs characterize a well-identified seasonality; however, exceptions can be identified. A stronger trend component is obtained in the silicified parts of the northern Penrith Sandstone, while the southern Penrith, containing Brockram (breccias) Formation, shows a greater relative variability of the seasonal component. Other boreholes drilled as shallow/deep pairs show differences in responses, revealing the potential vertical heterogeneities within the Penrith Sandstone. The differences in bedrock characteristics between and within the Penrith and St Bees Sandstone formations appear to influence the GWL response. The de-seasonalized and de-trended GWL time series were then used to characterize the response, for example in terms of memory effect (autocorrelation analysis). By applying the STL method, it is possible to analyse GWL hydrographs leading to better conceptual understanding of the groundwater flow. Thus, variation in groundwater response can be used to gain insight into the aquifer physical properties and understand differences in groundwater behaviour.

Aquifer storage and recovery: recent hydrogeological advances and system performance.

PubMed

Maliva, Robert G; Guo, Weixing; Missimer, Thomas M

2006-12-01

Aquifer storage and recovery (ASR) is part of the solution to the global problem of managing water resources to meet existing and future freshwater demands. However, the metaphoric "ASR bubble" has been burst with the realization that ASR systems are more physically and chemically complex than the general conceptualization. Aquifer heterogeneity and fluid-rock interactions can greatly affect ASR system performance. The results of modeling studies and field experiences indicate that more sophisticated data collection and solute-transport modeling are required to predict how stored water will migrate in heterogeneous aquifers and how fluid-rock interactions will affect the quality of stored water. It has been well-demonstrated, by historic experience, that ASR systems can provide very large volumes of storage at a lesser cost than other options. The challenges moving forward are to improve the success rate of ASR systems, optimize system performance, and set expectations appropriately.

Groundwater components in the alluvial aquifer of the alpine Rhone River valley, Bois de Finges area, Wallis Canton, Switzerland

NASA Astrophysics Data System (ADS)

Schürch, Marc; Vuataz, François-D.

2000-09-01

Source, type, and quantity of various components of groundwater, as well as their spatial and temporal variations were determined by different hydrochemical methods in the alluvial aquifer of the upper Rhone River valley, Bois de Finges, Wallis Canton, Switzerland. The methods used are hydrochemical modeling, stable-isotope analysis, and chemical analysis of surface water and groundwater. Sampling during high- and low-water periods determined the spatial distribution of the water chemistry, whereas monthly sampling over three years provided a basis for understanding seasonal variability. The physico-chemical parameters of the groundwater have spatial and seasonal variations. The groundwater chemical composition of the Rhone alluvial aquifer indicates a mixing of weakly mineralized Rhone River water and SO4-rich water entering from the south side of the valley. Temporal changes in groundwater chemistry and in groundwater levels reflect the seasonal variations of the different contributors to groundwater recharge. The Rhone River recharges the alluvial aquifer only during the summer high-water period. Résumé. Origine, type et quantité de nombreux composants d'eau de l'aquifère alluvial dans la vallée supérieure du Rhône, Bois de Finges, Valais, Suisse, ainsi que leurs variations spatiales et temporelles ont été déterminés par différentes méthodes hydrochimiques. Les méthodes utilisées sont la modélisation hydrochimique, les isotopes stables, ainsi que l'échantillonnage en période de hautes eaux et de basses eaux pour étudier la distribution spatiale de la composition chimique, alors qu'un échantillonnage mensuel pendant trois ans sert à comprendre les processus de la variabilité saisonnière. Les paramètres physico-chimiques des eaux souterraines montrent des variations spatiales et saisonnières. La composition chimique de l'aquifère alluvial du Rhône indique un mélange entre une eau peu minéralisée venant du Rhône et une eau sulfatée s

New isotopic evidence for the origin of groundwater from the Nubian Sandstone Aquifer in the Negev, Israel

USGS Publications Warehouse

Vengosh, A.; Hening, S.; Ganor, J.; Mayer, B.; Weyhenmeyer, C.E.; Bullen, T.D.; Paytan, A.

2007-01-01

The geochemistry and isotopic composition (H, O, S, Osulfate, C, Sr) of groundwater from the Nubian Sandstone (Kurnub Group) aquifer in the Negev, Israel, were investigated in an attempt to reconstruct the origin of the water and solutes, evaluate modes of water-rock interactions, and determine mean residence times of the water. The results indicate multiple recharge events into the Nubian sandstone aquifer characterized by distinctive isotope signatures and deuterium excess values. In the northeastern Negev, groundwater was identified with deuterium excess values of ???16???, which suggests local recharge via unconfined areas of the aquifer in the Negev anticline systems. The ??18OH2O and ??2H values (-6.5??? and -35.4???) of this groundwater are higher than those of groundwater in the Sinai Peninsula and southern Arava valley (-7.5??? and -48.3???) that likewise have lower deuterium excess values of ???10???. Based on the geochemical differences between groundwater in the unconfined and confined zones of the aquifer, a conceptual geochemical model for the evolution of the groundwater in the Nubian sandstone aquifer has been reconstructed. The isotopic composition of shallow groundwater from the unconfined zone indicates that during recharge oxidation of pyrite to SO4 (??34SSO4 ???-13???; ??18OSO4 ???+7.7???) and dissolution of CaCO3 (87Sr/86Sr ???0.70787; ??13CDIC = -3.7???) occur. In the confined zone of the aquifer, bacterial SO4 reduction removes a significant part of dissolved SO42 -, thereby modifying its isotopic composition (??34SSO4 ???-2???; ??18OSO4 ???+8.5???) and liberating dissolved inorganic C that contains little or no radiocarbon (14C-free) with low ??13CDIC values (<-12???). In addition to local recharge, the Sr and S isotopic data revealed contribution of external groundwater sources to the Nubian Sandstone aquifer, resulting in further modifications of the groundwater chemical and isotopic signatures. In the northeastern Negev, it is shown that

Ground-Water Occurrence and Movement, 2006, and Water-Level Changes in the Detrital, Hualapai, and Sacramento Valley Basins, Mohave County, Arizona

USGS Publications Warehouse

Anning, David W.; Truini, Margot; Flynn, Marilyn E.; Remick, William H.

2007-01-01

Ground-water levels for water year 2006 and their change over time in Detrital, Hualapai, and Sacramento Valley Basins of northwestern Arizona were investigated to improve the understanding of current and past ground-water conditions in these basins. The potentiometric surface for ground water in the Basin-Fill aquifer of each basin is generally parallel to topography. Consequently, ground-water movement is generally from the mountain front toward the basin center and then along the basin axis toward the Colorado River or Lake Mead. Observed water levels in Detrital, Hualapai, and Sacramento Valley Basins have fluctuated during the period of historic water-level records (1943 through 2006). In Detrital Valley Basin, water levels in monitored areas have either remained the same, or have steadily increased as much as 3.5 feet since the 1980s. Similar steady conditions or water-level rises were observed for much of the northern and central parts of Hualapai Valley Basin. During the period of historic record, steady water-level declines as large as 60 feet were found in wells penetrating the Basin-Fill aquifer in areas near Kingman, northwest of Hackberry, and northeast of Dolan Springs within the Hualapai Valley Basin. Within the Sacramento Valley Basin, during the period of historic record, water-level declines as large as 55 feet were observed in wells penetrating the Basin-Fill aquifer in the Kingman and Golden Valley areas; whereas small, steady rises were observed in Yucca and in the Dutch Flat area.

Ground-water flow and quality in Wisconsin's shallow aquifer system

USGS Publications Warehouse

Kammerer, P.A.

1995-01-01

In terms of chemical quality, the water is suitable for potable supply and most other uses, but objectionable hardness in large areas and concen- trations of iron and manganese that exceed State drinking-water standards cause aesthetic problems that may require treatment of the water for some uses. Concentrations of major dissolved constitu- ents (calcium, magnesium, and bicarbonate), hard- ness, alkalinity, and dissolved solids are highest where the bedrock component of the aquifer is dolo- mite and lowest where the shallow aquifer is almost entirely sand and gravel. Concentrations of other minor constituents (sodium, potassium, sulfate, chloride, and fluoride) are less closely related to common minerals that compose the aquifer system. Sulfate and fluoride concentrations exceed State drinking-water standards locally. Extreme variability in concentrations of iron and manganese are common locally. Iron and manganese concentra- tions exceed State drinking-water standards in water from one-third and one-quarter of the wells, respectively. Likely causes of nitrate-nitrogen con- centrations that exceed State drinking-water stan- dards include local contamination from plant fertilizers, animal wastes, waste water disposed of on land, and septic systems. Water quality in the shallow aquifer system has been affected by saline water from underlying aquifers, primarily along the eastern and western boundaries of the State where the thickness of Paleozoic rocks is greatest.

Water-level surface in the Chicot equivalent aquifer system in southeastern Louisiana, 2009

USGS Publications Warehouse

Tomaszewski, Dan J.

