United States
Environmental Protection
Agency
Risk Reduction
Engineering Laboratory
Cincinnati OH 45268
EPA/600/8-89/054
January 1990
Research and Development
Storm and Combined
Sewer Overflow:
An Overview of EPA's
Research Program
-------
-------
EPA/600/8-89/054
January 1990
STORM AND COMBINED SEWER OVERFLOW:
AN OVERVIEW OF EPA's
RESEARCH PROGRAM
by
Richard Field
Storm and Combined Sewer Pollution Control Program
Risk Reduction Engineering Laboratory—Cincinnati
Edison, New Jersey 08837
RISK REDUCTION ENGINEERING LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
DISCLAIMER
This report has been reviewed in accordance with the U.S. Environmental
Protection Agency's peer and administrative review policies and approved for
publication. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
11
-------
FOREWORD
Today's rapidly developing and changing technologies and industrial
products and practices frequently carry with them the increased generation of
materials that, if improperly dealt with, can threaten both public health and
the environment. The U.S. Environmental Protection Agency is charged by the
Congress with protecting the Nation's land, air, and water systems. Under a
mandate of national environmental laws, the agency strives to formulate and
implement actions leading to a compatible balance between human activities and
the ability of natural system to support and nurture life. These laws direct
the EPA to perform research to define our environmental problems, measure the
impacts, and search for solutions.
The Risk Reduction Engineering Laboratory is responsible for planning,
implementing, and managing research, development, and demonstration programs
to provide an authoritative, defensible engineering basis in support of the
policies, programs, and regulations of the EPA with respect to drinking water,
wastewater, pesticides, toxic substances, solid and hazardous wastes, and
Superfund-related activities. This publication is one of the products of that
research and provides a vital communication link between the researcher and
the user community. .
It covers the gamut of urban storm-induced pollution environmental
engineering requirements from pollution-problem assessment and associated
tools to management and control planning and design. This report represents
an overview of the agency's Storm & Combined Sewer Pollution Control Research
Program (SCSP) performed over a 20-year period, beginning with the mid-1960s.
As controls to reduce water pollution from traditional point sources have been
implemented, it became more evident that diffuse sources of pollutants,
including discharges from separate storm drainage systems and combined sewer
overflows (CSO) are major causes of water quality problems. In response to
this situation Congress required the EPA, by adding Section 402 (p) to the
Clean Water Act (CWA) of 1987s to regulate stormwater discharges to protect
water quality by establishing comprehensive programs for permit applications,
guidance, and management and treatment requirements. In addition, Section 319
was added to the CWA requiring States to develop nonpoint source assessment
and management programs. EPA has also recently implemented a "National CSO
Control Strategy" to ensure that CSO meet the technology and water quality-
based requirements of the CWA. It is a handy reference for the user community
faced with the challenges and mandates to combat urban wet-weather-induced
water pollution.
E. Timothy Oppelt, Director
Risk Reduction Engineering Laboratory
-------
ABSTRACT
This report represents an overview of the EPA's Storm & 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 (BMPs) erosion control, infiltration/inflow (I/I)
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.
-------
CONTENTS
Disclaimer ii
Foreword '....... iii
Abstract ...... iv
Figures vii
Tables . ... .viii
1. Introduction .............. 1
2. Conclusions ............ .... 2
3. Recommendations For The Future. ........... 3
Receiving: Water Impacts 3
Indicator Microorganisms/Disinfection
Requirements and Technology ..... 3
Toxics Characterization/Problem
Assessment/Control-Treatment. .... 3
Industrial Stormwater Runoff Problem
Assessment/Control. 3
Moratorium Sources Runoff Problem
Assessment/Control. „ 4
Sewer System Cross-connections. 4
Leaking Underground Storage Tanks (UST) ..... 4
Integrated Stormwater Management. 4
New and Innovative Stormwater Control ...... 5
Surface and Groundwater Interfacing . 5
Landfill and Waste Site Runoff Control. 5
Institutional/Socio/Economic Conflicts 5
4. Pollution Problem Assessment . 6
Background. ..... . 6
Characterization. . 6
Case Studies 7
Receiving Water Impacts 8
Oxygen Demand Loads ..... 8
Aesthetic Deterioration and Solids 9
Coliform Bacteria and Pathogenic Microorganisms 9
Biological Impacts 9
Toxicity. 9
Sediment. ...» 12
5. Solution Methodology. . 12
6. User's Assistance Tools 14
Instrumentation . 14
Simulation Models ..... 15
Reports 15
7. Management Alternatives . . . . 16
Land Management 16
Land Use Planning 16
Natural Drainage.,. 17
v
-------
Dual-Purpose Detention/Retention. ...... 17
Major-Mi nor Flooding 17
Controlled Stormwater Entry 18
Porous Pavement; 18
Surface Sanitation 19
Litter Control , 19
Chemical Control. '19
Street Sweeping/Cleaning 20
Deicing Practices . . . . , , . 21
Collection System Controls. . . . 21
Sewer Separation 21
Catchbasins . ,..-..' 22
Sewers • . . " 22
Sewer Flushing.! 22
Polymers to Increase Capacity 22
In-S'ewer Storage and Flow Routing ....... 22
Sewer System Cross-connections 23
Flow Regulations and Tide Gates 24
Swirl and Helical Flow Regulators/
Solids Concentrators. .......... 24
Flow Regulators for Separate Stormwater
Pollution Control . . 25
Vortex Energy Dissipators •. . 27
Rubber "Duck Bill" Tide Gate, . ..... 28
Maintenance . 29
Infiltration/Inflow (I/I) Control ...... 29
Storage i ............... 29
Treatment ............. „ . 31
Physical/Chemical Treatment 32
Biological Treatment. . 33
Disinfection. 33
Treatment/Control Design Guidebook. ..... 33
Treatment Proces? Performance ........ 33
Maximizing Treatment 34
SI udge/Solids . . 35
Integrated Systems, i. 35
Storage/Treatment „ 35
Dual Use Wet-Weather/Dry-Weather. ...... 35
Control/Treatment/Reuse . ..., . . . 36
Wetlands. 36
8. References ; 37
-------
FIGURES
Number
1
2
3
4
5
6
7
Page
Urban Sediment Enrichment: Lake Washington,
Seattle, Washington 11
Hypothetical Example Solution
Methodology. 13
Typical Loading Curve Relating Pollutant Load to Water
Quality Response
14
Porous Asphalt Paving Typical Section ........... 19
Computer Console for Augmented Flow Control System;
Seattle, Washington ........... . ........ 23
Isometric View of Swirl Combined Sewer Overflow Regulator/
Separator. .... ....... ... ..... ...... 26
Urban Stormwater Runoff Pollution control by Connecting to
Existing Sanitary Sewerage System - Schematic. . ..... 27
Prototype Rubber "Duck Bill" Tide Gate, New York, City,
New York ........ ......... ..... ... 28
In-Receiving Water Flow Balance Mathod .......... 31
-------
Number
1 .
2
3
4
5
6
7
TABLES
Comparison of Typical! Values for Storm Flow Discharges . 7
National Annual Urban, Wet/Dry-Weather Flow (WWF/DWF) BODs
and COD Comparisons, j. . . „ . . . 3
I
Metals Discharged in harbor from New York City Sources . 10
Total Versus Particulate Mass from Storm Sewer Overflow
Point; Lake Washington, Seattle, Washington. ....... 10
Estimated Sources of Petroleum Hydrocarbons in Delaware
Bay 12
Swirl Regulator/Separator Suspended Solids Removal:
Syracuse, New York Results
26
Wet-Weather Treatment Plant Performance Data ...... 34
vn i
-------
INTRODUCTION
The Storm and Combined Sewer Pollution Control Research, Development, and
Demonstration Program (SCSP) was initiated back in 1964. Congress
acknowledged the problem 23 years ago by authorizing funds under the Water
Quality Act of 1965 for researching ways of stormwater pollution management.
The research effort was directed by the Storm and Combined Sewer Technology
Program (SCSP)' located in Edison, New Jersey until 1983 when it wa.s
disestablished. About 300 projects totaling approximately $150 million have
been awarded under the U. S. Environmental Protection Agency (EPA) Research
Program which resulted in approximately 320 final reports. More than 100
conference papers and over 100 articles and in-house reports have been
presented and published, respectively by the Program. The goal has been user
assistance with emphasis on planning and design oriented material.
Many in-house papers and reports have been published on Program over-
views, state-of-the-arts (SOTA), and special topics. These are important
management tools having been read and used internationally. The Prdgram
paper, appearing in the American Society of Civil Engineers (ASCE) Journal,
of the Environment Engineering Division, won the ASCE SOTA of Civil
Engineering Award; and a paper presentation on the swirl regulator won a New
York Water Pollution Control Association award for excellence and a similar
Journal of the Water Pollution Control Federation paper won the Level-1 EPA
Award for Scientific and Technological Achievement.
The mission of the SCSP was to develop methods for controlling pollution
from urban stormwater discharges and combined sewer overflows (CSO), and
excessive inflow and infiltration (I/I).
The Program had two facets. The first was problem definition that led to
the second -- development of effective control alternatives.
The Program has been involved in the development of a diverse technology
including pollution-problem assessments/solution methodology and associated
instrumentation and stormwater management models, best management practices
(BMP), erosion control, infiltration/inflow (I/I) control, CSO and Stormwater
control-Treatment Technology and associated sludge and solids residue handling
and disposal methods, and many others. This report covers SCSP products and
accomplishments in these areas covering 18 years of efforts. The vastness of
the Program makes it difficult to allow complete coverage. Therefore SCSP
outputs and developments will be selectively emphasized.
-------
CONCLUSIONS
In general, on a mass basis, toxics, bacteria, oxygen demanding,
suspended, and visual matter in CSO and urban stormwater are significant.
Ignoring the problem because it seems to be too costly to solve, will not
make the problem go away. The integrated approach to wet-weather pollution
control is the only way which is going to be feasible, economical and,
therefore, acceptable. Potentially tremendous "bangs-for-the-bucks" can
be derived from wet-weather pollution control research fostering integrated
solutions. As you can see, the SCSP has investigated a problem, proven
its significance, and developed a gamut of design and control techniques
that has led our nation and been accepted internationally. Better
advantage needs to be taken of proven technology.
