Science.gov

Sample records for rising main sewers

  1. Impact of oxygen injection on CH4 and N2O emissions from rising main sewers.

    PubMed

    Ganigué, Ramon; Yuan, Zhiguo

    2014-11-01

    Oxygen injection is a commonly used mitigation strategy for sulfide control in sewers. Methane, a potent greenhouse gas, is also produced in sewers. Oxygen injection may reduce methane generation/emission, but could potentially lead to N2O production due to the development of a nitrifying microbial community. The impact of oxygen dosing for sulfide control in sewers on CH4 and N2O production was assessed in this study in laboratory sewer reactors. Results showed that oxygen injection is able to reduce CH4 formation in sewers, although full control of CH4 was not achieved, likely due to partial oxygen penetration into sewer biofilm. The experimental results also revealed a nitrogen loss of around 5 mN/L. However, no significant N2O accumulation was detected. PMID:24975803

  2. Constructing and dismantling frameworks of disease etiology: the rise and fall of sewer gas in America, 1870-1910.

    PubMed Central

    An, Perry G.

    2004-01-01

    For roughly forty years, from 1870 to 1910, Americans recognized and feared gases emanating from sewers, believing that they were responsible for causing an array of diseases. Fears of sewer gas arose from deeper anxieties toward contact with decomposing organic matter and the vapors emitted from such refuse. These anxieties were exacerbated by the construction of sewers across the country during the mid-to-late-nineteenth century, which concentrated waste emanations and connected homes to one another. The result was the birth of sewer gas and the attribution of sickness and death to it, as well as the development of a host of plumbing devices and, especially, bathroom fixtures, to combat sewer gas. The rise of the germ theory, laboratory science, and belief in disease specificity, however, transformed the threat of sewer gas, eventually replacing it (and the larger fear of miasmas) with the threat of germs. The germ theory framework, by 1910, proved more suitable than the sewer gas framework in explaining disease causation; it is this suitability that often shapes the relationship between science and society. PMID:15829149

  3. State of Technology for Renewal of Sewer Force Mains

    EPA Science Inventory

    This paper presents the results of a review of the state of technology for renewal of force mains (EPA, 2010). The review identified several needs, including the need for rational and common design approaches for rehabilitation systems, quality assurance/quality control procedur...

  4. Gas pockets in a wastewater rising main: a case study.

    PubMed

    Pozos-Estrada, Oscar; Fuentes-Mariles, Oscar A; Pozos-Estrada, Adrian

    2012-01-01

    This paper presents a case study of an existing wastewater rising main (WWRM) in which an extreme transient event produced by simultaneous power failure of the pumps caused the rupture of a 1.2 m (48 in) prestressed concrete cylinder pipe (PCCP), causing an important leakage of sewage. The event and the methodology followed in order to validate the diagnostics of the failure are described. The detail study included in situ observation of the system, experimental investigation in a setup, hydraulic analysis, as well as details of the structural strength of the WWRM. After the extensive investigation and several simulations of fluid transients for different scenarios and flow conditions, it was found that stationary small gas pockets accumulated at high points of the WWRM were identified as the principal contributory factor of the failure. This case study serves as clear warning of the consequences of operating a WWRM with gas pockets at its high points. PMID:22949261

  5. Degradability of creatinine under sewer conditions affects its potential to be used as biomarker in sewage epidemiology.

    PubMed

    Thai, Phong K; O'Brien, Jake; Jiang, Guangming; Gernjak, Wolfgang; Yuan, Zhiguo; Eaglesham, Geoff; Mueller, Jochen F

    2014-05-15

    Creatinine was proposed to be used as a population normalising factor in sewage epidemiology but its stability in the sewer system has not been assessed. This study thus aimed to evaluate the fate of creatinine under different sewer conditions using laboratory sewer reactors. The results showed that while creatinine was stable in wastewater only, it degraded quickly in reactors with the presence of sewer biofilms. The degradation followed first order kinetics with significantly higher rate in rising main condition than in gravity sewer condition. Additionally, daily loads of creatinine were determined in wastewater samples collected on Census day from 10 wastewater treatment plants around Australia. The measured loads of creatinine from those samples were much lower than expected and did not correlate with the populations across the sampled treatment plants. The results suggested that creatinine may not be a suitable biomarker for population normalisation purpose in sewage epidemiology, especially in sewer catchment with high percentage of rising mains. PMID:24631876

  6. Remaining Sites Verification Package for the 100-C-9:1 Main Process Sewer Collection Line, Waste Site Reclassification Form 2004-012

    SciTech Connect

    L. M. Dittmer

    2007-06-11

    The 100-C-9:1 main process sewer pipeline, also known as the twin box culvert, was a dual reinforced process sewer that collected process effluent from the 183-C and 190-C water treatment facilities, discharging at the 132-C-2 Outfall. For remedial action purposes, the 100-C-9:1 waste site was subdivided into northern and southern sections. The 100-C-9:1 subsite has been remediated to achieve the remedial action objectives specified in the Remaining Sites ROD. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  7. Effects of nitrate dosing on sulfidogenic and methanogenic activities in sewer sediment.

    PubMed

    Liu, Yiwen; Sharma, Keshab R; Ni, Bing-Jie; Fan, Lu; Murthy, Sudhir; Tyson, Gene Q; Yuan, Zhiguo

    2015-05-01

    Nitrate dosing is widely used to control sulfide and methane formation in sewers. The impact of nitrate on sulfide and methane production by sewer biofilms in rising mains has been elucidated recently. However, little is known about the effect of nitrate on biologically active sewer sediment, which is substantially thicker than rising main biofilms (centimeters vs. hundreds of micrometers, respectively). In this study, we investigated the effect of nitrate addition to sewer sediment cultivated in lab-scale sewer sediment reactors. Batch test results showed that nitrate addition does not suppress sulfide production in sewer sediment, but it reduces sulfide accumulation through anoxic sulfide oxidation in the sediment and hence, also reduces sulfide accumulation in the bulk water. Microsensor measurement of sediment sulfide revealed the presence of sulfide oxidation and sulfide production zones with the interface dynamically regulated by the depth of nitrate penetration. In contrast, the methane production activity of sewer sediment was substantially reduced, likely due to the long-term inhibitory effects of nitrate on methanogens. Pore water measurements showed that methane production activity in the sediment zone with frequent nitrate exposure was completely suppressed, and consequently, the methane production zone re-established deeper in the sediment where nitrate penetration was infrequent. PMID:25727155

  8. Rise of the main meniscus in rectangular capillaries: Experiments and modeling.

    PubMed

    Wu, Pingkeng; Zhang, Hua; Nikolov, Alex; Wasan, Darsh

    2016-01-01

    The rise of the main meniscus in rectangular capillaries is important in interpreting the phenomenon of fluid flow in porous media. Despite many experimental studies reported in the literature, there is no universal model for the rise of the main meniscus in either rectangular or square capillaries. In this work, we present an extensive experimental study and modeling of the rise of the main meniscus in both square and rectangular capillaries. Experimental work was carried out using three different liquids (water, ethanol, and hexadecane) in borosilicate glass and plastic (polystyrene) capillaries to investigate the effect of the contact angle and capillary size on the equilibrium main meniscus height. A universal model (an extended two-wall model) based on the Laplace equation was developed to predict the equilibrium height of the main meniscus in rectangular capillaries. Results have shown that, in a wide range of capillary sizes and contact angles, the predicted equilibrium heights of the main meniscus are in good agreement with the experimentally measured values. PMID:26402778

  9. [Sewer gas induced myocardial toxicity].

    PubMed

    Antonelli, Dante; Sabanchiev, Avi; Rosner, Ehud; Turgeman, Yoav

    2014-07-01

    We report the case of a 19 year-old worker who collapsed after acute exposure to sewer gas. He rapidly developed cardiorespiratory failure with electrocardiographic, echocardiographic and laboratory findings of myocardial involvement. The mainstay of the therapy was mainly supportive treatment with a successful outcome. PMID:25189024

  10. Online dissolved methane and total dissolved sulfide measurement in sewers.

    PubMed

    Liu, Yiwen; Sharma, Keshab R; Fluggen, Markus; O'Halloran, Kelly; Murthy, Sudhir; Yuan, Zhiguo

    2015-01-01

    Recent studies using short-term manual sampling of sewage followed by off-line laboratory gas chromatography (GC) measurement have shown that a substantial amount of dissolved methane is produced in sewer systems. However, only limited data has been acquired to date due to the low frequency and short span of this method, which cannot capture the dynamic variations of in-sewer dissolved methane concentrations. In this study, a newly developed online measuring device was used to monitor dissolved methane concentrations at the end of a rising main sewer network, over two periods of three weeks each, in summer and early winter, respectively. This device uses an online gas-phase methane sensor to measure methane under equilibrium conditions after being stripped from the sewage. The data are then converted to liquid-phase methane concentrations according to Henry's Law. The detection limit and range are suitable for sewer application and can be adjusted by varying the ratio of liquid-to-gas phase volume settings. The measurement presented good linearity (R² > 0.95) during field application, when compared to off-line measurements. The overall data set showed a wide variation in dissolved methane concentration of 5-15 mg/L in summer and 3.5-12 mg/L in winter, resulting in a significant average daily production of 24.6 and 19.0 kg-CH₄/d, respectively, from the network with a daily average sewage flow of 2840 m³/day. The dissolved methane concentration demonstrated a clear diurnal pattern coinciding with flow and sulfide fluctuation, implying a relationship with the wastewater hydraulic retention time (HRT). The total dissolved sulfide (TDS) concentration in sewers can be determined simultaneously with the same principle. PMID:25462721

  11. Sea level rise and tidal power plants in the Gulf of Maine

    NASA Astrophysics Data System (ADS)

    Pelling, Holly E.; Mattias Green, J. A.

    2013-06-01

    The response of the Bay of Fundy and Gulf of Maine to large-scale tidal power plants and future sea-level rise is investigated using an established numerical tidal model. Free stream tidal turbines were simulated within the Bay of Fundy by implementing an additional bed friction term, Kt. The present-day maximum tidal power output was determined to be 7.1 GW, and required Kt = 0.03. Extraction at this level would lead to large changes in the tidal amplitudes across the Gulf of Maine. With future SLR implemented, the energy available for extraction increases with 0.5-1 GW per m SLR. SLR simulations without tidal power extraction revealed that the response of the semidiurnal tides to SLR is highly dependent on how changes in sea level are implemented in the model. When extensive flood defenses are assumed at the present-day coast line, the response to SLR is far larger than when land is allowed to (permanently) flood. For example, within the Bay of Fundy itself, the M2 amplitude increases with nearly 0.12 m per m SLR without flooding, but it changes with only 0.03 m per m SLR with flooding. We suggest that this is due to the flooding of land cells changing the resonant properties of the basin.

  12. Remaining Sites Verification Package for the 100-F-26:12, 1.8-m (72-in.) Main Process Sewer Pipeline, Waste Site Reclassification Form 2007-034

    SciTech Connect

    J. M. Capron

    2008-04-29

    The 100-F-26:12 waste site was an approximately 308-m-long, 1.8-m-diameter east-west-trending reinforced concrete pipe that joined the North Process Sewer Pipelines (100-F-26:1) and the South Process Pipelines (100-F-26:4) with the 1.8-m reactor cooling water effluent pipeline (100-F-19). In accordance with this evaluation, the verification sampling results support a reclassification of this site to Interim Closed Out. The results of verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.

  13. Methane emission from sewers.

    PubMed

    Liu, Yiwen; Ni, Bing-Jie; Sharma, Keshab R; Yuan, Zhiguo

    2015-08-15

    Recent studies have shown that sewer systems produce and emit a significant amount of methane. Methanogens produce methane under anaerobic conditions in sewer biofilms and sediments, and the stratification of methanogens and sulfate-reducing bacteria may explain the simultaneous production of methane and sulfide in sewers. No significant methane sinks or methanotrophic activities have been identified in sewers to date. Therefore, most of the methane would be emitted at the interface between sewage and atmosphere in gravity sewers, pumping stations, and inlets of wastewater treatment plants, although oxidation of methane in the aeration basin of a wastewater treatment plant has been reported recently. Online measurements have also revealed highly dynamic temporal and spatial variations in methane production caused by factors such as hydraulic retention time, area-to-volume ratio, temperature, and concentration of organic matter in sewage. Both mechanistic and empirical models have been proposed to predict methane production in sewers. Due to the sensitivity of methanogens to environmental conditions, most of the chemicals effective in controlling sulfide in sewers also suppress or diminish methane production. In this paper, we review the recent studies on methane emission from sewers, including the production mechanisms, quantification, modeling, and mitigation. PMID:25889543

  14. Sewer Maintenance Manual.

    ERIC Educational Resources Information Center

    Ontario Ministry of the Environment, Toronto.

    Outlined are practices and procedures that should be followed in order to protect and fully realize the benefits of sewer systems and also to maximize service and minimize inconveniences to the public. Written in practical terms, the manual is designed to be of immediate use to municipal employees and others involved in sewer maintenance…

  15. Feasibility of sulfide control in sewers by reuse of iron rich drinking water treatment sludge.

    PubMed

    Sun, Jing; Pikaar, Ilje; Sharma, Keshab Raj; Keller, Jürg; Yuan, Zhiguo

    2015-03-15

    Dosage of iron salt is the most commonly used method for sulfide control in sewer networks but incurs high chemical costs. In this study, we experimentally investigate the feasibility of using iron rich drinking water treatment sludge for sulfide control in sewers. A lab-scale rising main sewer biofilm reactor was used. The sulfide concentration in the effluent decreased from 15.5 to 19.8 mgS/L (without dosing) to below 0.7-2.3 mgS/L at a sludge dosing rate achieving an iron to total dissolved inorganic sulfur molar ratio (Fe:S) of 1:1, with further removal of sulfide possible by prolonging the reaction time. In fact, batch tests revealed an Fe consumption to sulfide removal ratio of 0.5 ± 0.02 (mole:mole), suggesting the possible occurrence of other reactions involving the removal of sulfide. Modelling revealed that the reaction between iron in sludge and sulfide has reaction orders of 0.65 ± 0.01 and 0.77 ± 0.02 with respect to the Fe and sulfide concentrations, respectively. The addition of sludge slightly increased the total chemical oxidation demand (tCOD) concentration (by approximately 12%) as expected, but decreased the soluble chemical oxidation demand (sCOD) concentration and methane formation by 7% and 20%, respectively. Some phosphate removal (13%) was also observed at the sludge dosing rate of 1:1 (Fe:S), which is beneficial to nutrient removal from the wastewater. Overall, this study suggests that dosing iron-rich drinking water sludge to sewers could be an effective strategy for sulfide removal in sewer systems, which would also reduce the sludge disposal costs for drinking water treatment works. However, its potential side-effects on sewer sedimentation and on the wastewater treatment plant effluent remain to be investigated. PMID:25616115

  16. City sewer collectors biocorrosion

    NASA Astrophysics Data System (ADS)

    Ksiażek, Mariusz

    2014-12-01

    This paper presents the biocorrosion of city sewer collectors impregnated with special polymer sulphur binders, polymerized sulphur, which is applied as the industrial waste material. The city sewer collectors are settled with a colony of soil bacteria which have corrosive effects on its structure. Chemoautotrophic nitrifying bacteria utilize the residues of halites (carbamide) which migrate in the city sewer collectors, due to the damaged dampproofing of the roadway and produce nitrogen salts. Chemoorganotrophic bacteria utilize the traces of organic substrates and produce a number of organic acids (formic, acetic, propionic, citric, oxalic and other). The activity of microorganisms so enables the origination of primary and secondary salts which affect physical properties of concretes in city sewer collectors unfavourably.

  17. SSOAP - A TOOLBOX FOR SANITARY SEWER OVERFLOW ANALYSIS AND PLANNING

    EPA Science Inventory

    Rainfall Derived Infiltration and Inflow (RDII) into sanitary sewer systems has long been recognized as a source of operating problems in sewerage systems. RDII is the main cause of sanitary sewer overflows (SSOs) to basements, streets, or nearby streams and can also cause serio...

  18. Sanitary Sewer Overflow Analysis and Planning (SSOAP) Toolbox

    EPA Science Inventory

    Rainfall-derived infiltration and inflow (RDII) into sanitary sewer systems has long been recognized as a source of operating problems in sewerage systems. RDII is the main cause of sanitary sewer overflows (SSOs) to basements, streets, or nearby receiving waters and can also ...

  19. DEVELOPMENT OF SANITARY SEWER OVERFLOW ANALYSIS AND PLANNING (SSOAP) TOOLBOX

    EPA Science Inventory

    Rainfall Derived Infiltration and Inflow (RDII) into sanitary sewer systems has long been recognized as a source of operating problems in sewerage systems. RDII is the main cause of sanitary sewer overflows (SSOs) to basements, streets, or nearby streams. RDII can also cause se...

  20. SSOAP - A TOOLBOX FOR SANITARY SEWER OVERFLOW ANALYSIS AND PLANNING

    EPA Science Inventory

    Rainfall Derived Infiltration and Inflow (RDII) into sanitary sewer systems has long been recognized as a source of operating problems in sewerage systems. RDII is the main cause of sanitary sewer overflows (SSOs) to basements, streets, or nearby streams and can also cause seriou...

  1. COMPUTER TOOLS FOR SANITARY SEWER SYSTEM CAPACITY ANALYSIS AND PLANNING

    EPA Science Inventory

    Rainfall-derived infiltration and inflow (RDII) into sanitary sewer systems has long been recognized as a major source of operating problems, causing poor performance of many sewer systems. RDII is the main cause of SSOs to customer basements, streets, or nearby streams and can a...

  2. Review of Sewer Design Criteria and RDII Prediction Methods

    EPA Science Inventory

    Rainfall-derived Infiltration and Inflow (RDII) into sanitary sewer systems has long been recognized as a source of operating problems in sewerage systems. RDII is the main cause of sanitary sewer overflows (SSOs) to basements, streets, or nearby streams and can also cause serio...

  3. Future sea-level rise from Greenland's main outlet glaciers in a warming climate.

    PubMed

    Nick, Faezeh M; Vieli, Andreas; Andersen, Morten Langer; Joughin, Ian; Payne, Antony; Edwards, Tamsin L; Pattyn, Frank; van de Wal, Roderik S W

    2013-05-01

    Over the past decade, ice loss from the Greenland Ice Sheet increased as a result of both increased surface melting and ice discharge to the ocean. The latter is controlled by the acceleration of ice flow and subsequent thinning of fast-flowing marine-terminating outlet glaciers. Quantifying the future dynamic contribution of such glaciers to sea-level rise (SLR) remains a major challenge because outlet glacier dynamics are poorly understood. Here we present a glacier flow model that includes a fully dynamic treatment of marine termini. We use this model to simulate behaviour of four major marine-terminating outlet glaciers, which collectively drain about 22 per cent of the Greenland Ice Sheet. Using atmospheric and oceanic forcing from a mid-range future warming scenario that predicts warming by 2.8 degrees Celsius by 2100, we project a contribution of 19 to 30 millimetres to SLR from these glaciers by 2200. This contribution is largely (80 per cent) dynamic in origin and is caused by several episodic retreats past overdeepenings in outlet glacier troughs. After initial increases, however, dynamic losses from these four outlets remain relatively constant and contribute to SLR individually at rates of about 0.01 to 0.06 millimetres per year. These rates correspond to ice fluxes that are less than twice those of the late 1990s, well below previous upper bounds. For a more extreme future warming scenario (warming by 4.5 degrees Celsius by 2100), the projected losses increase by more than 50 per cent, producing a cumulative SLR of 29 to 49 millimetres by 2200. PMID:23657350

  4. The hazard of Sea Level Rise (SLR) in Greece: from scientific knowledge towards risk awareness of main actors

    NASA Astrophysics Data System (ADS)

    Dandoulaki, Miranda; Karymbalis, Efthimios; Yorgos, Melissourgos; Skordili, Sophia; Valkanou, Kanella

    2014-05-01

    A natural hazard that is expected to affect coastal areas in the near future is Sea-Level Rise (SLR) due to climate change. According to recent reports the eustatic sea-level rise caused by global warming will reach approximately 18-59 cm by the year 2100. Potential impacts of future sea-level rise include coastal erosion, frequent and intensified cyclonic activity and associated storm surge flooding that may affect the coastal zones, saltwater intrusion into groundwater aquifers, the inundation of ecologically significant wetlands, and threats to cultural and historical resources, as well as to infrastructure. The identification of sensitive sections of coasts and the assessment of potential impacts of SLR on these is therefore a fundamental, yet initial, step towards their protection. Greece has the most extensive coastline among all Mediterranean countries with most of the socio-economic activities concentrated along the coastal zone. Almost all big urban centres are coastal ones and the same stands for a great part of infrastructure (ports, airports, roads, electricity and telecommunications network etc). As a result, the impacts of a potential rise of the sea level are expected to seriously affect the entire country. The paper examines the vulnerability to SLR of coastal zones in Greece; however its main focus is how knowledge can lead to policy making and the protection of coastal areas. The main actors in respect to protection from SLR in Greece are identified and there is an attempt to pin point how the knowledge is communicated and shared between them. Barriers, bridges and gaps are detected as regards how information and knowledge lead to risk awareness and finally to the implementation of protection policies. A main finding of the paper is that SLR risk is far from becoming a policy priority in Greece, although steps are taken for addressing impacts attributed to SLR such as coastal erosion. In order to address this risk, there are many potential

  5. Dosing free nitrous acid for sulfide control in sewers: results of field trials in Australia.

    PubMed

    Jiang, Guangming; Keating, Anthony; Corrie, Shaun; O'halloran, Kelly; Nguyen, Lam; Yuan, Zhiguo

    2013-09-01

    Intermittent dosing of free nitrous acid (FNA), with or without the simultaneous dosing of hydrogen peroxide, is a new strategy developed recently for the control of sulfide production in sewers. Six-month field trials have been carried out in a rising main sewer in Australia (150 mm in diameter and 1080 m in length) to evaluate the performance of the strategy that was previously demonstrated in laboratory studies. In each trial, FNA was dosed at a pumping station for a period of 8 or 24 h, some with simultaneous hydrogen peroxide dosing. The sulfide control effectiveness was monitored by measuring, on-line, the dissolved sulfide concentration at a downstream location of the pipeline (828 m from the pumping station) and the gaseous H2S concentration at the discharge manhole. Effective sulfide control was achieved in all nine consecutive trials, with sulfide production reduced by more than 80% in 10 days following each dose. Later trials achieved better control efficiency than the first few trials possibly due to the disrupting effects of FNA on sewer biofilms. This suggests that an initial strong dose (more chemical consumption) followed by maintenance dosing (less chemical consumption) could be a very cost-effective way to achieve consistent control efficiency. It was also found that heavy rainfall slowed the recovery of sulfide production after dosing, likely due to the dilution effects and reduced retention time. Overall, intermittent dose of FNA or FNA in combination with H2O2 was successfully demonstrated to be a cost-effective method for sulfide control in rising main sewers. PMID:23764584

  6. SANITARY SEWER CALCULATION

    SciTech Connect

    Roy D. Clark

    1995-01-13

    This analysis defines and evaluates the surface sanitary sewer system on the North Portal, and addresses the requirements for the collection of sanitary sewage from each of the proposed surface buildings. A sewage treatment system will be defined that meets the needs of the North Portal, conforms to the existing site conditions, and meets the needs of the state and local permitting agencies.

