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Reports
11022-DMU-07/70
1970
Current design, operation and maintenance practices used by local jurisdictions in the United States and Canada were determined by personal interviews and compiled in the report. Particular attention was given to the performance of various types of regulators, the use of tide gates, new designs, European practices and the systems concept of combined sewer regulation. Thirty-seven drawings and photographs of regulators are included. Seventeen recommendations are made, the adoption of which would upgrade regulator facilities and tend to reduce receiving water pollution from combined sewer overflows...Continue Reading.
11022-DMU-08/70
1970
Design application, operation and maintenance of combined sewer overflow regulator facilities are detailed in this Manual of Practice, developed in conjunction with a report prepared on combined sewer overflow regulators.
Design calculations are given for various types of regulators and tide gates. A sample regulator facility control program is given to illustrate the development of a control system. Operation and maintenance guidelines are also given. Thirtyeight sketches and photographs are included...Continue Reading.
EPA-600/2-75-027
1975
A brief review of the characteristics of storm and combined sewer flows is given, followed by a general discussion of the need for such flow measurement, the types of flow data required, and the time element in flow data. A discussion of desirable flow measuring equipment characteristics presents both equipment requirements as well as desirable features and includes an equipment evaluation sheet that can be used for a particular application.
A compendium of over 70 different generic types of primary flow measurement devices, arranged according to the fundamental physical principles involved, ispresented along with evaluations as to their suitability for measurement of storm or combined sewer flows. To illustrate the implementation of the physical principles, a number of commercially available devices for flow measurement are briefly described...Continue Reading.
EPA-600/2-75-065
1975
A brief review of the characteristics of storm and combined sewer flows is given followed by a general discussion of the purposes for and requirements of a sampling program. The desirable characteristics of automatic sampling equipment are set forth and problem areas are outlined.
A compendium of 82 model classes covering over 200 models of commercially available and custom designed automatic samplers is given with descriptions and characterizations of each unit presented along with an evaluation of its suitability for a storm and/or combined sewer application...Continue Reading.
EPA-600/2-76-286
1976
Data for estimating average construction costs and operation and maintenancerequirements are presented for combined sewer overflow treatment plants ranging from about 5 to 200 million gallons per day in capacity, and storage facilities ranging in size from I to 240 million gallons. Estimating data are included for 14 separate process functions associated with combined sewer overflow treatment plants and storage facilities. An example of the use of the data is given.
Estimated average construction costs and operation and maintenance requirements are related graphically to appropriate single parameters for respective plant components. In addition, cost components of the process functions are presented to enable inflating costrelated materials and wages...Continue Reading.
EPA-600/8-77-014
1977
A continuation and reexamination of the state-of-the-art of storm and combined sewer overflow technology is presented. Essential areas of progress of the stormwater research and development program are keyed to the approach methodology and user assistance tools available, stormwater characterization, and evaluation of control measures. Results of the program are visible through current and ongoing master planning efforts.
Assessment of urban runoff pollution is referenced to the developing national data base, localized through selective monitoring and analysis, and quantified as to potential source and magnitude using techniques ranging from simplified desktop procedures to complex simulation models. Stormwater pollutants are characterized by (1) source potential, (2) discharge characteristics, (3) residual products, and (4) receiving water impacts...Continue Reading.
EPA-600/2-77-051
1977
Various catchbasin configurations and sizes were evaluated for hydraulic and pollutant removal efficiencies using hydraulic modeling analyses.
Detailed study findings are presented in sections dealing with (1) a state-of-the-art review, (2) a review of variables affecting catchbasin efficiency, (3) hydraulic modeling analyses, (4) an assessment of the role of catchbasins, (5) an economic evaluation of alternative storm and combined sewer designs, and (6) a review of recent developments and continuing program needs. Detailed example problems of the evaluation of catchbasin performance andeconomics are included...Continue Reading.
EPA-600/2-77-053a
1977
This report summarizes the results of a characterization and treatment test program undertaken to develop optimum means of handling and disposal of residual sludges from combined sewer overflow (CSO) treatment systems. Desk top engineering reviews were also conducted to gather, analyze and evaluate pertinent information relating to pump/bleedback of the treatment residuals to the dryweather sludge handling/treatment and disposal facilities.
The results indicate that the volumes and characteristics of the residuals produced from CSO treatment vary widely. For the residuals evaluated in this study, the volumes ranged from less than 1% to 6% of the raw volume treated and contained 0.12% to 11% suspended solids. The volatile content of these sludges varied between 25% and 63% with biological treatment residuals showing the highest volatile content and fuel values. The heavy metal and pesticide concentrations of the various sludges were observed to be significant and are presented...Continue Reading.