An extremely important area where the SCSP can provide valuable
assistance to the operating programs and the user,community is through
increased availability for consulting services and for
dissemination/technology transfer of its products.
And as was discussed and because of the hundreds of millions of
dollars being spent annually, much more research still needs to be done.
-------
RECOMMENDATIONS FOR THE FUTURE
RECEIVING WATER IMPACTS
Ties between receiving water quality and storm flow discharges must be
clearly established and delineated. Quantification of the impairment of
beneficial uses and water quality by such discharges is a major goal. Project
results indicate the potential for significant impact to receiving waters of
wet-weather flows. Control of runoff pollution can be a viable alternative
for maintaining receiving water quality standards. However, the problems
found seem to be site-sepcific in nature. Therefore, site-specific surveys
are required that must consider the effects of larger materials and floatables
near the outfalls (the nearfield). Based on results from these surveys,
control may be warranted.
INDICATOR MICROORGANISMS/DISINFECTION REQUIREMENTS AND TECHNOLOGY
As discussed earlier, research is warranted for finding better indicator
microorganisms for the disease causing potential of CSO and stormwater,
associated disinfection requirements, and disinfection technology since
disinfection costs will be great for the high storm flows encountered.
TOXICS CHARACTER IZATION/PROBLEM ASSESSMENT/CONTROL-TREATMENT
'.• Results from a limited in-house effort, and EPA OWRS studies (including
the Nationwide Urban Runoff Program (NURP) study) indicate that urban
'stormwater runoff and CSO contain significant quantities of toxic substances
(priority pollutants). Without toxic and industrial runoff problem assessment
and control, our various hazardous substances cleanup and control programs
(under CERCLA/SARA, R RA, TSCA, etc.) may;be done in vain. Additional
investigation of the significance of concentrations and quantities of toxic
pollutants with regard to their health effects or potential health effects and
ecosystem effects is required. A need exists to evaluate the removal capacity
of conventional and alternative treatment technologies and BMP's for these
toxics and to compare their effectiveness with estimated removal needs to meet
water quality goals. From this comparison further advanced treatment and
control for toxic substances will need to be developed.
INDUSTRIAL STORMWATER RUNOFF PROBLEM ASSESSMENT/CONTROL
Permitting for industrial stormwater runoff along with follow-up
compliance and control is now a mandated requirement (WQA Section405 and CWA
Section 402 (p)). There are thousands of industrial sites in the country with
pollutants and toxicants in their runoff. Research and development for
problem assessment and control of industrial stormwater runoff is needed to
support these mandates; especially because research has never been done in
this area.
3
-------
MORATORIUM SOURCES RUNOFF PROBLEM[ASSESSMENT/CONTROL
Research support is required |for the assessment and control of storm-
water runoff from all moratorium sources (i.e., municipalities with
populations less than 100,000 and commercial/institutional areas) as mandated
by the WQA Section 405.
SEWER SYSTEM CROSS-CONNECTIONS |
I
Investigations have shown that sanitary and industrial contamination of
separate storm sewers (by cross-co;nnections) is a nationwide problem. In other
words, a significant number of separate stormwater drainage systems function
as combined sewer systems. Therefore, a nationwide effort on. both federal and
local levels to alleviate the pollution impacts from discharges of these
systens is required. It may be better to classify such bastardized drainage
systems as combined systems for pollution control purposes and priorities.
More research on detection and control is needed because of large sums of
money that will be spent on corrective action.
LEAKING UNDERGROUND STORAGE TANKS |(UST)
. | .
Many leaks from UST enter utility trenches and lines, e.g., sewer
networks. Pollution abatement costs would be significantly lower if
methodologies are developed to enable municipalities- to detect and control
UST leaks via these utility systems.
INTEGRATED STORMWATER MANAGEMENT
The most effective solution methodology for wet-weather pollution
problems must consider: (1) wet-weather pollution impacts in lieu of
blindly upgrading existing municipal plants, (2) structural vs. non-
structural techniques, (3): integrating dry- and wet-weather flow systems/
control to make maximum use of the| previously existing sewerage/drainage
systems during wet conditions and 'maximum use of wet-weather control/
treatment facilities during dry we'ather, and (4) the segment or bend on
the percent pollutant control vs. jcost curve in which cost differences
accelerate at much higher rates th|an pollutant control increases,. although
load discharge or receiving water [requirements will dictate, ultimately,
the degree of control/treatment required.
Flood and erosion control technology must be integrated with pollution
control, so that the retention and drainage facilities required for flood
and erosion control can be simultaneously designed or retrofitted for
pollution control. Upstream storage should also be designed to lessen
size and cost requirements for downstream drainage. If land management
and non-structural/low-structurally intensive techniques are maximized
and integrated, there will be less: to pay for the extraction of pollutants
from storm flows in the potentially more costly downstream plants-. There
is.a significant need to further develop and demonstrate various forms of
integrated stormwater management.
-------
NEW AND INNOVATIVE STORMWATER CONTROL
New research and development must be devoted to the low-cost separate
stormwater pollution control concepts, e.g., swirls and smaller storage units
for bleed back to the existing dry-weather plant.
SURFACE AND GROUNDWATER INTERFACING
Surface and groundwater have never been interfaced in the area of
pollutant routing. Runoff problems cannot be adequately assessed without
this interface. For example, enhancing surface runoff infiltration to
groundwater by applying certain BMP's, i.e., porous pavement may cause a
groundwater pollution problem that in turn may create a surface water
pollution problem later.
LANDFILL AND WASTE SITE RUNOFF CONTROL
Landfill and waste site runoff/leachate conveys vast quantities of
toxic and other pollution substances to surface and groundwater. Pollutant
routing and control technologies should be developed.
INSTITUTIONAL/SOCIO/ECONOMIC CONFLICTS
Some of the most promising opportunities for cost-effect environmental
control are multipurpose in nature. However, there are institutional
problems that hinder their implementation. First, the autonomous Federal
and local agencies and professions involved in flood and erosion control,
pollution control, and land management and environmental planning must be
integrated at both the planning and operation levels. Multi-agency
incentives (e.g., grant coverage) and rules must be adequate to stimulate
such an approach. For example, the EPA would have to join with the Corps of
Engineers, Soil Conservation Service, Department of Transportation, and
perhaps other Federal agencies as well as departments of pollution control,
sanitation, planning, and flood control at the local level.
v
' Another problem is that construction grant (and other) incentives are
geared towards structurally intensive projects which may counter research
findings in the area of optimal solutions. Optimized wet-weather pollution
involves a city-wide approach including the integration of structural as well
as low-structural controls. The low-structural measures are more labor
intensive. Construction grant funding does not presently address this expense
and accordingly, municipalities are discouraged from using them.
-------
POLLUTION PROBLEM ASSESSMENT
BACKGROUND
The background of sewer construction led to the present urban runoff
problem. Early drainage plans mad.e no provisions for storm flow pollutional
impacts. Untreated overflows occur from storm events giving rise to the storm
flow pollution problem. I
Simply stated the problem is:
with the dirty water? !
When a city takes a shower what do you do
Three types of discharges are involved: combined sewer overflow (CSO),
which is a mixture of storm drainage and municipal wastewater, which also
includes dry-weather flow (DWF) discharged from a combined sewer due to
clogged interceptors, inadequate interceptor capacity, or malfunctioning
regulators; storm drainage from separate storm systems either sewered or
unsewered; and another form of CSO, overflow from sanitary 1ines infiltrated
with stormwater.
CHARACTERIZATION |
The problem constituents in overflows are: visible matter, infect- ious
(pathogenic) bacteria and viruses, organics and solids, and in addition
include nutrients, and toxicants (e.g., heavy metals, pesticides and petroleum
hydrocarbons). >
The average five-day biochemical oxygen demand (BOD) concentration in CSO
is approximately one-half the raw sanitary sewage BOD. But storm discharges
must be considered in terms of their shockloading effect due to their relative
magnitude. Urban runoff flow rates from an average storm intensity of 0.1
1n./h are five to ten times greatef than the DWF from the same area. Likewise
a not uncommon rainfall intensity of 1.0 in./h will produce flow rates 50 to
100 times DWF. Even separate storm wastewaters are significant sources of
pollution, typically characterized as having solids concentrations equal to or
greater than those of untreated sanitary wastewater and BOD concentrations
approximately equal to those of secondary effluent. The bacterial and viral
pollution problem from wet-weathen flow (WWF) is also severe.
The quality and quantity characterization of WWF is necessary for problem
assessment, planning, and design. Summaries of characterization data from
many research studies are available^1-**'. The average pollutant
concentrations for urban runoff and CSO are compared to background pollution
and sanitary sewage in Table l^>.
.Since 1974, the SCSP supported the urban rainfal 1-runoff-quality data
^*0' for two important data requirements: characterization, and
calibration and verification of models. This project was initiated to bring
together the many widely scatteredjdata sources.
-------
Table 1. Comparison of Typical Values for Storm Flow Discharges
Kjeldahl Total po _p
TSS VSS BOD COD nitrogen nitrogen 4
OPVP Lead conforms
Background
levels
Stormwater
runoff
Combined
sewer overflow
Sanitary
sewage
415
370
90 20
140 115
115 1.4
375 3.8
n nR-0 1
3-10
9-10
An
0 01-0 2C
0.6
1.9
in
<0.1
0.4 0.35 14 500
1.0 0.37 670 000
7
a. All values mg/L except fecal conforms which are organisms/100 ml.
b. N03 as N.
c. Total phosphorus as P.
CASE STUDIES
A few municipal studies can serve to exemplify the problem. In
Northampton, England it was found that the total mass of BOD emitted from CSO
over a two year period was approximately equal to the mass of BOD emitted from
the secondary sewage treatment plant effluent. And that the mass emission of
suspended solids (SS) in CSO was three times that of the secondary effluent.