2011-01-01

The Chicot equivalent aquifer system is an important source of freshwater in southeastern Louisiana. In 2005, about 47 million gallons per day (Mgal/d) were withdrawn from the Chicot equivalent aquifer system in East Baton Rouge, East Feliciana, Livingston, Tangipahoa, St. Helena, St. Tammany, Washington, and West Feliciana Parishes. Concentrated withdrawals exceeded 5 Mgal/d in Bogalusa, the city of Baton Rouge, and in northwestern East Baton Rouge Parish. In the study area, about 30,000 wells screened in the Chicot equivalent aquifer system were registered with the Louisiana Department of Transportation and Development (LaDOTD). These wells were constructed for public-supply, industry, irrigation, and domestic uses. Most of the wells were registered as domestic-use wells and are small-diameter, low-yielding wells. Total withdrawal from the Chicot equivalent aquifer system for domestic use was estimated to be 12 Mgal/d in 2005. This report documents the 2009 water-level surface of the Chicot equivalent aquifer system in southeastern Louisiana. The report also shows differences in water-level measurements for the years 1991 and 2009 at selected sites. Understanding changes and trends in water levels is important for continued use, planning, and management of groundwater resources. The U.S. Geological Survey, in cooperation with the Louisiana Department of Transportation and Development, conducted this study of the water-level surface of the Chicot equivalent aquifer system as part of an ongoing effort to monitor groundwater levels in aquifers in Louisiana.

The Temporal and Spatial Variability of the Confined Aquifer Head and Storage Properties in the San Luis Valley, Colorado Inferred From Multiple InSAR Missions

NASA Astrophysics Data System (ADS)

Chen, Jingyi; Knight, Rosemary; Zebker, Howard A.

2017-11-01

Interferometric Synthetic Aperture Radar (InSAR) data from multiple satellite missions were combined to study the temporal and spatial variability of head and storage properties in a confined aquifer system on a decadal time scale. The area of study was a 4,500 km2 agricultural basin in the San Luis Valley (SLV), Colorado. We had available previous analyses of C-band ERS-1/2 data from June 1992 to November 2000, and L-band ALOS PALSAR data from October 2009 to March 2011. We used C-band Envisat data to fill in the time period from November 2006 to July 2010. In processing the Envisat data, we successfully employed a phase interpolation between persistent scatterer pixels to reduce the impact of vegetation decorrelation, which can significantly reduce the quality of C-band InSAR data over agricultural basins. In comparing the results from the L-band ALOS data and C-band Envisat data in a 10 month overlapping time period, we found that the shorter wavelength of C-band InSAR allowed us to preserve small deformation signals that were not detectable using L-band ALOS data. A significant result was the finding that the elastic storage properties of the SLV confined aquifer system remained stable over the 20 year time period and vary slowly in space, allowing us to combine InSAR data acquired from multiple missions to fill the temporal and spatial gaps in well data. The InSAR estimated head levels were validated with well measurements, which indicate little permanent water-storage loss over the study time period in the SLV.

Geophysical setting of the Wabash Valley fault system

USGS Publications Warehouse

Hildenbrand, T.G.; Ravat, D.

1997-01-01

Interpretation of existing regional magnetic and gravity data and new local high-resolution aeromagnetic data provides new insights on the tectonic history and structural development of the Wabash Valley Fault System in Illinois and Indiana. Enhancement of short-wavelength magnetic anomalies reveal numerous NW- to NNE-trending ultramafic dikes and six intrusive complexes (including those at Hicks Dome and Omaha Dome). Inversion models indicate that the interpreted dikes are narrow (???3 m), lie at shallow depths (500 km long and generally >50 km wide) and with deep basins (locally >3 km thick), the ancestral Wabash Valley faults express, in comparison, minor tectonic structures and probably do not represent a failed rift arm. There is a lack of any obvious relation between the Wabash Valley Fault System and the epicenters of historic and prehistoric earthquakes. Five prehistoric earthquakes lie conspicuously near structures associated with the Commerce geophysical lineament, a NE-trending magnetic and gravity lineament lying oblique to the Wabash Valley Fault System and possibly extending over 600 km from NE Arkansas to central Indiana.

Aquifer depletion in the Lower Mississippi River Basin: challenges and solutions

USDA-ARS?s Scientific Manuscript database

The Lower Mississippi River Basin (LMRB) is an internationally-important region of intensive agricultural crop production that relies heavily on the underlying Mississippi River Valley Alluvial Aquifer (MRVAA) for irrigation. Extensive irrigation coupled with the region’s geology have led to signifi...

Numerical Simulation of Nocturnal Drainage Flows in Idealized Valley-Tributary Systems.

NASA Astrophysics Data System (ADS)

O'Steen, Lance B.

2000-11-01

Numerical simulations of nocturnal drainage flow and transport in idealized valley-tributary systems are compared with the Atmospheric Science in Complex Terrain (ASCOT) meteorological field data and tracer studies from the Brush Creek valley of western Colorado. Much of the general valley-tributary flow behavior deduced from observations is qualitatively reproduced in the numerical results. The spatially complex, unsteady nature of the tributary flow found in the field data is also seen in the simulations. Oscillations in the simulated tributary flow are similar to some field observations. However, observed oscillations in the valley flow at the mouth of the tributary could not be reproduced in the numerical results. Thus, hypotheses of strongly coupled valley-tributary flow oscillations, based on field data, cannot be supported by these simulations. Along-valley mass flux calculations based on model results for the valley-tributary system indicate an increase of 5%-10% over a valley without a tributary. Enhanced valley mass fluxes were found from 8 km above the tributary to almost the valley mouth. However, the valley mass fluxes for topography with and without a tributary were nearly equal at the valley outflow. ASCOT field data suggested a tributary mass flow contribution of 5%-15% for a Brush Creek tributary of similar drainage area to the model tributary employed here. Numerical simulations of transport in the nocturnal valley-tributary flow strongly support ASCOT tracer studies in the Pack Canyon tributary of Brush Creek. These results suggest that the valley-tributary interaction can significantly increase plume dispersion under stable conditions. Overall, the simulation results presented here indicate that simple terrain geometries are able to capture many of the salient features of drainage flow in real valley-tributary systems.

Reactive solute transport in an asymmetric aquifer-aquitard system with scale-dependent dispersion

NASA Astrophysics Data System (ADS)

Zhou, R.; Zhan, H.

2017-12-01

Abstract: The understanding of reactive solute transport in an aquifer-aquitard system is important to study transport behavior in the more complex porous media. When transport properties are asymmetric in the upper and lower aquitards, reactive solute transport in such an aquifer-aquitard system becomes a coupled three domain problem that is more complex than the symmetric case in which the upper and lower aquitards have identical transport properties. Meanwhile, the dispersivity of transport in the aquifer is considered as a linear or exponential function of travel distance due to the heterogeneity of aquifer. This study proposed new transport models to describe reactive solute transport in such an asymmetric aquifer-aquitard system with scale-dependent dispersion. Mathematical models were developed for such problems under the first-type and third-type boundary conditions to analyze the spatial-temporal concentration and mass distribution in the aquifer and aquitards with the help of Laplace transform technique and the de Hoog numerical Laplace inversion method. Breakthrough curves (BTCs) and residence time distribution curves (RTDs) obtained from the models with scale-dependent dispersion, constant dispersion and constant effective dispersivity were compared to reflect the lumped scale-dispersion effect in the aquifer-aquitard system. The newly acquired solutions were then tested extensively against previous analytical and numerical solutions and were proven to be robust and accurate. Furthermore, to study the back diffusion of contaminant mass in aquitards, a zero-contaminant mass concentration boundary condition was imposed on the inlet boundary of the system after a certain time, which is also called the process of water flushing. The diffusion loss alone the aquifer/aquitard interfaces and mass stored ratio change in each of three domains (upper aquitard, aquifer, and lower aquitard) after water flushing provided an insightful and comprehensive analysis of

Geochemistry of the Cambrian-Ordovician aquifer system in the northern Midwest, United States: D in Regional aquifer-system analysis

USGS Publications Warehouse

Siegel, D.I.

1989-01-01

Distributions of dissolved trace constituents in the aquifers probably are related to the proximity to mineralogic sources as well as chemical and hydraulic mechanisms. For example, concentrations of some constituents, such as cadmium and arsenic, are largest in the vicinity of the Dakota Formation in northwestern Iowa. Other constituents, such as beryllium and vanadium, have larger concentrations near the edge of the Forest City basin in southwestern Iowa and northwestern Missouri. Strontium and fluoride concentrations generally increase from north to south, which suggests the input of these trace constituents during the recharge events. However, concentrations of bromide, radium-226, and lithium show distribution patterns similar to the "plume" defined by dissolved solids and isotopes of water, suggesting dilution of concentrations of trace constituents by Pleistocene recharge. Concentrations of other constituents are partly controlled by aquifer temperature, such as silica in south-central Iowa, and solubility controls, such as barium in northeastern Illinois. Additional information on the chemical and mineralogical composition of the aquifer matrix and the isotopically lightest ground water is needed to evaluate the hypothesis of Pleistocene mixing before more quantitative studies can be done to evaluate the different proposed mechanisms that have controlled and modified the water chemistry over time. This study, however, indicates that the ground water in the region is thousands of years old. The study also indicates that the major chemical trends in the aquifers probably are related as much to paleohydrogeologic flow systems during Pleistocene time as to the present flow system, which may postdate the retreat of the last ice sheet about 12,000 years ago.