EPA-600/2-77-053b
1977
This report documents the results of an assessment of the effort that the United States will have to exert in the area of sludge handling and disposal if, in fact, full-scale treatment of combined sewer overflows is to become a reality. The results indicate that nationwide an average yearly sludge volume of 156,000,000 cu m (41.5 x 10 to the 9th power gal.) could be expected from CSO if complete CSO treatment were achieved. Evaluation of the effect of bleed/pump-back of CSO sludge on the hydraulic, solids and/or organic loadings to the dry-weather plant indicated that overloading would occur in most instances. The most promising treatment trains were found to include possible grit removal, lime stabilization, optional gravity thickening, optional dewatering and land application or landfill. Land application systems can be considered as viable alternatives for CSO treatment and disposal. Estimates indicate that first investment capital costs range from $447-10,173/ha ($181-4129/ac) with annual costs of $139-1630/ha ($56-660/ac)...Continue Reading.
EPA-600/2-77-064
1977
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 costs were also determined. Continuous simulation runs using one year of hourly data were made to determine the attainable level of pollution control with a specified availability of storage volume and treatment rate in five cities: Atlanta, Denver, Minneapolis, San Francisco, and Washington, D.C. This procedure was used to derive generalized equations relating pollution control to storage and treatment. These results were combined into a simple optimization model which determined the optimal mix of storage and treatment for any feasible level of control for any city. Then the nationwide assessment is presented. The results indicate annual costs ranging from $297 million for 25 percent pollution control to $5,029 million for 85 percent control. These costs can be reduced significantly if stormwater pollution control is integrated with best management practices and integrated into a multipurpose program...Continue Reading.
EPA-600/2-77-087
1977
Microbiological quantitative assays of Baltimore City urban runoff were conducted throughout a 12 month period to show the relationships to several factors such as separate or combined sewer flow, urban characteristics of drainage area, rainfall, and quantity of flow during and between rain storms. In general, there was a consistently high recovery of both pathogenic and indicator organisms throughout the study except for Shigella sp. which is believed to have been present but could not be isolated due to interferences during the culture procedure. There appeared to be little relationship between pathogen recovery and season of the year, amount of rainfall, period of the antecedent rainfall, and stream flow...Continue Reading.
EPA-600/2-79-015
1979
Pilot plant studies were conducted at New York's Newtown Creek Water Pollution Control Plant from 1975-1977 to investigate the suspended solids (SS) removal capabilities of the deep bed, high rate gravity filtration process on raw sewage and combined sewer overflows. The treatment system was composed of a rotating screen followed by a dual media, and high rate filter. A continuous series of tests on dry weather (raw sewage) flows demonstrated SS removals across the filter averaging 67 percent. Tests on combined sewer overflow and average removal of 61 percent SS across the filter. Capital costs (ENR-2520) for a high rate filtration plant are estimated at $55,225 per mgd for a 200 mgd plant (757,000 cu m/day). Total annual treatment costs, including amortization, operation and maintenance charges, range from approximately $396,450 to $1,794,050 for dual treatment facilities in a 25 to 200 mgd (94,600 to 757,000 cu m/day) capacity range and $238,050 to $1,175,900 for the same capacity range of facilities treating only CSO. Comparison with alternative treatment systems show that HRF is cost competitive with conventional sedimentation facilities for dual-process or CSO treatment yet HRF has on 5-7 percent the area requirements. For strict CSO treatment, HRF is competitive with dissolved air flotation and microstraining processes...Continue Reading.
EPA-600/2-80-135
1980
Design and operational criteria, utilization concepts, benefits and disadvantages, as well as other characteristics of porous pavements are presented in this report. Particular emphasis is placed on porous asphalt pavements, but the criteria and design approach are applicable to all other porous pavement types. The design considerations presented in this report include siting problems, load bearing design, and hydrologic design. A brief history of porous pavement development and previous experience with porous pavement by several designers, contractors, and operators are described. A computer model for hydrologic performance evaluation of existing or proposed porous pavement systems is also described in this report. Load bearing design criteria are based on previous work conducted for porous asphalt pavements. Appendices to this report include a sample set of specifications for porous asphalt construction and a list of soils and their permeability classes as prepared by the U.S. Soil Conservation Service...Continue Reading.
EPA440/5-87-001
1986
Best Management Practices (BMPs) receive consideration for control of nonpoint source pollutant discharges (in this case, urban runoff) because of the favorable influence they are expected to exert on receiving water quality by reducing the mass loading of pollutants that would otherwise be carried into such waters by storm runoff. Studies conducted under the NURP program indicated detention and retention basins to be the most effective and reliable of the techniques examined for control of urban runoff pollutant loads. The principal mechanisms that influenced pollutant removals were either subsurface infiltration, or sedimentation...Continue Reading.