In Buffalo, New York a study concluded that 20 to 30% of the DWF solids
settled in the combined sewer which was subsequently flushed and bypassed
during high-velocity storm flows. ,
A study in Durham, North Carolina has shown that after providing
secondary treatment of municipal wastes, the largest single source of
pollution from the 1.67 mi2 watershed is separate urban runoff without the
sanitary constituent. When compared to the raw municipal waste generated
within the study area the annual urban runoff of chemical oxygen demand (COD)
was equal to 91% the raw sewage yield; the BOD yield was equal to 67%; and the
SS yield was 20 times that contained in the raw municipal wastes.
From an in-house project, preliminary screening of urban wet-weather
discharges from 24 samples from nine urban areas found approximately one half
of the 129 priority pollutants. The heavy metals were consistently found in
all samples. Polynuclear aromatic hydrocarbons, from petroleum were the most
frequently detected organics followed (in order) by phthalate esters, aromatic
hydrocarbons, halogenated hydrocarbons, and phenols. A Nationwide Urban
Runoff Program (NURP) and another EPA headquarters study also indicated that
CSO and stormwater contain significant quantities of priority pollutants.
-------
A project in Syracuse, .New. York used the Ames test to evaluate urban
runoff and CSO mutagenicity^b>/' . l Detectable responses have been
obtained on 22% of the samples. It is significant that some mutagenic
substances are present with a potential for entering the food chain.
Indicators such as fecal coli'form have long been known to be present in
stormwater discharges in densities sufficient to cause contravention of
standards. A study in Baltimore, [Marylapd identified actual pathogens and
enterovi ruses in storm sewer discharges^. Cross-connections from sanitary
sewers were strongly implicated as the major cause. Obviously, this problem
is not isolated to Baltimore. Fori instances, two surveys in Canada found that
13 and 5% of the houses had illicit sanitary connections to separate storm
sewers, respectively. At this juncture, because of the high expenses involved
for disinfection it is important to mention that better indicator organisms of
human disease potential are needed' since the conventional indicators, e.g.,
colifonm can come from animal fecal matter and soil in the. runoff whereas in
sanitary flow it is principally from human enteric origin. Perhaps direct
pathogen measurement is best.
RECEIVING WATER IMPACTS
Knowledge of the receiving water impacts resulting from urban wet-
weather discharges is a basis for determining the severity of problems and for
justifying control. Program studies of receiving water impacts are described
in a proceedings from a national conference^) and in a journal paper
Oxygen Demand Loads
Under certain conditions storm runoff can govern the quality of receiving
waters regardless of the level, of DWF treatment provided. Based on national
annual mass balance determinations (Table 2), urban wet-weather oxygen demand
loads are greater than the dry-weather (sanitary sewer] loads from the same
areas and ten times greater during storm- flow periods Ul>12)> Hence, control
of storm runoff pollution is a viable alternative for maintaining receiving
v/ater quality standards. ,
Table 2 National Annual Urban We
BOD5 and COD Compari
ry- We at her Flow (WWF/DWF)
Type
Combined Sewer
Storm Sewer
Unsewered
Totals
Percent of
Developed
Area
' 14.3
38.3
47.4
100
Annual DWF
8005
x 106 Lb
340
710;
310
i
1330
COD
x 106 Lb
910
1890
830
3630
Annual WWF
BOD5
x 106 Lb
880
440
360
1640
COD
x 106 Lb
2640
2500
2250
7390
Percent WWF
BOD5
72
36
54
55
COD
74
57
73 .
67
8-
-------
Aesthetic Deterioration and Solids
Stormwater conveys debris and solids to receiving water-bodies. This
material.can either disperse, float, or wash ashore onto beaches or
embankments, or eventually settle, creating such nuisances as: odors and
toxic/corrosive atmospheres1 from bottom mud deposits, and aesthetic upsets
either in general appearance (dirty, turbid, cloudy) or in the actual presence
of specific, objectionable items (floating debris, oil films, sanitary
discards/fecal matter, scum or slimes, tires, timber, etc.).
Coli form Bacteria and Pathogenic Microorganisms
Excess concentrations of bacterial
will hinder water supply, recreational,
receiving water'8"10'.
indicator organisms in urban runoff
and fishing/shell-fishing use of the
Elevated coliform levels in Mamaroneck Harbor, New York and subsequent
beach closings have been linked to stormwater runoff. Stormwater discharges
from the City of Myrtle Beach, South Carolina, directly onto the beach showed
high bacterial counts for short durations immediately after storm events. In
many instances these counts violated EPA recommended water quality criteria
for aquatic life and contact recreation. In Long Island, New York stormwater
runoff was identified as the major source of bacterial loading to marine
waters and the indirect cause of the closing of about one-fourth of the
shellfishing area.
Biological Impacts
An investigation of aquatic and benthic organisms in Coyote Creek,
San Jose, California found a diverse population of fish and benthic
macroinvertebrates in the non-urbanized section of the creek as compared to
the urbanized portion, which was completely dPmJPafgd by pollution tolerant
algae, mosquito fish, and tubificid worms t9»lu»lb»lb'. In the State of .
Washington, similar results were found in a Lake Washington project^9'10'1'',
where bottom organisms (aquatic earthworms) near storm sewer outfalls were
more pollution tolerant relative to those at a distance from these outfalls.
Aquatic earthworm numbers and biomass were found to be enhanced within the
zone of influence of the monitored storm drain in the Lake.
Toxicity
Toxicity problems can result from minute discharges of metals,
pesticides, and persistent organics which may exhibit subtle long-term effects
on the environment by gradually accumulating in sensitive areas. A large data
base exists that identifies urban runoff as a Significant source of toxic
pollutants, e.g., New York Harbor receives metals from treatment plant
effluents,,CSO,, separate storm sewer discharges, and untreated
wastewater'9'10'. As seen in Table 3, urban .runoff is the major contributor
of heavy metals to the harbor.
-------
Table 3. Metals Discharged in Harbor from New York City Sources
(9,10)
Source
Plant effluents
Runoff*t
Untreated wastewater
Total weight, Ib/day
Average concentration, mg/L
Copper
1,410
1,990
980
4,380
0.25
Chromium
780
690
570
2,050
0.12
Nickel
930
650
430
2,010
0.11
Zinc
2,520
6,920
1,500
10;940
0.62
Cadmi urn
95
110
60
"265
0.015
* In reality, shockload discharges are much greater.
t Runoff data includes separate storm sewer drainage and wet-weather combined
sewer overflows (CSO).
arm
s of selected constituents from a storm
'1v.»1/). A high percentage of the
Table 4 shows the total annual ma
overflow point in Seattle, Washington'
heavy metals and toxic materials is associated with the SS or particulates
which tend to concentrate in the sediment. This association is beneficial in
terms of control and treatment since it is easier to separate pollutants
attached to SS. ''..'.'
Table 4. Total Versus Particulate Mass from Storm Sewer Overflow
Point; Lake Washington, Seattle, Washington^9)
Variable
Suspended Solids
Copper
Lead
Zinc
Al umi num
Organic Carbon
Total Phororous
Oils and greases
Chlorinated Hydrocarbons
Selected Storm Drain Point
Total mass,
i in pounds
' 4,924.
2.55
! 13.29
; 6.03
213.8
658.
19.2
: 249.
inpt determined
Particulate mass,
in pounds
4,924.
1.64
11,7
3.87
207.
370.
8.93
not applicable
,0.8546
Sediment samples were analyzed for metals, organic carbon, phosphorous,
chlorinated hydrocarbons, and polychlorinated biphenyls (PCB). As can be seen
from Figure 1, a composite index tjo assess wet-weather impacts was 16 times
the minimum background control value. Also, pesticide levels in sediments
along the Seattle shoreline of Lake Washington were up to 37 times background
concentrations. i
10
-------
70
66
60
66
60
46
40
E 36
5 30
5
x
u
u 20
I 16
S 10
6
METALS
P04-J>
i CH'
STORM CONTROL
DRAIN SITE
Figure 1. Urban Sediment .Enrichment:
Washington^9'
Lake Washington, Seattle,
In the previously mentioned San Jose project'15'16), urban sediment
compared to nonurban sediment from Coyote Creek contained higher peak
concentrations of lead (up to 10 times greater) — 400 mg/kg vs 40 mg/kg,
arsenic (9 times greater) — 13 mg/kg vs 1.5 mg/kg, BOD (up to 4 times
greater) — 1,900 mg/kg vs 925 mg/kg, and ortho phosphates (4 times greater)
-- 6.7 mg/kg vs 1.8 mg/kg. Lead concentrations in urban samples of algae,
crawfish, and cattails were two to three times greater than in nonurban
samples, while zinc concentrations were about three times the nonurban
concentrations. Bioaccumulation of lead and zinc in the organisms compared to
water column concentrations was at least 100 to 500 times greater.
Petroleum hydrocarbons, particularly the polynuclear aromatics, are
suspected carcinogens. At New York City's Newton Creek treatment plant,
24,000 gal of oil and grease* equivalent to a moderate spill were bypassed
during one four hour storm^9'. A study of Jamaica Bay, New York, found that
50% of the hexane extractable material contributed to the bay is due to ,
wet-weather overflows^9). The major source of petroleum contamination in
Jamaica Bay was shown to be waste crankcase oil"3). This is in agreement
with studies of Delaware Bay^13). Petroleum hydrocarbons and associated
aromatic hydrocarbons are a cause of ecosystem degradation in New York
Bight^13). Accumulation of polynuclear aromatics in sediments eventually may
prove harmful to benthic communities in the Bight. From Table 5 it is clear
that urban runoff is the major factor to be considered once existing
regulations for point sources are adequately enforced.