Aquifer-test evaluation and potential effects of increased ground-water pumpage at the Stovepipe Wells Hotel area, Death Valley National Monument, California

USGS Publications Warehouse

Woolfenden, L.R.; Martin, Peter; Baharie, Brian

1988-01-01

Ground-water use in the Stovepipe Wells Hotel area in Death Valley National Monument is expected to increase significantly if the nonpotable, as well as potable, water supply is treated by reverse osmosis. During the peak tourist season, October through March, ground-water pumpage could increase by 37,500 gallons per day, or 76%. The effects of this additional pumpage on water levels in the area, particularly near a strand of phreatophytes about 10,000 feet east of the well field, are of concern. In order to evaluate the effects of increased pumpage on water levels in the Stovepipe Wells Hotel area well field, two aquifer tests were performed at the well field to determine the transmissivity and storage coefficients of the aquifer. Analysis of the aquifer test determined that a transmissivity of 1,360 feet squared per day was representative of the aquifer. The estimated value of transmissivity and the storage-coefficient values that are representative of confined (1.2 x .0004) and unconfined (0.25) conditions were used in the Theis equation to calculate the additional drawdown that might occur after 1, 10, and 50 years of increased pumpage. The drawdown calculated by using the lower storage-coefficient value represents the maximum additional drawdown that might be expected from the assumed increase in pumpage; the drawdown calculated by using the higher storage-coefficient value represents the minimum additional drawdown. Calculated additional drawdowns after 50 years of pumping range from 7.8 feet near the pumped well to 2.4 feet at the phreatophyte stand assuming confined conditions, and from 5.7 feet near the pumped well to 0.3 foot at the phreatophyte stand assuming unconfined conditions. Actual drawdowns probably will be somewhere between these values. Drawdowns measured in observation wells during 1973-85, in response to an average pumpage of 34,200 gallons per day at the Stovepipe Wells Hotel well field, are similar to the drawdowns calculated by the Theis

Factors controlling elevated lead concentrations in water samples from aquifer systems in Florida

USGS Publications Warehouse

Katz, B.G.; Bullen, M.P.; Bullen, T.D.; Hansard, Paul

1999-01-01

Concentrations of total lead (Pb) and dissolved Pb exceeded the U.S. Environmental Protection Agency action level of 15 micrograms per liter (mg/L) in approximately 19 percent and 1.3 percent, respectively, of ground-water samples collected during 1991-96 from a statewide network of monitoring wells designed to delineate background water quality of Florida's major aquifer systems. Differences in total Pb concentrations among aquifer systems reflect the combined influence of anthropogenic sources and chemical conditions in each system. A highly significant (p<0.001) difference in median total Pb concentrations was found for water samples from wells with water-level recording devices that contain Pb-counterweights (14 mg/L) compared to non-recorder wells (2 mg/L). Differences between total Pb concentrations for recorder and non-recorder wells are even more pronounced when compared for each aquifer system. The largest differences for recorder status are found for the surficial aquifer system, where median total Pb concentrations are 44 and 2.4 mg/L for recorder wells and non-recorder wells, respectively. Leaching of Pb from metal casing materials is another potential source of Pb in ground water samples. Median total Pb concentrations in water samples from the surficial, intermediate, and Floridan aquifer systems are higher from recorder wells cased with black iron than for recorder wells with steel and PVC casing material. Stable isotopes of Pb were used in this study to distinguish between anthropogenic and natural sources of Pb in ground water, as Pb retains the isotopic signature of the source from which it is derived. Based on similarities between slopes and intercepts of trend lines for various sample types (plots of 206Pb/204Pb versus 208Pb/204Pb and 207Pb/204Pb versus 208Pb/204Pb) the predominant source of total Pb in water samples from the surficial aquifer system is corrosion of Pb counterweights. It is likely that only ground-water samples, not the aquifer

Hydrology of the Bayou Bartholomew alluvial aquifer-stream system, Arkansas

USGS Publications Warehouse

Broom, M.E.; Reed, J.E.

1973-01-01

The study area comprises about 3,200 square miles of the Mississippi Alluvial Plain in southeast Arkansas. About 90 percent of the area drains south to the Ouachita River in Louisiana. The alluvial aquifer and the streams are hydraulically connected and are studied as an aquifer-stream system. Bayou Bartholomew is a principal stream of the system. The aquifer is underlain by confining strata of the Jackson Group and Cockfield Formation. The mean annual surface-water yield of the area that drains to the Ouachita River basin is nearly 2 million acre-feet. Flood-control projects have significantly reduced flooding in the area. Basin boundaries and low-flow characteristics of streams have been altered as a result of the flood-control projects and streamflow diversion for irrigation. The direction of ground-water flow generally is southward. Bayou Bartholomew functions mostly as a drain for ground-water flow from the west and as a recharge source to the aquifer east of the bayou. As a result of navigation pools, the Arkansas River is mostly a steady-recharge source to the aquifer. Pumpage from the aquifer and streams increased from about 20,000 acre-feet in 1941 to 237,000 acre-feet in 1970. Estimates of flow, derived from analog analysis but lacking field verification, indicate that recharge to the aquifer in 1970 was about 161,000 acre-feet. About 70 percent of the recharge was by capture from streams as a result of ground-water pumpage. Discharge from the aquifer was about 233,000 acre-feet. About 80 percent of the discharge was through wells. Stream diversion in 1970 from capture and open channel, excluding capture from the Arkansas and Mississippi Rivers, was about 110,000 acre-feet. Return flow to streams from rice irrigation and fishponds was about 60,000 acre-feet. The chemical quality of streamflows is excellent for irrigation. Water from the aquifer generally ranges from permissible to excellent for irrigation. The use of water from the aquifer in the flood

Aquifer-nomenclature guidelines

USGS Publications Warehouse

Laney, R.L.; Davidson, C.B.

1986-01-01

Guidelines and recommendations for naming aquifers are presented to assist authors of geohydrological reports in the United States Geological Survey, Water Resources Division. The hierarchy of terms that is used for water- yielding rocks from largest to smallest is aquifer system, aquifer, and zone. If aquifers are named, the names should be derived from lithologic terms, rock-stratigraphic units, or geographic names. The following items are not recommended as sources of aquifer names: time-stratigraphic names, relative position, alphanumeric designations, depositional environment, depth of occurrence, acronyms, and hydrologic conditions. Confining units should not be named unless doing so clearly promotes understanding of a particular aquifer system. Sources of names for confining units are similar to those for aquifer names, i.e. lithologic terms, rock-stratigraphic units or geographic names. Examples of comparison charts and tables that are used to define the geohydrologic framework are included. Aquifers are defined in 11 hypothetical examples that characterize geohydrologic settings throughout the country. (Author 's abstract)

Using Genetic Algorithm and MODFLOW to Characterize Aquifer System of Northwest Florida

EPA Science Inventory

By integrating Genetic Algorithm and MODFLOW2005, an optimizing tool is developed to characterize the aquifer system of Region II, Northwest Florida. The history and the newest available observation data of the aquifer system is fitted automatically by using the numerical model c...

Ground-water pumpage in the Willamette lowland regional aquifer system, Oregon and Washington, 1990

USGS Publications Warehouse

Collins, Charles A.; Broad, Tyson M.

1996-01-01

Ground-water pumpage for 1990 was estimated for an area of about 5,700 square miles in northwestern Oregon and southwestern Washington as part of the Puget-Willamette Lowland Regional Aquifer System Analysis study. The estimated total ground-water pumpage in 1990 was about 340,000 acre-feet. Ground water in the study area is pumped mainly from Quaternary sediment; lesser amounts are withdrawn from Tertiary volcanic materials. Large parts of the area are used for agriculture, and about two and one-half times as much ground water was pumped for irrigation as for either public- supply or industrial needs. Estimates of ground- water pumpage for irrigation in the central part of the Willamette Valley were generated by using image-processing techniques and Landsat Thematic Mapper data. Field data and published reports were used to estimate pumpage for irrigation in other parts of the study area. Information on public- supply and industrial pumpage was collected from Federal, State, and private organizations and individuals.

Water withdrawals and trends from the Floridan aquifer system in the southeastern United States, 1950-2000

USGS Publications Warehouse

Marella, Richard L.; Berndt, Marian P.

2005-01-01

The Floridan aquifer system in the southeastern United States is one of the most productive aquifers in the world (Miller, 1990). This aquifer system underlies an area of about 100,000 square miles in southern Alabama, eastern and southern Georgia, southeastern Mississippi, southern South Carolina, and all of Florida. The Floridan aquifer system is the primary source of water for nearly 10 million people and supports agriculture, industry, and tourism throughout most of the region. In most areas, water from this aquifer is potable and needs very little treatment before use. However, in southern Florida (south of Lake Okeechobee), northwestern Florida and southern Alabama and Mississippi (Pensacola and westward), and eastern South Carolina, water in the aquifer system generally is not potable. The purpose of this report is to: Provide a general description of the Floridan aquifer system; Discuss water withdrawals by category for 2000; Highlight trends in water withdrawals between 1950 and 2000; and Provide a brief summary on the effects that human impacts have on the Floridan aquifer system.

Hydrogeology, Ground-Water-Age Dating, Water Quality, and Vulnerability of Ground Water to Contamination in a Part of the Whitewater Valley Aquifer System near Richmond, Indiana, 2002-2003

USGS Publications Warehouse

Buszka, Paul M.; Watson, Lee R.; Greeman, Theodore K.