EPA/600/8-89/054
1989
The report represents an overview of the EPA's Storm and Combined Sewer Pollution Control Research Program performed over a 20-year period beginning with the mid-1960s. It covers Program involvements in the development of a diverse technology including pollution-problem assessment/solution methodology and associated instrumentation and stormwater management models, best management practices, erosion control, infiltration/inflow control, control-treatment technology and the associated sludge and solids residuals handling, and many others.
The report is a handy reference for the user community faced with the challenges and mandates to combat urban wet-weather-induced water pollution. It comprises the gamut of environmental engineering requirements from pollution problem assessment to management and control planning and design....Continue Reading.
EPA 600/R-92/238
January 1993
This User's Guide is the result of a series of EPA sponsored research tasks to develop a procedure to investigate non-stormwater entries into storm drainage systems . A number of past projects have found that dry-weather flows discharging from storm drainage systems can contribute significant pollutant loadings to receiving waters. If these loadings are ignored (e.g., by only considering wet-weather stormwater runoff), little improvement in receiving water conditions may occur with many stormwater control programs. These dry-weather flows may originate from many sources, the most important sources may include sanitary wastewater or industrial and commercial pollutant entries, failing septic tank systems, and vehicle maintenance activities. After identification of the outfalls that contain polluted dry-weather flows, additional survey activities are needed to locate and correct the non-stormwater entries into the storm drainage systems. This User's Guide contains information to allow the design and conduct of local investigations to identify the types and to estimate the magnitudes of these non-stormwater entries...Continue Rreading.
EPA 600/R-98/006
1998
This report describes applications of storage facilities in wet-weather flow management and presents step-by-step procedures for the analysis and design of storage-treatment facilities. Retention, detention, and sedimentation storage are classified and described, International as well as national state-of-the-art projects are discussed.
Retention storage facilities capture and dispose of stormwater runoff through infiltration, percolation, and evaporation. Detention storage is temporary storage for stormwater runoff or combined sewer overflow. Stored flows are subsequently returned to the sewerage system at a reduced rate of flow when downstream capacity is available, or the flows are discharged to the receiving water with or without further treatment. Sedimentation storage alters the wastewater stream by gravity separation. The stormwater runoff and combined sewer overflow must be characterized to estimate the efficiency of any sedimentation basin...Continue Reading.
EPA/600/R-98/157
1998
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-pollution load. Innovative methods for cleaning accumulated sludge and debris in CSO and stormwater conveyance systems and storage tanks have emerged over the last 15 years by creating high speed flushing waves to resuspend deposited sediments. Cleansing efficiency of periodic flush waves depends on flush volume, flush discharge rate, sewer slope, sewer length, sewer flow rate, sewer diameter and population density. Maximum flushing volumes at upstream points are limited by available space, hydraulic limitations and costs. Maximum flushing rates at the downstream point are limited by the regulator/interceptor capacities prior to overflow. The relationship between cleaning efficiency and pipe length is important. The aim of flushing is to wash the resuspended sediment to strategic locations, i.e., to a point where the waste stream is flowing with sufficient velocity, to another point where flushing will be initiated, to a storage sump which will allow later removal of the stored contents, or to the wastewater treatment plant (WWTP). This reduces the amount of solids resuspended during storm events, lessens the need for CSO treatment and sludge removal at downstream storage facilities, and allows the conveyance of more flow to the WWTP or to the drainage outlet. This report will 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 waters...Continue Reading.
EPA/600/R-99/017
1999
This is the first volume for this report series and describes the work conducted during the early years of this project through recent full-scale tests. Other volumes in this report series describe the results of field investigations of storm drain inlet devices and the use of filter media for stormwater treatment.
The first project phase investigated typical toxicant concentrations in stormwater, the origins of these toxicants, and storm and land-use factors that influenced these toxicant concentrations. Nine percent of the 87 stormwater source area samples analyzed were considered extremely toxic (using the Microtox™ toxicity screening procedure). Thirty-two percent of the samples exhibited moderate toxicity, while fifty-nine percent of the samples had no evidence of toxicity. Only a small fraction of the organic toxicants analyzed were frequently detected, with 1,3-dichlorobenzene and fluoranthene the most commonly detected organics investigated (present in 23 percent of the samples). Vehicle service and parking area runoff samples had many of the highest observed concentrations of organic toxicants. All metallic toxicants analyzed were commonly found in all samples analyzed...Continue Reading.