11
-------
Table 5. Estimated Sources of'Petroleum Hydrocarbons In Delaware Bay(13)
Spills
Municipal
Refineries
Other industrial >
Urban runoff
Without efficient
controls (Ib/day)
6,000
7,700-15,700
24,300
8,800
10,600
With efficient
controls (Ib/day)
6,000
2,000
2,000
6,200
10,600
Ove
^
. 8 6% of the total hydrocarbons in Philadelphia, Pennsylvania storm
runoff ^i<3' was associated with partticulates, a distribution that probably is
typical of most urban areas. Therefore, instream solids separation being
designed and considered for separate stormwater systems will result in
substantial lowering on non-point petroleum hydrocarbon inputs, provided the
solids are disposed of elsewhere. ;
Sediment
Direct evidence has been obtained (from the Milwaukee River project
of how a disturbed benthos depletes dissolved oxygen (DO) from the overlying
waters. Previously mentioned and other studies have also shown that
stormwater discharges and CSO's, adversely affect sediment by toxics enrichment
and resultant biological upsets^'10'16"1'' . Since particulate matter in
untreated stormwater discharges and CSO's is larger, heavier, and in
significant quantities when compared to treated sanitary effluent, more needs
to be known about the fate and transport of settleable and separable
materials. Hydrodynamic solids separation and sediment transport routines
must be added to receiving water models to take care of the neglected or
presently omitted significant particulate- and bed-flow fields.
SOLUTION METHODOLOGY
The concept of a simplified continuous receiving water quality model was
developed in the nationwide evaluation of CSO's and urban stormwater
discharges project^1B»iy' and refined into a user's manual during a subsequent
project. This model, termed "Level III -- Receiving," permits preliminary
planning and screening of area-wide wastewater treatment alternatives in terms
of frequency of water quality violations based on time and distance varying DO
profiles. Figure 2 represents a hypothetical example of the type of analysis
facilitated by this model. This ciase is for DO; actual studies should include
other parameters and should represent at least one year of continuous data.
12
-------
100
WET-II (75% R.m) OB
WET-I (PRIM)/LM
(75% R.m)
D.O.
CONTROL
ALTERNATIVES
, EXISTING
TERTIARY
WET-I (PRIMARY)
WET-II (ADV)
WET-I/LAND MGMT.
ft BOD REMOVAL
DRY WEATHER
85
08
86
85
85
WET WEATHER
0
0
26
75
75
COST
(»«106)
-
6
1
e '
3
Figure 2. Hypothetical Example Solution Methodology
Using this analysis a truer cost-effectiveness comparison can be made
based on the duration of the impact and associated abatement costs, e.g., if a
5 mg/1 DO is desired in the receiving water 75% of the time, an advanced form
of wet-weather treatment or primary wet-weather treatment integrated with land
management is required. The latter is the most cost- effective at $3,000,000.
This or similar tools will aid in setting cost- effective standards as well as
the selection of alternatives.
Also, a general methodology has been developed for evaluating the impact
of CSp's on receiving waters and for determining the abatement costs for
various water quality goals^20'. It was developed from actual municipal
pollution control (201) facility planning experience in Onondaga Lake in
Syracuse, New York. An important goal of studies to determine the impact of
waste discharges on a receiving water is to predict the waste loads that can
be assimilated without violation of water quality standards so that a loading
curve such as shown in Figure 3 can be defined.
This figure shows the potential effect storm loads may have in violating
a 5 mg/1 DO standard after dry-weather treatment is upgraded. It further
implies that CSO pollution loads should be abated next, since they are the
easiest of the storm loads to control and capture; and in this case would
reduce loads to meet the water quality goal.
13
-------
Figure 3. Typical Loading Curve Relating Pollutant Load to Water
Quality Response
In addition, a methodology for defining criteria for wet-weather quality
standards has been developed^2*"23' . In recognition of an important gap in
the developed methodologies, the duration of water quality standards vs.
species survival was taken into consideration.
USER'S ASSISTANCE TOOLS
User's assistance tools include instrumentation, stormwater management
models, manuals of practice (MOP),| methodologies, compendiurns, and SOTA
reports.
INSTRUMENTATION
Storm-flow measurement is essential for process planning, design,
control, evaluation, and enforcement. Sampling devices do not provide
representative aliquots. Conventional flowmeters apply to steady-state flows
and not to the highly varying storm flows.
j
Flowmeters have been developed to overcome these adverse storm
conditions^24'25' . A prototype sampler for capturing representative solids in
storm flow has also been developed and a design manual is available^26'.
This gave manufacturers the incentive to perfect samplers by increasing intake
velocities apsLolher ways. SOTA reports are available for flow measurement
and sampling^2''28'. Because storm-flow conditions are extremely adverse, the
manuals and instruments developed are useful for monitoring all types of flow.
14
-------
SIMULATION MODELS
The Program has fostered the development of models for assessment,
planning, design, and control of urban stormwater pollution. Program thinking
on urban water management analysis involves four levels of evaluation ranging
from simple to complex that can be worked together.
The various levels of the stormwater management model, SWMM, are the most
significant model products in terms of past resources and overall popularity.
SWMM is one of the most widely used urban models and its benefits for planning
and design have been demonstrated. It has been employed by consulting
engineers to design sewers and to analyze pollution control alternatives.
There have been significant enhancements of SWMM. Probably the most
significant is Version IIP29"31', which includes a flexible physically
based storage and treatment routine which provides estimates of treatment
(by settling) in storage basins.
Documentation and user's manuals are available for all. SWMM levels
including three continuous stormwater planning models w^-^/; .
Operational models that have been .implemented in Detroit. .
Michigan^38' ; Minneapolis, Minnesota ^3y' ; Seattle, Washington^40'; and
San Francisco, California produce control decisions during storm events.
REPORTS
A major emphasis of the Program was solution methodology through
developments of SOTA reports, MOP's, and user's manuals.
storm flow-rate determination
t estimatincn49"51', storm-sewer design
planning and design guidance^55'
assessment on urban stormwater
Separate engineering manuals
p
us pavement
, .
^5'
The SOTA texts, user's guide and the
technology are excellent documents^41''.
are availabl for
cost
and for conducting stormwater studies
Seminar proceedings with themes of "modeling, design, operation, and
costs," have been published.
The SOTA document on particle size and settling velocity'57) offers
significant information for solids treatability and their settlement in
receiving waters, important areas overlooked in planning and design. An
excellent film is being distributed by the General Services Administration
(GSA) National Audio Visual Center which covers the EPA CSO Research Program,
^8'
and in particular ful 1 -scale control technologies,^
Case
A repor.t entitled, "Urban Stormwater Management and Technology:
Histories, ^59' presents 12 case histories which represent the most
promising approaches to CSO and stormwater control. The case histories
were developed by evaluating operational facilities that have significant
information for future guidance.
Three
have been publ
illustrative methodologi
ublished^60-62'.
es for conducting CSO facility planning
15
-------
MANAGEMENT ALTERNATIVES
The next major Program area i's management alternatives. First is
the choice of where to attack the Iproblem; at the source by land manage-
ment, in the collection system, or off-line by storage. We can remove
pollutants by treatment and by employing integrated systems combining
control and treatment.
LAND MANAGEMENT
Land management includes structural, semi - structural, and non-structural
measures for reducing urban and construction site stprmwater runoff and
pollutants before they enter the downstream drainage system. Various concepts
have been fostered by the SC.SP including:
Land Use Planning
Traditional urbanization upsets the natural hydrologic and ecological
balance of a watershed. The degree of upset depends on the mix, location,
and distribution of the proposed land use activities. As man urbanizes,
the receiving waters are degraded by runoff from his activities. The
goal of urban development resources planning is a macroscopic management
concept to prevent problems from shortsighted planning. New variables of
land usage and its perviousness, population density, and total runoff'
control must be considered and integrated with desired water quality.
16
-------
Natural' Drainage
Natural Drainage will reduce drainage costs and pollution, and enhance
aesthetics, groundwater supplies, and flood protection. A project near
Houston, Texas, focused on how a "natural-drainage system" integrates into a
reuse scheme for recreation and aesthetics^59/. Runoff flows through
vegetative swales and into a network of wet-weather ponds, strategically
located in areas of porous soils. This system retards the flow of water
downstream preventing floods by development, and enhances pollution abatement.
An interesting technological answer to the problem of preserving
pervious areas is using an open-graded asphaltic-concrete as a paving
material. This will be discussed later under the subsection "Porous
Pavements" (pp. 14 and 15),
Dual-Purpose Detenti6h/Retention
Dual-Purpose detention/retention and drainage facilities, and other
management techniques required for flood and erosion control can be
simultaneously designed or retrofitted for pollution control. Retention
on-site or upstream can provide for the multi-benefits of aesthetics,
recreation, recharge, irrigation, or other uses. An existing detention
basin can be retrofitted to enhance pollution control by limiting or
eliminating the bottom effluent orifice and by routing most or all of
the effluent stormwaters through a surface overflow device, e.g., a weir
or standpipe drain. This will induce solid-liquid separation by settling
and enable entrapped solids and floatables to be disposed of at a later
time without causing downstream receiving water pollution.
Major-Minor Flooding
By utilizing the less densely populated and less commercialized
upstream, upland drainage areas for rainwater impoundment for the more
intense storms, .the relatively and significantly more costly and
upsetting downtown downstream flooding can be eliminated or alleviated.
The multi-benefits of pollution abatement and a reduced need for larger
pipes downstream will also be gained. The "major-minor flooding" concept
involves utilization of depression storage by brief flooding of curblines,
right-of-ways, and lawn areas.
17
-------
Controlled Stonmwater Entry
A project in Cleveland, Ohio, demonstrated how controlling the
rate at which stormwater stored upstream enters the sewerage system
alleviates basement flooding and overflow pollution. The flow rate is
regulated by a vortex internal-energy dissipator (Hydrobrake ). . This .
small device, which is located at the downstream end of a subsurface
holding tank beneath the right-of-way, delivers a pre-designed virtually
constant discharge rate, compatible with the downstream sewerage system
capacities and water quality objectives, regardless of head variations.
This is accomplished without the need of moving parts or external energy
sources.
Porous Pavement
Porous pavements provide storage, enhancing soil infiltration that
can be used to reduce runoff and CSO. Porous asphalt-concrete pavements
can be underlain by a gravel base course with Whatever storage capacity
is desired (Figure 4).
Results from a study in Rochester, New. York, indicate that peak*
runoff rates were reduced as much as 83%^63'. The structural integrity
of the porous pavement was not impaired by heavy-load vehicles. Clogging
did result from sediment from adjacent land areas during construction;
however, it was relieved from cleaning by flushing. The construction
cost of a porous pavement parking lot is about equal to that of a
conventional paved lot with stormwater inlets and subsurface piping.