  7. EXFILTRATION IN SEWER SYSTEMS

    EPA Science Inventory

    This study focused on the quantification of leakage of sanitary and industrial sewage from sanitary sewer pipes on a national basis. The method for estimating exfiltration amounts utilized groundwater talbe information to identify areas of the country where the hydraulic gradient...

  8. SEWER PIPELINE PERFORMANCE INDICATORS

    EPA Science Inventory

    Wastewater collection systems are an extensive part of the nation's infrastructure. In the United States, approximately 150 million people are served by about 19,000 municipal wastewater collection systems representing about 500,000 miles of sewer pipe (not including privately o...

  9. Vacuum Flushing of Sewer Solids

    EPA Science Inventory

    The vacuum sewer and tank cleaning (flushing) technology removes sewer solids from urban drainage systems, such as storage tanks and pipes. This technology is both effective and inexpensive. In addition, it can be considered a true green technology. It operates under atmospheri...

  10. Poison-based commensal rodent control strategies in urban ecosystems: some evidence against sewer-baiting.

    PubMed

    Mughini Gras, Lapo; Patergnani, Matteo; Farina, Marco

    2012-03-01

    Sewers are historically considered the main reservoir for commensal rodents, posing threats to urban ecosystem health. Aboveground rodent signs are often assumed to give clues to high sewer infestation, which can chronically restock surface areas. Thus, current sewer-baiting programmes are mostly reactive, responding to increased surface infestation. Conversely, proactive sewer-baiting (regardless of infestation levels) is often disregarded because cost-effectiveness is not always addressed. We explored the extent to which the surface infestation is related to rodent feeding activity on sewer and surface baits by analysing a set of proactive bait records in Bologna city, Italy. Sewer bait intakes were significantly lower than surface ones, suggesting that proactive sewer-baiting is generally less effective. As surface infestation increased, probability of recording surface bait intake increased significantly but this was not reflected by increased sewer bait intake, suggesting that surface infestation is not always a reliable indicator of sewer infestation. This should discourage the use of reactive sewer-baiting as a routine strategy. Poison-based control programmes by themselves are scarcely predictable and strategically limited, and ideally they should be handled within an ecologically based integrated pest management approach for achieving satisfactory results. PMID:22395957

  11. COMBINED-SEWER OVERFLOW CONTROL AND TREATMENT

    EPA Science Inventory

    Combined-sewer overflow (CSO), along with sanitary-sewer overflow and stormwater are significant contributors of contamination to surface waters. During a rain event, the flow in a combined sewer system may exceed the capacity of the intercepting sewer leading to the wastewater t...

  12. Inventory and protection of salt marshes from risks of sea-level rise at Acadia National Park, Maine

    USGS Publications Warehouse

    Dudley, Robert W.; Nielsen, Martha G.

    2011-01-01

    Recent U.S. Geological Survey (USGS) climate studies in the northeastern United States have shown substantial evidence of climate-related changes during the last 100 years, including earlier snowmelt runoff, decreasing occurrence of river ice, and decreasing winter snowpack. These studies related to climate change are being expanded to include investigation of coastal wetlands that might be at risk from sealevel rise. Coastal wetlands, particularly salt marshes, are important ecosystems that provide wildlife nursery and breeding habitat, migratory bird habitat, water quality enhancement, and shoreline erosion control. The USGS is investigating salt marshes in Acadia National Park with the goal of determining which salt marshes may be threatened by sea-level rise and which salt marshes may be able to adapt to sea-level rise by migrating into adjacent low-lying lands.

  13. A TOOLBOX FOR SANITARY SEWER OVERFLOW ANALYSIS AND PLANNING (SSOAP) AND APPLICATIONS

    EPA Science Inventory

    Rainfall-derived infiltration and inflow (RDII) into sanitary sewer systems has long been recognized as a source of operating problems in these systems. RDII is the main cause of sanitary sewer overflows (SSOs) to basements, streets, or nearby streams and the resulting high flows...

  14. A TOOLBOX FOR SANITARY SEWER OVERFLOW ANALYSIS AND PLANNING (SSOAP) AND APPLICATIONS

    EPA Science Inventory

    Rainfall Derived Infiltration and Inflow (RDII) into sanitary sewer systems has long been recognized as a source of operating problems in sewerage systems. RDII is the main cause of sanitary sewer overflows (SSOs) to basements, streets, or nearby streams and can also cause seriou...

  15. HANDBOOK: SEWER SYSTEM INFRASTRUCTURE ANALYSIS AND REHABILITATION

    EPA Science Inventory

    Many of our Nation's sewer systems date back to the 19th Century when brick sewers were common. hese and more recent sewer systems can be expected to fail in time, but because they are placed underground, signs of accelerated deterioration and capacity limitations are not readily...

  16. Demonstration of Innovative Sewer System Inspection Technology SewerBatt

    EPA Science Inventory

    The overall objective of this EPA-funded study was to demonstrate innovative a sewer line assessment technology that is designed for rapid deployment using portable equipment. This study focused on demonstration of a technology that is suitable for smaller diameter pipes (less th...

  17. Quantitative assessment of the groundwater-sewer network interaction in Bucharest city (Romania)

    NASA Astrophysics Data System (ADS)

    Boukhemacha, M. A.; Diaconescu, A.; Bica, I.; Gogu, C. R.; Gaitanaru, D.

    2012-04-01

    Groundwater management in urban area must take account of every possible and relevant phenomena arising from the complex interaction between subsurface water, surface water, and urban infrastructure. In Bucharest, the need of the sewer system rehabilitation initiated a study of the interaction between groundwater and the sewer network. Recent conclusions show that the sewer network acts mainly like a drainage system for the groundwater. However, it could be easily proven that several sewer segments located mainly in the unsaturated zone contaminate the groundwater by leakage. The groundwater infiltration in the sewer conduits can cause the decrease of the groundwater level leading to structures instability problems as well as to the increase flow-rates of the sewer system. The last one affects seriously the wastewater treatment plants efficiency. The sewer network leakage cause groundwater pollution and locally could increase the groundwater level triggering buildings instability or other urban operational problems. The current study focuses on the consequences of sealing a part of the sewer system and so disturbing the existing groundwater behavior which may lead to serious consequences. In this framework, the analysis results of a groundwater flow model used to quantify the interaction between the groundwater and the sewer network are presented. The two-layers groundwater flow model simulating the Colentina and Mostistea overlaid sedimentary aquifers covers about 75 km2. Its conceptual model relies on a 3D geological model made by using 23 accurate geological cross-sections of the studied domain. The model set-up and its calibration are done using pumping tests data, groundwater hydraulic heads, and water levels of the sewer system. Infiltration rates into sewers are modeled by applying a modified form of Darcy's law that uses the notion of infiltration factor. This last encompasses the hydraulic conductivity of the clogging layer, the infiltration area and the

  18. Space-Derived Sewer Monitor

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The QuadraScan Longterm Flow Monitoring System is a second generation sewer monitor developed by American Digital Systems, Inc.'s founder Peter Petroff. Petroff, a former spacecraft instrumentation designer at Marshall Space Flight Center, used expertise based on principles acquired in Apollo and other NASA programs. QuadraScan borrows even more heavily from space technology, for example in its data acquisition and memory system derived from NASA satellites. "One-time" measurements are often plagued with substantial errors due to the flow of groundwater absorbed into the system. These system sizing errors stem from a basic informational deficiency: accurate, reliable data on how much water flows through a sewer system over a long period of time is very difficult to obtain. City officials are turning to "permanent," or long-term sewer monitoring systems. QuadraScan offers many advantages to city officials such as the early warning capability to effectively plan for city growth in order to avoid the crippling economic impact of bans on new sewer connections in effect in many cities today.

  19. Changes in Microbial Biofilm Communities during Colonization of Sewer Systems.

    PubMed

    Auguet, O; Pijuan, M; Batista, J; Borrego, C M; Gutierrez, O

    2015-10-01

    The coexistence of sulfate-reducing bacteria (SRB) and methanogenic archaea (MA) in anaerobic biofilms developed in sewer inner pipe surfaces favors the accumulation of sulfide (H2S) and methane (CH4) as metabolic end products, causing severe impacts on sewerage systems. In this study, we investigated the time course of H2S and CH4 production and emission rates during different stages of biofilm development in relation to changes in the composition of microbial biofilm communities. The study was carried out in a laboratory sewer pilot plant that mimics a full-scale anaerobic rising sewer using a combination of process data and molecular techniques (e.g., quantitative PCR [qPCR], denaturing gradient gel electrophoresis [DGGE], and 16S rRNA gene pyrotag sequencing). After 2 weeks of biofilm growth, H2S emission was notably high (290.7±72.3 mg S-H2S liter(-1) day(-1)), whereas emissions of CH4 remained low (17.9±15.9 mg COD-CH4 liter(-1) day(-1)). This contrasting trend coincided with a stable SRB community and an archaeal community composed solely of methanogens derived from the human gut (i.e., Methanobrevibacter and Methanosphaera). In turn, CH4 emissions increased after 1 year of biofilm growth (327.6±16.6 mg COD-CH4 liter(-1) day(-1)), coinciding with the replacement of methanogenic colonizers by species more adapted to sewer conditions (i.e., Methanosaeta spp.). Our study provides data that confirm the capacity of our laboratory experimental system to mimic the functioning of full-scale sewers both microbiologically and operationally in terms of sulfide and methane production, gaining insight into the complex dynamics of key microbial groups during biofilm development. PMID:26253681

  20. Changes in Microbial Biofilm Communities during Colonization of Sewer Systems

    PubMed Central

    Auguet, O.; Pijuan, M.; Batista, J.; Gutierrez, O.

    2015-01-01

    The coexistence of sulfate-reducing bacteria (SRB) and methanogenic archaea (MA) in anaerobic biofilms developed in sewer inner pipe surfaces favors the accumulation of sulfide (H2S) and methane (CH4) as metabolic end products, causing severe impacts on sewerage systems. In this study, we investigated the time course of H2S and CH4 production and emission rates during different stages of biofilm development in relation to changes in the composition of microbial biofilm communities. The study was carried out in a laboratory sewer pilot plant that mimics a full-scale anaerobic rising sewer using a combination of process data and molecular techniques (e.g., quantitative PCR [qPCR], denaturing gradient gel electrophoresis [DGGE], and 16S rRNA gene pyrotag sequencing). After 2 weeks of biofilm growth, H2S emission was notably high (290.7 ± 72.3 mg S-H2S liter−1 day−1), whereas emissions of CH4 remained low (17.9 ± 15.9 mg COD-CH4 liter−1 day−1). This contrasting trend coincided with a stable SRB community and an archaeal community composed solely of methanogens derived from the human gut (i.e., Methanobrevibacter and Methanosphaera). In turn, CH4 emissions increased after 1 year of biofilm growth (327.6 ± 16.6 mg COD-CH4 liter−1 day−1), coinciding with the replacement of methanogenic colonizers by species more adapted to sewer conditions (i.e., Methanosaeta spp.). Our study provides data that confirm the capacity of our laboratory experimental system to mimic the functioning of full-scale sewers both microbiologically and operationally in terms of sulfide and methane production, gaining insight into the complex dynamics of key microbial groups during biofilm development. PMID:26253681

  1. Identifiability analysis in conceptual sewer modelling.

    PubMed

    Kleidorfer, M; Leonhardt, G; Rauch, W

    2012-01-01

    For a sufficient calibration of an environmental model not only parameter sensitivity but also parameter identifiability is an important issue. In identifiability analysis it is possible to analyse whether changes in one parameter can be compensated by appropriate changes of the other ones within a given uncertainty range. Parameter identifiability is conditional to the information content of the calibration data and consequently conditional to a certain measurement layout (i.e. types of measurements, number and location of measurement sites, temporal resolution of measurements etc.). Hence the influence of number and location of measurement sites on the number of identifiable parameters can be investigated. In the present study identifiability analysis is applied to a conceptual model of a combined sewer system aiming to predict the combined sewer overflow emissions. Different measurement layouts are tested and it can be shown that only 13 of the most sensitive catchment areas (represented by the model parameter 'effective impervious area') can be identified when overflow measurements of the 20 highest overflows and the runoff to the waste water treatment plant are used for calibration. The main advantage of this method is very low computational costs as the number of required model runs equals the total number of model parameters. Hence, this method is a valuable tool when analysing large models with a long runtime and many parameters. PMID:22864432

  2. Remote infrared thermal sensing of sewer voids

    NASA Astrophysics Data System (ADS)

    Weil, Gary J.

    1995-05-01

    Many sewers in America's cities are more than 125 years old and are subject to structural failure. In one year alone, St. Louis, Missouri had 4,000 sewer collapses that carried an astronomical repair tag. When a sewer caves in, it often takes the street, sidewalks, and surrounding buildings along with it endangering public health and safety. The ideal situation would be to repair a sewer before such cave-ins occur, as emergency repairs are far more costly than preventive measures. The question addressed by this paper is how to detect unseen problem areas in sewer systems before collapses occur. At the present, progressive sewer administrations may use crawl crews or remote controlled video cameras to inspect sewers at suspected problem locations. This can be extremely costly, dangerous, and not very accurate, as a void around the outside of the sewer is often invisible from within. Thus, even a crawl crew can fail to detect most voids. Sewer districts and independent engineering firms have found infrared thermography, a nondestructive testing method, to be extremely accurate in finding sewer voids, and accompanying pipeline leaks, before they can cause expensive and dangerous problems. Infrared thermography is a non-contact, remote sensing method, with the potential for surveying large areas quickly and efficiently.

  3. Corrosion and odor management in sewer systems.

    PubMed

    Jiang, Guangming; Sun, Jing; Sharma, Keshab R; Yuan, Zhiguo

    2015-06-01

    Sewers emit hydrogen sulfide and various volatile organic sulfur and carbon compounds, which require control and mitigation. In the last 5-10 years, extensive research was conducted to optimize existing sulfide abatement technologies based on newly developed in-depth understanding of the in-sewer processes. Recent advances have also led to low-cost novel solutions targeting sewer biofilms. Online control has been demonstrated to greatly reduce the chemical usage. Dynamic models for both the water, air and solid (concrete) phases have been developed and used for the planning and maintenance of sewer systems. Existing technologies primarily focused on 'hotspots' in sewers. Future research should aim to achieve network-wide corrosion and emission control and management of sewers as an integrated component of an urban water system. PMID:25827114

  4. CONTROL OF SEWER OVERFLOWS BY POLYMER INJECTION

    EPA Science Inventory

    In the past, the operator of a sewage collection system has had three alternatives for dealing with overloaded sanitary sewers; ignoring them, diverting them to storm sewers and streams, or pumping to other locations. An EPA-sponsored research program entitled, 'Polymers for Sewe...

  5. SANITARY-SEWER OVERFLOW CONTROL STRATEGY

    EPA Science Inventory

    This paper presents a strategy for the abatement of pollution from storm-generated sanitary-sewer overflows (SSO). Because of the great lengths of sanitary-sewer systems and their associated vast number of house-service laterals or building connections, it is often less expensive...

  6. In-place rehabilitation of process sewers

    SciTech Connect

    Arles, K.R.; Faller, C.C.

    1996-07-01

    The majority of petrochemical manufacturing facilities have thousands of feet of existing underground gravity sewers that convey the site`s industrial wastes to treatment facilities. The integrity of these sewer systems is a serious concern to owners. A potential consequence of leaks is soil and groundwater contamination. Prior to 1992, only two options were available to remedy this situation. The sewer systems could be replaced with either a new dual-walled, monitored underground pipe system via direct bury, or with an above ground pumped system. In 1992, Engineering, in conjunction with several trenchless technology vendors, developed and demonstrated modified relining systems that can rehabilitate existing sewers and result in monitored dual-walled gravity sewer systems. These proven systems have since been enhanced, upgraded, and installed at two operating facilities. With thorough sewer investigation and assessments, industry now has viable, cost effective options to rehabilitate underground chemical process sewers. These upgraded sewer systems provide the environmental security of monitored dual-walled pipe, enhanced flow characteristics, and retain accessibility for maintenance and inspections.

  7. MANAGEMENT AND CONTROL OF COMBINED SEWER OVERFLOWS

    EPA Science Inventory

    The paper gives a basic overview of the U.S. government's involvements in developing countermeasures for the abatement of combined sewer overflow pollution. batement or prevention of pollution stormwater runoff and combined sewer overflows is one of the most challenging areas in ...

  8. Vacuum Flushing of Sewer Solids (Slides)

    EPA Science Inventory

    The vacuum sewer and tank cleaning (flushing) technology removes sewer solids from urban drainage systems, such as storage tanks and pipes. This technology is both effective and inexpensive. In addition, it can be considered a true green technology. It operates under atmospheri...

  9. 40 CFR 35.927-2 - Sewer system evaluation survey.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Sewer system evaluation survey. 35.927... § 35.927-2 Sewer system evaluation survey. (a) The sewer system evaluation survey shall identify the... results of the sewer system evaluation survey. In addition, the report shall include: (1) A...

  10. 40 CFR 35.927-2 - Sewer system evaluation survey.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Sewer system evaluation survey. 35.927... § 35.927-2 Sewer system evaluation survey. (a) The sewer system evaluation survey shall identify the... results of the sewer system evaluation survey. In addition, the report shall include: (1) A...

  11. 40 CFR 35.927-2 - Sewer system evaluation survey.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Sewer system evaluation survey. 35.927... § 35.927-2 Sewer system evaluation survey. (a) The sewer system evaluation survey shall identify the... results of the sewer system evaluation survey. In addition, the report shall include: (1) A...

  12. Estimates of future inundation of salt marshes in response to sea-level rise in and around Acadia National Park, Maine

    USGS Publications Warehouse

    Nielsen, Martha G.; Dudley, Robert W.

    2013-01-01

    Salt marshes are ecosystems that provide many important ecological functions in the Gulf of Maine. The U.S. Geological Survey investigated salt marshes in and around Acadia National Park from Penobscot Bay to the Schoodic Peninsula to map the potential for landward migration of marshes using a static inundation model of a sea-level rise scenario of 60 centimeters (cm; 2 feet). The resulting inundation contours can be used by resource managers to proactively adapt to sea-level rise by identifying and targeting low-lying coastal areas adjacent to salt marshes for conservation or further investigation, and to identify risks to infrastructure in the coastal zone. For this study, the mapping of static inundation was based on digital elevation models derived from light detection and ranging (LiDAR) topographic data collected in October 2010. Land-surveyed control points were used to evaluate the accuracy of the LiDAR data in the study area, yielding a root mean square error of 11.3 cm. An independent accuracy assessment of the LiDAR data specific to salt-marsh land surfaces indicated a root mean square error of 13.3 cm and 95-percent confidence interval of ± 26.0 cm. LiDAR-derived digital elevation models and digital color aerial photography, taken during low tide conditions in 2008, with a pixel resolution of 0.5 meters, were used to identify the highest elevation of the land surface at each salt marsh in the study area. Inundation contours for 60-cm of sea-level rise were delineated above the highest marsh elevation for each marsh. Confidence interval contours (95-percent,± 26.0 cm) were delineated above and below the 60-cm inundation contours, and artificial structures, such as roads and bridges, that may present barriers to salt-marsh migration were mapped. This study delineated 114 salt marshes totaling 340 hectares (ha), ranging in size from 0.11 ha (marshes less than 0.2 ha were mapped only if they were on Acadia National Park property) to 52 ha, with a median

  13. Infrared Thermal Sensing Of Sewer Voids

    NASA Astrophysics Data System (ADS)

    Weil, Gary J.

    1984-03-01

    The deterioration of sewer systems and their associated infrastructure is one of the most serious problems facing city, state, federal, and world authorities. As an example, three large sewer voids in the St. Louis Metropolitan area caused over $2,000,000 in repair costs in only one year. The detection of voids in and around underground sewer lines, as well as the detection of effluent leakages is necessary when determining the priority of structures for repair. At the present time sewer voids are sometimes detected by manual methods which are expensive, time consuming, and not extremely accurate. Most of the time, the void is not detected until the street caves in. Infrared thermography has been found to be capable of detecting voids around underground sewer systems because under certain conditions, temperature differentials exist between various types of materials, effluents, and cavities. This paper describes the problem of deteriorating sewer systems, the field tests used to detect sewer voids, the equipment used in the field tests, the theories used to design the tests, various complicating factors, and anticipated future refinements on the procedure.

  14. Risk assessment of sewer condition using artificial intelligence tools: application to the SANEST sewer system.

    PubMed

    Sousa, V; Matos, J P; Almeida, N; Saldanha Matos, J

    2014-01-01

    Operation, maintenance and rehabilitation comprise the main concerns of wastewater infrastructure asset management. Given the nature of the service provided by a wastewater system and the characteristics of the supporting infrastructure, technical issues are relevant to support asset management decisions. In particular, in densely urbanized areas served by large, complex and aging sewer networks, the sustainability of the infrastructures largely depends on the implementation of an efficient asset management system. The efficiency of such a system may be enhanced with technical decision support tools. This paper describes the role of artificial intelligence tools such as artificial neural networks and support vector machines for assisting the planning of operation and maintenance activities of wastewater infrastructures. A case study of the application of this type of tool to the wastewater infrastructures of Sistema de Saneamento da Costa do Estoril is presented. PMID:24552736

  15. SEWER AND TANK SEDIMENT FLUSHING: CASE STUDIES

    EPA Science Inventory

    The objective of the report summarized here is to demonstrate that sewer system and storage tank flushing that reduces sediment deposition and accumulation is of prime importance to optimizing performance, maintaining structural integrity, and minimizing pollution of receiving wa...

  16. Handbook: Sewer system infrastructure analysis and rehabilitation

    SciTech Connect

    Not Available

    1991-10-01

    The Handbook provides guidance on the evaluation and rehabilitation of existing sewers. It presents information on typical problems, procedures and methods for rehabilitation, case study information, budgetary costs, advantages and disadvantages of rehabilitation techniques, and application of these techniques and materials/equipment used in rehabilitation. It also guides the reader in understanding the importance of, and ways for, conducting the sewer system evaluation and identifying the rehabilitation procedure that best suits a particular problem.