EPA/600/X-99/031
1999
This study is a side-by-side comparison of a traditional settling-column particle-settling- velocity distribution evaluation method and a new settling evaluation method. This portion of the study investigates whether these column tests are capable of capturing or representing the rapidly settling particles present in wet-weather flows (WWF). Equipment for the two testing methods was fabricated and laboratory tested and preliminary evaluations were made. This interim report reviews the sampling procedures and analytical methods used and presents data and results. Laboratory tests were conducted with well characterized settling media, in order to measure suspended solid (SS) concentrations and develop settling distributions on known substances in the columns prior to testing actual WWF which exhibits variable SS concentrations and settling distributions. The main purpose of this ongoing study is to obtain design data for WWF SS separator treatment devices, e.g., vortex separators, grit chambers and settling tanks. A summary of the performance as measured by predicted percent removal of both columns for 15 laboratory tests is presented, as well as a comparison of the advantages and shortcomings of the two methods...Continue Reading.
EPA/600/X-99/033
1999
Past studies have identified that a significant amount of wet weather flow pollutants is associated with colloidal and larger particulate solids. These particles can play an important role in water treatment and pollutant transport due to their large specific surface area and high energies that facilitate the sorption of significant quantities of substances. Since the colloidal particles adsorb heavy metal and organic ions and water borne microorganisms, removal of these particles is of paramount importance in the water treatment process. In this process, colloidal particles, coagulated with microcarriers (MC), can be removed by a high-rate sedimentation process. The MC plays a crucial role in enhancing settling properties, and in particular, the removal of colloidal particles and associated contaminants...Continue Reading.
EPA/600/R-00/010
2000
This is one volume in the report series entitled "Stormwater Treatment at Critical Areas" and describes the work conducted on filtration media for stormwater treatment between 1994 and 1996. Other volumes in this report series describe the results of field investigations to determine sources of urban stormwater runoff pollutants, field investigations of storm drain inlet devices, and development of a prototype treatment device that could be installed at the storm drain inlet in critical source areas...Continue Reading
EPA/600/R-00/016
2000
This project examined a common, but poorly understood, problem associated with land development, namely the modifications made to soil structure and the associated reduced rainfall infiltration and increased runoff. The project was divided into two separate major tasks:
- testing infiltration rates of impacted soils, and
- enhancing soils by amending with compost to increase infiltration and prevent runoff.
(PDF, 7.1 MB, 210 pp, about PDF)
EPA/600/R-00/020
2000
Available technologies were evaluated to demonstrate the technical feasibility and cost effectiveness of retrofitting existing facilities to handle wet-weather flow. Cost/benefit relationships were also compared t construction of new conventional control and treatment facilities. Desk top analyses of 13 separate retrofit examples were performed for (1) converting or retrofitting primary settling tanks with dissolved air flotation and lamellae and/or microsand-enhanced plate or tube settling units, (2) retrofitting existing wet-weather flow storage tanks to provide enhanced settling/treatment and post-storm solids removal, (3) converting dry ponds to wet ponds for enhanced treatment, (4) retrofitting wet-weather flow storage tanks for dry-weather flow augmentation, (5) using storage for sanitary sewer overflow control, (6) retrofitting for industrial wastewater control in a combined sewer system, and (7) bringing outdated/abandoned treatment plants back online as wet-weather flow treatment facilities. This analysis demonstrated that retrofitting existing wet-weather flow facilities can be technically feasible in most cases and may be more cost effective than construction of new conventional control and treatment facilities. The feasibility and cost effectiveness of retrofitting was found to be a function of site-specific conditions and treatment requirements. Retrofitting processes will better enable communities to meet EPA's National CSO Policy and stormwater permitting program requirements....Continue Reading.
EPA/600/R-00/027
2000
The full report reviews the application of Geographic Information System (GIS) technology to the field of urban stormwater modeling. The GIS literature is reviewed in the context of its use as a spatial database for urban stormwater modeling, integration of GIS and hydrologic time series, and integration of GIS and urban stormwater models. The available urban stormwater modeling software is reviewed and discussed with respect to their GIS integration capabilities. Decision Support Systems (DSS) are reviewed with respect to their integration with GIS, and their applicability to urban stormwater management problems. A simplified neighborhood scale decision support system (DSS) is presented that includes a GIS, a database, a stormwater system design template, and an optimization capability for screening alternatives. The area and soil based National Resources Conservation Service (NRCS) method is used for calculating runoff from GIS information. Using economic analysis that compares the costs of controls, including the opportunity cost of land for land intensive controls, the optimal selection of Best Management Practice (BMP) controls was accomplished by use of a linear programming (LP) method. The full report provides an example of the types of problems that become possible to explore with the application of DSS and GIS technology on a small scale. This field is evolving rapidly, and warrants carefully targeted research efforts, particularly at developing nonspecific software tools that aid in integrating existing models...Continue Reading.