A Project in Austin, Texas developed design criteria for porous
pavements'^6' and compared porous asphalt av/pmpnt. tn
-------
ronous ASCHALT COURSE
t ILTER COURSE
RESERVOIR COURSE
VOLUME DESIGNED FOR RUNOFF
DETENTION AND FROST PENETRATION
EXISTING SOIL
MINIMAL COMPACTION TO RETAIN
FOROSITV AND PEHMEAIIILITV
Figure 4. Porous Asphalt Paving Typical Section
Surface Sanitation
Maintaining and cleaning urban areas can have a significant impact
on the quantity of pollutants washed off by stormwater with secondary
benefits of a cleaner and healthier environment.
Litter Control >
Spent containers from food and drink, cigarettes, newspapers,
sidewalk sweepings, lawn trimmings, and a multitude of other materials
•carelessly discarded become street litter. Unless this material is '
prevented from reaching the street or is removed by street-cleaning,
it often is found in stormwater discharges. Enforcement of anti-litter
Jaws, convenient location of sidewalk waste disposal containers, and
public education programs are just some of the source control-meas-ticas
that can be taken at the local level. While difficult to measure, the
benefits include improved aesthetics and reduced pollution.
According to a recent California study(2), litter accumulates at a rate
of approximately 4 Ib/person-yr in urban areas. Of this total, about 1.8
Ib/person-yr appears between the curb lines of streets. For example, the
estimated annual litter deposition for a municipality having a population of
100,000 is 400,000 Ib. It was reported that about 21% of the material picked
up during mechanical street sweeping was Titter.
Chemical Control ;
One of the most often overlooked measures for reducing the pollution,
from stormwater runoff is the reduction in the indiscriminate use and
disposal of toxic substances such as fertilizers, pesticides, oil,
gasoline, and detergents.
19
-------
Operations such as tree spraying, weed control, and fertilization of
parks and parkways by municipal agencies, and the use of pesticides and
fertilizers by homeowners can be controlled by increasing public awareness
of the potential hazards, to receiving waters, and providing instruction
as to proper use and application. In many cases over-application is the
major problem, where use in moderation would achieve equal results. The
use of less toxic formulations is another alternative to minimize potential
pollution.
Pesticides have been detected in samples taken from several urban
areas with typical loadings, including PCB, between 0.000136 to 0.012 Ib
/curb-mi^'. Direct and indirect dumping and/or spills of chemicals,
hazardous substances, crankcase oil, and debris into streets and gutters,
catchbasins, inlets, and sewers are significant problems that may only be-
addressed through educational programs, ordinances, and enforcement.
Street Sweeping/Cleaning
Tests under real-world conditions in San Jose, California showed
that street cleaning can remove up to 50% of the total solids (including
litter) and heavy-metal yields in urban stormwater with once or twice a
day cleaning '°4'. Typical street cleaning programs of onceor tvyice a •
monthproved ineffective. Organics and nutrients that originate primarily
from surfaces upstream of streets and may be dissolved or dissolved
residue, could not be effectively controlled even with intensive cleaning.
In Bellevue, Washington, conventional street cleaning proved . • .. • i
ineffective; however, a modified regenerative air Tymco street cleaner showed
promise lob,bbj. The mai-n purpose Of street sweeping is to enhance
aesthetics by cleaning up litter and coarser solids. Street cleaning is ,
no panacea for stormwater pollution control (and is site specific dependent
upon rainfall/climatic conditions), but if integrated with other methods,
could reduce city-wide costs for pollution control and in general. When
considering that street sweeping is used in many locations for aesthetic
purposes only, it will also provide a dual benefit, i.e., low-level water
pollution control, especially enhancement of receiving water aesthetics.
20
-------
Deicing Practices
Effective management of street and highway deicing practices can
lessen environmental and receiving water impacts, often without a
substantial increase in costs. A 1973 assessment study concluded major
adverse environmental effects come from sloppy salt storage and over-
application, which resulted in MOP's for improvement in those areas. • -,-.
These manuals were recognized as highly significant. The Federal Highway •
Administration reprinted them and distributed approximately 10,000 copies.
Recommended modifications to current deicing practices include:
(a) judicious application of salt and abrasives; (b) reduced application rates
(using sodium and calcium salt premixes: rates of 150 to 400 Ib/lane-mi have
been recommended)^/, (c) using better spreading and metering equipment arid
calibrating application rates; (d) prohibiting use of chemical additives- '(e)
providing -improved (covered and/or properly drained) salt'storage areas-'and> .
(f) educating the public and operators about the effects of deicing technology
and the best management practices^' . The SCSP work encouraged states •(e.gv•-•'•'
Wisconsin) and local governments to abate salt usage. "
Use of chemical additives such as cyanide, phosphate, and chromium
can result in polluted snowmelt. Chromium concentrations of 39 mq/L'
have been reported^'. ,"••-,
Costs associated with salting of roadways, both direct, and indirect^ •
were estimated on an annual basis for the snowbelt states"). A total
annual cost of $3 billion was reported, of which only $200 million was
associated with salt purchase and application. Other costs in the total
estimate included: (a) loss and contamination of water supplies and
damage to health, $150 million; (b) vegetation damage, $50 million- (c)
damage to highway structures, $500 million; (d). vehicle corrosion damage
$2 billion; and (e) damage to utilities, $10 million.
COLLECTION SYSTEM CONTROLS • .•'., ,
..The next overall Program category, collection system controls, pertains
to management alternatives for wastewater interception and transport. These
include: sewer separation; improved maintenance and design of catchbasfns "
sewers, regulators, and tide gates; and remote flow monitoring and control!
The emphasis with the exception of sewer separation is on optimum use of
existing facilities and fully automated control. , '•'.
Sewer Separation
The concept of constructing new sanitary sewers to replace existing
combined sewers as a control alternative, has largely, been abandoned due
to enormous costs, limited abatement effectiveness, inconvenience to the
public and extended time for implementation. Again separate stormwater
is a significant pollutant and sewer separation wouldn't cope with this
load.
21
-------
Catchbasins
In a project conducted in Boston, Massachusetts catchbasins were. ^ y
shown to be potentially quite effective for solids reduction ,(60-97%) v * '.
Removals of associated pollutants such as COD and BOD were also significant
(10-56% and 54-88%, respectively). TO maintain the effectiveness of
catchbasins for pollutant removal requires a municipal commitment with
cleaning probably twice a year depending upon conditions. The SCSP __ ,-.
developed an optimal catchbasin configuration based on hydraulic modeling^ '.
Sewers
edimentation and resultant
J, and sewer design for
ffenuals on new sewer design to alleviate
first-flush pollution and premature bypassing
added CSO storage^ 5^' are available. j
Sewer Flushing
As a follow-up to an earlier study^69), providing simple equations
for predicting dry-weather deposition in sewers, a report was published
showing that sewer flushing. flush waves can effectively convey sewer deposits
including organic matter^70). In another study v/^, it was concluded
that sewer flushing could reduce CSO control costs 7% when compared to a CSO
storage/treatment and disinfection facility designed for a one-year storm.
Polymers to Increase Capacity :
Research has shown that polymeric injection can greatly increase flow
capacity (by reducing wall friction) and thus be used to correct pollution-
causing conditions such as localized flooding and excessive overflows^ /.
Direct cost savings are realized by eliminating relief-sewer construction^
In-Sewer Storage and Flow Routing
Another control method is in-sewer storage and routing tO: maximize use of
existing sewer capacity. The general approach comprises remote monitoring of
rainfall, flow levels, and sometimes quality, at selected locations in the
network, together with a centrally computerized console for positive
regulation,, This concept has proven effective in New York, New York; Detroit,
Michigan''38) ; Seattle, Washington^1^ (Figures). .
Cleveland, Ohio and San Francisco, California have also implemented this
concept. Other cities are considering its use. New York City used a
simple static weir which impounded upstream CSO up to a level where
flooding would not be encountered. It is not a remotely-controlled
intelligent system; however, it provides ten million gallons of storage at
practically no cost.
22
-------
Although never tried, storm sewers and channels can also be retro-fitted
with flow regulators (and sensing devices) for in-channel and in-pipe storage
applying CSO in-sewer storage and routing technology and other storage
facilities for ties into the existing sewage treatment system, thus making
better use of facilities and lowering costs for overall water pollution
control. Ties into the existing treatment system will be discussed in more
detail under the subsections, "Swirl and Helical Flow Regulators/Solids
Concentrators" and "Flow Regulators for Separate Stormwater Pollution Control"
(pp. 24, 25, 27).
Figure 5. Computer Console for Augmented Flow Control System,
Seattle, Washington.
Sewer System Cross-Connectlons
Research efforts have shown that sanitary and industrial contamination
(by cross-connections) of separate storm sewers is a nationwide problem. One
response to this problem includes simple,methods of checking for cross-
connections. Investigations should be made of the drainage network, using
visual observation and screening/mass balance techniques, to determine the
sources of sanitary or industrial contamination.
23
-------
First, stormwater outfalls can be checked by eye for discharges during
DWF conditions, and if flows are noticed, they should be observed further for
clarity, odor, and sanitary matter. These dry-weather discharges should then
be confirmed and quantified (for relative amounts of
stonmwater/groundwater/sanitary and industrial wastewater) by thermal
(temperature), chemical (specific ions), and/or biochemical (BOD/COD/TOC)
techniques and mass balances. Mass balances will depend on determined
con cent rations/ values of parameters (i.e., pollutants and/or specific ions
and/or temperatures) in the various potential sewer flows (i.e.,
stormwater/groundwater/sanitary and industrial wastewaters). If visual
outfall observations cannot be made during low tides, then upstream
observations or downstream sampling (during low-tide and non-tidal back-flow
conditions) should be conducted. The drainage/ sewer system flows as a branch
and tree-trunk network which enables the investigators to strategically work
upstream to isolate the sources of stormwater contamination or
cross-connections.
Once the sources have been isolated, an analysis will have to be made to
determine whether corrective action at the sources, i.e., eliminating the
cross-connection(s) , or downstream storage/treatment (dealing with the storm
sewer/channel network as though it were a combined sewer network) is most
feasible. This will depend on the amount, dispersion, and size of the
cross-connections.