2007-01-01

Results of detailed water-quality analyses, ground-waterage dating, and dissolved-gas analyses indicated the vulnerability of ground water to specific types of contamination, the sequence of contaminant introduction to the aquifer relative to greenfield development, and processes that may mitigate the contamination. Concentrations of chloride and sodium and chloride/bromide weight ratios in sampled water from five wells indicated the vulnerability of the upper aquifer to roaddeicer contamination. Ground-water-age estimates from these wells indicated the onset of upgradient road-deicer use within the previous 25 years. Nitrate in the upper aquifer predates the post-1972 development, based on a ground-water-age date (30 years) and the nitrate concentration (5.12 milligrams per liter as nitrogen) in water from a deep well. Vulnerability of the aquifer to nitrate contamination is limited partially by denitrification. Detection of one to four atrazine transformation products in water samples from the upper aquifer indicated biological and hydrochemical processes that may limit the vulnerability of the ground water to atrazine contamination. Microbial processes also may limit the aquifer vulnerability to small inputs of halogenated aliphatic compounds, as indicated by microbial transformations of trichlorofluoromethane and trichlorotrifluoroethane relative to dichlorodifluoromethane. The vulnerability of ground water to contamination in other parts of the aquifer system also may be mitigated by hydrodynamic dispersion and biologically mediated transformations of nitrate, pesticides, and some organic compounds. Identification of the sequence of contamination and processes affecting the vulnerability of ground water to contamination would have been unlikely with conventional assessment methods.

Long-term measurements of agronomic crop irrigation in the Mississippi Delta portion of the Lower Mississippi River Valley

USDA-ARS?s Scientific Manuscript database

With over 4 million ha irrigated cropland, the Lower Mississippi River Valley (LMRV) is a highly productive agricultural region where irrigation practices are similar and the Mississippi River Valley alluvial aquifer (MRVA) is a primary source of on-demand irrigation. Owing to agricultural exports, ...

Simulation of Groundwater Flow in the Coastal Plain Aquifer System of Virginia

USGS Publications Warehouse

Heywood, Charles E.; Pope, Jason P.

2009-01-01

The groundwater model documented in this report simulates the transient evolution of water levels in the aquifers and confining units of the Virginia Coastal Plain and adjacent portions of Maryland and North Carolina since 1890. Groundwater withdrawals have lowered water levels in Virginia Coastal Plain aquifers and have resulted in drawdown in the Potomac aquifer exceeding 200 feet in some areas. The discovery of the Chesapeake Bay impact crater and a revised conceptualization of the Potomac aquifer are two major changes to the hydrogeologic framework that have been incorporated into the groundwater model. The spatial scale of the model was selected on the basis of the primary function of the model of assessing the regional water-level responses of the confined aquifers beneath the Coastal Plain. The local horizontal groundwater flow through the surficial aquifer is not intended to be accurately simulated. Representation of recharge, evapotranspiration, and interaction with surface-water features, such as major rivers, lakes, the Chesapeake Bay, and the Atlantic Ocean, enable simulation of shallow flow-system details that influence locations of recharge to and discharge from the deeper confined flow system. The increased density of groundwater associated with the transition from fresh to salty groundwater near the Atlantic Ocean affects regional groundwater flow and was simulated with the Variable Density Flow Process of SEAWAT (a U.S. Geological Survey program for simulation of three-dimensional variable-density groundwater flow and transport). The groundwater density distribution was generated by a separate 108,000-year simulation of Pleistocene freshwater flushing around the Chesapeake Bay impact crater during transient sea-level changes. Specified-flux boundaries simulate increasing groundwater underflow out of the model domain into Maryland and minor underflow from the Piedmont Province into the model domain. Reported withdrawals accounted for approximately

Capture zone of a multi-well system in bounded peninsula-shaped aquifers.

PubMed

Zarei-Doudeji, Somayeh; Samani, Nozar

2014-08-01

In this paper we present the equation of capture zone for multi-well system in peninsula-shaped confined and unconfined aquifers. The aquifer is rectangular in plan view, bounded along three sides, and extends to infinity at the fourth side. The bounding boundaries are either no-flow (impervious) or in-flow (constant head) so that aquifers with six possible boundary configurations are formed. The well system is consisted of any number of extraction or injection wells or combination of both with any flow rates. The complex velocity potential equations for such a well-aquifer system are derived to delineate the capture envelop. Solutions are provided for the aquifers with and without a uniform regional flow of any directions. The presented equations are of general character and have no limitations in terms of well numbers, positions and types, extraction/injection rate, and regional flow rate and direction. These solutions are presented in form of capture type curves which are useful tools in hands of practitioners to design in-situ groundwater remediation systems, to contain contaminant plumes, to evaluate the surface-subsurface water interaction and to verify numerical models. Copyright © 2014 Elsevier B.V. All rights reserved.

INFILTRATION OF ATRAZINE AND METABOLOTES FROM A STREAM TO AN ALLUVIAL AQUIFER

EPA Science Inventory

The infiltration of atrazine, deethylatrazine, and deisopropylatrazine from Walnut Creek, a tributary stream, to the alluvial valley aquifer along the South Skunk River in central Iowa occurred where the stream transects the river's flood plain. A preliminary estimate indicated t...

Hydrogeology and water quality of the Dublin and Midville aquifer systems at Waynesboro, Burke County, Georgia, 2011

USGS Publications Warehouse

Gonthier, Gerard

2013-01-01

The hydrogeology and water quality of the Dublin and Midville aquifer systems were characterized in the City of Waynesboro area in Burke County, Georgia, based on geophysical and drillers’ logs, flowmeter surveys, a 24-houraquifer test, and the collection and chemical analysis of water samples in a newly constructed well. At the test site, the Dublin aquifer system consists of interlayered sands and clays between depths of 396 and 691 feet, and the Midville aquifer system consists of a sandy clay layer overlying a sand and gravel layer between depths of 728 and 936 feet. The new well was constructed with three screened intervals in the Dublin aquifer system and four screened intervals in the Midville aquifer system. Wellbore-flowmeter testing at a pumping rate of 1,000 gallons per minute indicated that 52.2 percent of the total flow was from the shallower Dublin aquifer system with the remaining 47.8 percent from the deeper Midville aquifer system. The lower part of the lower Midville aquifer (900 to 930 feet deep), contributed only 0.1 percent of the total flow. Hydraulic properties of the two aquifer systems were estimated using data from two wellbore-flowmeter surveys and a 24-hour aquifer test. Estimated values of transmissivity for the Dublin and Midville aquifer systems were 2,000 and 1,000 feet squared per day, respectively. The upper and lower Dublin aquifers have a combined thickness of about 150 feet and the horizontal hydraulic conductivity of the Dublin aquifer system averages 10 feet per day. The upper Midville aquifer, lower Midville confining unit, and lower Midville aquifer have a combined thickness of about 210 feet, and the horizontal hydraulic conductivity of the Midville aquifer system averages 6 feet per day. Storage coefficient of the Dublin aquifer system, computed using the Theis method on water-level data from one observation well, was estimated to be 0.0003. With a thickness of about 150 feet, the specific storage of the Dublin aquifer

Competition by aquifer materials in a bimetallic nanoparticle/persulfate system for the treatment of trichloroethylene.

PubMed

Al-Shamsi, Mohammed Ahmad; Thomson, Neil R

2013-10-01

It has been suggested in the literature that aquifer materials can compete with the target organic compounds in an activated peroxygen system. In this study, we employed a rapid treatment method using persulfate activated with bimetallic nanoparticles to investigate the competition between aquifer materials and the dissolved phase of a target organic compound. The concentration of dissolved trichloroethylene (TCE) remaining after using the activated persulfate system was two- to three-fold higher in a soil slurry batch system than in an aqueous batch system. For all five aquifer materials investigated, an increase in the mass of the aquifer solids significantly decreased the degradation of TCE. A linear relationship was observed between the mass of aquifer materials and the initial TCE degradation rate, suggesting that the organic carbon and/or aquifer material constituents (e.g., carbonates and bicarbonates) compete with the oxidation of TCE.

Recharge rates and aquifer hydraulic characteristics for selected drainage basins in middle and east Tennessee

USGS Publications Warehouse

Hoos, A.B.