EPA/600/R-00/065
2000
A case study approach, based primarily on two largely implemented street storage systems, is used to explain the concept through construction and operation aspects of street storage systems. More specifically, the case studies address analysis and design approaches, the regulatory and funding framework, public involvement, construction costs, operation and maintenance procedures, and system performance.
Street storage refers to the technology of temporarily storing stormwater in urban areas on the surface (off-street and on-street) and, as needed, below the surface close to the source. Close to the source means where the water falls as precipitation and prior to its entry into the combined, sanitary, or storm sewer system. The idea is to accept the full volume of stormwater runoff into the sewer system but greatly reduce the peak rate of entry of stormwater into the system. System components include street berms, flow regulators, and surface and subsurface stormwater storage sites...Continue Reading.
EPA/600/R-01/034
2001
The 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 table information to identify areas of the country where the hydraulic gradients of the sewage are typically positive, i.e., the sewage flow surface (within pipelines) is above the groundwater table...Continue Reading.
EPA/600/R-02/021
2002
This report presents information on the cost of stormwater pollution control facilities in urban areas, including collection, control, and treatment systems. Information on prior cost studies of control technologies and cost estimating models used in these studies was collected, reviewed, and evaluated...Continue Reading
EPA/600/R-02/029
2002
Water and wastewater infrastructure systems represent a major capital investment; utilities must ensure they are getting the highest yield possible on their investment, both in terms of dollars and water quality. Accurate information related to equipment, pipe characteristics, location, site conditions, age, hydraulic rates, and water quality is critical to industry and municipalities to enable the most cost-efficient operation, maintenance, and rehabilitation of existing systems...Continue Reading..
EPA/600/R-02/077
2002
This Research Summary presents the results of a pilot-scale disinfection study performed for the New York City Department of Environmental Protection and the U.S. Environmental Protection Agency (US EPA) under a contract No. 7C-R394-NTLX to Camp Dresser & McKee of Woodbury, New York. The main objective of the pilot study was to demonstrate alternatives to hypochlorite disinfection for application to the Spring Creek facility and potentially to other combined sewer overflow (CSO) facilities. The pilot testing was divided into two phases. Phase I was performed from December 1996 through March 1997, and Phase II was performed from August through November 1999...Continue Reading.
EPA/600/R-02/090
2002
This study was a side-by-side comparison of two settling column tests: one traditional and one new. The newer apparatus was developed by the Centre d'Enseignement et de Recherche pour la Gestion des Ressources Naturelles et de l'Environnement (CERGRENE) of France and uses several small columns to sequentially measure particle-settling velocities. The new apparatus was compared with a larger, more traditional column, which has been widely used in the past as a research and academic tool, but it is difficult to transport and set up in a field location due to its size...Continue Reading.
EPA/600/R-02/100
2002
Urban stormwater runoff, a leading cause of water quality impairment related to human activities in lakes and reservoirs, can have significant negative effects on receiving water quality. It can also create human health concerns when these waters are used for drinking water resources, shellfish harvesting, and recreational purposes. Watershed managers, who have 303(d) listed receiving water bodies for bacteria concentrations or a surface drinking water supply threatened with bacterial loadings linked to nonpoint sources, may consider the feasibility of best management practices (BMP) to reduce concentrations as recommended under both the Clean Water and Safe Drinking Water Acts...Continue Reading.
EPA/600/R-03/047
2003
This document summarizes the application of a particular molecular method to improve detection and differentiation of species and genotypes of Cryptosporidium oocysts found in environmental samples. Of particular interest is the method's potential for determining the source animal types of oocysts in water samples. The molecular method is a nested polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) procedure that characterizes the small sub-unit (SSU) ribosomal RNA gene...Continue Reading.
EPA/600/R-03/103
2003
For the past three decades, municipalities in the United States have successfully addressed pollution in the watershed by collecting and treating their wastewater. Currently, all municipalities provide secondary level treatment, and in some cases tertiary treatment, and industries provide best available/best practicable treatment. This has had great benefits. More rivers are meeting water quality standards, and the public health is being protected from waterborne disease. The challenge now facing us is to address pollution associated with storm water runoff, since this is now the last major threat to water quality...Continue Reading.
EPA/600/R-03/111
2003
This document is written as a resource for state and local watershed managers who have the responsibility of managing pathogen contamination in urban watersheds. In addition it can be an information source for members of the public interested in watershed mitigation efforts aimed at reducing microbial contamination. It is written to support specific steps of the total maximum daily load (TMDL) process for meeting water quality standards in urban watersheds...Continue Reading.