  17. The hydraulic capacity of deteriorating sewer systems.

    PubMed

    Pollert, J; Ugarelli, R; Saegrov, S; Schilling, W; Di Federico, V

    2005-01-01

    Sewer and wastewater systems suffer from insufficient capacity, construction flaws and pipe deterioration. Consequences are structural failures, local floods, surface erosion and pollution of receiving waters bodies. European cities spend in the order of five billion Euro per year for wastewater network rehabilitation. This amount is estimated to increase due to network ageing. The project CARE-S (Computer Aided RE-habilitation of Sewer Networks) deals with sewer and storm water networks. The final project goal is to develop integrated software, which provides the most cost-efficient system of maintenance, repair and rehabilitation of sewer networks. Decisions on investments in rehabilitation often have to be made with uncertain information about the structural condition and the hydraulic performance of a sewer system. Because of this, decision-making involves considerable risks. This paper presents the results of research focused on the study of hydraulic effects caused by failures due to temporal decline of sewer systems. Hydraulic simulations are usually carried out by running commercial models that apply, as input, default values of parameters that strongly influence results. Using CCTV inspections information as dataset to catalogue principal types of failures affecting pipes, a 3D model was used to evaluate their hydraulic consequences. The translation of failures effects in parameters values producing the same hydraulic conditions caused by failures was carried out through the comparison of laboratory experiences and 3D simulations results. Those parameters could be the input of 1D commercial models instead of the default values commonly inserted. PMID:16477988

  18. Influence of characteristics on combined sewer performance.

    PubMed

    Möderl, M; Kleidorfer, M; Rauch, W

    2012-01-01

    Elements of combined sewer systems are among others sub-catchments, junctions, conduits and weirs with or without storage units. The spatial distribution and attributes of all these elements influence both system characteristics and sewer performance. Until today, little work has been done to analyse the influence of such characteristics in a case unspecific approach. In this study, 250 virtual combined sewer systems are analysed by defining groups of systems, which are representative for their different characteristics. The set was created with a further development of the case study generator (CSG), a tool for automatic generation of branched sewer systems. Combined sewer overflow and flooding is evaluated using performance indicators based on hydrodynamic simulations. The analysis of system characteristics, like those presented in this paper, helps researchers to understand coherences and aids practitioners in designing combined sewers. For instance, it was found that characteristics that have a positive influence on emission reduction frequently have a negative influence on flooding avoidance and vice versa. PMID:22797234

  19. State of Technology Report for Force Main Rehabilitation

    EPA Science Inventory

    Force mains that carry sewage flows under pressure represent a special set of challenges for sewer rehabilitation. Force mains represent about 7.5% of the wastewater system and they typically use materials that are not commonly used in gravity sewer systems. Ductile iron (DI), ...

  20. Impacts and managerial implications for sewer systems due to recent changes to inputs in domestic wastewater - A review.

    PubMed

    Mattsson, Jonathan; Hedström, Annelie; Ashley, Richard M; Viklander, Maria

    2015-09-15

    Ever since the advent of major sewer construction in the 1850s, the issue of increased solids deposition in sewers due to changes in domestic wastewater inputs has been frequently debated. Three recent changes considered here are the introduction of kitchen sink food waste disposers (FWDs); rising levels of inputs of fat, oil and grease (FOG); and the installation of low-flush toilets (LFTs). In this review these changes have been examined with regard to potential solids depositional impacts on sewer systems and the managerial implications. The review indicates that each of the changes has the potential to cause an increase in solids deposition in sewers and this is likely to be more pronounced for the upstream reaches of networks that serve fewer households than the downstream parts and for specific sewer features such as sags. The review has highlighted the importance of educational campaigns directed to the public to mitigate deposition as many of the observed problems have been linked to domestic behaviour in regard to FOGs, FWDs and toilet flushing. A standardized monitoring procedure of repeat sewer blockage locations can also be a means to identify depositional hot-spots. Interactions between the various changes in inputs in the studies reviewed here indicated an increased potential for blockage formation, but this would need to be further substantiated. As the precise nature of these changes in inputs have been found to be variable, depending on lifestyles and type of installation, the additional problems that may arise pose particular challenges to sewer operators and managers because of the difficulty in generalizing the nature of the changes, particularly where retrofitting projects in households are being considered. The three types of changes to inputs reviewed here highlight the need to consider whether or not more or less solid waste from households should be diverted into sewers. PMID:26182992

  1. SMALL DIAMETER GRAVITY SEWERS: AN ALTERNATIVE FOR UNSEWERED COMMUNITIES

    EPA Science Inventory

    The most recently introduced wastewater collection alternative for small unsewered communities is septic tank effluent drains or small diameter gravity sewers (SDGS). Unlike conventional sewers, SDGS only collect settled wastewater. Grit, grease and other troublesome solids which...

  2. Hydrocarbon pollution fixed to combined sewer sediment: a case study in Paris.

    PubMed

    Rocher, Vincent; Garnaud, Stéphane; Moilleron, Régis; Chebbo, Ghassan

    2004-02-01

    Over a period of two years (2000-2001), sediment samples were extracted from 40 silt traps (STs) spread through the combined sewer system of Paris. All sediment samples were analysed for physico-chemical parameters (pH, organic matter content, grain size distribution), with total hydrocarbons (THs) and 16 polycyclic aromatic hydrocarbons (PAHs) selected from the priority list of the US-EPA. The two main objectives of the study were (1) to determine the hydrocarbon contamination levels in the sediments of the Paris combined sewer system and (2) to investigate the PAH fingerprints in order to assess their spatial variability and to elucidate the PAH origins. The results show that there is some important inter-site and intra-site variations in hydrocarbon contents. Despite this variability, TH and PAH contamination levels (50th percentile) in the Parisian sewer sediment are estimated at 530 and 18 microg g(-1), respectively. The investigation of the aromatic compound distributions in all of the 40 STs has underlined that there is, at the Paris sewer system scale, a homogeneous PAH background pollution. Moreover, the study of the PAH fingerprints, using specific ratios, suggests the predominance of a pyrolytic origin for those PAHs fixed to the sewer sediment. PMID:14637336

  3. Long-term impacts on sewers following food waste disposer installation in housing areas.

    PubMed

    Mattsson, Jonathan; Hedström, Annelie; Viklander, Maria

    2014-01-01

    To increase biogas generation and decrease vehicle transportation of solid waste, the integration of food waste disposers (FWDs) into the wastewater system has been proposed. However, concerns have been raised about the long-term impact of the additional load of the FWDs on sewer systems. To examine the said impact, this study has used closed-circuit television inspection techniques to evaluate the status of 181 concrete pipes serving single family housing areas with a diameter of 225 mm, ranging from a 100% connection rate of households with an FWD to none. A minor study was also performed on a multi-family housing area, where mainly plastic pipes (200 mm) were used. The extent and distribution of deposits related to the ratio of FWDs, inclination and pipe sagging (backfalls) were ascertained by using linear regression and analysis of variance. The results showed that FWDs have had an impact on the level of deposits in the sewer, but this has, in turn, been of minor significance. With a high connection rate of FWDs upstream of a pipe, the extent of the total level of deposits, as well as finer sediments, was statistically determined to be greater. However, the majority of the deposits were observed to be small, which would suggest the impact of FWDs on sewer performance to be minor. As food waste not compatible with the FWD was seen in the sewers, educational campaigns could be beneficial to further lower the risks of sewer blocking. PMID:25176297

  4. Cause and effect oriented sewer degradation evaluation to support scheduled inspection planning.

    PubMed

    Fuchs-Hanusch, D; Günther, M; Möderl, M; Muschalla, D

    2015-01-01

    Managing the subsurface urban infrastructure, while facing limited budgets, is one of the main challenges wastewater utilities currently face. In this context targeted planning of inspection and maintenance measures plays a crucial role. This paper introduces a cause and effect oriented sewer degradation evaluation approach to support decisions on inspection frequencies and priorities. Therefore, the application of logistic regression models, to predict the probability of failure categories as an alternative to the prediction of sewer condition classes, was introduced. We assume that analysing the negative effects resulting from different failure categories in extension to a condition class-based planning approach offers new possibilities for targeted inspection planning. In addition, a cross validation process was described to allow for a more accurate prediction of sewer degradation. The described approach was applied to an Austrian sewer system. The results show that the failure category-based regression models perform better than the conventional condition class-oriented models. The results of the failure category predictions are presented with respect to negative effects the failure may have on the hydraulic performance of the system. Finally, suggestions are given for how this performance-oriented sewer section evaluation can support scheduled inspection planning. PMID:26398033

  5. Groundwater intrusion into leaky sewer systems.

    PubMed

    Wittenberg, H; Aksoy, H

    2010-01-01

    Vast volumes of groundwater are drained by urban sewer systems. This unwanted flow component intrudes into sewer systems through leaky joints or connected house drains. However, unlike urban storm drainage, it has a high seasonal variation corresponding to groundwater storage and long slow recessions similar to baseflow in rivers also fed by shallow groundwater exfiltrating into the surface waters. By applying the nonlinear reservoir algorithm as used for baseflow separation from total flow in a river, groundwater flow is separated from daily measured influents to treatment plants in Lower Saxony and Baden-Württemberg, Germany and in the Terkos Lake watershed near Istanbul, Turkey. While waste water flows vary only moderately within a year, separated intruded groundwater flows show recessions and seasonal variations correlated to baseflow in neighbouring rivers. It is possible to conclude that recession characteristics of treatment plant influents allow quantification and prediction of groundwater intrusion into sewer systems. PMID:20595758

  6. Predicting concrete corrosion of sewers using artificial neural network.

    PubMed

    Jiang, Guangming; Keller, Jurg; Bond, Philip L; Yuan, Zhiguo

    2016-04-01

    Corrosion is often a major failure mechanism for concrete sewers and under such circumstances the sewer service life is largely determined by the progression of microbially induced concrete corrosion. The modelling of sewer processes has become possible due to the improved understanding of in-sewer transformation. Recent systematic studies about the correlation between the corrosion processes and sewer environment factors should be utilized to improve the prediction capability of service life by sewer models. This paper presents an artificial neural network (ANN)-based approach for modelling the concrete corrosion processes in sewers. The approach included predicting the time for the corrosion to initiate and then predicting the corrosion rate after the initiation period. The ANN model was trained and validated with long-term (4.5 years) corrosion data obtained in laboratory corrosion chambers, and further verified with field measurements in real sewers across Australia. The trained model estimated the corrosion initiation time and corrosion rates very close to those measured in Australian sewers. The ANN model performed better than a multiple regression model also developed on the same dataset. Additionally, the ANN model can serve as a prediction framework for sewer service life, which can be progressively improved and expanded by including corrosion rates measured in different sewer conditions. Furthermore, the proposed methodology holds promise to facilitate the construction of analytical models associated with corrosion processes of concrete sewers. PMID:26841228

  7. 40 CFR 35.2024 - Combined sewer overflows.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Combined sewer overflows. 35.2024... ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2024 Combined sewer... from the State allotment for correction of combined sewer overflows provided that the project is on...

  8. FLUSHING FOR SEWER SEDIMENT, CORROSION, AND POLLUTION CONTROL

    EPA Science Inventory

    This paper overviews causes of combined-sewer deterioration and their heavy pollutant discharges caused by rain events together with a discussion of their control methods. In particular, it covers in-sewer and combined-sewer overflow (CSO) storage-tank-flushing systems for removi...

  9. FLUSHING FOR SEWER SEDIMENT, CORROSION, AND POLLUTION CONTROL

    EPA Science Inventory

    This presentation overviews causes of sewer deterioration and heavy pollutant discharges caused by rain events together with a discussion of their control methods. In particular, it covers in-sewer- and combined sewer overflow- (CSO-) storage-tank-flushing systems for removal of ...

  10. SEWER SEDIMENT AND CONTROL: A MANAGEMENT PRACTICES REFERENCES GUIDE

    EPA Science Inventory

    Sewer-solids sediment is one of major sources of pollutants in urban wet-weather flow (WWF) discharges that include combined-sewer overflow (CSO), separate sanitary-sewer overflow (SSO), and stormwater runoff. During low-flow, dry-weather periods, sanitary wastewater solids depo...

  11. SANITARY SEWER OVERFLOW ANALYSIS AND PLANNING (SSOAP) TOOLBOX

    EPA Science Inventory

    Description: The Nation's sanitary-sewer infrastructure is aging, with some sewers dating back over 100 years. Nationwide, there are more than 19,500 municipal sanitary-sewer collection systems serving an estimated 150 million people and about 40,000 SSO events per year. Becau...

  12. Dynamic online sewer modelling in Helsingborg.

    PubMed

    Hernebring, C; Jönsson, L E; Thorén, U B; Møller, A

    2002-01-01

    Within the last decade, the sewer system in Helsingborg, Sweden has been rehabilitated in many ways along with the reconstruction of the WWTP Oresundsverket in order to obtain a high degree of nitrogen and phosphorus removal. In that context a holistic view has been applied in order to optimise the corrective measures as seen from the effects in the receiving waters. A sewer catchment model has been used to evaluate several operation strategies and the effect of introducing RTC. Recently, a MOUSE ONLINE system was installed. In this phase the objective is to establish a stable communication with the SCADA system and to generate short-term flow forecasts. PMID:11936663

  13. OPIMIZATION OF COMBINED SEWER OVERFLOW CONTROL SYSTEMS

    EPA Science Inventory

    The highly variable and intermittent pollutant concentrations and flowrates associated with wet-weather events in combined sewersheds necessitates the use of storage-treatment systems to control pollution. A strategy should be adopted to develop an optimized combined sewer overfl...

  14. An Environmental Innovation: The Sewer Mouse

    NASA Technical Reports Server (NTRS)

    1979-01-01

    In the effort to clean up America's waters, there is a little-known complicating factor: because they leak, sewer systems in many American cities are causing rather than preventing pollution of rivers and lakes. Fixing the leaks is difficult because their locations are unknown. Maintenance crews can't tear up a whole city looking for cracks in the pipes; they must first determine which areas are most likely suspects. An aerospace spinoff is providing help in that regard. The problem starts with heavy rains. Rainwater naturally flows into the sewers from streets, but sewage systems are designed to accommodate it. However, they are not designed to handle the additional flow of "groundwater", rain absorbed by the earth which seeps into the sewers through leaks in pipes and sewer walls. After a storm, groundwater seepage can increase the waterflow to deluge proportions, with the result that sewage treatment plants are incapable of processing the swollen flow. When that happens the sluices must be opened, dumping raw sewage into rivers and lakes.

  15. Real-time sewer effluent monitoring system

    SciTech Connect

    Koopman, S.; Yamauchi, R.K.

    1990-12-01

    Lawrence Livermore National Laboratory has upgraded its early sewer monitoring system from the 1970's. LLNL must insure that its waste water is of a consistent and acceptable nature for the City of Livermore's community sewer system. The Sewer Monitor UpGrade system (SMUG) is now monitoring the Lab's sewer effluent. SMUG monitors the effluent for pH, flow rate, metals, and alpha, beta and gamma emitting isotopes. It turns on the appropriate alarms if present alarm levels are exceeded. The hardware consists of DEC Micro VAX II/GPX that has been repackaged by Nuclear Data Company as the Genie 9900 Data Acquisition and Display System. The gamma detector, three XRFAs, pH meter, and flow rate meter are commercially available. The metals sample cells are custom built at the Lab. The operating system is the VMS version 5.4. The application software is written in DEC's Fortran-77 and MACRO, and Nuclear Data software library. 3 refs., 3 figs.

  16. Multistakeholder Evaluation of Condominial Sewer Services

    ERIC Educational Resources Information Center

    Nance, Earthea

    2005-01-01

    A multistakeholder evaluation procedure is presented to address the many challenges in evaluating the performance of condominial sewer projects in Brazil. Condominial sewerage is a promising appropriate technology that is coproduced by users and public agencies, but little is known about project performance. This article shows that…

  17. MANUAL: REAL TIME CONTROL OF COMBINED SEWERS

    EPA Science Inventory

    Managers, engineers, and operators of combined urban sewer systems are faced with difficult problems related to the operation and maintenance of their facilities. In addition to the issues related to the operation and upkeep of the system, many sewerage agencies are facing increa...

  18. Urban Runoff and Combined Sewer Overflow.

    ERIC Educational Resources Information Center

    Field, Richard; Gardner, Bradford B.

    1978-01-01

    Presents a literature review of wastewater treatment, covering publications of 1976-77. This review includes areas such as: (1) urban runoff quality and quantity; (2) urban hydrology; (3) management practices; and (4) combined sewer overflows. A list of 140 references is also presented. (HM)

  19. OPTIMIZATION OF COMBINED SEWER OVERFLOW CONTROL SYSTEMS

    EPA Science Inventory

    The highly variable and intermittent pollutant concentrations and flowrates associated with wet-weather events in combined sewersheds necessitates the use of storage-treatment systems to control pollution.An optimized combined-sewer-overflow (CSO) control system requires a manage...

  20. Modelling total suspended solids, E. coli and carbamazepine, a tracer of wastewater contamination from combined sewer overflows

    NASA Astrophysics Data System (ADS)

    Pongmala, Khemngeun; Autixier, Laurène; Madoux-Humery, Anne-Sophie; Fuamba, Musandji; Galarneau, Martine; Sauvé, Sébastien; Prévost, Michèle; Dorner, Sarah

    2015-12-01

    Urban source water protection requires knowledge of sources of fecal contamination upstream of drinking water intakes. Combined and sanitary sewer overflows (CSOs and SSOs) are primary sources of microbiological contamination and wastewater micropollutants (WWMPs) in urban water supplies. To quantify the impact of sewer overflows, predictive simulation models are required and have not been widely applied for microbial contaminants such as fecal indicator bacteria and pathogens in urban drainage networks. The objective of this study was to apply a simulation model to estimate the dynamics of three contaminants in sewer overflows - total suspended solids, Escherichia coli (E. coli) and carbamazepine, a WWMP. A mixed combined and pseudo-sanitary drainage network in Québec, Canada was studied and modelled for a total of 7 events for which water quality data were available. Model results were significantly correlated with field water quality data. The model confirmed that the contributions of E. coli from runoff and sewer deposits were minor and their dominant source was from sewage. In contrast, the main sources of total suspended solids were stormwater runoff and sewer resuspension. Given that it is not present in stormwater, carbamazepine was found to be a useful stable tracer of sewage contributions to total contaminant loads and also provided an indication of the fraction of total suspended solids originating from sewer deposits because of its similar response to increasing flowrates.

  1. Effects Of Leaky Sewers On Groundwater Quality

    NASA Astrophysics Data System (ADS)

    Leschik, S.; Musolff, A.; Reinstorf, F.; Strauch, G.; Oswald, S. E.; Schirmer, M.

    2007-12-01

    The impact of urban areas on groundwater quality has become an emerging research field in hydrogeology. Urban subsurface infrastructures like sewer networks are often leaky, so untreated wastewater may enter the urban aquifer. The transport of wastewater into the groundwater is still not well understood under field conditions. In the research platform WASSER Leipzig (Water And Sewershed Study of Environmental Risk in Leipzig- Germany) the effects of leaky sewers on the groundwater quality are investigated. The research is focused on the occurrence and transport of so-called "xenobiotics" such as pharmaceuticals and personal care product additives. Xenobiotics may pose a threat on human health, but can also be considered a marker for an urban impact on water resources. A new test site was established in Leipzig to quantify mass fluxes of xenobiotics into the groundwater from a leaky sewer. Corresponding to the leaks which were detected by closed circuit television inspections, monitoring wells were installed up- and downstream of the sewer. Concentrations of eight xenobiotics (technical-nonylphenol, bisphenol-a, caffeine, galaxolide, tonalide, carbamazepine, phenazone, ethinylestradiol) obtained from first sampling programmes were found to be highly heterogeneous, but a relation between the position of the sampling points and the sewer could not be clearly identified. However, concentrations of sodium, chloride, potassium and nitrate increased significantly downstream of the sewer which may be due to wastewater exfiltration, since no other source is known on the water flowpath from the upstream to the downstream wells. Because of the highly heterogeneous spatial distribution of xenobiotics at the test site, a monitoring concept was developed comprising both high-resolution sampling and an integral approach to obtain representative average concentrations. Direct-push techniques were used to gain insight into the fine-scale spatial distribution of the target compounds

  2. Control of sulfide and methane production in anaerobic sewer systems by means of Downstream Nitrite Dosage.

    PubMed

    Auguet, Olga; Pijuan, Maite; Borrego, Carles M; Gutierrez, Oriol

    2016-04-15

    Bioproduction of hydrogen sulfide (H2S) and methane (CH4) under anaerobic conditions in sewer pipes causes detrimental effects on both sewer facilities and surrounding environment. Among the strategies used to mitigate the production of both compounds, the addition of nitrite (NO2(-)) has shown a greater long-term inhibitory effect compared with other oxidants such as nitrate or oxygen. The aim of this study was to determine the effectiveness of a new method, the Downstream Nitrite Dosage strategy (DNO2D), to control H2S and CH4 emissions in sewers. Treatment effectiveness was assessed on H2S and CH4 abatement on the effluent of a laboratory sewer pilot plant that mimics a full-scale anaerobic rising sewer. The experiment was divided in three different periods: system setup (period 1), nitrite addition (period 2) and system recovery (period 3). Different process and molecular methods were combined to investigate the impact of NO2(-) addition on H2S and CH4 production. Results showed that H2S load was reduced completely during nitrite addition when compared to period 1 due to H2S oxidation but increased immediately after nitrite addition stopped. The H2S overproduction during recovery period was associated with the bacterial reduction of different sulfur species (elemental sulfur/thiosulfate/sulfite) accumulated within the sewer biofilm matrix. Oxidation of CH4 was also detected during period 2 but, contrary to sulfide production, re-establishment of methanogenesis was not immediate after stopping nitrite dosing. The analysis of bulk and active microbial communities along experimental treatment showed compositional changes that agreed with the observed dynamics of chemical processes. Results of this study show that DNO2D strategy could significantly reduce H2S and CH4 emissions from sewers during the addition period but also suggest that microbial agents involved in such processes show a high resilience towards chemical stressors, thus favoring the re

  3. Urban flood risk assessment using sewer flooding databases.

    PubMed

    Caradot, Nicolas; Granger, Damien; Chapgier, Jean; Cherqui, Frédéric; Chocat, Bernard

    2011-01-01

    Sustainable water management is a global challenge for the 21st century. One key aspect remains protection against urban flooding. The main objective is to ensure or maintain an adequate level of service for all inhabitants. However, level of service is still difficult to assess and the high-risk locations difficult to identify. In this article, we propose a methodology, which (i) allows water managers to measure the service provided by the urban drainage system with regard to protection against urban flooding; and (ii) helps stakeholders to determine effective strategies for improving the service provided. One key aspect of this work is to use a database of sewer flood event records to assess flood risk. Our methodology helps urban water managers to assess the risk of sewer flooding; this approach does not seek to predict flooding but rather to inform decision makers on the current level of risk and on actions which need to be taken to reduce the risk. This work is based on a comprehensive definition of risk, including territorial vulnerability and perceptions of urban water stakeholders. This paper presents the results and the methodological contributions from implementing the methodology on two case studies: the cities of Lyon and Mulhouse. PMID:22097068

  4. Characterization of Washoff Behavior of In-Sewer Deposits in Combined Sewer Systems.

    PubMed

    Kim, WeonJae; Furumai, Hiroaki

    2016-06-01

    In-sewer deposits in combined sewer systems (CSSs) are closely related with the behavior of first foul flush and combined sewer overflows. The artificial flushing experiment separating the washoff of in-sewer deposits from the inflow of surface pollutants was carried out to simulate first foul flush in a CSS. The washoff behaviors of each pollutant including chemical pollutants, bacterial indicators, and enteric viruses were intensively investigated. By using several morphological analyses, some of which were suggested through this study, the characteristics of first foul flush were examined. As a result, the washoff behaviors of each pollutant were characterized according to their (i) event load ratios (ELRs), (ii) time-series concentration and load curves, (iii) concentration vs. flow rate curves, and (iv) dimensionless runoff concentrations (DRCs). The first foul flush patterns of each parameter were categorized into 3 typical groups: the strong-, partial-, and no first foul flush group. The order of these groups signifies their different physicochemical properties of in-sewer deposits in CSSs, their strength of first foul flush phenomena, and the washoff priority as well. PMID:27225785