Flow Regulators and Tide Gates
Pace-setters, in the a
Program's SOTA^73' and
of CSO regulator technology were the
Conventional regulators malfunction, lack flow-control ability, and cause
excessive overflows. Devices such as the fluidic regulator, and the positive
control gate, regulator, have been demonstrated in Philadelphia,
Pennsylvania^75' , and Seattle, Washington ^°) respectively.
Swirl and Helical Flow Regulators/ Sol ids Concentrators
The dual functioning swirl flow regul ator/solids concentrator has
shown outstanding potential for simultaneous quality and quantity
control t
24
-------
The swirl has beep demonstrated for CSO in Syracuse, New York and
Lancaster, Pennsylvania by the SCSP and elsewhere by others, the device
(Figure 6) of eimple annular construction requires no moving parts. It
controls flow by a central circular wire, while simultaneously treating
combined wastewater by a "swirl" action which imparts liquid-solids
separation. Tests indicate at least 50% removal for SS and BOD. Table 6
shows the Syracuse prototype results. Tankage is small compared to
sedimentation making the device highly cost effective.
A helical type regulator/separator has also been developed based on
principles similar to the swirl. A project in West Roxubry, Massachusetts
represents the first trial on separate stormwater (78<>. There have been
anumber of full-scale projects throughout the country using the
swirl. A complete swirl/helical design textbook has been published^78).
* . .. - -1 • " " •• . •- ^' '
Flow Regulators for Separate Stormwater Pollution Control , ' !
To protect receiving water from the" effects of stormwater discharges
conventional static- or dynamic-flow regulators used for CSO control78) '
can be installed in separate storm sewers to divert stormwater to either
a sanitary interceptor and/or to a storage tank for coarse solids and
floatables removal \''>.
25
-------
A Inlet reiBp
B Flow dcftoetor
C Scum ring
0
E SpotlM*
f FlaaUbtMtrip
Q
H Floor flatten
I Oowmlufl
J SMondiry owltow w«lr
K SMondciy.outtar
Figure 6. Isometric View of Swirl Combined Sewer Overflow
Regulator/Separater
Table,6. Swirl Regulator/Separator Suspended Solid Removal
Syracuse, New York| Prototype Results
Masi loading (kg)
per storm ••
Inf.
374
103
463
Etr.
179
24
167
Removal
52%
s77%
64%
Average SS
per storm (mg/f )
Inf.
535
374
342
EfT.
345
165
202
Removal
36%
55%
41%
* 26
-------
At present, there is a strong need to develop and have a reserve of
control hardware for urban runoff control and to effectively reduce the
associated high cost implications for conventional storage tanks, etc. It is
felt that the swirl/helical type regulators, previously applied only to CSO,
can also be installed on separate storm drains before discharge and the
resultant concentrate flow can be stored in relatively small tanks, since
concentrate flow is only a few percent of the total flow.
Stored concentrate can later be directed to the sanitary sewer for
subsequent treatment during low-flow or dry-weather periods, or if capacity is
available in the sanitary interceptor/treatment system, the concentrate may be
diverted directly to it without storage.
This method of stormwater control (illustrated in Figure 7) is more
economical than building huge holding reservoirs for untreated run-off, and
offers a feasible approach to the control and treatment of separately sewered
urban stormwater^' '<.
—~ SMALL CONCtNTXATt
TANK
\
£
-------
compatible with the downstream sewerage system capacities and water quality
objectives regardless of upstream head variations. This is accomplished
without the need of moving parts, orifice closure, or external energy.
Rubber "Duck Bill" Tide Gate
i _ '
Figure 8 shows a prototype rubber "duck bill" tide gate. The prevailing
problems with conventional flap-type gates are their failure to close tight
and the need for constant maintenance. Poor tide gate performance results in
higher treatment costs, treatment plant upsets,.and greater pollutional loads
due to downstream overflows and plant bypassing^01'.
project with New York City demonstrated the "duck bill" tide
L/. It is a totally passive device, requiring no outside energy
to operate and was maintenance-free, yet sealed tightly around large solid
objects. Because of its successful demonstration in NYC the city is planning
its installation in other locations and it is being used in many other
municipalities today. !
Figure 8. Prototype Rubber "Duck Bill" Tide Gate,
New York City, New York
28
-------
Maintenance !
The Program has fostered concepts for improved sewerage system
inspection and maintenance emphasizing that it is absolutely necessary
for a total system approach to municipal water pollution control.
Premature overflows and backwater intrusion during dry as well as wet
weather caused by malfunctioning regulators and tide gates, improper
diversion settings, and partially blocked interceptors can thus be
alleviated. The resulting pollution abatement obtained is a dual benefit
of required system maintenance. Some cities have adopted this approach
and have gained high CSO control cost benefits.
Infiltration/In flow (I/I) Control
Various methods to reduce or eliminate I/I and for infrastructure
improvement have been developed and demonstrated by the Program, e.g.,
inspection, installation (including trenchless plowing in) and rehabili-
tation (including liners and InsitufornA8.13' [now used by industry])
practices, and new piping (including sulfur impregnation of concrete pipe
[which increases pipe strength and corrosion resistance thereby lowering pipe
costs and reducing infiltration from deterioration]) and
jointing materials (including heat shrinkable tubing [which expands after ,
installation creating tighter joints]). •-., ••.,•-.
STORAGE ..'.' . '. • '.'•
Because of the high volume and variability associated with storm flow,
storage is considered a necessary control Alternative. It is the Program's
best documented .abatement measure. But it is only the upstream part (process)
of,the control-treatment system. Project results and theory indicate storage
must be considered at all times in system planning, because it allows for
maximum use of existing dry-weather plant and downstream drainage facilities,
optimum economic sizing of new CSO and stonnwater treatment facilities, and
results in the lowest cost in terms of pollutant removal.
Storage facilities may be constructed in-line (flow through by gravity)
or off-line (flow through by pumping); they may be open or closed; they may be
constructed inland and upstream, on the shoreline, or in the receiving water;
and they may have auxiliary functions, such as sedimentation -treatment, flood
protection, flow attenuation to enhance receiving water pollutant
assimilation, hazardous materials capture, sewer relief, flow transmission,
and dry-weather flow equalization.
29
-------
It is important to state that storage facilities can be applied to
separate stormwater the same way they are applied to CSO for bleed or pump
back to the sewage treatment plant.
Storage concepts investigated include the conventional concrete
holding tanks and earthen basins, and the minimum land requirement concepts
of: tunnels, underground and underwater containers, underground "silos",
natural and mined under and above ground formations, and the use of abandoned
facilities and existing sewer lines\82'83'.
The in-receiving water flow balance method (Figure 9) is a recently
developed storage alternative^84'. iIn-receiving water storage facilities
contain CSO or stormwater between plastic curtains suspended from floating
wooden pontoons. After cessation of the overflow, pumps start and the
surrounding waterbody will enter the compartments and push the storm flow
back towards the first compartment where it is pumped to the plant. Thus,
the waterbody is used as a flow balance medium. The pumps will stop based
on receiving sewer and treatment plant handling capacity and an override
from a specific ionic (e.g. chlorides) or other parameter sensors that
indicates too high a receiving water dilution.
The storage method is low cost, due to the employment of low cost
materials (plastic and wood), the time required to install the unit
(several days to months vs. months to a year), and the absence of land
requirements. Studies show that costs could be about 5 to 15% of
conventional concrete tank costs, j
The facility which was tested at three locations for stormwater control
in Sweden performed very satisfactorily, and was able to take ice and wind
loads without adverse impact. It is desirable to demonstrate a facility in a
harsh urban estuarine or marine site, such as a project will be doing shortly
in Fresh Creek Basin in New York City.
A storage/sedimentation design;manual'85' has been finalized.
30
-------
Figure 9. Isometric View of In-Receiving-Water
Flow Balance Method
TREATMENT
Due to adverse and intense flow conditions and unpredictable shock
loading effects, it has been difficult to adapt existing treatment methods
to storm-generated overflows, especially the microorganism dependent
biological processes. Physical/chemical treatment techniques have shown
more promise than biological processes in overcoming storm shock loading
effects. To reduce capital investments, projects have been directed
towards high-rate operations approaching maximum loading.
31 .
-------
Storm-flow treatment methods demonstrated by the Program include
physical, physical-chemical, wetlands, biological, and disinfection^80'.
These processes, or combinations of these processes, can be adjuncts to the
existing sanitary plant or serve as remote,satellite facilities at the
outfall.
Physical/Chemical Treatment ;
Physical processes with or without chemicals, such as: fine screens,
swirl degritters, high-rate filters (HRF), sedimentation, and dissolved air
flotation (DAF), have been successfully demonstrated. Physical processes have
shown importance for storm-flow treatment because they are adaptable to
automated operation, rapid startup and shutdown, high-rate operation, and
resistance to shock loads.
The Program thought that the high-rate processes: DAF, fine mesh
screening, and HRF are ready for municipal installation.
The microstrainer conventionally designed for polishing secondary
sewage plant effluent, has successfully been applied to Q§91S; and nigh~ '
rate applications have given SS removals higher than 90%^0/;.
Full-scale microscreening units were demonstrated in two,locations.
In Syracuse, New York, SS removals of about 50% were achieved^"'.
i
A past Cleveland, Ohio pilot study using 6 in. columns.showed high
potential for treating CSO's by a fine screening/HRF system^y'. A large
scale (30 in. diameter) fine screening/HRF pilot system was evaluated in New '
York City for the dual treatment of dry- and wet-weather flows^{J1, Removals
of SS and BOD were 70% and 40%, respectively. The screening portion of the
NYC project used a 70 mesh Discrostrainer which produced a high solids
content cake which can eliminate a sludge-concentrating step. Results from a
5.0 MGD screening and DAF demonstration pilot plant in Milwaukee indicate that
greater than 70% removals of BOD and SS are possible^yi»y^. By adding
chemical coagulants, 85 to 97% phosphate reduction can be achieved as an
additional benefit. ,
Based on Program pilot plant studies, two ful l-scale.^screening/DAF
prototype systems (20 and 40 MGD) have been demonstrated^-3'. Removals of SS
and BOD were 70% and 55%, respectively. Treatment processes, e.g.,
microscreens and DAF are now being used by municipalities.