EPA/600/R-04/059
2004
Sewer 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 deposited in combined sewers have significant adverse impacts on the integrity of the sewerage system and receiving-water quality. In the US, estimates of dry-weather flow deposition in combined sewers vary from 5 to 30% of the daily inputs of solids and pollutants. In Europe, average deposition rates have been measured at between 30 and 500 g/m/d. Even sewers that are supposedly designed to be 'self-cleansing' will have transient sediment deposits and part of the load in transport will move near the sewer invert...Continue Reading.
EPA/600/R-04/121
2004
As this document is being published by U.S. Environmental Protection Agency’s Office of Research and Development, its primary focus is not the promulgation of regulation or the enforcement of policy. Instead, this is a forward looking document that tries to develop ways to address water quality issues of best management practices (BMPs) in the absence of a complete regulatory framework. The intended audience for this document is the municipal planners, regulators and watershed managers who will be deciding how BMPs will be applied in their locality.
In the past, BMP models were purely hydrologic; now they require two components: hydrology and quality. The purpose of this document is two-fold:
- to present the state-of-the-practice for BMP design for water quality control
- to aid the end user in making better choices.
Volume 2 provides specific design guidance for a group of onsite BMP control practices that are referred to as vegetative biofilters, and includes the following BMP control practices:
- grass swales
- filter and buffer strips
- bioretention cells.
- extended detention basins (dry)
- retention ponds (wet)
- constructed wetland ponds
- infiltration basins.
The purpose of this three-volume series is to guide the selection of BMPs that will be effective in preventing or mitigating the adverse impacts of urbanization either through retrofitting of existing BMPs or application of newly constructed BMPs to new development. There is sufficient evidence to indicate that urbanization is causing environmental impacts. Existing BMP technologies can resolve some of the impacts. There are continuing innovative BMP efforts such as bioretention, infiltration basins and low impact development that are being pursued at the research level and in some actual applications, which should improve our ability to reduce or prevent impacts due to urbanization and land-use changes.
The authors have also developed a spreadsheet tool - Integrated Design and Assessment for Environmental Loadings (IDEAL) - which can aid the reader in examining the hydrology, sediment transport and water quality for BMP devices. Aspects of the capabilities of the IDEAL spreadsheet tool are demonstrated through the use of relevant equations for BMP water quality design and several examples as presented in Volume 2 and Volume 3...Continue Reading.
EPA/600/R-04/184
2004
Stormwater is part of a natural hydrologic process. However, human activities, especially those in an urban environment, cause significant changes in patterns of stormwater flow from land into receiving waters. The undesirable impacts of stormwater runoff can be controlled by prudent management efforts, referred to as best management practices (BMPs). The purpose of this report is to provide a general information on the most commonly used structural BMP options, the design considerations involved, and the general guidelines for monitoring, selection, implementation, and associated costs of BMPs in urban watersheds...Continue Reading.
EPA/600/R-04/185
2004
The focus of environmental policy and regulation is increasing on water quality issues. Particularly, there is a more widespread awareness that sediment is one of the most prevalent pollutants and that the impacts of excess sediment released into lakes and rivers can be as damaging as those caused by agricultural or industrial chemicals. Due to their nature, construction sites are typically principal sources of undesirable sediment releases. To make construction activity easier, sites are generally cleared of all vegetation. The exposed soil is then made further susceptible to erosion by being disturbed by grading and vehicle traffic. Frequently, the only action taken to attempt to control sediment releases is the installation of a filter/silt fence. This approach is not generally successful, for several reasons:
- The fence is not installed as recommended by existing guidelines.
- The fence is not adequately maintained over time.
- The fence is not located for effective control of sediment.
- The site is not suitable for a silt fence.
EPA/600/R-05/038
2005
The improvement of water main structural integrity monitoring (SIM) capability as an approach for reducing high risk drinking water main breaks and inefficient maintenance scheduling is explored in this white paper. Inadequate SIM capability for water mains can cause repair, rehabilitation, or replacement (R3) to be scheduled either late or early. Late R3 can allow serious deterioration, main breaks, and their associated consequences to occur. Early R3 is inefficient, which adversely affects system maintenance priorities and economics. Existing SIM technologies inadequately characterize various combinations of pipe materials, configurations, and failure modes. Fortunately, substantial research to improve SIM is underway or planned, but mostly for high risk, non-drinking water applications. A systematic effort by EPA and other Federal agencies, in cooperation with relevant stakeholders, is recommended to identify, prioritize, and capitalize on opportunities to accelerate SIM capability improvement. Acceleration of SIM improvement research is especially important at this time, since: (1) for the next 30+ years a steep rise in R3 decision-making is projected for our aging water mains; (2) multiple technology transfer, collaboration, and leveraging opportunities exist; and, (3) SIM capability improvement takes time...Continue Reading.