  5. Impact of in-sewer transformation on 43 pharmaceuticals in a pressurized sewer under anaerobic conditions.

    PubMed

    Jelic, Aleksandra; Rodriguez-Mozaz, Sara; Barceló, Damia; Gutierrez, Oriol

    2015-01-01

    The occurrence of 43 pharmaceuticals and 2 metabolites of ibuprofen was evaluated at the inlet and the outlet of a pressure sewer pipe in order to asses if in-sewer processes affect the pharmaceutical concentrations during their pass through the pipe. The target compounds were detected at concentrations ranging from low ng/L to a few μg/L, which are in the range commonly found in municipal wastewater of the studied area. The changes in concentrations between two sampling points were negligible for most compounds, i.e. from -10 to 10%. A higher decrease in concentrations (25-60 %) during the pass through the pipe was observed for diltiazem, citalopram, clarithromycin, bezafibrate and amlodipine. Negative removal was calculated for sulfamethoxazole (-66 ± 15%) and irbesartan (-58 ± 25%), which may be due to the conversion of conjugates back to their parent compounds in the sewer. The results show that microbial transformation of pharmaceuticals begins in sewer, albeit to different extents for different compounds. Therefore, the in-sewer transformation of pharmaceuticals should be assessed especially when their concentrations are used to estimate and refine the estimation of their per capita consumption in a catchment of interest in the sewage epidemiology approach. PMID:25462720

  6. Estimating sewer leakage from continuous tracer experiments.

    PubMed

    Rieckermann, Jörg; Bares, Vojtech; Kracht, Oliver; Braun, Daniel; Gujer, Willi

    2007-05-01

    Direct measurements of sewer leakage with continuous dosing of tracers are often considered too imprecise for practical applications. However, no mathematical framework for data analysis is reported in literature. In this paper, we present an improved experimental design and data analysis procedure together with a comprehensive framework for uncertainty assessment. Test runs in a 700 m-long watertight sewer showed no significant bias and a very high precision of the methodology. The standard error in the results was assessed to 2.6% of the labeled flow with a simplified model. It could be reduced to 1.2% when a dynamic data analysis procedure was applied. The major error contribution was caused by transient transport phenomena, which suggests that careful choosing of the experimental time is more important than the choice of a very specific tracer substance. Although the method is not intended to replace traditional CCTV inspections, it can provide complementary information for rational rehabilitation planning. PMID:17363025

  7. A review of sulfide emissions in sewer networks: overall approach and systemic modelling.

    PubMed

    Carrera, Lucie; Springer, Fanny; Lipeme-Kouyi, Gislain; Buffiere, Pierre

    2016-01-01

    The problems related to hydrogen sulfide in terms of deterioration of sewer networks, toxicity and odor nuisance have become very clear to the network stakeholders and the public. The hydraulic and (bio)chemical phenomena and parameters controlling sulfide formation, emission and their incidences in sewer networks are very complex. Recent research studies have been developed in gravity and pressure sewers and some transfer models have been published. Nevertheless, the models do not take into account all the physical phenomena influencing the emission process. After summing up the main scientific knowledge concerning the production, oxidation, transfer and emission processes, the present review includes: (i) a synthetic analysis of sulfide and hydrogen sulfide emission models in sewer networks, (ii) an estimation of their limit, (iii) perspectives to improve the modelling approach. It shows that sulfide formation and uptake models still need refinements especially for some phenomena such as liquid to gas mass transfer. Transfer models that have been published so far are purposely simplified and valid for simple systems. More efforts have to be undertaken in order to better understand the mechanisms and the dynamics of hydrogen sulfide production and emission in real conditions. PMID:27003062

  8. Measuring Flow Reductions in a Combined Sewer System using Green Infrastructure - abstract

    EPA Science Inventory

    In 2009, the Louisville and Jefferson County Metropolitan Sewer District (MSD) submitted an Integrated Overflow Abatement Plan (IOAP) addressing combined sewer overflows (CSOs) and sanitary sewer overflows. Many of the solutions involve gray infrastructure, such as large, end-of...

  9. Real-time control of sewer systems using turbidity measurements.

    PubMed

    Lacour, C; Schütze, M

    2011-01-01

    Real-time control (RTC) of urban drainage systems has been proven useful as a means to reduce pollution by combined sewer overflow discharges. So far, RTC has been investigated mainly with a sole focus on water quantity aspects. However, as measurement techniques for pollution of wastewater are advancing, pollution-based RTC might be of increasing interest. For example, turbidity data sets from an extensive measurement programme in two Paris catchments allow a detailed investigation of the benefits of using pollution-based data for RTC. This paper exemplifies this, comparing pollution-based RTC with flow-based RTC. Results suggest that pollution-based RTC indeed has some potential, particularly when measurements of water-quality characteristics are readily available. PMID:22049758

  10. Transformation of AgCl nanoparticles in a sewer system--A field study.

    PubMed

    Kaegi, Ralf; Voegelin, Andreas; Sinnet, Brian; Zuleeg, Steffen; Siegrist, Hansruedi; Burkhardt, Michael

    2015-12-01

    Silver nanoparticles (Ag-NP) are increasingly used in consumer products and their release during the use phase may negatively affect aquatic ecosystems. Research efforts, so far, have mainly addressed the application and use of metallic Ag(0)-NP. However, as shown by recent studies on the release of Ag from textiles, other forms of Ag, especially silver chloride (AgCl), are released in much larger quantities than metallic Ag(0). In this field study, we report the release of AgCl-NP from a point source (industrial laundry that applied AgCl-NP during a piloting phase over a period of several months to protect textiles from bacterial regrowth) to the public sewer system and investigate the transformation of Ag during its transport in the sewer system and in the municipal wastewater treatment plant (WWTP). During the study period, the laundry discharged ~85 g of Ag per day, which dominated the Ag loads in the sewer system from the respective catchment (72-95%) and the Ag in the digested WWTP sludge (67%). Combined results from electron microscopy and X-ray absorption spectroscopy revealed that the Ag discharged from the laundry to the sewer consisted of about one third AgCl and two thirds Ag2S, both forms primarily occurring as nanoparticles with diameters<100 nm. During the 800 m transport in the sewer channel to the nearby WWTP, corresponding to a travel time of ~30 min, the remaining AgCl was transformed into nanoparticulate Ag2S. Ag2S-NP also dominated the Ag speciation in the digested sludge. In line with results from earlier studies, the very low Ag concentrations measured in the effluent of the WWTP (<0.5 μg L(-1)) confirmed the very high removal efficiency of Ag from the wastewater stream (>95%). PMID:25582606

  11. Modelling the effects of on-site greywater reuse and low flush toilets on municipal sewer systems.

    PubMed

    Penn, R; Schütze, M; Friedler, E

    2013-01-15

    On-site greywater reuse (GWR) and installation of water-efficient toilets (WET) reduce urban freshwater demand. Research on GWR and WET has generally overlooked the effects that GWR may have on municipal sewer systems. This paper discusses and quantifies these effects. The effects of GWR and WET, positive and negative, were studied by modelling a representative urban sewer system. GWR scenarios were modelled and analysed using the SIMBA simulation system. The results show that, as expected, the flow, velocity and proportional depth decrease as GWR increases. Nevertheless, the reduction is not evenly distributed throughout the day but mainly occurs during the morning and evening peaks. Examination of the effects of reduced toilet flush volumes revealed that in some of the GWR scenarios flows, velocities and proportional depths in the sewer were reduced, while in other GWR scenarios discharge volumes, velocities and proportional depths did not change. Further, it is indicated that as a result of GWR and installation of WET, sewer blockage rates are not expected to increase significantly. The results support the option to construct new sewer systems with smaller pipe diameters. The analysis shows that as the penetration of GWR systems increase, and with the installation of WET, concentrations of pollutants also increase. In GWR scenarios (when toilet flush volume is not reduced) the increase in pollutant concentrations is lower than the proportional reduction of sewage flow. Moreover, the results show that the spatial distribution of houses reusing GW does not significantly affect the parameters examined. PMID:23220603

  12. INNOVATIVE METHODS FOR THE OPTIMIZATION OF GRAVITY STORM SEWER DESIGN

    EPA Science Inventory

    The purpose of this paper is to describe a new method for optimizing the design of urban storm sewer systems. Previous efforts to optimize gravity sewers have met with limited success because classical optimization methods require that the problem be well behaved, e.g. describ...

  13. 40 CFR 35.927-4 - Sewer use ordinance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Sewer use ordinance. 35.927-4 Section... ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.927-4 Sewer use ordinance. Each applicant for grant assistance for a step 2 or step 3 project...

  14. 7. VIEW TO NORTH SHOWING SEWER CONSTRUCTION IN FOREGROUND AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW TO NORTH SHOWING SEWER CONSTRUCTION IN FOREGROUND AND BUILDING F IN THE LEFT BACKGROUND. 8X10 black and white gelatin print. United States Coast Guard, Air Station Contract 1247, Sewer System. 1956. - U.S. Coast Guard Air Station San Francisco, 1020 North Access Road, San Francisco, San Francisco County, CA

  15. CONTROL STRATEGY FOR STORM-GENERATED SANITARY-SEWER OVERFLOWS

    EPA Science Inventory

    This paper presents a strategy for the abatement of pollution from storm-generated sanitary-sewer overflows (SSO). Because of the great lengths of sanitary sewer systems, it is often less expensive to use alterantives to sewerline rehabilitation for infiltration/inflow (I/I) and ...

  16. CONTROL STRATEGY FOR STORM-GENERATED SANITARY-SEWER OVERFLOWS

    EPA Science Inventory

    This paper presents a strategy for the abatement of pollution from storm-generated sanitary-sewer overflows (SSO). Because of the great lengths of sanitary-sewer systems and their associated vast number of house-service laterals or building connections, it is often less expensiv...

  17. HIGH-RATE DISINFECTION OF COMBINED SEWER OVERFLOW

    EPA Science Inventory

    Wet-weather flow (WWF), including combined-sewer overflow (CSO, sanitary-sewer overflow, and stormwater (SW), is a significant contributor of microbial contamination to surface water and ground water. By using effective wastewater or SW disinfection, introduction of pathogen con...

  18. GATE AND VACUUM FLUSHING OF SEWER SEDIMENT: LABORATORY TESTING

    EPA Science Inventory

    The objective of this study was to test the performance of a traditional gate-flushing device and a newly-designed vacuum-flushing device in removing sediment from combined sewers and CSO storage tanks. A laboratory hydraulic flume was used to simulate a reach of sewer or storag...

  19. EVALUATION OF TRENCHLESS SEWER CONSTRUCTION AT SOUTH BETHANY BEACH, DELAWARE

    EPA Science Inventory

    The purpose of this project was to determine whether the trenchless method of sewer construction had inherent cost, safety and other advantages over conventional methods of sewer construction. Under similar site conditions, the trenchless method was more cost effective than conve...

  20. SEWER SEDIMENT GATE AND VACUUM FLUSHING TANKS: LABORATORY FLUME STUDIES

    EPA Science Inventory

    The objective of this study was to test the performance of a traditional gate-flushing device and a newly designed vacuum-flushing device in removing sediments from combined sewers and CSO storage tanks. A laboratory hydraulic flune was used to simulate a reach of sewer or storag...

  1. 40 CFR 35.927 - Sewer system evaluation and rehabilitation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... environmental factors. (b) A sewer system evaluation will generally be used to determine whether or not... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Sewer system evaluation and rehabilitation. 35.927 Section 35.927 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND...

  2. Control Strategy for Storm-Generated Sanitary Sewer Overflows

    EPA Science Inventory

    This presentation covers a strategy for the abatement of pollution from sanitary-sewer overflows (SSO). Because of the great lengths of sanitary sewer systems, it is often less expensive to use alternatives to sewerline rehabilitation for infiltration/inflow (I/I) and associated ...

  3. Moon Rise

    NASA Video Gallery

    Aboard the International Space Station in May 2012, Expedition 31 astronaut Don Pettit opened the shutters covering the cupola observation windows in time to watch the moon rise. The time-lapse sce...

  4. Modelling the viability of heat recovery from combined sewers.

    PubMed

    Abdel-Aal, M; Smits, R; Mohamed, M; De Gussem, K; Schellart, A; Tait, S

    2014-01-01

    Modelling of wastewater temperatures along a sewer pipe using energy balance equations and assuming steady-state conditions was achieved. Modelling error was calculated, by comparing the predicted temperature drop to measured ones in three combined sewers, and was found to have an overall root mean squared error of 0.37 K. Downstream measured wastewater temperature was plotted against modelled values; their line gradients were found to be within the range of 0.9995-1.0012. The ultimate aim of the modelling is to assess the viability of recovering heat from sewer pipes. This is done by evaluating an appropriate location for a heat exchanger within a sewer network that can recover heat without impacting negatively on the downstream wastewater treatment plant (WWTP). Long sewers may prove to be more viable for heat recovery, as heat lost can be reclaimed before wastewater reaching the WWTP. PMID:25051477

  5. Prediction of sulphide build-up in filled sewer pipes.

    PubMed

    Alani, Amir M; Faramarzi, Asaad; Mahmoodian, Mojtaba; Tee, Kong Fah

    2014-08-01

    Millions of dollars are being spent worldwide on the repair and maintenance of sewer networks and wastewater treatment plants. The production and emission of hydrogen sulphide has been identified as a major cause of corrosion and odour problems in sewer networks. Accurate prediction of sulphide build-up in a sewer system helps engineers and asset managers to appropriately formulate strategies for optimal sewer management and reliability analysis. This paper presents a novel methodology to model and predict the sulphide build-up for steady state condition in filled sewer pipes. The proposed model is developed using a novel data-driven technique called evolutionary polynomial regression (EPR) and it involves the most effective parameters in the sulphide build-up problem. EPR is a hybrid technique, combining genetic algorithm and least square. It is shown that the proposed model can provide a better prediction for the sulphide build-up as compared with conventional models. PMID:24956763

  6. Water Quality of Combined Sewer Overflows, Stormwater, and Streams, Omaha, Nebraska, 2006-07

    USGS Publications Warehouse

    Vogel, Jason R.; Frankforter, Jill D.; Rus, David L.; Hobza, Christopher M.; Moser, Matthew T.

    2009-01-01

    criterion in all but four stream samples (266 of 270). Similarly, only 2 of 84 Missouri River samples had total phosphorus concentrations less than the proposed criterion. The proposed total nitrogen criterion for the Corn Belt and Northern Great Plains ecoregion was surpassed in 80 percent of the water samples collected from the stream sites. Samples with total nitrogen concentrations greater than the proposed criterion were most common at Papillion Creek and Big Papillion Creek sites, where the proposed criterion was surpassed in 90 and 96 percent of the samples collected, respectively. Elevated concentrations of total nitrogen were less common at the Missouri River sites, with 33 percent of the samples analyzed having concentrations that surpassed the proposed nutrient criterion for total nitrogen. The three constituents with measured concentrations greater than their respective health-based screening levels were nickel, zinc, and dichlorvos. Differences in water quality during the beginning, middle, and end of the combined sewer overflow discharge and the stream hydrograph rise, peak, and recession were investigated. Concentrations from the ending part of the combined sewer overflow hydrograph were significantly different than those from the beginning and middle parts for 3 and 11 constituents, respectively. No constituents were significantly different between the beginning and middle parts of the combined sewer overflow discharge hydrograph. For the stream site upstream from combined sewer overflow outfalls on Cole Creek, the constituents with geometric mean values for the hydrograph rise that were at least twice those for the values of the peak and recession were specific conductance, magnesium, nitrite, N,N-diethyl-meta-toluamide (DEET), methyl salicylate, p-cresol, and Escherichia coli. Similarly, the constituents where the hydrograph peak was at least twice that for the rise and recession at the upstream Cole Creek site were total suspended solids, silver, an

  7. Valuing information for sewer replacement decisions.

    PubMed

    van Riel, Wouter; Langeveld, Jeroen; Herder, Paulien; Clemens, François

    2016-01-01

    Decision-making for sewer asset management is partially based on intuition and often lacks explicit argumentation, hampering decision transparency and reproducibility. This is not to be preferred in light of public accountability and cost-effectiveness. It is unknown to what extent each decision criterion is appreciated by decision-makers. Further insight into this relative importance improves understanding of decision-making of sewer system managers. As such, a digital questionnaire (response ratio 43%), containing pairwise comparisons between 10 relevant information sources, was sent to all 407 municipalities in the Netherlands to analyse the relative importance and assess whether a shared frame of reasoning is present. Thurstone's law of comparative judgment was used for analysis, combined with several consistency tests. Results show that camera inspections were valued highest, while pipe age was considered least important. The respondents were pretty consistent per individual and also showed consistency as a group. This indicated a common framework of reasoning among the group. The feedback of the group showed, however, the respondents found it difficult to make general comparisons without having a context. This indicates decision-making in practice is more likely to be steered by other mechanisms than purely combining information sources. PMID:27533854

  8. U.S. EPA Issues Technical Guides and Computer Tools for Sewer Condition and Capacity Assessment

    EPA Science Inventory

    The nation's sanitary sewer infrastructure is aging, with some sewers more than100 years old. Nationwide, there are more than 19,500 municipal sanitary-sewer collection systems serving an estimated 150 million people and about 40,000 sanitary sewer overflow (SSO) events per year...

  9. Factors That Influence Properties of FOG Deposits and Their Formation in Sewer Collection Systems.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the formation of Fat, Oil, and Grease (FOG) deposits in sewer systems is critical to the sustainability of sewer collection systems since they have been implicated in causing sewerage blockages, which eventually lead to sanitary sewer overflows (SSOs). Recently, FOG deposits in sewer ...

  10. Advances in Sewer Condition and Capacity Assessment – Development and Applications of EPA SSOAP Toolbox

    EPA Science Inventory

    In the United States, sanitary sewer infrastructure is aging, with some sewers dating back over 100 years. Nationwide, there are more than 19,500 municipal sanitary-sewer collection systems serving an estimated 150 million people and about 40,000 sanitary sewer overflow (SSO) ev...

  11. Reducing pathogens in combined sewer overflows using ozonation or UV irradiation.

    PubMed

    Tondera, Katharina; Klaer, Kassandra; Gebhardt, Jens; Wingender, Jost; Koch, Christoph; Horstkott, Marina; Strathmann, Martin; Jurzik, Lars; Hamza, Ibrahim Ahmed; Pinnekamp, Johannes

    2015-11-01

    Fecal contamination of water resources is a major public health concern in densely populated areas since these water bodies are used for drinking water production or recreational purposes. A main source of this contamination originates from combined sewer overflows (CSOs) in regions with combined sewer systems. Thus, the treatment of CSO discharges is urgent. In this study, we explored whether ozonation or UV irradiation can efficiently reduce pathogenic bacteria, viruses, and protozoan parasites in CSOs. Experiments were carried out in parallel settings at the outflow of a stormwater settling tank in the Ruhr area, Germany. The results showed that both techniques reduce most hygienically relevant bacteria, parasites and viruses. Under the conditions tested, ozonation yielded lower outflow values for the majority of the tested parameters. PMID:26431869

  12. Surface water sewer misconnections in England and Wales: Pollution sources and impacts.

    PubMed

    Ellis, J B; Butler, D

    2015-09-01

    In urban areas served by separate sewerage consisting of separate pipe systems it is not uncommon for misconnections to be made either accidentally or deliberately, whereby the wrong effluent is connected to the wrong sewer. The main focus of this problem has been on in-household appliances that are wrongly connected to separate surface water sewers, potentially leading to pollution of receiving waters and non-compliance with statutory water quality standards. This paper examines the available evidence to evaluate the potential scale, severity and cost of the problem in England and Wales in comparison to that reported from investigations in the United States. The particular difficulties associated with distinguishing specific sewage sources in the wastewater "cocktail" discharged at polluted surface water outfalls are reviewed. The deficiencies of existing legislation and enforcing compliance with respect to misconnections are also discussed and the pollution potential resulting from domestic misconnections is explored based on sampled data. PMID:25918897

  13. 300 Area process sewer piping upgrade and 300 Area treated effluent disposal facility discharge to the City of Richland Sewage System, Hanford Site, Richland, Washington

    SciTech Connect

    1995-05-01

    The U.S. Department of Energy (DOE) is proposing to upgrade the existing 300 Area Process Sewer System by constructing and operating a new process sewer collection system that would discharge to the 300 Area Treated Effluent Disposal Facility. The DOE is also considering the construction of a tie-line from the TEDF to the 300 Area Sanitary Sewer for discharging the process wastewater to the City of Richland Sewage System. The proposed action is needed because the integrity of the old piping in the existing 300 Area Process Sewer System is questionable and effluents might be entering the soil column from leaking pipes. In addition, the DOE has identified a need to reduce anticipated operating costs at the new TEDF. The 300 Area Process Sewer Piping Upgrade (Project L-070) is estimated to cost approximately $9.9 million. The proposed work would involve the construction and operation of a new process sewer collection system. The new system would discharge the effluents to a collection sump and lift station for the TEDF. The TEDF is designed to treat and discharge the process effluent to the Columbia River. The process waste liquid effluent is currently well below the DOE requirements for radiological secondary containment and is not considered a RCRA hazardous waste or a State of Washington Hazardous Waste Management Act dangerous waste. A National Pollutant Discharge Elimination, System (NPDES) permit has been obtained from the U.S. Environmental Protection Agency for discharge to the Columbia River. The proposed action would upgrade the existing 300 Area Process Sewer System by the construction and operation of a new combined gravity, vacuum, and pressurized process sewer collection system consisting of vacuum collection sumps, pressure pump stations, and buried polyvinyl chloride or similar pipe. Two buildings would also be built to house a main collection station and a satellite collection station.

  14. A sewer ventilation model applying conservation of momentum.

    PubMed

    Ward, M; Hamer, G; McDonald, A; Witherspoon, J; Loh, E; Parker, W

    2011-01-01

    The work presented herein was completed in an effort to characterize the forces influencing ventilation in gravity sewers and to develop a mathematical model, based on conservation of momentum, capable of accounting for friction at the headspace/pipe interface, drag at the air/water interface, and buoyancy caused by air density differences between a sewer headspace and ambient. Experiments were completed on two full scale sewer reaches in Australia. A carbon monoxide-based tracer technique was used to measure the ventilation rate within the sewer headspaces. Additionally, measurements of pressure, relative humidity, and temperature were measured in the ambient air and sewer headspace. The first location was a five kilometre long sewer outfall beginning at a wastewater treatment plant and terminating at the ocean. The second location was a large gravity sewer reach fitted with ventilation fans. At the first location the headspace was entirely sealed except for openings that were controlled during the experiments. In this situation forces acting on the headspace air manifested mostly as a pressure distribution within the reach, effectively eliminating friction at the pipe wall. At the second location, air was forced to move near the same velocity as the wastewater, effectively eliminating drag at the air/water interface. These experiments allowed individual terms of the momentum equation to be evaluated. Experimental results were compared to the proposed mathematical model. Conclusions regarding model accuracy are provided along with model application guidance and assumptions. PMID:22214094

  15. Use of sanitary sewers as wastewater pre-treatment systems

    SciTech Connect

    Warith, M.A.; Kennedy, K.; Reitsma, R.