1990-01-01

Quantitative information concerning aquifer hydrologic and hydraulic characteristics is needed to manage the development of ground-water resources. These characteristics are poorly defined for the bedrock aquifers in Middle and East Tennessee where demand for water is increasing. This report presents estimates of recharge rate, storage coefficient, diffusivity, and transmissivity for representative drainage basins in Middle and East Tennessee, as determined from analyses of stream-aquifer interactions. The drainage basins have been grouped according to the underlying major aquifer, then statistical descriptions applied to each group, in order to define area1 distribution of these characteristics. Aquifer recharge rates are estimated for representative low, average, and high flow years for 63 drainage basins using hydrograph analysis techniques. Net annual recharge during average flow years for all basins ranges from 4.1 to 16.8 in/yr (inches per year), with a mean value of 7.3 in. In general, recharge rates are highest for basins underlain by the Blue Ridge aquifer (mean value11.7 in/yr) and lowest for basins underlain by the Central Basin aquifer (mean value 5.6 in/yr). Mean recharge values for the Cumberland Plateau, Highland Rim, and Valley and Ridge aquifers are 6.5, 7.4, and 6.6 in/yr, respectively. Gravity drainage characterizes ground-water flow in most surficial bedrock aquifer in Tennessee. Accordingly, a gravity yield analysis, which compares concurrent water-level and streamflow hydrographs, was used to estimate aquifer storage coefficient for nine study basins. The basin estimates range from 0.002 to 0.140; however, most estimates are within a narrow range of values, from 0.01 to 0.025. Accordingly, storage coefficient is estimated to be 0.01 for all aquifers in Middle and East Tennessee, with the exception of the aquifer in the inner part of the Central Basin, for which storage coefficient is estimated to be 0.002. Estimates of aquifer hydraulic

Base of principal aquifer for parts of the North Platte, South Platte, and Twin Platte Natural Resources Districts, western Nebraska

USGS Publications Warehouse

Hobza, Christopher M.; Abraham, Jared D.; Cannia, James C.; Johnson, Michaela R.; Sibray, Steven S.

2014-01-01

Water resources in the North and South Platte River valleys of Nebraska, including the valley of Lodgepole Creek, are critical to the social and economic health of the area, and for the recovery of threatened and endangered species in the Platte River Basin. Groundwater and surface water are heavily used resources, and uses are regulated in the study area. Irrigation is the dominant water use and, in most instances, is supplied by both groundwater and surface-water sources. The U.S. Geological Survey and its partners have collaborated to use airborne geophysical surveys for areas of the North and South Platte River valleys including the valley of Lodgepole Creek in western Nebraska. The objective of the surveys was to map the aquifers and underlying bedrock topography of selected areas to help improve the understanding of groundwater–surface-water relations to guide water-management decisions. This project was a cooperative study involving the North Platte Natural Resources District, the South Platte Natural Resources District, the Twin Platte Natural Resources District, the Conservation and Survey Division of the University of Nebraska-Lincoln, and the Nebraska Environmental Trust. This report presents the interpreted base-of-aquifer surface for part of the area consisting of the North Platte Natural Resources District, the South Platte Natural Resources District, and the Twin Platte Natural Resources District. The interpretations presented herein build on work done by previous researchers from 2008 to 2009 by incorporating additional airborne electromagnetic survey data collected in 2010 and additional test holes from separate, related studies. To make the airborne electromagnetic data useful, numerical inversion was used to convert the measured data into a depth-dependent subsurface resistivity model. An interpretation of the elevation and configuration of the base of aquifer was completed in a geographic information system that provided x, y, and z

Hydrogeologic framework and hydrologic budget components of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

USGS Publications Warehouse

Kahle, S.C.; Morgan, D.S.; Welch, W.B.; Ely, D.M.; Hinkle, S.R.; Vaccaro, J.J.; Orzol, L.L.

2011-01-01

The Columbia Plateau Regional Aquifer System (CPRAS) covers an area of about 44,000 square miles in a structural and topographic basin within the drainage of the Columbia River in Washington, Oregon, and Idaho. The primary aquifers are basalts of the Columbia River Basalt Group (CRBG) and overlying sediment. Eighty percent of the groundwater use in the study area is for irrigation, in support of a $6 billion per year agricultural economy. Water-resources issues in the Columbia Plateau include competing agricultural, domestic, and environmental demands. Groundwater levels were measured in 470 wells in 1984 and 2009; water levels declined in 83 percent of the wells, and declines greater than 25 feet were measured in 29 percent of the wells. Conceptually, the system is a series of productive basalt aquifers consisting of permeable interflow zones separated by less permeable flow interiors; in places, sedimentary aquifers overly the basalts. The aquifer system of the CPRAS includes seven hydrogeologic units-the overburden aquifer, three aquifer units in the permeable basalt rock, two confining units, and a basement confining unit. The overburden aquifer includes alluvial and colluvial valley-fill deposits; the three basalt units are the Saddle Mountains, Wanapum, and Grande Ronde Basalts and their intercalated sediments. The confining units are equivalent to the Saddle Mountains-Wanapum and Wanapum-Grande Ronde interbeds, referred to in this study as the Mabton and Vantage Interbeds, respectively. The basement confining unit, referred to as Older Bedrock, consists of pre-CRBG rocks that generally have much lower permeabilities than the basalts and are considered the base of the regional flow system. Based on specific-capacity data, median horizontal hydraulic conductivity (Kh) values for the overburden, basalt units, and bedrock are 161, 70, and 6 feet per day, respectively. Analysis of oxygen isotopes in water and carbon isotopes in dissolved inorganic carbon from

Acoustic valley edge states in a graphene-like resonator system

NASA Astrophysics Data System (ADS)

Yang, Yahui; Yang, Zhaoju; Zhang, Baile

2018-03-01

The concept of valley physics, as inspired by the recent development in valleytronic materials, has been extended to acoustic crystals for manipulation of air-borne sound. Many valleytronic materials follow the model of a gapped graphene. Yet the previously demonstrated valley acoustic crystal adopted a mirror-symmetry-breaking mechanism, lacking a direct counterpart in condensed matter systems. In this paper, we investigate a two-dimensional (2D) periodic acoustic resonator system with inversion symmetry breaking, as an analogue of a gapped graphene monolayer. It demonstrates the quantum valley Hall topological phase for sound waves. Similar to a gapped graphene, gapless topological valley edge states can be found at a zigzag domain wall separating different domains with opposite valley Chern numbers, while an armchair domain wall hosts no gapless edge states. Our study offers a route to simulate novel valley phenomena predicted in gapped graphene and other 2D materials with classical acoustic waves.

Predicted pH at the domestic and public supply drinking water depths, Central Valley, California

USGS Publications Warehouse

Rosecrans, Celia Z.; Nolan, Bernard T.; Gronberg, Jo Ann M.

2017-03-08

This scientific investigations map is a product of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project modeling and mapping team. The prediction grids depicted in this map are of continuous pH and are intended to provide an understanding of groundwater-quality conditions at the domestic and public supply drinking water zones in the groundwater of the Central Valley of California. The chemical quality of groundwater and the fate of many contaminants is often influenced by pH in all aquifers. These grids are of interest to water-resource managers, water-quality researchers, and groundwater modelers concerned with the occurrence of natural and anthropogenic contaminants related to pH. In this work, the median well depth categorized as domestic supply was 30 meters below land surface, and the median well depth categorized as public supply is 100 meters below land surface. Prediction grids were created using prediction modeling methods, specifically boosted regression trees (BRT) with a Gaussian error distribution within a statistical learning framework within the computing framework of R (http://www.r-project.org/). The statistical learning framework seeks to maximize the predictive performance of machine learning methods through model tuning by cross validation. The response variable was measured pH from 1,337 wells and was compiled from two sources: USGS National Water Information System (NWIS) database (all data are publicly available from the USGS: http://waterdata.usgs.gov/ca/nwis/nwis) and the California State Water Resources Control Board Division of Drinking Water (SWRCB-DDW) database (water quality data are publicly available from the SWRCB: http://www.waterboards.ca.gov/gama/geotracker_gama.shtml). Only wells with measured pH and well depth data were selected, and for wells with multiple records, only the most recent sample in the period 1993–2014 was used. A total of 1,003 wells (training dataset) were used to train the BRT

Summary of hydrologic testing of the Floridan aquifer system at Fort Stewart, coastal Georgia, 2009-2010

USGS Publications Warehouse

Gonthier, Gerald J.

2011-01-01

Two test wells were completed at Fort Stewart, coastal Georgia, to investigate the potential for using the Lower Floridan aquifer as a source of water to satisfy anticipated, increased water needs. The U.S. Geological Survey, in cooperation with the U.S. Department of the Army, completed hydrologic testing of the Floridan aquifer system at the study site, including flowmeter surveys, slug tests, and 24- and 72-hour aquifer tests by mid-March 2010. Analytical approaches and model simulation were applied to aquifer-test results to provide estimates of transmissivity and hydraulic conductivity of the multilayered Floridan aquifer system. Data from a 24-hour aquifer test of the Upper Floridan aquifer were evaluated by using the straight-line Cooper-Jacob analytical method. Data from a 72-hour aquifer test of the Lower Floridan aquifer were simulated by using axisymmetric model simulations. Results of aquifer testing indicated that the Upper Floridan aquifer has a transmissivity of 100,000 feet-squared per day, and the Lower Floridan aquifer has a transmissivity of 7,000 feet-squared per day. A specific storage for the Floridan aquifer system as a result of model calibration was 3E-06 ft–1. Additionally, during a 72-hour aquifer test of the Lower Floridan aquifer, a drawdown response was observed in two Upper Floridan aquifer wells, one of which was more than 1 mile away from the pumped well.

Framework for regional synthesis of water-quality data for the glacial aquifer system in the United States

USGS Publications Warehouse

Warner, Kelly L.; Arnold, Terri L.