BMP
Modeling Concepts and Simulation
EPA 600/R-06/033
2006
In order to minimize impacts of urban non point source pollution and associated
costs of control (storage and treatment) associated with wet-weather flows
(WWFs), stormwater runoff volumes and pollutant loads must be reduced. A
number of control strategies and so-called “best management practices” (BMPs)
are being used to mitigate runoff volumes and associated non point source
(diffuse) pollution due to WWFs and include ponds, bioretention facilities,
infiltration trenches, grass swales, filter strips, dry wells, and cisterns.
Another control option is popularly termed “low impact development” (LID) – or
hydrologic source control – and strives to retain a site’s pre-development
hydrologic regime, reducing WWF and the associated non point source pollution
and treatment needs.
Methodologies are needed to evaluate these BMPs, their effectiveness in attenuating flow and pollutants, and for optimizing their cost/performance since most models only partially simulate BMP processes. Enhanced simulation capabilities will help planners derive the least-cost combination for effectively treating WWFs. There is currently a confusing array of options for analyzing hydrologic regimes and planning for LID. Integrating available BMP and LID processes into one model is highly desirable.
This work analyzes several current modeling methods to evaluate BMP performance with the intention of facilitating the integration of improved BMP modeling methods into the U.S. Environmental Protection Agency (EPA) Storm Water Management Model (SWMM). Several other models are examined as part of this study. Options for enhancement of SWMM’s LID simulation capabilities are also presented. Two extensive case studies in Portland, Oregon help to clarify current SWMM capabilities and needs for enhancement. The effort documented in this report is linked to a parallel effort at the University of Colorado related to optimization strategies for WWF control...Continue Reading.
Methods
for Optimizing Urban Wet-Weather Control System (PDF by Chapters,
394 Kb, 15 pp)
EPA/600/R-06/034
2006
To minimize impacts of urban nonpoint source pollution and associated
costs of control (storage and treatment) associated with wet-weather flows
(WWFs), stormwater runoff volumes and pollutant loads must be reduced. A number
of control strategies, so-called “best management practices” (BMPs)
are being used to mitigate runoff volumes and associated nonpoint source (diffuse)
pollution due to WWFs. They include ponds, bioretention facilities, infiltration
trenches, grass swales, filter strips, dry wells, and cisterns. Another control
option is popularly termed “low impact development” (LID) – or
hydrologic source control – and strives to retain a site’s pre-development
hydrologic regime, reducing WWF and the associated nonpoint source pollution
and treatment needs.
Methods are needed to evaluate these BMPs, their effectiveness in attenuating flow and pollutants, and to optimize their cost/performance since most models only partially simulate BMP processes. Enhanced simulation capabilities will help planners derive the least-cost combination for effectively treating WWFs. There is a confusing array of options for analyzing hydrologic regimes and planning for LID. Integrating available BMP and LID processes into one model is highly desirable.
Described in this report is a methodology that integrates simulation (“what–if” analysis) and optimization (“what’s– best” analysis) for evaluating which of the myriad of alternative wet-weather controls deserves the title of “best.” The optimization analysis integrates process simulation, cost-effectiveness analysis, performance specification, and optimization methods to find this “best” solution. All of these analyses are performed using a spreadsheet platform. Following a general review of optimization methods and previous applications to wet-weather control optimization, a series of spreadsheet based tools are described. Use of these spreadsheets allows for an improved method for spatial analysis and therefore, to a more accurate representation of land use. A spreadsheet-based method for analyzing precipitation records to partition them into storm events or to develop intensity-duration-frequency curves is presented, along with simple methods for estimating infiltration and performing flow routing. Influent pollutant loads may be described simply as event mean concentrations (EMCs). A spreadsheet version of the STORM model for continuous simulations is presented, followed by an update on the cost of wet-weather controls. A primer on optimization methods describes the ease of using these techniques in a spreadsheet environment and the application of these tools to optimize storm sewer design is discussed. At the conclusion, an integrated stormwater management optimization model that combines land use optimization and a storage-release system is outlined.
The effort documented in this report is linked to a parallel effort at Oregon State University titled: BMP Modeling Concepts and Simulation. This work analyzes several current modeling methods to evaluate BMP performance with the intention of facilitating integration of improved BMP modeling methods into the EPA’s Storm Water Management Model (SWMM). Several other models are examined as part of this study. Options for enhancement of SWMM’s LID simulation capabilities are also presented. Two extensive case studies in Portland, Oregon help to clarify current SWMM capabilities and needs for enhancement...Continue Reading.