    1998-12-31

    As wastewater travels through a sewer system it undergoes changes in composition. The changes in composition may be caused by chemical, physical and/or biological processes. At present engineers do not take into consideration the impacts of these processes on the wastewater quality when designing wastewater treatment systems. However, the impact of these processes on the chemical oxygen demand, biochemical oxygen demand, nitrogen and phosphorus content of the wastewater can be significant. In the case of the biological processes, microorganisms present in the water as it travels through the sewer system are similar to those found in an activated sludge process. Given that the microorganism population and the hydraulic retention time often resembles that of an activated sludge process, it would seem only reasonable to look further into the possibility of using sewers as wastewater treatment systems. Furthermore, the plug flow regime of a sanitary sewer is inherently beneficial in terms of wastewater treatment as it is not subject to short-circuiting. The first part of this paper provides a technical review of the processes which take place in a sewer system and the resulting degradation of some of the more significant substances found in wastewater. The contribution of both the suspended biomass and the attached biomass to the degradation of substrate is also examined. The second part of this paper examines the use of the Toxchem computer model to predict the processes which are taking place in the sewer under a variety of conditions. The goal being to determine the magnitude of the degradation of substrate and dissolved oxygen depletion in a sewer system. In obtaining a better understanding of the processes that are taking place in sewer systems, engineers will be able to more accurately predict the degradation of substrates in sanitary sewer systems. This will result in a reduction in the size of wastewater treatment facilities (WWTFs).

  16. Stable isotopes of water as a natural tracer for infiltration into urban sewer systems

    NASA Astrophysics Data System (ADS)

    Kracht, O.; Gresch, M.; de Bénédittis, J.; Prigiobbe, V.; Gujer, W.

    2003-04-01

    endmembers is basically sufficient to estimate the ratio of infiltrating water in the sewer. Uncertainties yet derive from varying amounts of local groundwater in the water supply mains. These will be substituted by additionally purchased lake water in the next experimental stage. 2) The experimental site Toraccia (suburb of Rome, Italy) obtains drinking water from the Peschiera springs group that is situated in the central Apennines chain about 90 km north east of Rome. This spring water is transported to Rome by an aqueduct. A first campaign revealed an average mains water δ18O value of -8,4 per mill and δ^2H value of -53 per mill. Potential sources of infiltration are occurrences of perched groundwater. These appear to be enriched compared to the drinking water about 2 to 3 per mill in the δ18O and 10 to 20 per mill in the δ^2H value, but show disadvantageous strong variations. 3) Investigations in the urban area of Lyon (France) benefit from the isotopic differences between underground waters originating from the two rivers Rhone and Saone and their associated alluvial aquifers. The oxygen isotope composition of the Rhone water is roughly 3 per mill lighter than that of the river Saone, due to the large differences in the mean altitude and topographic situation of their catchment basins. Considerable amounts of mains water are extracted by production wells in the Rhone aquifer. In consequence a usable difference in the oxygen isotope composition between wastewater and local groundwater of about 1.5 per mill is available for application studies in certain parts of the city.

  17. Transport of large solids in sewer pipes.

    PubMed

    Walski, Thomas; Edwards, Bryce; Helfer, Emil; Whitman, Brian E

    2009-07-01

    This paper presents a method for determining the conditions under which large solids (i.e., solids with a vertical dimension greater than the depth of water) are able to move in a pipe. Depending on the value of a dimensionless number [s(d/y) - 1], where s = specific gravity of the solids, d = water depth, and y = height of solids, motion will occur if a sufficient velocity (also reported as a Froude number or modified "solids" Froude number) is exceeded. Flume experiments were used to determine the coefficients to be used in the design. The velocity required to reach fluid movement was approximately 0.6 to 1.0 m/s (2 to 3 ft/s), which is consistent, although slightly higher than values generally used in conventional sewer design practice. However, it was demonstrated that increasing the pipe slope to achieve a higher velocity does not ensure that the solid will move. PMID:19691252

  18. First flush in a combined sewer system.

    PubMed

    Barco, Janet; Papiri, Sergio; Stenstrom, Michael K

    2008-03-01

    Pollutant first flush was examined in an urban catchment with area of 12.7 ha and drained by a combined sewer system located in northern Italy. A total of 23 rainfall-runoff events were monitored and 281 samples were analyzed. The selected quality parameters were biochemical oxygen demand, chemical oxygen demand, suspended solids, settleable solids, total phosphorus, total nitrogen, ammonium nitrogen, lead, and zinc, specific conductivity and hydrocarbons. A subset of representative storms was selected for first flush analysis. The catchment presented a strong first flush for almost all storms and most constituents. The analysis shows that treating the maximum amount of the early part of the runoff is a better strategy than treating a constant flow rate. Best management practices that can treat or store the first runoff are favored in this kind of system for these water quality parameters. PMID:18191441

  19. Treatment shaft for combined sewer overflow detention.

    PubMed

    Wright, Steven J; Ghalib, Saad; Eloubaidy, Aziz

    2010-05-01

    A deep, large-diameter underground shaft to provide detention storage for combined sewer overflow control may be advantageous in urban environments, where space limitations require solutions with a small footprint. An underflow baffle wall is provided at the center of the treatment shaft to prevent short-circuiting of the flow. An additional objective is to maintain low headlosses through the structure. A physical model study was conducted to determine the effect of the bottom elevation of the baffle wall on the headloss and breakthrough curve for dye injected to the inflow. It was found that there is a considerable range of elevations for which the structure behaves acceptably in providing adequate contact time for disinfectant while maintaining small headlosses. PMID:20480764

  20. Quantification and relative comparison of different types of uncertainties in sewer water quality modeling.

    PubMed

    Willems, Patrick

    2008-07-01

    Quantifiable sources of uncertainty have been identified for a case study of integrated modeling of a sewer system with a more downstream wastewater treatment plant and storage sedimentation tank. The different sources were classified in model input and model-structure-related uncertainties. They were quantified and propagated towards the uncertainty in the event-based prediction of sewer emissions (flow, and physico-chemical water quality concentrations and loads). Based on the concept of variance decomposition, the total prediction uncertainty was split into the contributions of the various uncertainty sources and the different submodels. Although the results strongly depend on the water quality variable considered, it is in most general terms concluded that the uncertainty contribution by the water quality submodels is an order of magnitude higher than that for the flow submodels. Future model improvement should therefore mainly focus on water quality data collection, which would reduce current problems of spurious model calibration and verification, but also of knowledge gaps in in-sewer processes. PMID:18554682

  1. Sandia National Laboratories, California sewer system management plan.

    SciTech Connect

    Holland, Robert C.

    2010-02-01

    A Sewer System Management Plan (SSMP) is required by the State Water Resources Control Board (SWRCB) Order No. 2006-0003-DWQ Statewide General Waste Discharge Requirements (WDR) for Sanitary Sewer Systems (General Permit). DOE, National Nuclear Security Administration (NNSA), Sandia Site Office has filed a Notice of Intent to be covered under this General Permit. The General Permit requires a proactive approach to reduce the number and frequency of sanitary sewer overflows (SSOs) within the State. SSMPs must include provisions to provide proper and efficient management, operation, and maintenance of sanitary sewer systems and must contain a spill response plan. Elements of this Plan are under development in accordance with the SWRCB's schedule.

  2. INTEGRATED CONTROL OF COMBINED SEWER REGULATORS USING WEATHER RADAR

    EPA Science Inventory

    Integrated operation was simulated of ten dynamic combined sewer regulators on a Montreal interceptor. Detailed review of digital recording weather radar capabilities indicated that it is potentially the best rainfall estimation means for accomplishing the runoff prediction that ...

  3. 40 CFR 35.925-21 - Storm sewers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-21 Storm sewers. That, under section 211(c) of the Act, the allowable project costs do not include costs...

  4. 40 CFR 35.925-21 - Storm sewers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-21 Storm sewers. That, under section 211(c) of the Act, the allowable project costs do not include costs...

  5. 40 CFR 35.925-21 - Storm sewers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-21 Storm sewers. That, under section 211(c) of the Act, the allowable project costs do not include costs...

  6. 40 CFR 35.925-21 - Storm sewers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-21 Storm sewers. That, under section 211(c) of the Act, the allowable project costs do not include costs...

  7. 40 CFR 35.925-21 - Storm sewers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.925-21 Storm sewers. That, under section 211(c) of the Act, the allowable project costs do not include costs...

  8. COMBINED SEWER OVERFLOW CHARACTERISTICS FROM TREATMENT PLANT DATA

    EPA Science Inventory

    This research was undertaken to evaluate the adequacy of using a mass balance technique with daily municipal wastewater treatment plant data to determine combined sewer runoff and overflow characteristics. The bias and variability associated with the mass balance technique togeth...

  9. MANAGEMENT OF COMBINED SEWER OVERFLOW RESEARCH PROGRAM CAPSTONE

    EPA Science Inventory


    Combined-sewer overflow (CSO) is a mixture of urban storm drainage, municipal-industrial wastewater, and subterranean infiltration. Untreated discharges of CSOs have caused substantial pollution impacts on the quality of receiving-water bodies. Problem constituents include ...

  10. SANITARY SEWER SYSTEMS - LAND APPLICATION AREAS, NEUSE RIVER WATERSHED, NC

    EPA Science Inventory

    The North Carolina Rural Economic Development Center (NCREDC) in conjunction with Hobbs, Upchurch & Associates developed the digital Sewer system land applications as mapped by individual system owners as required by contract. The data collected will facilitate planning, siting a...

  11. FLOCCULATION-FLOTATION AIDS FOR TREATMENT OF COMBINED SEWER OVERFLOWS

    EPA Science Inventory

    The objectives of this study were to investigate the flocculation/flotation characteristics of combined sewer overflow through laboratory and field testing. The concept involves the introduction of chemicals and buoyant flotation aids into the overflow and the subsequent cofloccu...

  12. Urban runoff and combined sewer overflow. [Wastewater treatment

    SciTech Connect

    Moffa, P.E.; Freedman, S.D.; Owens, E.M.; Field, R.; Cibik, C.

    1982-06-01

    The control, treatment and management of urban runoff and sewer overflow are reviewed. Simplified modeling and monitoring techniques are used to characterize urban runoff and to assess control alternatives. (KRM)

  13. MANAGEMENT OF COMBINED SEWER OVERFLOW: RESEARCH PROGRAM CAPSTONE

    EPA Science Inventory

    Combined-sewer overflow (CSO) is a mixture of urban storm drainage, municipal-industrial wastewater, and subterranean infiltration. Untreated discharges of CSOs have caused substantial pollution impacts on the quality of receiving-water bodies. Problem constituents include visi...

  14. SANITARY SEWER SYSTEMS - DISCHARGES, NEUSE RIVER WATERSHED, NC

    EPA Science Inventory

    The North Carolina Rural Economic Development Center (NCREDC) in conjunction with Hobbs, Upchurch & Associates developed the digital Sewer system discharges as mapped by individual system owners as required by contract. The data collected will facilitate planning, siting and impa...

  15. Exposure to airborne endotoxins among sewer workers: an exploratory study.

    PubMed

    Duquenne, Philippe; Ambroise, Denis; Görner, Pierre; Clerc, Frédéric; Greff-Mirguet, Guylaine

    2014-04-01

    Exploratory bioaerosol sampling was performed in order to assess exposure to airborne endotoxins during sewer work. Personal samples were collected in underground sewer pipes using 37-mm closed-face cassettes containing fibreglass filters (CFC-FG method) or polycarbonate filters (CFC-PC method). Endotoxins were quantified using the limulus amoebocyte lysate assay. Concentrations of airborne endotoxins at sewer workplaces (16-420 EU m(-3)) were higher than those measured outside the sewer network (0.6-122 EU m(-3)). Sewer worker exposure to airborne endotoxins depended on the workplace and on the tasks. Exposure levels were the highest for tasks involving agitation of water and matter, especially for 'chamber cleanup' and 'pipes cleanup' with a high-pressure water jet. Airborne endotoxin levels at the workplace tended to be higher when CFC-FG was used as the sampling method rather than CFC-PC. The adjusted mean of the measured concentrations for CFC-PC represents 57% of the mean observed with CFC-FG. The number of samples collected in the descriptive study was too low for drawing definitive conclusions and further exposure investigations are needed. Therefore, our exploratory study provides new exposure data for the insufficiently documented sewer working environment and it would be useful for designing larger exposures studies. PMID:24470536

  16. Modelling of biofilters for ammonium reduction in combined sewer overflow.

    PubMed

    Henrichs, M; Welker, A; Uhl, M

    2009-01-01

    Biofiltration has proved to be a useful system to treat combined sewer overflow (CSO). The study presented uses numerical simulation to detect the critical operating conditions of the filter. The multi-component reactive transport module CW2D was used for the simulation study. Single-event simulations of lab-scale-column experiments with varying boundary conditions regarding the throttle outflow rate were carried out. For the calibration of the CW2D model measurement results of four experiments in two lab-scale columns were used. The model was validated by simulating four events of two further columns filled with the same filter material. These columns were operating with higher throttle outflow rates than the columns used for calibration. For ammonium (NH(4)-N) a good fit between measured and simulated data could be achieved. However, the comparison of simulated and measured effluent concentrations of nitrate (NO(3)-N) showed that there is a need for further investigations mainly due to the uncertainties in the degradation process during dry periods between the loadings. PMID:19657178

  17. 3D geological model developed to analyse the aquifer - sewer network interaction in Bucharest city

    NASA Astrophysics Data System (ADS)

    Serpescu, I.; Radu, E.; Gogu, R. G.; Priceputu, A.; Boukhemacha, M. A.; Bica, I.; Gaitanaru, D.

    2012-04-01

    Due to the fact that several important Bucharest city sewer segments drain the groundwater and provide high input flow-rates for the existing waste-water treatment plant, their rehabilitation is necessary. A hydrogeological model, currently under development, will permit to compute the groundwater-sewer network interaction allowing the simulation of distinct design solutions to prevent city disturbances. For groundwater modelling the geological model represents the fundament of understanding the aquifers system behaviour. In this respect a 3D accurate and detailed geological model, covering a region of about 75 km2 has been developed to identify its contact with the major collecting sewer conduit. The shallow aquifer stratum of quaternary formations called Colentina is made of gravels and sands. This unconfined aquifer can be found mainly in the Bucharest city region at depths up to 20 m. A clayey-marl layer is located between Colentina and a lower confined aquifer called Mostistea. This second one is located at depths between 25 m and 70 m and is made of fine and medium sands with gravel intercalations. It overlays on a very thick sequence (40 m to 150 m) of marl and clay layers with slim sandy intercalations. The geological model has been developed on the basis of a large number of geological and geotechnical boreholes. A set of 400 boreholes with depths between 5m to 200 m showing a detailed geological and lithological description stored in a geospatial database have been used. The geological analysis has been performed using a software platform that integrates the spatial database and a set of tools and methodologies developed in a GIS environment with the aim of facilitating the development of 3D geological models for sedimentary media. Taking into account the first 50 m in depth, 25 geological profiles have been interpreted on the basis of chronostratigraphycal, lithological, and sedimentological criteria to delineate the geological formations and assess

  18. Copernicus Rising

    NASA Astrophysics Data System (ADS)

    Rose, Michael A.

    2007-08-01

    Copernicus Rising began as a historical biography when it was first conceived, but as the writing progressed it quickly became a rather absurd play that took historical research and twisted it through the lens of my own wit, philosophy and personal affection for the characters. When working with historical figures--characters who existed in a very tangible way in our own history--the playwriting process opens a dialogue between different points in time and space. The difficulty lies in finding a unique and clear voice amongst the discordant personalities involved in this time and space overlap, both in the writing and production processes, in order to get to the heart of what the play is really all about. This thesis follows the journey of the play from its historical roots through the creation of an absurd journey both insides and outside time, space and the human mind. The first part of the thesis explains the beginnings of the concept and outlines much of the research and development that went into the play. The next part outlines the process of production and integrating the world on paper with that of moving bodies on stage. In the final part, post-production discussions and audience feedback sessions shape the play into the draft included in this thesis.

  19. Using data from monitoring combined sewer overflows to assess, improve, and maintain combined sewer systems.

    PubMed

    Montserrat, A; Bosch, Ll; Kiser, M A; Poch, M; Corominas, Ll

    2015-02-01

    Using low-cost sensors, data can be collected on the occurrence and duration of overflows in each combined sewer overflow (CSO) structure in a combined sewer system (CSS). The collection and analysis of real data can be used to assess, improve, and maintain CSSs in order to reduce the number and impact of overflows. The objective of this study was to develop a methodology to evaluate the performance of CSSs using low-cost monitoring. This methodology includes (1) assessing the capacity of a CSS using overflow duration and rain volume data, (2) characterizing the performance of CSO structures with statistics, (3) evaluating the compliance of a CSS with government guidelines, and (4) generating decision tree models to provide support to managers for making decisions about system maintenance. The methodology is demonstrated with a case study of a CSS in La Garriga, Spain. The rain volume breaking point from which CSO structures started to overflow ranged from 0.6 mm to 2.8 mm. The structures with the best and worst performance in terms of overflow (overflow probability, order, duration and CSO ranking) were characterized. Most of the obtained decision trees to predict overflows from rain data had accuracies ranging from 70% to 83%. The results obtained from the proposed methodology can greatly support managers and engineers dealing with real-world problems, improvements, and maintenance of CSSs. PMID:25461106

  20. Stratified Microbial Structure and Activity in Sulfide- and Methane-Producing Anaerobic Sewer Biofilms

    PubMed Central

    Sun, Jing; Hu, Shihu; Sharma, Keshab Raj; Ni, Bing-Jie

    2014-01-01

    Simultaneous production of sulfide and methane by anaerobic sewer biofilms has recently been observed, suggesting that sulfate-reducing bacteria (SRB) and methanogenic archaea (MA), microorganisms known to compete for the same substrates, can coexist in this environment. This study investigated the community structures and activities of SRB and MA in anaerobic sewer biofilms (average thickness of 800 μm) using a combination of microelectrode measurements, molecular techniques, and mathematical modeling. It was seen that sulfide was mainly produced in the outer layer of the biofilm, between the depths of 0 and 300 μm, which is in good agreement with the distribution of SRB population as revealed by cryosection-fluorescence in situ hybridization (FISH). SRB had a higher relative abundance of 20% on the surface layer, which decreased gradually to below 3% at a depth of 400 μm. In contrast, MA mainly inhabited the inner layer of the biofilm. Their relative abundances increased from 10% to 75% at depths of 200 μm and 700 μm, respectively, from the biofilm surface layer. High-throughput pyrosequencing of 16S rRNA amplicons showed that SRB in the biofilm were mainly affiliated with five genera, Desulfobulbus, Desulfomicrobium, Desulfovibrio, Desulfatiferula, and Desulforegula, while about 90% of the MA population belonged to the genus Methanosaeta. The spatial organizations of SRB and MA revealed by pyrosequencing were consistent with the FISH results. A biofilm model was constructed to simulate the SRB and MA distributions in the anaerobic sewer biofilm. The good fit between model predictions and the experimental data indicate that the coexistence and spatial structure of SRB and MA in the biofilm resulted from the microbial types and their metabolic transformations and interactions with substrates. PMID:25192994

  1. Sulfide elimination by intermittent nitrate dosing in sewer sediments.

    PubMed

    Liu, Yanchen; Wu, Chen; Zhou, Xiaohong; Zhu, David Z; Shi, Hanchang

    2015-01-01

    The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards, and requires expensive programs for its prevention. The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments. The study was carried out based on lab-scale experiments and batch tests using real sewer sediments. The intermittent nitrate dosing mode and the optimal control condition were investigated. The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment. The oxidation-reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S (nitrate/sulfide) ratio with slight excess nitrate is necessary for optimal conditions of efficient sulfide control with lower carbon source loss. The optimal control condition is feasible for the sulfide elimination in sewer systems. PMID:25597685

  2. On-line monitoring of methane in sewer air

    PubMed Central

    Liu, Yiwen; Sharma, Keshab R.; Murthy, Sudhir; Johnson, Ian; Evans, Ted; Yuan, Zhiguo

    2014-01-01

    Methane is a highly potent greenhouse gas and contributes significantly to climate change. Recent studies have shown significant methane production in sewers. The studies conducted so far have relied on manual sampling followed by off-line laboratory-based chromatography analysis. These methods are labor-intensive when measuring methane emissions from a large number of sewers, and do not capture the dynamic variations in methane production. In this study, we investigated the suitability of infrared spectroscopy-based on-line methane sensors for measuring methane in humid and condensing sewer air. Two such sensors were comprehensively tested in the laboratory. Both sensors displayed high linearity (R2 > 0.999), with a detection limit of 0.023% and 0.110% by volume, respectively. Both sensors were robust against ambient temperature variations in the range of 5 to 35°C. While one sensor was robust against humidity variations, the other was found to be significantly affected by humidity. However, the problem was solved by equipping the sensor with a heating unit to increase the sensor surface temperature to 35°C. Field studies at three sites confirmed the performance and accuracy of the sensors when applied to actual sewer conditions, and revealed substantial and highly dynamic methane concentrations in sewer air. PMID:25319343

  3. Wastewater-Enhanced Microbial Corrosion of Concrete Sewers.

    PubMed

    Jiang, Guangming; Zhou, Mi; Chiu, Tsz Ho; Sun, Xiaoyan; Keller, Jurg; Bond, Philip L

    2016-08-01

    Microbial corrosion of concrete in sewers is known to be caused by hydrogen sulfide, although the role of wastewater in regulating the corrosion processes is poorly understood. Flooding and splashing of wastewater in sewers periodically inoculates the concrete surface in sewer pipes. No study has systematically investigated the impacts of wastewater inoculation on the corrosion of concrete in sewers. This study investigated the development of the microbial community, sulfide uptake activity, and the change of the concrete properties for coupons subjected to periodic wastewater inoculation. The concrete coupons were exposed to different levels of hydrogen sulfide under well-controlled conditions in laboratory-scale corrosion chambers simulating real sewers. It was evident that the periodic inoculation induced higher corrosion losses of the concrete in comparison to noninoculated coupons. Instantaneous measurements such as surface pH did not reflect the cumulative corrosion losses caused by long-term microbial activity. Analysis of the long-term profiles of the sulfide uptake rate using a Gompertz model supported the enhanced corrosion activity and greater corrosion loss. The enhanced corrosion rate was due to the higher sulfide uptake rates induced by wastewater inoculation, although the increasing trend of sulfide uptake rates was slower with wastewater. Increased diversity in the corrosion-layer microbial communities was detected when the corrosion rates were higher. This coincided with the environmental conditions of increased levels of gaseous H2S and the concrete type. PMID:27390870

  4. On-line monitoring of methane in sewer air

    NASA Astrophysics Data System (ADS)

    Liu, Yiwen; Sharma, Keshab R.; Murthy, Sudhir; Johnson, Ian; Evans, Ted; Yuan, Zhiguo

    2014-10-01

    Methane is a highly potent greenhouse gas and contributes significantly to climate change. Recent studies have shown significant methane production in sewers. The studies conducted so far have relied on manual sampling followed by off-line laboratory-based chromatography analysis. These methods are labor-intensive when measuring methane emissions from a large number of sewers, and do not capture the dynamic variations in methane production. In this study, we investigated the suitability of infrared spectroscopy-based on-line methane sensors for measuring methane in humid and condensing sewer air. Two such sensors were comprehensively tested in the laboratory. Both sensors displayed high linearity (R2 > 0.999), with a detection limit of 0.023% and 0.110% by volume, respectively. Both sensors were robust against ambient temperature variations in the range of 5 to 35°C. While one sensor was robust against humidity variations, the other was found to be significantly affected by humidity. However, the problem was solved by equipping the sensor with a heating unit to increase the sensor surface temperature to 35°C. Field studies at three sites confirmed the performance and accuracy of the sensors when applied to actual sewer conditions, and revealed substantial and highly dynamic methane concentrations in sewer air.