The swirl has also been developed for grit removal. The small size,
high efficiency and absence of moving parts offer economical and operational
advantages over conventional degritfnng facilities.
32
-------
A full-scale demonstration of a (16 ft, diameter/11 MGD design flow rate)
swirl degritt'er has been completed -in Tamworth, Australia™4,95).
Removal efficiencies confirmed laboratory results. Compared with a
conventional grit chamber, construction costs are halved, and operation
and maintenance costs are considerably lower.
Biological Treatment
The biological.processes: trickling filtration, contact
stabilization^5"^' , biodisks, and lagoons have been demonstrated. They have
had positive evaluation, but with the exception of long-term storage lagoons
they must operate conjunctively with dry-weather flow plants to supply,
biomass, and require some form of flow equalization.
Disinfection
Because disinfectant and contact demands are great for storm flows
research has centered on high-rate applications
mixing, hiaher disinfectant, r.nnrpnt rat inns (100-
oxidants
ixing, higher disinfectant concentrations
xidants, i.e., chlorine dioxide^1J)|"J0L
on)^0
U04).
ne
'
e" o
(UV) light; and on-site generation)^0'105'1
Rochester and Syracuse, New York U04). £ast Chicago, Indiana^' ; and
^103^
static and mechanical
more rapid •
and ultraviolet
Demonstrations in
Philadelphia, Pennsyl vania^100', indicate that adequate reductions of
fecal coliform can be obtained with contact times of two minutes or less
by induced mixing and dosing with chlorine and/or chlorine dioxide. A
pilot scale UV light demonstration with a contact time of less than ten
seconds was conducted at New York City.
n
New Orleans,
The SCSP
now bei ng
The hypochlorite batching facility is still being us
Louisiana to protect swimming beaches in Lake Poncetrain(
supported the development of a brine hypochlorite generator
used in industry^105'.
Treatment/Control Design Guidebook
A compilation of ,the SCSP's best research efforts in CSO treatment/,
control over its 18 year duration has been published^6'. Because of
flow similarities, this Is also an important reference for, urban storm-
water treatment. . , . .- .
Treatment Process Performance ,
-Treatment process costs and performance in terms.:pf design influx
(gpm/ft d) and BO.D and SS removal efficiency is provided in Table 7. The
high-rate performance of the swirl, microstrainer, screening/HRF and
screening/DAF systems, is apparent when compared to sedimentation. ,
33
-------
Table 7. Wet-Weather Treatment. Plant Performance Data
Removal efficiency (%)
Device Control alternatives
Primary . Swirl concentrator
Microstrainer
High-rate filtration
Dissolved air floialion
Sedimentation
Representative performance
Secondary Contact stabilization
Physical-chemical
Representative performance
Design loading rate
(gpm/fl'l
60
20
24
2.5
0.5
BQU,
25—60
40-
-------
SLUDGE/SOLIDS
Another Program area is the sludge, and solids associated with storm, flow
treatment. Sludge handling and disposal must be considered an integral part
of CSO treatment because insignificantly affects the efficiency and cost of
the, total waste treatment system. Studies have shown that the annual quantity
of CSO solids is at least equal to solids from dry-weather flow^v8). This is
a significant finding for the Municipal Pollution Control Program. The
results of a project on CSO sludges are covered in thr^e published reports
ub' "
covering: characterization ^
^110'
i&r
treatability
sludge and residuals
INTEGRATED SYSTEMS
impact assessment'1^', and
ilar study was conducted for separate stormwater
The most promising and common approach to urban storm flow management- •
involves the integration of control and treatment. Integrated systems is
divided into storage/treatment, .duaUuse wet-weather flow/dry-weather flow-
facilities, and control/treatment/reuse.
Storage/Treatment
When there is storage, there is treatment by settling, pump-back/
bleed-back to the municipal works, and sometimes disinfection. Treatment
which receives detention also provides storage. The break-even economics of
supplying storage must be evaluated when treatment is considered. The Program
has demonstrated all of these storage/treatment concepts full scale.
Dual Use Wet-Heather Flow/Dry-Weather Flow Facilities
The concept of dual use is maximum Utilization of wet-weather facilities
during non-storm periods and maximum utilization of dry-weather facilities
during storm flows. The Program has-demonstrated the full scale dual-use of
high-rate trickling filterst112', contact stabilization^96-98), HRF™0', and
equalization basins^11-3' . Various municipalities are employing dual-use
microscreening.
In Clatskanie, Oregon, a full-scale dual facility constructed to
alleviate flow bypassing caused by excessive infiltration was evaluated. The
plant is in permanent use. Both wet- and dry-weather flow treatment is
provided for in the same units and consists of primary sedimentation and
conventional activated sludge for dry-weather periods conver^jng^o higher
rate DAF and contact stabilization for wet-weather periods.
35
-------
Control/Treatment/Reuse !
j -jiinir.- --.___f.Li_r-j-rr- . j
"Control/Treatment/Reuse" is a catch-all for all integrated systems. A
prime consideration should be the various nonstructural and land management
techniques. In Mt. Clemens, Michigan, a series of-.three "lakelets" have been
incorporated into a CSO treatment/park development\LL^>. Treatment is being
provided so that these lakes are aesthetically pleasing and allow for
recreation and reuse for irrigation.
ASCE
.An in-house paper covering subportable reuse was published by the
Wetlands
The use/of wetlands for urban runoff pollution control has been
investigated^116'. It has been found that with controlled runoff entry and
wetlands management and maintenance that significant.receiving-lake water
benefits are obtained without degrading the wetlands*"117'.
36
-------
1.
2.
3.
REFERENCES. , - '
Lager, J.A., and Smith, William G., Metcalf & Eddy Engineers, Inc., Palo
Alto, CA, "Urban Stormwater Management and Technology: An Assessment,
"USEPA Report No. EPA-670/2-74-040, NTIS No. PB 240 687.
Lager, J.A., et al., Metcalf & Eddy Engineers, Inc., Palo Alto, CA,
"Urban Stormwater Management and Technology: Update and User's Guide,"
USEPA Report EPA-600/8-77-014, NTIS No. PB 275 654. .,-..-•
Sullivan, R.H., et al .. Aneri can Public Works As soc., Chicago, IL,
"Nationwide Evaluation of Combined Sewer Overflows and Urban Stormwater -
Discharges, Vol. Ill - Characterization of Discharges >," USEPA Report No.
EPA-600/2-77-064c, NTIS No. PB 272 107. •'. .
4. Huber, W.C., et al., University of Florida, Gainesville, FL, "Urban
Rainfall-Runoff-Quality Data Base," USEPA Report No. EPA-600/2-81-238,
NTIS No. PB 82-221 094.
5. Huber, W.C., et al., University of Florida, Gainesville, .FL, "Urban
Rainfal 1-Runoff-Quality Database," USEPA Project Summary No. EPA- ,
600/S2-81-238, NTIS No. PB 82-221 094.
6. Spiegel, S.J., et al., O'Brien & Gere Engineers, Inc., Syracuse, NY, and
Ott, R., Department of Dratnage and Sanitation, Onondaga County, North
Syracuse, NY, "Evaluation of Urban Runoff and Combined Sewer Overflow
Mutagenicity," USEPA Report No. EPAi-600/2-84-116, NTIS No. PB84-211168.
7. Spiegel, S.J*, et al., O'Brien & Gere Engineers, Inc., Syracuse, NY, and
Ott, R., Department of Drainage and Sanitation, Onondaga County, North
Syracuse, NY, "Evaluation of Urban Runoff and Combined Sewer Overflow
Mutagenicity," Project Summary No. EPA-600/S2-84-116. ' •
8. Olivieri, V.P., et al., The Johns Hopkins University, Baltimore, MD,
"Microorganisms in Urban Stormwater," USEPA Report No. EPA-600/2-77- 087,
NTIS No. PB 272 245. .
9,
10.
Proceedings of National Conference Orlando, Florida, November 26-28,
1979, "Urban Stormwater and Combined Sewer Overflow Impact-on Receiving
Water Bodies," USEPA Report No. EPA-600/9-80-056, NTIS No. PB 81-155 6.
Field, .R., and Turkeltaub, R., USEPA, Edison, NJ, "Urban Runoff Receiving
Water Impacts: Program Overview,, "Journal of the Environmental
Engineering Division, ASCE, Vol. 107, No. EE1, Feb., 1981, pp. 83-100.
37
-------
11. Sullivan, R.H., et al., American Public Works Assoc., Chicago, IL -
"Nationwide Evaluation of Combined Sewer Overflows and Urban Storm- water
Discharges, Volume I - Executive Summary," USEPA Report No.
EPA-600/2-77-064a, NT IS No. PB 273 133.
12. Heaney, J.F., et al., University of Florida, Gainesville, FL, "Nationwide
Evaluation of Combined Sewer Overflows and Urban Storm- water Discharges,
Volume II - Cost Assessment and Impacts," USEPA Report No.
EPA-600/2-77-064b, NTIS No. PB!266 005.
s" i
13. Keefer, N., et al., The Sutron Corporation, Arlington, VA, "Dissolved
Oxygen Impact from Urban Storm Runoff," USEPA Report No. EPA-600/2-79-
156, NO NTIS.
14. Meinholz, T.L., et al., (Rexnord) Metropolitan Sewage District of County
of Milwaukee, WI, "Verification of the Water Quality Impacts of Combined
Sewer Overflows," USEPA Report |No. EPA-600/2-79-155, NTIS No.
15. Pitt, R., Private Consultant, Blue Mounds, WI; Bozeman, M., Woodward-
Clyde Consultants, San Francisco, CA, "Sources of Urban Runoff Pollution
and Its Effects on an Urban Creek," USEPA Report No. EPA- 60Q/2-82-090,
NTIS No. PB 83-111 021. '
16. Pitt, R., Private Consultant, Blue Mounds, WI; Bozeman, M., Woodward-
Clyde Consultants, San Francisco, CA, "Sources of Urban Runoff Pollution
and Its Effects on an Urban Creek," USEPA Project Summary No.