2005-01-01

The glacial aquifer system is the largest principal aquifer in aerial extent and ground-water use for public supply in the United States. A principal aquifer is defined as a regionally extensive aquifer or aquifer system that has the potential to be used as a source of potable water (U.S. Geological Survey, 2003). Multiple aquifers often are grouped into large, extensive aquifer systems such as the glacial aquifer system. The glacial aquifer system is considered here to include all unconsolidated aquifers above bedrock north of the line of continental glaciation throughout the country (fig. 1). Total withdrawals from the glacial aquifer system were 3,560 million gallons per day in 2000, which constitutes almost 5 percent of total withdrawals from all aquifers in the United States (Maupin and Barber, 2005). Approximately 41 million people relied on the glacial aquifer for public supply and domestic use in 2000. The U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program began assessing the glacial aquifer system in 1991. The assessment of water-quality data on a regional scale, such as the glacial aquifer system, is coincident with the regional framework established by the Regional Aquifer-System Analysis Program (RASA) (Sun and others, 1997). From 1978 to 1995, the RASA Program systematically evaluated 25 of the Nation's most important groundwater systems including studies in the glacial aquifer system in the northeast, Midwest, and northern Midwest United States. The NAWQA Program is building on the work of the RASA Program to study the water quality of 16 of the most important ground-water systems (Lapham and others, 2005). Over 1,700 water-quality samples have been collected by the NAWQA Program from 1991 to 2004 to assess the glacial aquifer system. This large data set is unique in that the samples have been collected using a consistent sampling protocol, and multiple nested samples. The nested samples address the recently recharged shallow

Revised hydrogeologic framework of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina

USGS Publications Warehouse

Williams, Lester J.; Kuniansky, Eve L.

2015-04-08

The hydrogeologic framework for the Floridan aquifer system has been revised throughout its extent in Florida and parts of Georgia, Alabama, and South Carolina. The updated framework generally conforms to the original framework established by the U.S. Geological Survey in the 1980s, except for adjustments made to the internal boundaries of the Upper and Lower Floridan aquifers and the individual higher and contrasting lower permeability zones within these aquifers. The system behaves as one aquifer over much of its extent; although subdivided vertically into two aquifer units, the Upper and Lower Floridan aquifers. In the previous framework, discontinuous numbered middle confining units (MCUI–VII) were used to subdivide the system. In areas where less-permeable rocks do not occur within the middle part of the system, the system was previously considered one aquifer and named the Upper Floridan aquifer. In intervening years, more detailed data have been collected in local areas, resulting in some of the same lithostratigraphic units in the Floridan aquifer system being assigned to the Upper or Lower Floridan aquifer in different parts of the State of Florida. Additionally, some of the numbered middle confining units are found to have hydraulic properties within the same order of magnitude as the aquifers. A new term “composite unit” is introduced for lithostratigraphic units that cannot be defined as either a confining or aquifer unit over their entire extent. This naming convention is a departure from the previous framework, in that stratigraphy is used to consistently subdivide the aquifer system into upper and lower aquifers across the State of Florida. This lithostratigraphic mapping approach does not change the concept of flow within the system. The revised boundaries of the Floridan aquifer system were mapped by considering results from local studies and regional correlations of lithostratigraphic and hydrogeologic units or zones. Additional zones within

Simulating selenium and nitrogen fate and transport in coupled stream-aquifer systems of irrigated regions

NASA Astrophysics Data System (ADS)

Shultz, Christopher D.; Bailey, Ryan T.; Gates, Timothy K.; Heesemann, Brent E.; Morway, Eric D.

2018-05-01

Elevated levels of selenium (Se) in aqueous environments can harm aquatic life and endanger livestock and human health. Although Se occurs naturally in the rocks and soils of many alluvial aquifers, mining and agricultural activities can increase its rate of mobilization and transport to surface waters. Attention is given here to regions where nonpoint source return flows from irrigated lands carry pollutant loads to aquifers and streams, contributing to concentrations that violate regulatory and performance standards. Of particular concern is the heightened level and mobilization of Se influenced by nitrate (NO3), a harmful pollutant in its own right. We present a numerical model that simulates the reactive transport of Se and nitrogen (N) species in a coupled groundwater-surface water system. Building upon a conceptual model that incorporates the major processes affecting Se and NO3 transport in an irrigated watershed, the model links the finite-difference models MODFLOW, UZF-RT3D, and OTIS, to simulate flow and reactive transport of multiple chemical species in both the aquifer and a stream network, with mass exchange between the two. The capability of the new model is showcased by calibration, testing, and application to a 500 km2 region in Colorado's Lower Arkansas River Valley using a rich data set gathered over a 10-yr period. Simulation of spatial and temporal distributions of Se concentration reveals conditions that exceed standards in groundwater for approximately 20% of the area. For the Arkansas River, standards are exceeded by 290%-450%. Simulation indicates that river concentrations of NO3 alone are near the current interim standard for the total of all dissolved N species. These results indicate the need for future use of the developed model to investigate the prospects for land and water best management practices to decrease pollutant levels.

Simulating selenium and nitrogen fate and transport in coupled stream-aquifer systems of irrigated regions

USGS Publications Warehouse

Shultz, Christopher D.; Bailey, Ryan T.; Gates, Timothy K.; Heesemann, Brent E.; Morway, Eric D.

2018-01-01

Elevated levels of selenium (Se) in aqueous environments can harm aquatic life and endanger livestock and human health. Although Se occurs naturally in the rocks and soils of many alluvial aquifers, mining and agricultural activities can increase its rate of mobilization and transport to surface waters. Attention is given here to regions where nonpoint source return flows from irrigated lands carry pollutant loads to aquifers and streams, contributing to concentrations that violate regulatory and performance standards. Of particular concern is the heightened level and mobilization of Se influenced by nitrate (NO3), a harmful pollutant in its own right. We present a numerical model that simulates the reactive transport of Se and nitrogen (N) species in a coupled groundwater-surface water system. Building upon a conceptual model that incorporates the major processes affecting Se and NO3 transport in an irrigated watershed, the model links the finite-difference models MODFLOW, UZF-RT3D, and OTIS, to simulate flow and reactive transport of multiple chemical species in both the aquifer and a stream network, with mass exchange between the two. The capability of the new model is showcased by calibration, testing, and application to a 500 km2 region in Colorado’s Lower Arkansas River Valley using a rich data set gathered over a 10-yr period. Simulation of spatial and temporal distributions of Se concentration reveals conditions that exceed standards in groundwater for approximately 20% of the area. For the Arkansas River, standards are exceeded by 290%–450%. Simulation indicates that river concentrations of NO3 alone are near the current interim standard for the total of all dissolved N species. These results indicate the need for future use of the developed model to investigate the prospects for land and water best management practices to decrease pollutant levels.

Plan of study for the Northern Atlantic Coastal Plain Regional Aquifer System Analysis

USGS Publications Warehouse

Meisler, Harold

1980-01-01

Sediments of Cretaceous to Holocene age compose the Northern Atlantic Coastal Plain aquifer system in an area of 50,000 square miles in parts of New York, New Jersey, Delaware, Maryland, Virginia, and North Carolina. The aquifer system is a major source of water supply in the area. About 1.4 billion gallons is withdrawn from its aquifers each day. Increasing withdrawal of ground water has created or intensified several problems such as declining water levels, development of large cones of depression, saltwater intrusion, spreading of ground-water contamination, and land subsidence. The U.S. Geological Survey has begun a comprehensive study that will define the geology, hydrology, and geochemistry of the aquifer system. The effects of future utilization of the aquifer system will be determined and alternative plans for water withdrawal will be evaluated through computer simulation modeling. This report describes the objectives, organization, and work plans of the study, and describes the work to be accomplished in each U.S. Geological Survey District of the study area.

Fens, seasonal wetlands, and the unconfined pumice aquifer east of the Cascade Range, south-central Oregon

NASA Astrophysics Data System (ADS)

Cummings, M. L.; Large, A.; Mowbray, A.; Weatherford, J.; Webb, B.

2013-12-01

Fens and seasonal wetlands in the headwaters of the Klamath and Deschutes river basins in south-central Oregon are present in an area blanketed by 2 to 3 m of pumice during the Holocene eruption of Mount Mazama. The lower pumice unit, moderately sorted coarse pumice lapilli to blocks (0.3 to 0.7 cm), phenocrysts, and lithics is 1.5 to 2 m thick; the upper pumice unit, poorly sorted lapilli to blocks (0.2 to 6 cm), minor phenocrysts, and lithics is 1 m thick. Pumice is a perched, unconfined aquifer over low permeability bedrock or pre-eruption fine-grained sediment. Early landscape response included partial erosion of pumice from pre-eruption valleys followed by partial filling by alluvium: phenocryst- and lithic-rich sand grading upward to glassy silt with rounded pumice pebbles. Groundwater-fed wetlands, fens, associated with the unconfined pumice aquifer occur as areas of diffuse groundwater discharge through gently sloping, convex surfaces underlain by up to 1.4 m of peat. Locally, focused discharge through the confining peat layer feeds low discharge streams. Carnivorous plants (sundews and pitcher plants) may be present. The sharp contact between peat and underlying pumice is an erosion surface that cuts progressively deeper into the upper and lower pumice units downslope. At the base of the slope peat with fen discharge feeding surface flow, alluvium with no surface flow, or a subtle berm separating the slope underlain by peat from the valley bottom underlain by alluvium may be present. Distinct vegetation changes take place at this transition. The erosion surface that underlies the peat layer in the fen is at the surface on the opposing valley wall and progressively rises up through the lower and upper pumice units: iron staining and cementation of pumice is locally prominent. Up to 1.5 m difference in water table occurs between the fen and opposing valley wall. Water table in piezometers screened in peat is at the surface. Locally, water table screened in

Precipitation and Runoff Simulations of the Carson Range and Pine Nut Mountains, and Updated Estimates of Ground-Water Inflow and the Ground-Water Budgets for Basin-Fill Aquifers of Carson Valley, Douglas County, Nevada, and Alpine County, California

USGS Publications Warehouse

Jeton, Anne E.; Maurer, Douglas K.