  5. On-line monitoring of methane in sewer air.

    PubMed

    Liu, Yiwen; Sharma, Keshab R; Murthy, Sudhir; Johnson, Ian; Evans, Ted; Yuan, Zhiguo

    2014-01-01

    Methane is a highly potent greenhouse gas and contributes significantly to climate change. Recent studies have shown significant methane production in sewers. The studies conducted so far have relied on manual sampling followed by off-line laboratory-based chromatography analysis. These methods are labor-intensive when measuring methane emissions from a large number of sewers, and do not capture the dynamic variations in methane production. In this study, we investigated the suitability of infrared spectroscopy-based on-line methane sensors for measuring methane in humid and condensing sewer air. Two such sensors were comprehensively tested in the laboratory. Both sensors displayed high linearity (R(2) > 0.999), with a detection limit of 0.023% and 0.110% by volume, respectively. Both sensors were robust against ambient temperature variations in the range of 5 to 35°C. While one sensor was robust against humidity variations, the other was found to be significantly affected by humidity. However, the problem was solved by equipping the sensor with a heating unit to increase the sensor surface temperature to 35°C. Field studies at three sites confirmed the performance and accuracy of the sensors when applied to actual sewer conditions, and revealed substantial and highly dynamic methane concentrations in sewer air. PMID:25319343

  6. Combined sewer overflow: A management study. Technical report

    SciTech Connect

    Reilly, A.

    1988-01-01

    This project is part of the National Network for Environmental Management Studies under the auspices of the Office of Cooperative Environmental Management of the U.S. Environmental Protection Agency. In many older cities in the U.S., the capacity of the combined sewer is exceeded on a daily basis due to both-wet weather storm surges and increased volumes of waste generated by new development. As a result, billions of gallons of untreated sewage are discharged on an annual basis into the nation's marine bays and estuaries in episodes called 'combined sewer overflow.' There are two primary reasons for the increasing frequency and severity of overflow episodes: the population of cities in coastal areas are growing at rates that far exceed the ability of the sewer infrastructure to accommodate them; the built-in inefficiencies of the original design of the combined sewer are being exploited by many municipalities to compensate for the increased volumes of sewage associated with the growth in population. Because each combined sewer, the area that it drains, and the receiving water into which it discharges constitutes a unique system, a management strategy should be site-specific. The document proposes a framework within which a site-specific and cost-effective management strategy may be formulated. By necessity, the emphasis is on providing tools and methods rather than explicit solutions.

  7. REVIEW OF ALTERNATIVES FOR EVALUATION OF SEWER FLUSHING DORCHESTER AREA--BOSTON

    EPA Science Inventory

    Alternatives employing sewer flushing were developed for the Dorchester area of Boston and their cost effectiveness compared with the decentralized combined sewer overflow (CSO) storage/treatment and disinfection facilities proposed as Eastern Massachusetts Metropolitan Area (EMM...

  8. SSOAP - A USEPA Toolbox for Sanitary Sewer Overflow Analysis and Control Planning - Presentation

    EPA Science Inventory

    The United States Environmental Protection Agency (USEPA) has identified a need to use proven methodologies to develop computer tools that help communities properly characterize rainfall-derived infiltration and inflow (RDII) into sanitary sewer systems and develop sanitary sewer...

  9. Molecular survey of concrete sewer biofilm microbial communities.

    PubMed

    Santo Domingo, Jorge W; Revetta, Randy P; Iker, Brandon; Gomez-Alvarez, Vicente; Garcia, Jarissa; Sullivan, John; Weast, James

    2011-10-01

    The microbial composition of concrete biofilms within wastewater collection systems was studied using molecular assays. SSU rDNA clone libraries were generated from 16 concrete surfaces of manholes, a combined sewer overflow, and sections of a corroded sewer pipe. Of the 2457 sequences analyzed, α-, β-, γ-, and δ-Proteobacteria represented 15%, 22%, 11%, and 4% of the clones, respectively. β-Proteobacteria (47%) sequences were more abundant in the pipe crown than any of the other concrete surfaces. While 178 to 493 Operational Taxonomic Units (OTUs) were associated with the different concrete samples, only four sequences were shared among the different clone libraries. Bacteria implicated in concrete corrosion were found in the clone libraries while archaea, fungi, and several bacterial groups were also detected using group-specific assays. The results showed that concrete sewer biofilms are more diverse than previously reported. A more comprehensive molecular database will be needed to better study the dynamics of concrete biofilms. PMID:21981064

  10. Long-term pollution simulation in combined sewer networks.

    PubMed

    Masse, B; Zug, M; Tabuchi, J P; Tisserand, B

    2001-01-01

    This paper presents results of long term pollution simulations on the example of the sewerage system of Grand-Couronne. This modelling work is part of a study where objective is to develop a method to define the reference flow of a WWTP. The model HYDROWORKS DM has been successfully validated in hydraulics and pollution for the sewer network, for long time simulations. A conceptual model has been built to model the pollution in the tank at the outlet of the combined system. One synthetic year of rain has been used to simulate the working of the "up stream system" of the WWTP (combined sewer + tank + separate sewer + pre-treatments) and has been successfully validated by measurements of the 1998-1999 year. If this paper is focused on the "up stream system", the SIMBA/SIMBAD WWTP model has been successfully calibrated and validated too, and the combination represents a fully validated "Integrated Model" for the sewerage system. PMID:11385878

  11. Contaminant transport pathways between urban sewer networks and water supply wells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water supply wells and sanitary sewers are critical components of urban infrastructure, but sewer leakage threatens the quality of groundwater in sewered areas. Previous work by our group has documented the presence of human enteric viruses in deep public supply wells. Our current research uses such...

  12. Ocean waste disposal: Outfall sewers. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-01-01

    The bibliography contains citations concerning design, construction, and environmental effects of outfall sewers. The citations discuss the impact of domestic sewage on aquatic ecosystems, and pollution control of outfall sewers. Monitoring of pollutants in outfall sewage and sludge, and modeling of outfall sewers are also included. (Contains 250 citations and includes a subject term index and title list.)

  13. Sewer rehabilitation. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-02-01

    The bibliography contains citations concerning the maintenance and rehabilitation of sewers. The citations discuss joint weatherization treatments, sewer grouts, and plastic sleeves for cover cracked pipes. Maintenance and rehabilitation programs in specific cities are also discussed. The citations also reference the economics of sewer repair. (Contains a minimum of 164 citations and includes a subject term index and title list.)

  14. 40 CFR 35.935-16 - Sewer use ordinance and evaluation/rehabilitation program.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .../rehabilitation program. 35.935-16 Section 35.935-16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...-Clean Water Act § 35.935-16 Sewer use ordinance and evaluation/rehabilitation program. (a) The grantee... sewer use ordinance, and the grantee is complying with the sewer system evaluation and...

  15. 40 CFR 35.935-16 - Sewer use ordinance and evaluation/rehabilitation program.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .../rehabilitation program. 35.935-16 Section 35.935-16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...-Clean Water Act § 35.935-16 Sewer use ordinance and evaluation/rehabilitation program. (a) The grantee... sewer use ordinance, and the grantee is complying with the sewer system evaluation and...

  16. 40 CFR 35.935-16 - Sewer use ordinance and evaluation/rehabilitation program.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .../rehabilitation program. 35.935-16 Section 35.935-16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...-Clean Water Act § 35.935-16 Sewer use ordinance and evaluation/rehabilitation program. (a) The grantee... sewer use ordinance, and the grantee is complying with the sewer system evaluation and...

  17. 40 CFR 35.935-16 - Sewer use ordinance and evaluation/rehabilitation program.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .../rehabilitation program. 35.935-16 Section 35.935-16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...-Clean Water Act § 35.935-16 Sewer use ordinance and evaluation/rehabilitation program. (a) The grantee... sewer use ordinance, and the grantee is complying with the sewer system evaluation and...

  18. 40 CFR 35.2208 - Adoption of sewer use ordinance and user charge system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Adoption of sewer use ordinance and user charge system. 35.2208 Section 35.2208 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 35.2208 Adoption of sewer use ordinance and user charge system. The grantee shall adopt its sewer...

  19. 40 CFR 35.2208 - Adoption of sewer use ordinance and user charge system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Adoption of sewer use ordinance and user charge system. 35.2208 Section 35.2208 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 35.2208 Adoption of sewer use ordinance and user charge system. The grantee shall adopt its sewer...

  20. 40 CFR 35.2208 - Adoption of sewer use ordinance and user charge system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Adoption of sewer use ordinance and user charge system. 35.2208 Section 35.2208 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 35.2208 Adoption of sewer use ordinance and user charge system. The grantee shall adopt its sewer...

  1. SEWER SYSTEM EVALUATION, REHABILITATION AND NEW CONSTRUCTION. A MANUAL OF PRACTICE

    EPA Science Inventory

    This Manual of Practice has been prepared for use by local authorities and consulting engineers for the investigation of sewer systems for infiltration/inflow. This Manual discusses three areas: sewer system evaluation, sewer rehabilitation, and design of new systems to minimize ...

  2. COMPUTER MODEL ANALYSIS FOR CONTROL PLANNING OF SANITARY-SEWER OVERFLOWS

    EPA Science Inventory

    The Nation's sanitary-sewer infrastructure is aging with some sewers dating back over 100 years. There are more than 19,500 municipal sanitary-sewer collection systems nationwide serving an estimated 150 million people and comprising about 800,000 km (500,000 mi) of municipally ...

  3. Idaho National Engineering Laboratory Sewer System Upgrade Project. Environmental Assessment

    SciTech Connect

    Not Available

    1994-04-01

    The Department of Energy (DOE) has prepared an environmental assessment for a proposed Sewer System Upgrade Project at the Idaho National Engineering Laboratory (INEL) near Idaho Falls, Idaho. The proposed action would include activities conducted at the Central Facilities Area, Test Reactor Area, and the Containment Test Facility at the Test Area North at INEL. The proposed action would consist of replacing or remodeling the existing sewage treatment plants at the Central Facilities Area, Test Reactor Area, and Containment Test Facility. Also, a new sewage testing laboratory would be constructed at the Central Facilities Area. Finally, the proposed action would include replacing, repairing, and/or adding sewer lines in areas where needed.

  4. FIELD TESTING OF PROTOTYPE ACOUSTIC EMISSION SEWER FLOWMETER

    EPA Science Inventory

    This investigation concerns verifying the operating principles of the acoustic emission flowmeter (U.S. Patent 3,958,458) in the natural environment of three different storm sewer field sites in Nassau County, New York. The flowmeter is a novel, passive, nonintrusive method that ...

  5. COMBINED SEWER OVERFLOW SEDIMENT TRANSPORT MODEL: DOCUMENTATION AND EVALUATION

    EPA Science Inventory

    A modeling package for studying the movement and fate of combined sewer overflow (CSO) sediment in receiving waters is described. The package contains a linear, implicit, finite-difference flow model and an explicit, finite-difference sediment transport model. The sediment model ...

  6. ASSESSMENT OF DISEASE RATES AMONG SEWER WORKERS IN COPENHAGEN, DENMARK

    EPA Science Inventory

    Sewer workers in Copenhagen, Denmark, have a higher death rate than the comparable male population. An alarmingly high proportion of the deaths occur within the year that employment terminates. Attempts to correlate the statistics with sick leave records or chemicals in the envir...

  7. DEMONSTRATE REAL TIME AUTOMATIC CONTROL OF COMBINED SEWER SYSTEMS

    EPA Science Inventory

    The primary objective of this study was to develop a real time automatic control model that could be used in connection with a combined sewer system to minimize overflows during storms. The model was applied to the North Shore Outfall Consolidation Project in San Francisco. This ...

  8. 40 CFR 35.927 - Sewer system evaluation and rehabilitation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... rehabilitation. 35.927 Section 35.927 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER... § 35.927 Sewer system evaluation and rehabilitation. (a) All applicants for step 2 or step 3 grant... evaluation survey and, if appropriate, a program, including an estimate of costs, for rehabilitation of...

  9. Sanitary sewer rehabilitation at Lawrence Livermore National Laboratory

    SciTech Connect

    Vellinger, R. J.; Burton, R.; Fritschy, B.

    1995-04-01

    The objectives of this paper are the following: to present LLNL`s collection system and innovative approach to sanitary sewer rehabilitation; share issues identified and lessons learned from over four (4) years of rehabilitation work; and discuss proposed system standards for ongoing maintenance and repair activities.

  10. 40 CFR 35.927 - Sewer system evaluation and rehabilitation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... rehabilitation. 35.927 Section 35.927 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER... § 35.927 Sewer system evaluation and rehabilitation. (a) All applicants for step 2 or step 3 grant... evaluation survey and, if appropriate, a program, including an estimate of costs, for rehabilitation of...

  11. 40 CFR 35.927 - Sewer system evaluation and rehabilitation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... rehabilitation. 35.927 Section 35.927 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER... § 35.927 Sewer system evaluation and rehabilitation. (a) All applicants for step 2 or step 3 grant... evaluation survey and, if appropriate, a program, including an estimate of costs, for rehabilitation of...

  12. Incorporating Storm Sewer Exfiltration into SWMM: Proof of Concept

    EPA Science Inventory

    This study evaluates the peak flow and volume reduction achieved by exfiltration from a perforated storm sewer in an urban catchment. There are three related objectives: [1] quantify peak flow and volume reduction; [2] demonstrate adaptability to climate change; and [3] evaluate ...

  13. LAWRENCE AVENUE UNDERFLOW SEWER SYSTEM: MONITORING AND EVALUATION

    EPA Science Inventory

    A new and bold concept in design of urban drainage systems was developed as a step forward in the solution of combined sewer overflow problems. A deep tunnel in bed rock about 200 to 250 feet (61 to 76 m) below the surface was designed and constructed for the Lawrence Avenue drai...

  14. 40 CFR 35.2130 - Sewer use ordinance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... binding document shall also require that all wastewater introduced into the treatment works not contain... selection of the most cost-effective alternative for wastewater treatment and sludge disposal. (Approved by... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2130 Sewer use ordinance....

  15. 40 CFR 35.2130 - Sewer use ordinance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... binding document shall also require that all wastewater introduced into the treatment works not contain... selection of the most cost-effective alternative for wastewater treatment and sludge disposal. (Approved by... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2130 Sewer use ordinance....

  16. 40 CFR 35.2130 - Sewer use ordinance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... binding document shall also require that all wastewater introduced into the treatment works not contain... selection of the most cost-effective alternative for wastewater treatment and sludge disposal. (Approved by... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2130 Sewer use ordinance....

  17. 40 CFR 35.2130 - Sewer use ordinance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... binding document shall also require that all wastewater introduced into the treatment works not contain... selection of the most cost-effective alternative for wastewater treatment and sludge disposal. (Approved by... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2130 Sewer use ordinance....

  18. 40 CFR 35.2130 - Sewer use ordinance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... binding document shall also require that all wastewater introduced into the treatment works not contain... selection of the most cost-effective alternative for wastewater treatment and sludge disposal. (Approved by... STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works § 35.2130 Sewer use ordinance....

  19. PERFORMANCE OF OZONE AS A DISINFECTANT FOR COMBINED SEWER OVERFLOW

    EPA Science Inventory

    Disinfection of combined sewer overflow (CSO) minimizes the amount of disease-causing microorganisms (pathogens) released into receiving waters. Currently, the primary disinfecting agent used in the US for wastewater treatment is chlorine (Cl2); however, Cl2 produces problems in ...

  20. Demonstration of Innovative Sewer System Inspection Technology: SL-RAT

    EPA Science Inventory

    The overall objective of this EPA-funded study was to demonstrate innovative sewer line assessment technologies that are designed for rapid deployment using portable equipment. This study focused on demonstration of technologies that are suitable for smaller diameter pipes (less ...

  1. REAL TIME CONTROL OF SEWERS: US EPA MANUAL

    EPA Science Inventory

    The problem of sewage spills and local flooding has traditionally been addressed by large scale capital improvement programs that focus on construction alternatives such as sewer separation or construction of storage facilities. The cost of such projects is often high, especiall...

  2. EVALUATION OF URBAN RUNOFF AND COMBINED SEWER OVERFLOW MUTAGENICITY

    EPA Science Inventory

    The introduction of potential mutagens to the human environment may serve to increase the rate of contact with substances that contribute to cancer incidence in the general population. The primary purpose of this study was to evaluate combined sewer overflows and urban runoff for...

  3. HIGH-RATE DISINFECTION TECHNIQUES FOR COMBIND SEWER OVERFLOW

    EPA Science Inventory

    This paper presents high-rate disinfection technologies for combined sewer overflow (CSO). The high-rate disinfection technologies of interest are: chlorination/dechlorination, ultraviolet light irradiation (UV), chlorine dioxide (ClO2 ), ozone (O3), peracetic acid (CH3COOOH )...

  4. 40 CFR 35.927-2 - Sewer system evaluation survey.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act... transportation and treatment for each defined source of infiltration/inflow. (b) A report shall summarize the... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Sewer system evaluation survey....

  5. COTTAGE FARM COMBINED SEWER DETENTION AND CHLORINATION STATION, CAMBRIDGE, MASSACHUSETTS

    EPA Science Inventory

    The Cottage Farm Detention and Chlorination Station was placed in operation by the Metropolitan District Commission on April 29, 1971. The station, located in Cambridge, Massachusetts, diverts and treats combined sewage flows from the Charles River Valley sewer system (15,600 acr...

  6. SEWER INFILTRATION AND INFLOW CONTROL PRODUCT AND EQUIPMENT GUIDE

    EPA Science Inventory

    The report lists and discusses new and existing equipment, materials, and practices available to prevent the entry of unwanted water into the sewer system from infiltration and inflow, and thereby needlessly usurping the capacity of the sewerage system. The report has six section...

  7. EXFILTRATION IN SANITARY SEWER SYSTEMS IN THE U.S.

    EPA Science Inventory

    Many municipalities throughout the US have sewerage systems (separate and combined) that may experience exfiltration of untreated wastewater. This study was conducted to focus on the magnitude of the exfiltration problem from sewer pipes on a national basis. The method for estima...

  8. EXFILTRATION IN SEWER SYSTEMS: IS IT A NATIONAL PROBLEM?

    EPA Science Inventory

    Many municipalities throughout the US have sewerage systems (separate and combined) that may experience exfiltration of untreated wastewater. This study was conducted to focus on the magnitude of the exfiltration problem from sewer pipes on a national basis. The method for estima...

  9. 31. RECORD PLAN, METROPOLITAN SEWER, GENERAL PLAN OF PUMPING STATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    31. RECORD PLAN, METROPOLITAN SEWER, GENERAL PLAN OF PUMPING STATION GROUNDS, DEER ISLAND. METROPOLITAN SEWERAGE COMMISSION, JUNE 1896. Photocopy of image of aperture card 4977-1. Aperture cards and original drawings at Massachusetts Water Resources Authority Archives, Building 39, Charlestown Navy Yard, Boston, MA - Deer Island Pumping Station, Boston, Suffolk County, MA

  10. Episode of toxic gas exposure in sewer workers.

    PubMed Central

    Watt, M M; Watt, S J; Seaton, A

    1997-01-01

    OBJECTIVES: Sewer workers are used to unpleasant smells, but may be required to investigate unusual ones. Twenty six men were involved in investigation of episodes of such a smell after neighbourhood complaints over several weeks. METHODS: Workers exposed to the smell were investigated by clinical follow up, lung function tests, and measurement of pituitary function. RESULTS: 14 of the 26 developed subacute symptoms including sore throat, cough, chest tightness, breathlessness, thirst, sweating, irritability, and loss of libido. Severity of symptoms seemed to be dose related. Minor symptoms resolved over several weeks but those more seriously affected have shown deteriorating respiratory symptoms and lung function and remain unable to work a year after the incident. In one, evidence of mild cranial diabetes insipidus was found. Analysis of gas from the sewer showed the presence of a mixture of thiols and sulphides, known to be highly odorous and not normally found in sewers. The source remains unknown. CONCLUSIONS: Several of these men seem to have developed delayed airways disease and disturbances of hypothalamic function. Such an outcome has not to our knowledge been described before. Despite the presence of the smell, standard safety gas detection equipment used to ensure the sewer was safe to enter failed to indicate the presence of a hazard. Protection against such incidents can only be provided by the use of positive pressure breathing apparatus. PMID:9166135

  11. ULTRAVIOLET LIGHT DISINFECTION OF COMBINED SEWER OVERFLOW (NEW ORLEANS)

    EPA Science Inventory

    The objective of this state-of-the-art review is to examine the performance and effectiveness of ultraviolet (UV) light disinfection for combined sewer overflow (CSO) applications. Topics presented include the use of UV light as a disinfecting agent, its practical applications, d...

  12. Impervious surfaces and sewer pipe effects on stormwater runoff temperature

    NASA Astrophysics Data System (ADS)

    Sabouri, F.; Gharabaghi, B.; Mahboubi, A. A.; McBean, E. A.

    2013-10-01

    The warming effect of the impervious surfaces in urban catchment areas and the cooling effect of underground storm sewer pipes on stormwater runoff temperature are assessed. Four urban residential catchment areas in the Cities of Guelph and Kitchener, Ontario, Canada were evaluated using a combination of runoff monitoring and modelling. The stormwater level and water temperature were monitored at 10 min interval at the inlet of the stormwater management ponds for three summers 2009, 2010 and 2011. The warming effect of the ponds is also studied, however discussed in detail in a separate paper. An artificial neural network (ANN) model for stormwater temperature was trained and validated using monitoring data. Stormwater runoff temperature was most sensitive to event mean temperature of the rainfall (EMTR) with a normalized sensitivity coefficient (Sn) of 1.257. Subsequent levels of sensitivity corresponded to the longest sewer pipe length (LPL), maximum rainfall intensity (MI), percent impervious cover (IMP), rainfall depth (R), initial asphalt temperature (AspT), pipe network density (PND), and rainfall duration (D), respectively. Percent impervious cover of the catchment area (IMP) was the key parameter that represented the warming effect of the paved surfaces; sensitivity analysis showed IMP increase from 20% to 50% resulted in runoff temperature increase by 3 °C. The longest storm sewer pipe length (LPL) and the storm sewer pipe network density (PND) are the two key parameters that control the cooling effect of the underground sewer system; sensitivity analysis showed LPL increase from 345 to 966 m, resulted in runoff temperature drop by 2.5 °C.