Performance
of Stormwater Retention Ponds and Constructed Wetlands in Reducing Microbial
Concentrations
EPA/600/R-06/102
2006
Stormwater runoff can transport high concentrations of pathogens
to receiving waters. Bacteria indicator organisms, as surrogates for pathogens,
are the most often reported cause of receiving water impairments. Stormwater
best management practices (BMPs) are often considered effective tools to
mitigate the effects of stormwater pollutants before they appear in receiving
waters. However, BMP performance for pathogen removal is not well documented.
Many questions remain on the transport and fate of indicator bacteria that
enter and exit stormwater BMPs.
The National Risk Management Research Laboratory (NRMRL), part of U.S. EPA’s Office of Research and Development (ORD) investigated the fate of indicator organisms in the stormwater runoff entering and exiting two commonly used BMPs, constructed wetlands and retention ponds. This research used controlled-condition, pilot-scale systems that represent larger field-scale systems to determine the dominant mechanisms that influence the reduction of indicator organism concentrations. The pilot-scale work was supported by bench-scale laboratory experiments investigating the effects of single parameters such as temperature, sunlight, and salinity on indicator organism inactivation rates. Presented in this report are the results of developing techniques for creating bacterially enriched stormwater, bench-scale studies, and the pilot-scale BMP research. Bench-scale study results show that the temperature and sunlight affect the inactivation rates significantly. Results from the pilot-scale research suggest that constructed wetlands and retention ponds lower microbial concentrations in stormwater runoff. Bacteria inactivation generally followed the first-order, K-C* empirical model that acknowledges an irreducible concentration. Factors such as sunlight and temperature provide much of the inactivation in indicator bacteria, but other factors (e.g., predation, sedimentation, filtration, sorption, pH, and BOD) appear to also influence indicator bacteria concentrations. Future research validating results of the pilot-scale systems to field-scale systems should be done.
Developing microbial inactivation models to predict effluent concentrations from BMPs will help reduce the uncertainty and improve the capabilities of surface water quality models. First-order models that do not consider background concentrations or resuspension, may underestimate actual bacterial concentrations....Continue Reading.
Real
Time Control of Urban Drainage Networks
EPA/600/R-06/120
2006
Real-time control (RTC) is a custom-designed, computer-assisted management
technology for a specific sewerage network to meet the operational objectives
of its collection/conveyance system. RTC can operate in several modes, including
a mode that is activated during a wet weather flow event to control local
flooding and sewage releases. RTC of conveyance systems has been emerging
as an attractive and cost-effective approach that can be undertaken in addition
to (or in lieu of) more traditional construction-focused alternatives such
as sewer separation or construction of storage facilities. Although there
are still relatively few documented applications of RTC to large urban sewerage
systems, the technology has been successfully implemented.
RTC implementation includes several different aspects, including hydraulics, instrumentation, remote monitoring, process control, software development, mathematical modeling, organizational issues, and forecasting of rainfall or flows. Addressing each of these issues in detail would require a large document, beyond the scope of this report. Accordingly, the report provides a summary and a broad introduction to these different issues and does not elaborate on them in great detail.
The main goal of the report is to provide a guide on RTC technology to facilitate its understanding and acceptance by the user community. The primary audience is the practicing engineer, in a municipality or in a consulting firm, who has had limited exposure to RTC. Also, the report should serve as a resource document for use by federal and state program officials and regulators, researchers, and the interested public.
There is no simple or single “recipe” for successful RTC implementation. The report provides some guidance for the methodology to be used in the design, development, and implementation of RTC systems, but it does not identify or recommend a single solution that will fit any municipality or any set of operational issues...Continue Reading.
EPA 625/R-93/007
1993
This manual presents technical guidance for use in selecting and designing controls for discharges from combined sewer overflows (CSOs). This manual will assist municipalities and regional sewer authorities that are required to provide adequate control of overflows from combined sewer systems. The manual concentrates primarily on the six most often applied CSO control technologies:
- In-system Controls/In-line Storage
- Off-line Near-surface Storage/Sedimentation
- Deep Tunnel Storage
- Coarse Screening
- Swirl/Vortex Technologies
- Disinfection
EPA-670/2-74-045
1974
This report contains the results of a study conducted for the U.S. Environmental Protection Agency to minimize the loss to the environment to chemicals used in controlling snow and ice on highways. Based on the best current practices for highway maintenance as observed during two years of study, practical guidelines are presented for the use of deicing chemicals...Continue Reading.
EPA-670/2-75-011
1975
An investigation was conducted, as part of model studies utilizing a swirl concentrator as a primary separator, helical combined sewer overflow regulator, and related studies, to characterize the properties of solids in sanitary sewage, combined sewer overflows, and stormwater runoff. To effectuate this study, material suitable for monitoring removal efficiencies in hydraulic models of the swirl concentrator unit has been developed...Continue Reading.