2007-01-01

Recent estimates of ground-water inflow to the basin-fill aquifers of Carson Valley, Nevada, and California, from the adjacent Carson Range and Pine Nut Mountains ranged from 22,000 to 40,000 acre-feet per year using water-yield and chloride-balance methods. In this study, watershed models were developed for watersheds with perennial streams and for watersheds with ephemeral streams in the Carson Range and Pine Nut Mountains to provide an independent estimate of ground-water inflow. This report documents the development and calibration of the watershed models, presents model results, compares the results with recent estimates of ground-water inflow to the basin-fill aquifers of Carson Valley, and presents updated estimates of the ground-water budget for basin-fill aquifers of Carson Valley. The model used for the study was the Precipitation-Runoff Modeling System, a physically based, distributed-parameter model designed to simulate precipitation and snowmelt runoff as well as snowpack accumulation and snowmelt processes. Geographic Information System software was used to manage spatial data, characterize model drainages, and to develop Hydrologic Response Units. Models were developed for * Two watersheds with gaged perennial streams in the Carson Range and two watersheds with gaged perennial streams in the Pine Nut Mountains using measured daily mean runoff, * Ten watersheds with ungaged perennial streams using estimated daily mean runoff, * Ten watershed with ungaged ephemeral streams in the Carson Range, and * A large area of ephemeral runoff near the Pine Nut Mountains. Models developed for the gaged watersheds were used as index models to guide the calibration of models for ungaged watersheds. Model calibration was constrained by daily mean runoff for 4 gaged watersheds and for 10 ungaged watersheds in the Carson Range estimated in a previous study. The models were further constrained by annual precipitation volumes estimated in a previous study to provide

Goldstone-Apple Valley Radio Telescope System Theory of Operation

NASA Technical Reports Server (NTRS)

Stephan, George R.

1997-01-01

The purpose of this learning module is to enable learners to describe how the Goldstone-Apple Valley Radio Telescope (GAVRT) system functions in support of Apple Valley Science and Technology Center's (AVSTC) client schools' radio astronomy activities.

Hydrogeology and simulation of ground-water flow in the thick regolith-fractured crystalline rock aquifer system of Indian Creek basin, North Carolina

USGS Publications Warehouse

Daniel, Charles C.; Smith, Douglas G.; Eimers, Jo Leslie

1997-01-01

The Indian Creek Basin in the southwestern Piedmont of North Carolina is one of five type areas studied as part of the Appalachian Valleys-Piedmont Regional Aquifer-System analysis. Detailed studies of selected type areas were used to quantify ground-water flow characteristics in various conceptual hydrogeologic terranes. The conceptual hydrogeologic terranes are considered representative of ground-water conditions beneath large areas of the three physiographic provinces--Valley and Ridge, Blue Ridge, and Piedmont--that compose the Appalachian Valleys-Piedmont Regional Aquifer-System Analysis area. The Appalachian Valleys-Piedmont Regional Aquifer-System Analysis study area extends over approximately 142,000 square miles in 11 states and the District of Columbia in the Appalachian highlands of the Eastern United States. The Indian Creek type area is typical of ground-water conditions in a single hydrogeologic terrane that underlies perhaps as much as 40 percent of the Piedmont physiographic province. The hydrogeologic terrane of the Indian Creek model area is one of massive and foliated crystalline rocks mantled by thick regolith. The area lies almost entirely within the Inner Piedmont geologic belt. Five hydrogeologic units occupy major portions of the model area, but statistical tests on well yields, specific capacities, and other hydrologic characteristics show that the five hydrogeologic units can be treated as one unit for purposes of modeling ground-water flow. The 146-square-mile Indian Creek model area includes the Indian Creek Basin, which has a surface drainage area of about 69 square miles. The Indian Creek Basin lies in parts of Catawba, Lincoln, and Gaston Counties, North Carolina. The larger model area is based on boundary conditions established for digital simulation of ground-water flow within the smaller Indian Creek Basin. The ground-water flow model of the Indian Creek Basin is based on the U.S. Geological Survey?s modular finite

Temperature Distribution and Thermal Performance of an Aquifer Thermal Energy Storage System

NASA Astrophysics Data System (ADS)

Ganguly, Sayantan

2017-04-01

Energy conservation and storage has become very crucial to make use of excess energy during times of future demand. Excess thermal energy can be captured and stored in aquifers and this technique is termed as Aquifer Thermal Energy Storage (ATES). Storing seasonal thermal energy in water by injecting it into subsurface and extracting in time of demand is the principle of an ATES system. Using ATES systems leads to energy savings, reduces the dependency on fossil fuels and thus leads to reduction in greenhouse gas emission. This study numerically models an ATES system to store seasonal thermal energy and evaluates the performance of it. A 3D thermo-hydrogeological numerical model for a confined ATES system is presented in this study. The model includes heat transport processes of advection, conduction and heat loss to confining rock media. The model also takes into account regional groundwater flow in the aquifer, geothermal gradient and anisotropy in the aquifer. Results show that thermal injection into the aquifer results in the generation of a thermal-front which grows in size with time. Premature thermal-breakthrough causes thermal interference in the system when the thermal-front reaches the production well and consequences in the fall of system performance and hence should be avoided. This study models the transient temperature distribution in the aquifer for different flow and geological conditions. This may be effectively used in designing an efficient ATES project by ensuring safety from thermal-breakthrough while catering to the energy demand. Based on the model results a safe well spacing is proposed. The thermal energy discharged by the system is determined and strategy to avoid the premature thermal-breakthrough in critical cases is discussed. The present numerical model is applied to simulate an experimental field study which is found to approximate the field results quite well.

The Southern Hills regional aquifer system of southeastern Louisiana and southwestern Mississippi

USGS Publications Warehouse

Buono, A.

1983-01-01

The Southern Hills regional aquifer system, named in a petition to the Environmental Protection Agency for designation as a sole or principal source of drinking water, is the primary source of public and domestic supplies in the northern 10 parishes of southeastern Louisiana. The gulfward dipping and thickening, complexly interbedded aquifer system extends from the northern limit of the recharge area near Vicksburg, Mississippi, as far as the Baton Rouge area in southeastern Louisiana. As many as 13 interdependent aquifer units compose the system in the southern part of the area and are known to coalesce or pinch out northward (updip) into fewer units. Aquifer water is almost exclusively a soft, sodium bicarbonate type with an average dissolved-solids concentration of about 220 milligrams per liter in southeastern Louisiana. Although several streams are available as alternatives for supply, they have not been accepted by local officials because of the additional water treatment that would be necessary and the extensive distribution system needed to deliver water to areas not near a source stream. Groundwater use in 1980 for public and domestic supply averaged 121 Mgal/d (million gallons per day), serving 744,000 people in southeastern Louisiana. In southwestern Mississippi, where the aquifer system is also the primary source for public and domestic supply, water use for these categories in 1980 totaled 25 Mgal/d, serving about 273,000 people. (USGS)

Evaluation of Selected Model Constraints and Variables on Simulated Sustainable Yield from the Mississippi River Valley Alluvial Aquifer System in Arkansas

USGS Publications Warehouse

Czarnecki, John B.

2008-01-01

An existing conjunctive use optimization model of the Mississippi River Valley alluvial aquifer was used to evaluate the effect of selected constraints and model variables on ground-water sustainable yield. Modifications to the optimization model were made to evaluate the effects of varying (1) the upper limit of ground-water withdrawal rates, (2) the streamflow constraint associated with the White River, and (3) the specified stage of the White River. Upper limits of ground-water withdrawal rates were reduced to 75, 50, and 25 percent of the 1997 ground-water withdrawal rates. As the upper limit is reduced, the spatial distribution of sustainable pumping increases, although the total sustainable pumping from the entire model area decreases. In addition, the number of binding constraint points decreases. In a separate analysis, the streamflow constraint associated with the White River was optimized, resulting in an estimate of the maximum sustainable streamflow at DeValls Bluff, Arkansas, the site of potential surface-water withdrawals from the White River for the Grand Prairie Area Demonstration Project. The maximum sustainable streamflow, however, is less than the amount of streamflow allocated in the spring during the paddlefish spawning period. Finally, decreasing the specified stage of the White River was done to evaluate a hypothetical river stage that might result if the White River were to breach the Melinda Head Cut Structure, one of several manmade diversions that prevents the White River from permanently joining the Arkansas River. A reduction in the stage of the White River causes reductions in the sustainable yield of ground water.

Hydrogeology, ground-water movement, and subsurface storage in the Floridan aquifer system in southern Florida

USGS Publications Warehouse

Meyer, Frederick W.