  13. Particle velocity and sediment transport at the limit of deposition in sewers.

    PubMed

    Ota, J J; Perrusquía, G S

    2013-01-01

    This paper focuses on the sediment particle while it is transported at the limit of deposition in storm sewers, i.e. as bed load at the limit of concentration that leads to sediment deposition. Although many empirical sediment transport equations are known in the literature, there is only limited knowledge concerning particle velocity. Sediment particle and sphere velocity measurements were carried out in two pipe channels and these results led to the development of a semi-theoretical equation for sediment transport at the limit of deposition in sewers. Even in the transport process without deposition, sediment movement is slower than water velocity and depends on the angle of repose of sediment with a diameter d on the roughness k of the pipe channel. Instead of classical dimensionless bed shear stress ψ, a modified dimensionless bed shear stress ψ (d/k)(2/3) was suggested, based on the angle of repose and this parameter was proved to be significant for quantifying the transport capacity. The main purpose of this article is to emphasize the importance of careful observation of experiments. Not only number of tests, but physical understanding are essential for better empirical equations. PMID:23416585

  14. Sulfide and methane production in sewer sediments: Field survey and model evaluation.

    PubMed

    Liu, Yiwen; Tugtas, A Evren; Sharma, Keshab R; Ni, Bing-Jie; Yuan, Zhiguo

    2016-02-01

    Sewer sediment processes have been reported to significantly contribute to overall sulfide and methane production in sewers, at a scale comparable to that of sewer biofilms. The physiochemical and biological characteristics of sewer sediments are heterogeneous; however, the variability of in-sediments sulfide and methane production rates among sewers has not been assessed to date. In this study, five sewer sediment samples were collected from two cities in Australia with different climatic conditions. Batch assays were conducted to determine the rates of sulfate reduction and methane production under different flow velocity (shear stress) conditions as well as under completely mixed conditions. The tests showed substantial and variable sulfate reduction and methane production activities among different sediments. Sulfate reduction and methane production from sewer sediments were confirmed to be areal processes, and were dependent on flow velocity/shear stress. Despite of the varying characteristics and reactions kinetics, the sulfate reduction and methane production processes in all sediments could be well described by a one-dimensional sewer sediment model recently developed based on results obtained from a laboratory sewer sediment reactor. Model simulations indicated that the in-situ contribution of sewer sediment emissions could be estimated without the requirement of measuring the specific sediment characteristics or the sediment depths. PMID:26650449

  15. Degradation of methanethiol in anaerobic sewers and its correlation with methanogenic activities.

    PubMed

    Sun, Jing; Hu, Shihu; Sharma, Keshab Raj; Ni, Bing-Jie; Yuan, Zhiguo

    2015-02-01

    Methanethiol (MT) is considered one of the predominant odorants in sewer systems. Therefore, understanding MT transformation in sewers is essential to sewer odor assessment and abatement. In this study, we investigated the degradation of MT in laboratory anaerobic sewers. Experiments were carried out in seven anaerobic sewer reactors with biofilms at different stages of development. MT degradation was found to be strongly dependent on the methanogenic activity of sewer biofilms. The MT degradation rate accelerated with the increase of methanogenic activity of sewer biofilms, resulting in MT accumulation (i.e. net production) in sewer reactors with relatively low methanogenic activities, and MT removal in reactors with higher methanogenic activities. A Monod-type kinetic expression was developed to describe MT degradation kinetics in anaerobic sewers, in which the maximum degradation rate was modeled as a function of the maximum methane production rate through a power function. It was also found that MT concentration had a linear relationship with acetate concentration, which may be used for preliminary assessment of MT presence in anaerobic sewers. PMID:25437340

  16. Impacts of Sewer Leaks on Surrounding Groundwater and Surface Water Quality in Singapore

    NASA Astrophysics Data System (ADS)

    Ly, D.; Chui, T. M.

    2011-12-01

    Underground sewers deteriorate over time resulting in cracks and joint defects. Sewage thus leaks out of the sewers and contaminates the surrounding groundwater. Singapore does not directly use groundwater as a water supply. However, contaminated groundwater flows into the drains nearby through weep holes, and subsequently enters water supply reservoirs. This study examines the impacts of sewage leaks on surrounding groundwater and surface water quality by modeling the interactions between leaky sewers, groundwater and drains. It first explores the representations of important yet challenging boundary conditions, namely weep holes and leaky sewers, so that their fluxes vary realistically with water pressure throughout a simulation. It then simulates groundwater flow and contaminant transport from leaky sewers to nearby drains over a period of ten years. It further rehabilitates the sewers and models the attenuation of contamination plume for another ten years. The results of this project contribute to the modeling and understanding of the potential impacts of sewer leaks on surrounding groundwater and surface water quality. For example, groundwater quality changes with hydrologic conditions, and it is highest during heavy rainfall and times of high water table because of the low leakage and high dilution rates. Water quality fluctuates daily or even hourly in the vicinity of the sewers, but is more stable in the flow through the weep holes into the drains. Overall, this study benefits the sewer leak monitoring and sewer rehabilitation in many urban areas worldwide.

  17. Contemporary sea level rise.

    PubMed

    Cazenave, Anny; Llovel, William

    2010-01-01

    Measuring sea level change and understanding its causes has considerably improved in the recent years, essentially because new in situ and remote sensing observations have become available. Here we report on most recent results on contemporary sea level rise. We first present sea level observations from tide gauges over the twentieth century and from satellite altimetry since the early 1990s. We next discuss the most recent progress made in quantifying the processes causing sea level change on timescales ranging from years to decades, i.e., thermal expansion of the oceans, land ice mass loss, and land water-storage change. We show that for the 1993-2007 time span, the sum of climate-related contributions (2.85 +/- 0.35 mm year(-1)) is only slightly less than altimetry-based sea level rise (3.3 +/- 0.4 mm year(-1)): approximately 30% of the observed rate of rise is due to ocean thermal expansion and approximately 55% results from land ice melt. Recent acceleration in glacier melting and ice mass loss from the ice sheets increases the latter contribution up to 80% for the past five years. We also review the main causes of regional variability in sea level trends: The dominant contribution results from nonuniform changes in ocean thermal expansion. PMID:21141661

  18. Melting Ice, Rising Seas

    NASA Video Gallery

    Sea level rise is an indicator that our planet is warming. Much of the world's population lives on or near the coast, and rising seas are something worth watching. Sea level can rise for two reason...

  19. Airflow in Gravity Sewers - Determination of Wastewater Drag Coefficient.

    PubMed

    Bentzen, Thomas Ruby; Østertoft, Kristian Kilsgaard; Vollertsen, Jes; Fuglsang, Emil Dietz; Nielsen, Asbjørn Haaning

    2016-03-01

    Several experiments have been conducted in order to improve the understanding of the wastewater drag and the wall frictional force acting on the headspace air in gravity sewers. The aim of the study is to improve the data basis for a numerical model of natural sewer ventilation. The results of the study shows that by integrating the top/side wall shear stresses the log-law models for the air velocity distribution along the unwetted perimeter resulted in a good agreement with the friction forces calculated by use of the Colebrook-White formula for hydraulic smooth pipes. Secondly, the water surface drags were found by log-law models of the velocity distribution in turbulent flows to fit velocity profiles measured from the water surface and by integrating the water surface drags along the wetted perimeter, mean water surface drags were found and a measure of the water surface drag coefficient was found. PMID:26931535

  20. Quality of local control for simple sewer networks

    NASA Astrophysics Data System (ADS)

    Kolechkina, Alla; van Nooijen, Ronald

    2016-04-01

    Combined sewer networks, where both foul water and storm water are transported through the same system, tend to develop into complex networks due to expansion of towns and villages. The transport capacity of these systems is always limited, so occasional controlled spills into surface water, combined sewer overflows (CSO), are part of the normal operating procedure. Occasionally the ideas and rules present in the original design are not respected when the system is extended to cover a larger area. One way to deal with this problem is to implement central control. Another is to add pipes and hardware to bring the extended system into line with the original rules and ideas. We show that for a design rule often followed in the Netherlands, local control does quite well as long as the rule is respected and there are no large variations in precipitation intensity over the area covered by the system.

  1. A software-based sensor for combined sewer overflows.

    PubMed

    Leonhardt, G; Fach, S; Engelhard, C; Kinzel, H; Rauch, W

    2012-01-01

    A new methodology for online estimation of excess flow from combined sewer overflow (CSO) structures based on simulation models is presented. If sufficient flow and water level data from the sewer system is available, no rainfall data are needed to run the model. An inverse rainfall-runoff model was developed to simulate net rainfall based on flow and water level data. Excess flow at all CSO structures in a catchment can then be simulated with a rainfall-runoff model. The method is applied to a case study and results show that the inverse rainfall-runoff model can be used instead of missing rain gauges. Online operation is ensured by software providing an interface to the SCADA-system of the operator and controlling the model. A water quality model could be included to simulate also pollutant concentrations in the excess flow. PMID:22864433

  2. Life cycle assessment of urban wastewater systems: Quantifying the relative contribution of sewer systems.

    PubMed

    Risch, Eva; Gutierrez, Oriol; Roux, Philippe; Boutin, Catherine; Corominas, Lluís

    2015-06-15

    This study aims to propose a holistic, life cycle assessment (LCA) of urban wastewater systems (UWS) based on a comprehensive inventory including detailed construction and operation of sewer systems and wastewater treatment plants (WWTPs). For the first time, the inventory of sewers infrastructure construction includes piping materials and aggregates, manholes, connections, civil works and road rehabilitation. The operation stage comprises energy consumption in pumping stations together with air emissions of methane and hydrogen sulphide, and water emissions from sewer leaks. Using a real case study, this LCA aims to quantify the contributions of sewer systems to the total environmental impacts of the UWS. The results show that the construction of sewer infrastructures has an environmental impact (on half of the 18 studied impact categories) larger than both the construction and operation of the WWTP. This study highlights the importance of including the construction and operation of sewer systems in the environmental assessment of centralised versus decentralised options for UWS. PMID:25839834

  3. Different approaches for modelling of sewer caused urban flooding.

    PubMed

    Obermayer, A; Guenthert, F W; Angermair, G; Tandler, R; Braunschmidt, S; Milojevic, N

    2010-01-01

    The correct prediction of flooding in urban areas is an important challenge to secure the values and fulfil public regulations. Traditional sewer simulations deliver the basic information for a rudimental flood protection, but the interaction between sewer and surface runoff can only be considered by a bi-directional modelling. Therefore detailed information about the relevant structures on the surface is necessary, which can partially be delivered by airborne laser scan data. This data have to be refined to get as detailed information about the endangered areas as possible. But the plenitude of information leads to high requirements on computer capacity and performance. This paper shows different approaches to predict the sewer caused flooding in urban areas. The approaches have been checked on two testing areas in Germany and the developed tool will be implemented in a commercial software system soon. This approaches, which partially base on each other, make a stepwise refinement of the model and narrowing of the affected areas possible. The developed algorithms to thin the digital terrain model and the well proven method to parallelize the calculation on more than one processing units secure an effective calculating process. PMID:21045347

  4. Model adaptation in a central controller for a sewer system

    NASA Astrophysics Data System (ADS)

    van Nooijen, Ronald; Kolechkina, Alla; Mol, Bart

    2013-04-01

    For small sewer systems that combine foul water and storm water sewer functions in flat terrain, central control of the sewer system may have problems during dry weather. These systems are a combination of local gravity flow networks connected by pumps. Under those conditions the level in the wet well (local storage at the pumping station) should be kept below the entrance pipe but above the top of the intake of the pump. The pumps are dimensioned to cope with the combined flow of foul water and precipitation run off so their capacity is relatively large when compared wityh the volume available in the wet well. Under local control this is not a major problem because the effective controller time step is very short. For central control the control time step can become a problem. Especially when there is uncertainty about the relation between level and volume in the wet well. In this paper we describe a way to dynamically adapt the level to volume relation based on dry weather behaviour. This is important because a better estimate of this volume will reduce the number of on/off cycles for the pumps. It will also allow detection and correction for changes in pump performance due to aging.

  5. Investigation of sewer exfiltration using integral pumping tests and wastewater indicators

    NASA Astrophysics Data System (ADS)

    Leschik, Sebastian; Musolff, Andreas; Martienssen, Marion; Krieg, Ronald; Bayer-Raich, Marti; Reinstorf, Frido; Strauch, Gerhard; Schirmer, Mario

    2009-11-01

    Leaky sewers affect urban groundwater by the exfiltration of untreated wastewater. However, the impact of sewer exfiltration on the groundwater is poorly understood. Most studies on sewer exfiltration focus on water exfiltration, but not on the impact on groundwater quality. In this paper we present a new monitoring approach to estimate mass flow rates Mex of different wastewater indicators (WWIs) from leaky sewers by applying integral pumping tests (IPTs). The problem of detecting and assessing heterogeneous concentrations in the vicinity of leaky sewers can be overcome with the IPT approach by the investigation of large groundwater volumes up- and downstream of leaky sewers. The increase in concentrations downstream of a leaky sewer section can be used to calculate Mex with a numerical groundwater model. The new monitoring approach was first applied using four IPT wells in Leipzig (Germany). Over a pumping period of five days we sampled five inorganic WWIs: B , Cl -, K +, NO 3-, NH 4+ and three xenobiotics: bisphenol-a, caffeine and tonalide. The resulting concentration-time series indicated an influence of wastewater at one IPT well downstream of the leaky sewer. We defined ranges of Mex by implementing the uncertainty of chemical analyses. The results showed a Mex of 0-10.9 g m - 1 d - 1 . The combination of Mex with wastewater concentrations from the target sewer yielded an exfiltration rate Qex of 28.0-63.9 L m - 1 d - 1 for the conservative ion Cl -. Most non-conservative WWIs showed reduced mass flow rates in the groundwater downstream of the leaky sewer that indicate a mass depletion during their passage from the sewer to the pumping well. Application of the IPT methodology at other field sites is possible. The IPT monitoring approach provides reliable Mex values that can help to assess the impact of leaky sewers on groundwater.

  6. Impact of water source management practices in residential areas on sewer networks - a review.

    PubMed

    Marleni, N; Gray, S; Sharma, A; Burn, S; Muttil, N

    2012-01-01

    Prolonged drought which has occurred everywhere around the world has caused water shortages, leading many countries to consider more sustainable practices, which are called source management practices (SMPs) to ensure water availability for the future. SMPs include the practices of water use reduction, potable water substitution and wastewater volume reduction such as water demand management, rainwater harvesting, greywater recycling and sewer mining. Besides the well known advantages from SMPs, they also contribute to the alteration of wastewater characteristics which finally affect the process in downstream infrastructure such as sewerage networks. Several studies have shown that the implementation of SMPs decreases the wastewater flow, whilst increasing its strength. High-strength wastewater can cause sewer problems such as sewer blockage, odour and corrosion. Yet, not all SMPs and their impact on existing sewer networks have been investigated. Therefore, this study reviews some examples of four common SMPs, the wastewater characteristics and the physical and biochemical transformation processes in sewers and the problems that might caused by them, and finally the potential impacts of those SMPs on wastewater characteristics and sewer networks are discussed. This paper provides sewer system managers with an overview of potential impacts on the sewer network due to the implementation of some SMPs. Potential research opportunities for the impact of SMPs on existing sewers are also identified. PMID:22277221

  7. Design and performance evaluation of a simplified dynamic model for combined sewer overflows in pumped sewer systems

    NASA Astrophysics Data System (ADS)

    van Daal-Rombouts, Petra; Sun, Siao; Langeveld, Jeroen; Bertrand-Krajewski, Jean-Luc; Clemens, François

    2016-07-01

    Optimisation or real time control (RTC) studies in wastewater systems increasingly require rapid simulations of sewer systems in extensive catchments. To reduce the simulation time calibrated simplified models are applied, with the performance generally based on the goodness of fit of the calibration. In this research the performance of three simplified and a full hydrodynamic (FH) model for two catchments are compared based on the correct determination of CSO event occurrences and of the total discharged volumes to the surface water. Simplified model M1 consists of a rainfall runoff outflow (RRO) model only. M2 combines the RRO model with a static reservoir model for the sewer behaviour. M3 comprises the RRO model and a dynamic reservoir model. The dynamic reservoir characteristics were derived from FH model simulations. It was found that M2 and M3 are able to describe the sewer behaviour of the catchments, contrary to M1. The preferred model structure depends on the quality of the information (geometrical database and monitoring data) available for the design and calibration of the model. Finally, calibrated simplified models are shown to be preferable to uncalibrated FH models when performing optimisation or RTC studies.

  8. Localization of groundwater infiltration in the combined sewers of Brussels by stable isotopes measurements (δ18O, δD) by Cavity Ring Down Spectroscopy.

    NASA Astrophysics Data System (ADS)

    De Bondt, Kevin; Claeys, Philippe

    2014-05-01

    In the last 20 years research has been conducted to quantify the infiltration of groundwater into the sewers. This groundwater, called parasitic water, increases the volume of waste-water to be treated and consequently the cost of this treatment. Moreover, in the case of combined sewer systems, the parasitic water also limits the sewer capacity and indirectly increases the risks of combined sewer overflows and floods. The infiltration of groundwater occurs trough cracks, sewer collapses and from direct connections with old springs. Different methods quantify the intrusion of parasitic water. Among these, the use of the stable isotopes of water (δ18O & δD) shows good result in catchments or cities close to Mountainous regions (example from Lyon, Zurich), where isotopic signals vary significantly because of continental and altitude effects. However many cities, such as Brussels, are located in more oceanic settings and theoretically offer less potential for the application of the stable isotopes method. In the case of Brussels, river-water from the Meuse is used to produce domestic-water. The catchment of this river extends into the Ardennes, which are affected by slightly different climatic conditions. δ18O & δD analyzes of groundwater from the main aquifer (Ledo-Paniselian-Brusselian) and domestic-water from the Callois reservoir fed by the Meuse River show sufficient isotopic differences in the south of Brussels, but only during the summer. The discrimination potential is better with δD than with δ18O. The improvement of δD measurements (precision, costs,...) brought by Cavity Ring Down Spectroscopy largely contributes to the potential of using stable isotopes method to trace water in Brussels. The first campaigns in the sewers also show a little enrichment (in heavy isotopes) of the waste-water in comparison with the reservoir waters and tap waters. This increases the potential of the method but constrains the sampling to pure waste-water in sewer segments

  9. PPCPs wet weather mobilization in a combined sewer in NW Spain.

    PubMed

    Del Río, Héctor; Suárez, Joaquín; Puertas, Jerónimo; Ures, Pablo

    2013-04-01

    An intense campaign was carried out over a 14 month period to characterize concentrations and loads of 7 well-known Pharmaceuticals and Personal Care Products (PPCPs), during dry and wet weather conditions, in an urban combined catchment in the northwest of Spain, a geographical zone with an average annual rainfall over 1500 mm. The main objective was to gather more in-depth knowledge of the mobilization of these "micropollutants" in an urban combined sewer and the possible pressures on water receiving bodies due to combined sewer overflows (CSOs). Hydrographs and pollutographs of these substances in dry weather flows (DWF), on weekdays and weekends, and wet weather flows (WWF) during 10 rain events have been characterized to obtain data that are sufficiently representative for statistical analysis. The research findings show that there is a considerable mobilization of these substances during rain events, mainly in the first part of the hydrographs, especially HHCB galaxolide, ibuprofen and paracetamol with maximum concentrations of 9.76, 8.51 and 5.71 μg/L respectively, whereas these concentrations in dry weather only reached 2.57, 2.11 and 0.72 μg/L respectively. There is a good correlation between the degree of mobilization in wet weather flows and the percentage of dry weather particulate phase of each studied substance, indicating that such mobilization may be associated with adsorption on the sediments deposited on the collectors during the antecedent dry period. These results are in good agreement with removal in conventional WWTP, especially for compounds that tend to adsorb onto sewage sludge. PMID:23425796

  10. Remote Infrared Thermal Sensing of Sewer Voids, Four-Year Update

    NASA Astrophysics Data System (ADS)

    Weil, Gary J.

    1988-01-01

    When a sewer caves in, it often takes the street, sidewalks, and surrounding buildings along for the ride. These collapses endanger public health and safety. Repairing a sewer before such a cave-in is obviously the preferred method. Emergency repairs cost far more than prevention measures - often millions of dollars more. Many combined sewers in the St. Louis area, as in many of America's cities, are more than 125 years old and are subject to structural failure. In 1981 alone, St. Louis had 4,000 sewer collapses and an astronomical repair bill. These and similar problems have been described as "a crisis of national proportions. The question addressed by this paper is how to detect unseen problem areas in sewer systems before they give way. At the present, progressive sewer administrations may use crawl crews to inspect sewers when problems are suspected. This can be extremely costly and dangerous, and a void around the outside of the sewer is often invisible from within. Thus, even a crawl crew can fail to detect most voids. Infrared Thermography has been found by sewer districts and independent evaluation engineering firms to be an extremely accurate method of finding sewer voids, before they can cause expensive and dangerous problems. This technique uses a non-contact, remote sensing method, with the potential for surveying large areas quickly and efficiently. This paper reviews our initial paper presented to The International Society for Optical Engineering in October of 1983 and presents an update of our experience, both successes and failures, in several large-scale void detection projects. Infrared Thermographic techniques of non-destructive testing will have major implications for cities and for the engineering profession because it promises to make the crisis of infrastructure repair and rehabilitation more manageable. Intelligent, systematic use of this relatively low cost void detection method, Infrared Thermography, may revolutionize the way sewer

  11. Quality Assurance and Quality Control Practices for Rehabilitation of Sewer and Water Mains

    EPA Science Inventory

    As part of the US Environmental Protection Agency (EPA)’s Aging Water Infrastructure Research Program, several areas of research are being pursued, including a review of quality assurance and quality control (QA/QC) practices and acceptance testing during the installation of reha...

  12. Quality Assurance and Quality Control Practices For Rehabilitation of Sewer and Water Mains

    EPA Science Inventory

    As part of the US Environmental Protection Agency (EPA)’s Aging Water Infrastructure Research Program, several areas of research are being pursued including a review of quality assurance and quality control (QA/QC) practices and acceptance testing during the installation of rehab...

  13. Association between Gastrointestinal Illness and Precipitation in Areas Impacted by Combined Sewer Systems: Utilizing a Distributed Lag Model

    EPA Science Inventory

    Combined sewer systems collect rainwater runoff, sewage, and industrial wastewater for transit to treatment facilities. With heavy precipitation, volumes can exceed capacity of treatment facilities, and wastewater discharges directly to receiving waters. These combined sewer over...

  14. Evidence for fat, oil and grease (FOG) deposit formation mechanisms in sewer lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The presence of hardened and insoluble fats, oil, and grease (FOG) deposits in sewer lines is a major cause of line blockages leading to sanitary sewer overflows (SSOs). Despite the central role that FOG deposits play in SSOs, little is known about the mechanisms of FOG deposit formation in sanitary...

  15. Understanding the Spatial Formation and Accumulation of Fats, Oils & Grease Deposits in the Sewer Collection System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sanitary sewer overflows are caused by the accumulation of insoluble calcium salts of fatty acids, which are formed by the reaction between fats, oils and grease (FOG) and calcium found in wastewaters. Different sewer structural configurations (i.e., manholes, pipes, wet wells), which vary spatially...

  16. 40 CFR 35.935-16 - Sewer use ordinance and evaluation/rehabilitation program.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Sewer use ordinance and evaluation... GRANTS AND OTHER FEDERAL ASSISTANCE STATE AND LOCAL ASSISTANCE Grants for Construction of Treatment Works-Clean Water Act § 35.935-16 Sewer use ordinance and evaluation/rehabilitation program. (a) The...

