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Reports
SUSTAIN--A Framework for Placement of Best Management Practices in Urban Watersheds to Protect Water Quality (PDF) (156 pp, 3.48 MB) (EPA/600/R-09/095) September 2009 - Abstract
Appendices (PDF) (46 pp, 552 KB)
Innovative Approaches for Urban Watershed Wet-Weather Flow Management and Control:
State-of-the-Technology Interim Report (PDF) (97 pp, 2.42 MB) (EPA/600/R-09/128) August 2009 - Abstract
Condition Assessment of Wastewater Collection Systems - State of Technology Review Report (PDF) (74 pp, 1.30 MB) (EPA/600/R-09/049) May 2009 - Abstract
Rehabilitation of Wastewater Collection and Water Distribution Systems - State of Technology Review Report (PDF) (92 pp, 1.09 MB) (EPA/600/R-09/048) May 2009 - Abstract
Green Roofs for Stormwater Runoff Control (PDF) (81 pp, 2.76 MB) (EPA/600/R-09/026) February 2009 - Abstract
Evaluation of Receiving Water Improvements from Stream Restoration (Accotink Creek, Fairfax City, VA) (PDF) (69 pp, 2.05 MB) (EPA/600/R-08/110) September 2008
Combined Sewer Regulator Overflow Facilities
Report
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.
Combined Sewer Regulation and Management a Manual
of Practice
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.
Sewer Flow Measurement: A State-Of-The-Art Assessment
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.
An Assessment of Automatic Sewer Flow Samplers
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.
Cost Estimating Manual Combined Sewer Overflow
Storage and Treatment
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.
Urban Stormwater Management and Technology Update
and Users Guide
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.
Catchbasin Technology Overview and Assessment
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.
Handling and Disposal of Sludges from Combined
Sewer Overflow Treatment: Phase I Characterization
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.
Handling and Disposal of Sludges from Combined
Sewer Overflow Treatment: Phase II Impact Assessment
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.
Nationwide Evaluation of Combined Sewer Overflows
and Urban Stormwater Discharges Volume II: Cost Assessment and Impacts
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.
Microorgansims in Urban Stormwater
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.
Dual Process Highrate Filtration of Raw Sanitary
Sewage and Combined Sewer Overflows
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.
Porous Pavement Phase I Design and Operational
Criteria
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.
Methodology for Analysis of Detention Basins
for Control of Urban Runoff Quality
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.
Storm and Combined Sewer Overflow - An Overview
of EPA's Research Program
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.
Investigation of Inappropriate Pollutant Entries into Sorm Drainage Systems:
A User's Guide
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.
Storage Sedimentation Facilities for Control
of Storm
and Combined Sewer Overflows: Design Manual
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.
Sewer and Tank Sediment Flushing: Case Studies
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.
Stormwater Treatment
at Critical Areas The Multi-Chambered Treatment Train
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.
Development of Bench-Scale Settling Apparatus:
Settling Velocity Data for Design and Operation of Wet-Weather Flow Solids-Liquid
Separation Processes
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.
Assessment of High-Rate Sedimentation Processes:
Microcarrier Weighted Coagulation Jar Tests
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.
Stormwater
Treatment At Critical Areas Evaluation of Filtration Media
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
Infiltration Through Disturbed Urban Soils and Compost-Amended Soil Effects
on Runoff Quality and Quantity
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.
Retrofitting Control Facilities for Wet Weather Flow Treatment
(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.
Geographical Information Systems, Decision Support
Systems, and Urban Stormwater Management
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.
Street
Storage System for Control of Combined Sewer Surcharge: Retrofitting Stormwater
Storage into Combined Sewer Systems
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.
Exfiltration in Sewer Systems
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.
Costs
of Urban Stormwater Control
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
Decision-Support
Tools for Predicting the performance of Water Distribution and Wastewater
Collection Systems
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..
Research
Summary: CSO Disinfection Pilot Study: Spring Creek CSO Storage Facility
Upgrade
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.
Testing
Solids Settling Apparatuses for Design and Operation of Wet-Weather Flow
Solids-Liquid Separation Processes
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.
Continuous
Deflection Separation, Fuzzy Filter and UV Treatment of SSO-Type Wastewaters:
Pilot Study Results
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.
Animal
Source Identification Using A Cryptosporidium DNA Characterization Technique
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.
Considerations
in the Design of Treatment Best Management Practices (BMPs) to Improve
Water Quality
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.
Managing
Urban Watershed Pathogen Contamination
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.
Sewer
Sediment and Control A Management Practices Reference Guide
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.
Stormwater Best Management Practice Design Guide
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.
The Use of Best Management Practices (BMPs)
in Urban Watersheds
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.
Filter Fence Design Aid for Sediment Control
at Construction Sites
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.
White Paper on Improvement of Structural Integrity
Monitoring for Drinking Water Mains
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.
Combined Sewer Overflow Control
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
Manual for Deicing Chemicals: Application Practices
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.
Physical and Settling Characteristics of Particulates
in Storm and Sanitary Wastewaters
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.