1989-01-01

The Floridan aquifer system of southern Florida is composed chiefly of carbonate rocks that range in age from early Miocene to Paleocene. The top of the aquifer system in southern Florida generally is at depths ranging from 500 to 1,000 feet, and the average thickness is about 3,000 feet. It is divided into three general hydrogeologic units: (1) the Upper Floridan aquifer, (2) the middle confining unit, and (3) the Lower Floridan aquifer. The Upper Floridan aquifer contains brackish ground water, and the Lower Floridan aquifer contains salty ground water that compares chemically to modern seawater. Zones of high permeability are present in the Upper and Lower Floridan aquifers. A thick, cavernous dolostone in the Lower Floridan aquifer, called the Boulder Zone, is one of the most permeable carbonate units in the world (transmissivity of about 2.5 x 107 feet squared per day). Ground-water movement in the Upper Floridan aquifer is generally southward from the area of highest head in central Florida, eastward to the Straits of Florida, and westward to the Gulf of Mexico. Distributions of natural isotopes of carbon and uranium generally confirm hydraulic gradients in the Lower Floridan aquifer. Groundwater movement in the Lower Floridan aquifer is inland from the Straits of Florida. The concentration gradients of the carbon and uranium isotopes indicate that the source of cold saltwater in the Lower Floridan aquifer is seawater that has entered through the karat features on the submarine Miami Terrace near Fort Lauderdale. The relative ages of the saltwater suggest that the rate of inland movement is related in part to rising sea level during the Holocene transgression. Isotope, temperature, and salinity anomalies in waters from the Upper Floridan aquifer of southern Florida suggest upwelling of saltwater from the Lower Floridan aquifer. The results of the study support the hypothesis of circulating relatively modern seawater and cast doubt on the theory that the

Nomenclature of regional hydrogeologic units of the Southeastern Coastal Plain aquifer system

USGS Publications Warehouse

Miller, J.A.; Renken, R.A.

1988-01-01

Clastic sediments of the Southeastern Coastal Plain aquifer system can be divided into four regional aquifers separated by three regional confining units. The four regional aquifers have been named for major rivers that cut across their outcrop areas and expose the aquifer materials. From youngest to oldest, the aquifers are called the Chickasawhay River, Pearl River, Chattahoochee River, and Black Warrior River aquifers, and the regional confining units separating them are given the same name as the aquifer they overlie. Most of the regional hydrogeologic units are subdivided within each of the four States that comprise the study area. Correlation of regional units is good with hydrogeologic units delineated by a similar regional study to the west and southwest. Because of complexity created by a major geologic structure to the northeast of the study area and dramatic facies change from clastic to carbonate strata to the southeast, correlation of regional hydrogeologic units is poor in these directions. (Author 's abstract)

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.

Identifying Stream/Aquifer Exchange by Temperature Gradient in a Guarani Aquifer System Outcrop Zone

NASA Astrophysics Data System (ADS)

Wendland, E.; Rosa, D. M. S.; Anache, J. A. A.; Lowry, C.; Lin, Y. F. F.

2017-12-01

Recharge of the Guarani Aquifer System (GAS) in South America is supposed to occur mainly in the outcrop zones, where the GAS appears as an unconfined aquifer (10% of the 1.2 Million km2 aquifer extension). Previous evaluations of recharge are based essentially on water balance estimates for the whole aquifer area or water table fluctuations in monitoring wells. To gain a more detailed understanding of the recharge mechanisms the present work aimed to study the stream aquifer interaction in a watershed (Ribeirão da Onça) at an outcrop zone. Two Parshall flumes were installed 1.3 km apart for discharge measurement in the stream. Along this distance an optic fiber cable was deployed to identify stretches with gaining and losing behavior. In order to estimate groundwater discharge in specific locations, 8 temperature sticks were set up along the stream reach to measure continuously the vertical temperature gradient. A temperature probe with 4 thermistors was also used to map the shallow streambed temperature gradient manually along the whole distance. The obtained results show a discharge difference of 250 m3/h between both flumes. Since the last significant rainfall (15 mm) in the watershed occurred 3 months ago, this value can be interpreted as the base flow contribution to the stream during the dry season. Given the temperature difference between groundwater ( 24oC) and surface water ( 17oC) the fiber-optic distributed temperature sensing (FO-DTS) allowed the identification of stretches with gaining behavior. Temperature gradients observed at the streambed varied between 0.67 and 14.33 oC/m. The study demonstrated that heat may be used as natural tracer even in tropical conditions, where the groundwater temperature is higher than the surface water temperature during the winter. The obtained results show that the discharge difference between both flumes can not be extrapolated without detailed analysis. Gaining and loosing stretches have to be identified on order

Hydrology of the Coastal Lowlands aquifer system in parts of Alabama, Florida, Louisiana, and Mississippi

USGS Publications Warehouse

Martin, Angel; Whiteman, C.D.

1999-01-01

Existing data on water levels, water use, water quality, and aquifer properties were used to construct a multilayer digital model to simulate flow in the aquifer system. The report describes the geohydrologic framework of the aquifer system, and the development, calibration, and sensitivity analysis of the ground-water-flow model, but it is primarily focused on the results of the simulations that show the natural flow of ground water throughout the regional aquifer system and the changes from the natural flow caused by development of ground-water supplies.

Projected ground-water development, ground-water levels, and stream-aquifer leakage in the South Fork Solomon River Valley between Webster Reservoir and Waconda Lake, north-central Kansas, 1979-2020

USGS Publications Warehouse

Kume, Jack; Lindgren, R.J.; Stullken, L.E.

1985-01-01

A two-dimensional finite difference computer model was used to project changes in the potentiometric surface, saturated thickness, and stream aquifer leakage in an alluvial aquifer resulting from four instances of projected groundwater development. The alluvial aquifer occurs in the South Fork Solomon River valley between Webster Reservoir and Waconda Lake in north-central Kansas. In the first two projections, pumpage for irrigation was held constant at 1978 rates throughout the projection period (1979-2020). In the second two projections, the 1978 pumpage was progressively increased each yr through 2020. In the second and fourth projections, surface water diversions in the Osborne Irrigation Canal were decreased by 50 %. For the third and fourth projections, each grid-block in the modeled area was classified initially as one of six types according to whether it represented irrigable or nonirrigable land, to its saturated thickness, to its location inside or outside the canal-river area, and to its pumping rate. The projected base-flow rates (leakage from the aquifer to the river) were lower during the irrigation season (June, July, and August) than during the other months of the yr because of the decline in hydraulic head produced by groundwater pumpage. Stream depletion, calculated as a decrease below the average (1970-78) estimated winter base-flow rate of 16.5 cu ft/sec, varied inversely with base flow. For the first two projections, a constant annual cycle of well pumpage and recharge was used throughout the projection period. Aquifer leakage to the river was nearly constant by the mid-to-late 1990's, implying that flow conditions had attained a stabilized annual cycle. The third and fourth projections never attained an annual stabilized cycle because the irrigation pumpage rate was increased each year. By the early 1980's, the hydraulic head had fallen below river stage, reversing the hydraulic gradient at the stream-aquifer interface and resulting in net

Simulated effects of groundwater withdrawals from the Kirkwood-Cohansey aquifer system and Piney Point aquifer, Maurice and Cohansey River Basins, Cumberland County and vicinity, New Jersey

USGS Publications Warehouse

Gordon, Alison D.; Buxton, Debra E.

2018-05-10

The U.S. Geological Survey, in cooperation with the New Jersey Department of Environmental Protection, conducted a study to simulate the effects of withdrawals from the Kirkwood-Cohansey aquifer system on streamflow and groundwater flow and from the Piney Point aquifer on water levels in the Cohansey and Maurice River Basins in Cumberland County and surrounding areas. The aquifer system consists of gravel, sand, silt, and clay sediments of the Cohansey Sand and Kirkwood Formation that dip and thicken to the southeast. The aquifer system is generally an unconfined aquifer, but semi-confined and confined conditions exist within the Cumberland County study area. The Kirkwood-Cohansey aquifer system is present throughout Cumberland County and is the principal source of groundwater for public, domestic, agricultural-irrigation, industrial, and commercial water uses. In 2008, reported groundwater withdrawals from the Kirkwood-Cohansey aquifer system in the study area totaled about 21,700 million gallons—about 36 percent for public supply; about 49 percent for agricultural irrigation; and about 15 percent for industrial, commercial, mining by sand and gravel companies, and non-agricultural irrigation uses. A transient numerical groundwater-flow model of the Kirkwood-Cohansey aquifer system was developed and calibrated by incorporating monthly recharge, base-flow estimates, water-level data, surface-water diversions and discharges, and groundwater withdrawals from 1998 to 2008.The groundwater-flow model was used to simulate five withdrawal scenarios to observe the effects of additional groundwater withdrawals on the Kirkwood-Cohansey aquifer system and streams. These scenarios include (1) average 1998 to 2008 monthly groundwater withdrawals (baseline scenario); (2) monthly full-allocation groundwater withdrawals, but agricultural-irrigation withdrawals were decreased for October through March; (3) monthly full-allocation groundwater withdrawals; (4) estimated monthly

Hydrogeologic framework and salinity distribution of the Floridan aquifer system of Broward County, Florida

USGS Publications Warehouse

Reese, Ronald S.; Cunningham, Kevin J.