  17. Flood Grouting for Infiltration Reduction on Private Side Sewers (WERF Report INFR5R11)

    EPA Science Inventory

    The sewers in Seattle’s Broadview neighborhood, built in the 1950s, experience significant inflow and infiltration. Intense wet weather events have resulted in sewer overflows into private residences and the environment and previous work indicates that the majority of this excess...

  18. SEWER AND TANK SEDIMENT FLUSHING: CASE STUDIES (EPA/600/R-98/157)

    EPA Science Inventory

    Past studies have identified urban combined sewer overflow (CSO) and stormwater runoff as major contributors to the degradation of many urban lakes, streams, and rivers. Sewage solids deposited in combined sewer (CS) systems during dry weather are major contributors to the CSO-po...

  19. SEWER-SEDIMENT CONTROL: OVERVIEW OF AN EPA WET-WEATHER FLOW RESEARCH PROGRAM

    EPA Science Inventory

    This paper presents a historical overview of the sewer sediment control projects conducted by the Wet-Weather Flow Research Program of the USEPA. Research presented includes studies of the causes of sewer solids deposition and development/evaluation of control methods that can pr...

  20. Focused Field Investigations for Sewer Condition Assessment with EPA SSOAP Toolbox

    EPA Science Inventory

    The Nation’s sanitary sewer infrastructure is aging, and is currently one of the top national water program priorities. The U.S. Environmental Protection Agency (EPA) developed the Sanitary Sewer Overflow Analysis and Planning (SSOAP) Toolbox to assist communities in developing ...

  1. Focused Field Investigations for Sewer Condition Assessment with EPA SSOAP Toolbox - slides

    EPA Science Inventory

    The Nation’s sanitary sewer infrastructure is aging, and is currently one of the top national water program priorities. The U.S. Environmental Protection Agency (EPA) developed the Sanitary Sewer Overflow Analysis and Planning (SSOAP) Toolbox to assist communities in developing S...

  2. Focused Field Investigations for Sewer Condition Assessment with EPA SSOAP Toolbox - abstract

    EPA Science Inventory

    The Nation’s sanitary sewer infrastructure is aging, and it is currently one of the top national water program priorities, and is one of the top priorities of the U.S. Conference of Mayors. The U.S. Environmental Protection Agency developed the Sanitary Sewer Overflow Analysis a...

  3. HYDRAULIC CHARACTERISTICS OF SEWER SEDIMENT GATE FLUSHING TANKS: LABORATORY FLUME STUDIES

    EPA Science Inventory

    The objective of this study was to test the performance of gate flushing tanks, simulated in a laboratory flume, to remove sediments from combined sewers and storage tanks. A significant amount of sediment/debris/sludge may accumulate at the bottom of a sewer during dry weather o...

  4. Cost Comparison of Conventional Gray Combined Sewer Overflow Control Infrastructure versus a Green/Gray Combination

    EPA Science Inventory

    This paper outlines a life-cycle cost analysis comparing a green (rain gardens) and gray (tunnels) infrastructure combination to a gray-only option to control combined sewer overflow in the Turkey Creek Combined Sewer Overflow Basin, in Kansas City, MO. The plan area of this Bas...

  5. Focused Field Investigations for Sewer Condition Assessment with EPA SSOAP Toolbox

    EPA Science Inventory

    The Nation’s sanitary sewer infrastructure is aging, and it is currently one of the top national water program priorities, and is one of the top priorities of the U.S. Conference of Mayors. The U.S. Environmental Protection Agency (EPA) developed the Sanitary Sewer Overflow Anal...

  6. NATIONWIDE EVALUATION OF COMBINED SEWER OVERFLOWS AND URBAN STORMWATER DISCHARGES. VOLUME II. COST ASSESSMENT AND IMPACTS

    EPA Science Inventory

    A nationwide assessment has been made of the quantity and quality of urban storm flow emanating from combined sewers, storm sewers, and unsewered portions of all 248 urbanized areas and other urban areas in the United States. Available control alternatives and their associated co...

  7. Update on the Status of Sanitary Sewer Overflow Analysis and Planning (SSOAP) Toolbox

    EPA Science Inventory

    A properly designed, operated and maintained sanitary sewer system is meant to collect and convey all of the sewage that flows into it to a wastewater treatment plant. However, occasional unintentional discharges of raw sewage from municipal sanitary sewers – called sanitary sewe...

  8. SEWER SEDIMENT CONTROL: AN OVERVIEW OF THE EPA WET WEATHER FLOW (WWF) RESEARCH PROGRAM

    EPA Science Inventory

    This paper presents an overview of EPA WWF Research Program projects related to causes of sewer solids deposition and control methods that can prevent accumulation of sewer sediments. In particular, discussion will focus on the relationship of wastewater characteristics to flow ...

  9. HYDRAULIC CHARACTERISTICS OF SEWER SEDIMENT GATE-FLUSHING TANKS: LABORATORY FLUME STUDIES

    EPA Science Inventory

    The objective of this study was to test the performance of gate-flushing tanks, simulated in a laboratory flume, to remove sediments from combined sewers and storage tanks. A significant amount of sediment/debris/sludge may accumulate at the bottom of a sewer during dry weather o...

  10. Priority pollutants in wastewater and combined sewer overflow.

    PubMed

    Gasperi, Johnny; Garnaud, Stéphane; Rocher, Vincent; Moilleron, Régis

    2008-12-15

    Implementation of the European Water Framework Directive and its affiliated directives requires Member States to improve their understanding of priority pollutants (PPs) in urban areas and obviously within wastewater systems. As a direct consequence, this study is intended to furnish data on both PP occurrence and the significance of concentrations in wastewater during dry and wet periods within combined sewers. Various sampling sites within the Paris combined sewer network were selected; for each sample, a total of 66 determinants, including metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, organotins, volatile organic compounds, chlorobenzenes, phthalates and alkylphenols, were analysed. A broad range of PPs was observed in wastewater during dry as well as wet weather periods. Of the 66 elements investigated, 33 and 40 priority substances could be observed in raw sewage and wet weather effluent, respectively. As expected, a majority of metals were present in all samples, reflecting their ubiquitous nature. For both periods, chlorobenzenes and most of the pesticides always remained below the limit of quantification, while the majority of other organic pollutants assessed were identified within the microg l(-1) range. As highlighted by the larger number of substances detected in wet weather samples and the significance of their concentrations, runoff via atmospheric inputs and/or surface leaching was found to induce a wider range of PPs (n=40) and lead to higher concentrations of certain metals, PAHs, pesticides and other individual compounds. The data generated during this survey, which constitutes one of the first studies conducted in Europe to report concentrations for a variety of priority substances in wastewater within combined sewers, may be used in the future to identify PPs of potential significance for dry and wet weather periods and targeted for further investigation. PMID:18814902

  11. STORM-SEWER FLOW MEASUREMENT AND RECORDING SYSTEM.

    USGS Publications Warehouse

    Kilpatrick, Frederick A.; Kaehrle, William R.

    1986-01-01

    A comprehensive study and development of instruments and techniques for measuring all components of flow in a storm-sewer drainage system were undertaken by the U. S. Geological Survey under the sponsorship of FHWA. The study involved laboratory and field calibration and testing of measuring flumes, pipe insert meters, weirs, and electromagnetic velocity meters as well as the development and calibration of pneumatic bubbler and pressure transducer head-measuring systems. Tracer dilution and acoustic-flowmeter measurements were used in field verification tests. A single micrologger was used to record data from all the instruments and also to activate on command the electromagnetic velocity meter and tracer dilution systems.

  12. Comparison of core sampling and visual inspection for assessment of concrete sewer pipe condition.

    PubMed

    Stanić, N; de Haan, C; Tirion, M; Langeveld, J G; Clemens, F H L R

    2013-01-01

    Sewer systems are costly to construct and even more costly to replace, requiring proper asset management. Sewer asset management relies to a large extent on available information. In sewer systems where pipe corrosion is the dominant failure mechanism, visual inspection by closed circuit television (CCTV) and core sampling are among the methods mostly applied to assess sewer pipe condition. This paper compares visual inspection and drill core analysis in order to enhance further understanding of the limitations and potentials of both methods. Both methods have been applied on a selected sewer reach in the city of The Hague, which was reportedly subject to pipe corrosion. Results show that both methods, visual inspection and core sampling, are associated with large uncertainties and that there is no obvious correlation between results of visual inspection and results of drill core analysis. PMID:23752377

  13. Prioritizing sewer rehabilitation projects using AHP-PROMETHEE II ranking method.

    PubMed

    Kessili, Abdelhak; Benmamar, Saadia

    2016-01-01

    The aim of this paper is to develop a methodology for the prioritization of sewer rehabilitation projects for Algiers (Algeria) sewer networks to support the National Sanitation Office in its challenge to make decisions on prioritization of sewer rehabilitation projects. The methodology applies multiple-criteria decision making. The study includes 47 projects (collectors) and 12 criteria to evaluate them. These criteria represent the different issues considered in the prioritization of the projects, which are structural, hydraulic, environmental, financial, social and technical. The analytic hierarchy process (AHP) is used to determine weights of the criteria and the Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE II) method is used to obtain the final ranking of the projects. The model was verified using the sewer data of Algiers. The results have shown that the method can be used for prioritizing sewer rehabilitation projects. PMID:26819383

  14. Detention storage volume for combined sewer overflow into a river.

    PubMed

    Temprano, J; Tejero, I

    2002-06-01

    This article discusses the storage volume needed in a combined sewer system tank in order to preserve the water quality. There are a lot of design criteria which do not take into account the conditions of the receiving water, and as a result are inappropriate. A model was used to simulate the performance of a theoretical combined sewer system where a tank was located downstream. Results were obtained from the overflows produced by the rain recorded in Santander (Spain) for 11 years, with several combinations of storage volume and treatment capacity in the wastewater treatment plant. Quality criteria were also proposed for faecal coliforms, BOD, and total nitrogen to evaluate the effects from the overflows in the river water quality. Equations have been obtained which relate the number of overflows, the storage volume and the treatment plant capacity. The bacteriological pollution, quantified by means of faecal coliforms, was the analytical parameter which produced the most adverse effects in the river, so that more storage volume is needed (45 to 180 m3 ha(-1) net) than with other simulated pollutants (5 to 50 m3 ha(-1) net for BOD, and less than 4 m3 ha(-1) net for the total nitrogen). The increase in the treatment plant's capacity, from two to three times the flow in dry weather, reduces the impact on the river water in a more effective way, allowing a reduction of up to 65% in the number of overflows rather than increasing the storage volume. PMID:12118618

  15. Chromium and copper removed, wastewater can now go to sewer

    SciTech Connect

    Smith, L.W.; Toy, D.A.

    1987-06-01

    Alco Gravure faced a wastewater problem at its printing facility in Broadview, IL. Hexavalent chrome-bearing wastewater was generated during chrome plating and etching and acidic copper wastewater was produced during the plating of rotogravure printing rolls. The chromium and copper levels in the wastewater were too high to discharge to the municipal sewer. At the company's previous location, the wastewater had been stored in underground tanks and periodically removed by a hazardous waste treatment firm. Because the wastewater contained less than 1% heavy metals, volume reduction of the waste became an economic necessity when Alco moved to the Broadview site. A metals precipitation and removal system was chosen with the following equipments: oil/water separator, chrome reduction tank, neutralization tank, clarifier, filter press, and all associated instrumentation, metering pumps, valves, piping and mixers. The system was chosen after company personnel inspected a similar treatment system in a plating operation at a plant across the street from Alco. Since installation in the fall of 1984, the heavy metal treatment system has reduced the volume of waste to less than 1% of the initial wastewater volume. By treating the 99 + % of the aqueous waste for disposal to the municipal water treatment works, significant savings have been achieved in waste disposal costs. Effluent quality exceeds all standards established by the sewer district and by the EPA.

  16. Main features of meiosis

    SciTech Connect

    1993-12-31

    Chapter 17, outlines the main features of meiosis, beginning with its significance and proceeding through the meiotic stages. Meiosis is the most important modification of mitosis because it is the reduction division that gives rise to the haploid generation in the life cycle. 17 refs., 6 figs.

  17. The rising risks of rising tides

    SciTech Connect

    Hanson, H.; Lindh, G.

    1996-12-31

    The erosion of beaches, flooding of agricultural land, and intrusion of saltwater into coastal streams could become a reality if temperatures climb. Over the past century, sea levels have risen 4 to 6 inches. Now, the Intergovernmental panel on Climate Change (IPCC) predicts that sea levels will rise between 8 and 28 inches by 2070, say Hans Hanson, associate professor emeritus in the Department of Water Resources Engineering at the University of Lund in Sweden. Coastal communities, which harbor more than half the world`s population, are poorly equipped to combat the threat of encroaching waters. {open_quotes}Few public officials have developed comprehensive strategies to address the potential consequences of sea-level rise,{close_quotes} the authors say. In response to the lack of long-term strategies to address the potential consequences of sea-level rise,{close_quotes} the authors say. In response to the lack of long-term strategies, the IPCC has recommended that coastal nations implement coastal-zone management plans by 2000. {open_quotes}Low-lying islands and high-use, developed coastal areas... face an urgent need to develop strategies for coping with sea-level rise,{close_quotes} the authors conclude.

  18. Factors that influence properties of FOG deposits and their formation in sewer collection systems.

    PubMed

    Iasmin, Mahbuba; Dean, Lisa O; Lappi, Simon E; Ducoste, Joel J

    2014-02-01

    Understanding the formation of Fat, Oil, and Grease (FOG) deposits in sewer systems is critical to the sustainability of sewer collection systems since they have been implicated in causing sewerage blockages that leads to sanitary sewer overflows (SSOs). Recently, FOG deposits in sewer systems displayed strong similarities with calcium-based fatty acid salts as a result of a saponification reaction. The objective of this study was to quantify the factors that may affect the formation of FOG deposits and their chemical and rheological properties. These factors included the types of fats used in FSEs, environmental conditions (i.e. pH and temperature), and the source of calcium in sewer systems. The results of this study showed that calcium content in the calcium based salts seemed to depend on the solubility limit of the calcium source and influenced by pH and temperature conditions. The fatty acid profile of the calcium-based fatty acid salts produced under alkali driven hydrolysis were identical to the profile of the fat source and did not match the profile of field FOG deposits, which displayed a high fraction of palmitic, a long chain saturated fatty acid. It is hypothesized that selective microbial metabolism of fats and/or biologically induced hydrogenation may contribute to the FOG deposit makeup in sewer system. Therefore, selective removal of palmitic in pretreatment processes may be necessary prior to the discharge of FSE wastes into the sewer collection system. PMID:24317022

  19. The use of multiple tracers to evaluate the impact of sewered and non-sewered development on coastal water quality in a rural area of Florida.

    PubMed

    Meeroff, Daniel E; Bloetscher, Frederick; Long, Sharon C; Bocca, Thais

    2014-05-01

    When onsite wastewater treatment and disposal systems (OSTDS) are not sited appropriately or installed properly, wastewater constituents can be a source of adverse environmental impacts to soil and groundwater, which can lead to potential public health risks. A paired monitoring design developed to compare water quality in sewered and non-sewered areas is presented here. It is suggested as a possible monitoring scheme for assessing the impact of sewer installation projects. As such, two sets of single-family, rural residential Florida neighborhoods were evaluated over a two-year period to gain insight into the effects of small-community use of OSTDS on coastal water quality. One set of two neighborhoods were connected to the sanitary sewer network and the other set of two were served exclusively by OSTDS. Water quality sampling was conducted at the paired sites during seasonal high water table (SHWT) and seasonal low water table (SLWT) events. Measured surface water quality during the SHWT showed indications of environmental impacts from OSTDS in terms of nutrients, microbial pathogen indicators, and other water quality measures, such as turbidity and conductivity. However, during the SLWT events, no obvious impacts attributable to OSTDS were detected. The water quality results indicate that OSTDS impacts may be measureable in rural areas. Other factors, such as microbial indicator survival and regrowth potential, may confound the understanding of water quality impacts of sewer projects. For example, the microbial indicators Escherichia coli and enterococci were found to persist over time and therefore did not always represent true comparisons of OSTDS and sewered areas between seasons. The timeframe for evaluating the effects of sewer projects may be longer than anticipated because of this survival and regrowth phenomenon. PMID:24961071

  20. MAINE POPULATION

    EPA Science Inventory

    MEPOP250 depicts Maine's 1950-1990 population data by town or Census in unorganized territories. Populations were compiled from US Census Bureau data where available or from Maine Municipal Information (mainly for older records). Unorganized towns with very low or zero pop...

  1. Acronical Risings and Settings

    NASA Astrophysics Data System (ADS)

    Hockey, Thomas A.

    2012-01-01

    A concept found in historical primary sources, and useful in contemporary historiography, is the acronical rising and setting of stars (or planets). Topocentric terms, they provide information about a star's relationship to the Sun and thus its visibility in the sky. Yet there remains ambiguity as to what these two phrases actually mean. "Acronical” is said to have come from the Greek akros ("point,” "summit,” or "extremity") and nux ("night"). While all sources agree that the word is originally Greek, there are alternate etymologies for it. A more serious difficulty with acronical rising and setting is that there are two competing definitions. One I call the Poetical Definition. Acronical rising (or setting) is one of the three Poetical Risings (or Settings) known to classicists. (The other two are cosmical rising/setting, discussed below, and the more familiar helical rising/setting.) The term "poetical" refers to these words use in classical poetry, e. g., that of Columella, Hesiod, Ovid, Pliny the Younger, and Virgil. The Poetical Definition of "acronical” usually is meant in this context. The Poetical Definition of "acronical” is as follows: When a star rises as the Sun sets, it rises acronically. When a star sets as the Sun sets, it sets acronically. In contrast with the Poetical Definition, there also is what I call the Astronomical Definition. The Astronomical Definition is somewhat more likely to appear in astronomical, mathematical, or navigational works. When the Astronomical Definition is recorded in dictionaries, it is often with the protasis "In astronomy, . . . ." The Astronomical Definition of "acronical” is as follows: When a star rises as the Sun sets, it rises acronically. When a star sets as the Sun rises, it sets acronically. I will attempt to sort this all out in my talk.

  2. Gamma and beta logging of underground sewer and process lines

    SciTech Connect

    Rangel, M.J.; Martz, D.E.; Langner, G.H. Jr.

    1989-11-01

    The GammaSnake can be useful for locating uranium mill tailings used as backfill for sewer lines or storm drains where the lines can be readily accessed from a cleanout access port or other opening. The time required to determine if contamination is present using the GammaSnake method is considerably less than when using the delta gamma or drilling methods. There is, also, less potential hazard to the equipment operators when using the GammaSnake method. The GammaSnake method is generally limited to a distance of 100 feet or less. Used with the MAC-51B line locator, the GammaSnake method can provide useful information without extensive drilling or surveying. 7 figs., 2 tabs.

  3. Parsimonious hydrological modeling of urban sewer and river catchments

    NASA Astrophysics Data System (ADS)

    Coutu, Sylvain; Del Giudice, Dario; Rossi, Luca; Barry, D. A.

    2012-09-01

    SummaryA parsimonious model of flow capable of simulating flow in natural/engineered catchments and at WWTP (Wastewater Treatment Plant) inlets was developed. The model considers three interacting, dynamic storages that account for transfer of water within the system. One storage describes the “flashy” response of impervious surfaces, another pervious areas and finally one storage describes subsurface flow. The sewerage pipe network is considered as an impervious surface and is thus included in the impervious surface storage. In addition, the model assumes that water discharged from several CSOs (combined sewer overflows) can be accounted for using a single, characteristic CSO. The model was calibrated on, and validated for, the Vidy Bay WWTP, which receives effluent from Lausanne, Switzerland (population about 200,000), as well as for an overlapping urban river basin. The results indicate that a relatively simple approach is suitable for predicting the responses of interacting engineered and natural hydrosystems.

  4. The evaluation of rainfall influence on combined sewer overflows characteristics: the Berlin case study.

    PubMed

    Sandoval, S; Torres, A; Pawlowsky-Reusing, E; Riechel, M; Caradot, N

    2013-01-01

    The present study aims to explore the relationship between rainfall variables and water quality/quantity characteristics of combined sewer overflows (CSOs), by the use of multivariate statistical methods and online measurements at a principal CSO outlet in Berlin (Germany). Canonical correlation results showed that the maximum and average rainfall intensities are the most influential variables to describe CSO water quantity and pollutant loads whereas the duration of the rainfall event and the rain depth seem to be the most influential variables to describe CSO pollutant concentrations. The analysis of partial least squares (PLS) regression models confirms the findings of the canonical correlation and highlights three main influences of rainfall on CSO characteristics: (i) CSO water quantity characteristics are mainly influenced by the maximal rainfall intensities, (ii) CSO pollutant concentrations were found to be mostly associated with duration of the rainfall and (iii) pollutant loads seemed to be principally influenced by dry weather duration before the rainfall event. The prediction quality of PLS models is rather low (R² < 0.6) but results can be useful to explore qualitatively the influence of rainfall on CSO characteristics. PMID:24355858

  5. Condition Assessment of Wastewater Collection Systems Using the Sanitary Sewer Overflow Analysis and Planning (SSOAP) Toolbox

    EPA Science Inventory

    The Sanitary Sewer Overflow Analysis and Planning (SSOAP) Toolbox can serve as the foundation of wastewater collection system infrastructure research, among several applications, for analyzing monitored flow data to prioritize where to inspect, monitor, and to assess the performa...

  6. ENVIRONMENTAL FOOTPRINT OF PHARMACEUTICALS - THE SIGNIFICANCE OF FACTORS BEYOND DIRECT EXCRETION TO SEWERS

    EPA Science Inventory

    The combined excretion of active pharmaceutical ingredients (APIs) via urine and feces is considered the primary route by which APIs from human pharmaceuticals enter the environment. Disposal of unwanted, leftover medications by flushing into sewers has been considered a secondar...

  7. Demonstration of an Innovative Large-Diameter Sewer Rehabilitation Technology in Houston, Texas - slides

    EPA Science Inventory

    While sewer renewal technologies currently being used for the repair, replacement and/or rehabilitation of deteriorating wastewater collection systems are generally effective, there is still room for improvement of existing technologies and for the development of new technologies...

  8. TYPE A SERVICE AREAS IN THE SANITARY SEWER SYSTEMS, NEUSE RIVER WATERHSED, NC

    EPA Science Inventory

    The North Carolina Rural Economic Development Center (NCREDC) in conjunction with Hobbs, Upchurch & Associates developed the digital Type ``A' Sewer Systems as mapped by individual system owners as required by contract. The data collected will facilitate planning, siting and impa...

  9. Demonstration of an Innovative Large-Diameter Sewer Rehabilitation Technology in Houston, Texas

    EPA Science Inventory

    While sewer renewal technologies currently being used for the repair, replacement and/or rehabilitation of deteriorating wastewater collection systems are generally effective, there is still room for improvement of existing technologies and for the development of new technologies...

  10. USING VISUAL PLUMES PREDICTIONS TO MODULATE COMBINED SEWER OVERFLOW (CSO) RATES

    EPA Science Inventory

    High concentrations of pathogens and toxic residues in creeks and rivers can pose risks to human health and ecological systems. Combined Sewer Overflows (CSOs) discharging into these watercourses often contribute significantly to elevating pollutant concentrations during wet weat...