EPA-600/S2-82-090, NTIS No. PB 83-111 021.
17. Tomlinson, R.D., et al., Municipality of Metropolitan Seattle, Seattle,
WA, "Fate and Effects of Particulates Discharged by Combined Sewers and
Storm Drains," USEPA Report No. EPA-600/2-80-111, NTIS No. PB 81-118
390. I
18. Medina, M., Duke University, Durham, NC, "Level III: Receiving Water
Quality Modeling for Urban Stormwater Management," -USEPA Report No.
EPA-600/2-79-100, NTIS No. PB 80-134 406.
19. Medina, M.A., et al.. Duke University, Durham, NC, "River Quality Model
for Urban Stormwater Impacts,"!USEPA Journal No. EPA-600/J-81- 234, NTIS
No. PB 81-221 087.
20. Moffa, P.E., et al., Stearns & Wheler, Civil and Sanitary Engineers,
Cazenovia, NY, "Methodology for Evaluating the Impact and Abatement of
Combined Sewer Overflows: A Case Study of Onondaga Lake, New York,"
USEPA Report No. EPA-600/8-80-048, NTIS No. PB 81-141 913.
38
-------
21. Mancini, J.L., Mancini &. DiToro Assoc., Valley, NB, "Development of
Mathods to Define Water Quality Effects of Urban Runoff," USEPA Project
Summary No. EPA-600/S2-83-125, NTIS No. PB 84-122,928. , , '
22. Mancini, J.L., Mancini & DiToro Assoc., Valley, NB, "Development of
Methods to Define Water Quality Effects of Urban Runoff," USEPA Report
No. EPA-600/2-83-125, NTIS No. PB 84-122 928. . . , .
23. Mancini, J.L., Mancini &,DiToro Assoc., Valley, NB, "A Method for
Calculating Effects on Aquatic Organisms, Of Time .Varying
Concentrations," Water Research, Vol.17, No. 10, pp. 1355-1362, 1983.
24. Foreman, K.M., Grumman Aerospace, Corp., Bethpage," NY, "Field Testing of
Prototype Acoustic Flowmeter," USEPA Report No. EPA-600/2-79-084, -NTIS "
No. PB80-121 544.
25. Anderson, R.J., and Bell, S.S., City of Milwaukee, WI, "Wastewater Flow
Measurement in Sewers Using Ultrasound," USEPA Report No. EPA-
600/2-76-243, NTIS No. PB 262 902. . .
26. Shelley, P.E., E6&G Washington Analytical Services Center, Inc.,
Rockville, MD, "Design and Testing of Prototype Automatic Sewer Sampling
System," USEPA Report No. EPA-600/2-76-006, NTIS No. PB 252 613.
27. Shelley, P.E., and Kirkpatrick, G.A., EG&G Washington Analytical Services.
Center, Inc., Rockville, MD,'"Sewer Flow Measurement - A State-of-the-Art
, assessment," USEPA Report No. EPA-600/2-75-027, NTIS No. PB 250 371.
28. Shelley, P.E., and Kirkpatrick, G.A., EG&G Washington Analytical Services
Center, Inc., Rockville, MD, "An Assessment of Automatic Sewer Flow
Samplers-1975," USEPA Report No. EPA-600/2-75-065, NTIS No. ,PB 250 .987.
29. Huber, W.C., et al., University of Florida, Gainesville, FL, "Storm Water
Management Model User1 s Manual, Version III," USEPA Report No. Pending
(Interim availability: University of Florida).
30. Huber, W.C., et al ., University of Florida, Gainesville, FL, "Storm Water
.Management Model User's Manual, Version-Ill," USEPA Project Summary No.
Pending,- (Interim availability: University of Florida).
31. Roesner, L.A., et al ., Camp Dresser & McKee Inc., Annadale, VA, "Storm
Water Management Model User's Manual Version III, Addendum I - Extran,"
USEPA Report No. Pending, (Interim availability: University of Florida).
39
-------
32. Geiger, W.F., and Dorsch, H.R., Dorsch Consult Ltd., Toronto, Ontario,
Canada, "Quantity-Quality Simulation (QQS): A Detailed Continuous
Planning Model for Urban Runoff Control - Volume I Model Description,
Testing, and Applications," USEPA Report No. EPA-600/2-80-0119 NTIS No.
PB 80-190 507. ,'
33. Geiger, W.F., and Dorsch, H.R., Dorsch Consult Ltd., Toronto, Ontario,
Canada, "Quantity-Quality Simulation (QQS): A Detailed Continuous
Planning Model for Urban Runoff Control - Volume II User's Manual," USEPA
Report No. EPA-600/2-80-116, NTIS No. PB 80-221 872.
34. Litwin, Y.J., et al., Ramlit Assoc., Berkeley, CA, "Areawide Stormwater
pollution Analysis with the Macroscopic Planning (ABMAC) Model," USEPA
Project Summary No. EPA-600/S2-81-223, NTIS No. PB 82- 107 947.
35. Litwin, Y.J., etal_., Ramlit Assoc., Berkeley, CA, "Areawide Stormwater
Pollution Analysis with the Macroscopic Planning (ABMAC) Model," USEPA
Report No. EPA-600/2-81-223, NTIS No. PB 82-107 947.
36. Smith, W.G., and Strickfaden, M.E., Metcalf & Eddy Engineers, Inc., Palo
Alto, CA, "EPA Macroscopic Planning Model (EPAMAC) for Stormwater and
Combined Sewer Overflow Control: Application Guide and User's Manual,"
USEPA Report No. EPA-600/2-83-086, NTIS No. PB 83-259 689.
37. Smith, W.G., and Strickfaden, M.E., Metcalf & Eddy Engineers, Inc., Palo
Alto., CA, "EPA Macroscopic Planning Model (EPAMAC) for Storm- water and
Combined Sewer Overflow Control]: Application Guide and User's Manual,"
USEPA Report No. EPA-600/S2-83-086, NTIS No. PB 83- 259 689.
38. Watt, T.R., et a! ., Detroit Matro Water Department, Detroit, MI,
"Sewerage System Monitoring and Remote Control," USEPA Report No.
EPA-670/2-75-020, NTIS No. PB 2 107.
39. Metropolitan Sewer Board, St. j>aul, MN, "Dispatching Systems for Control
of Combined Sewer Losses," USEPA Report No. 11020FAQ03/71, NTIS No. PB
203 678.
40. Leiser, C.P., Municipality of Metropolitan Seattle, Seattle, WA,
"Computer Management of a Combined Sewer System," USEPA Report No.
EPA-670/2-74-022, NTIS No. PB 235 717.
41. Lager, O.A., et a!., Matcalf & Eddy, Inc., Palo Alto, CA, "Urban
Stormwater Management and Technology: Update and User's Guide," USEPA
Report No. EPA-600/8-77-014, NTIS No. PB 275 654.
40
-------
42. Lager, J.A., and Smith, W.G., Metcalf & Eddy Engineers, Inc., Palo Alto,
CA, "Urban Stormwater Management and Technology : An Assessment "USE PA
Report No. EPA-670/2-74-040, NTIS No. PB 240 687.
43. Brater, E.F., and Sherrill, J.D., University of Michigan, Ann Arbor, MI,
Rainfall-Runoff Relations on Urban and Rural Areas,": USEPA Report No
EPA-670/2T75-046, NTIS No. PB 2 830.
44. Yen, B.C., and Chow, V.T., University of Illinois, Urbana, IL, "Urban
Stormwater and Runoff Determination of Volumes and Flowrates " USEPA
. Report No. EPA-600/2-76-116, NTIS No. PB 253 410.
45. Field, R., et al., USEPA, Storm and Combined Sewer Program, Edison, NJ,
'Porous Pavement: Research; Development; and Demonstration," •
Transportation Engineering Journal of ASCE. Vol. 108, No. TE3, May 1982
pp. 244-258 ! -
46. Diniz, E., Espey, Huston & Assoc., Inc., Albuquerque, NM, "Porous
.Pavement:-. Phase I - Design and Operational Criteria," USEPA Report No. .
EPA-600/2-80-135, NTIS No. PB 81-104 796.
47. Goforth, G.F., Espey, Huston & Assoc., Inc., Austin, TX; Diniz, E-.V.,
Resource Technology, Inc., Albuquerque, NM; and Rauhut, J.B., Austin, TX,
Stormwater Hydrological Characteristics of Porous and Conventional
'Paving Systems," USEPA Report No.; EPA-600/2-83-106, NTIS No. PB 84-123
728.
48. Goforth, G.F., Espey, Huston & Assoc., Inc., Austin, TX; Diniz, E.V.,
Resource Technology, Inc., Albuquerque, NM; and Rauhut, J.B., Austin, TX,
Stormwater-Hydrological Characteristics of Porous and Conventional
Paving Systems," USEPA Project Summary No. EPA-600/S2-83- 106, NTIS No.
PB 84-123 728.
49. Benjes, H.H., Gulp, Wesner, Gulp Consulting Engineers, El Dorado, CA,
Cost Estimating Manual- Combined Sewer Overflow Storage Treatment "
USEPA Report No. EPA-600/2-76-286, NTIS No. PB 266 359. .
50. Benjes, H.H. Jr., Gulp, Wesner, Gulp Consulting Engineers, El. Dorado, CA,
Field, R., Storm and Combined Sewer Program, Edison, NJ, "Estimate Sewer
Overflow Facility Costs," Water & Wastes Engineering.-September 1978, pp.
56-62. ~~~
41
-------
51. Heaney, J.F., et al., University of Florida, Gainesville, FL, "Nationwide
Evaluation of Combined Sewer Overflows and Urban Stormwater Discharges,
Volume II - Cost Assessment and Impacts, USEPA Report No.
EPA-*600/2-77-064b, NTIS No. PB 266 005.
52. Sonnen, M., Water Research Engineers, Walnut Creek, CA, "Abatement of
Deposition and Scour in Sewers/ USEPA Report No. EPA-600/2-77-212, NTIS
No. PB 276 585. j
53. Yen, B.C., et al., University of Illinois, Urbana, IL, "Stormwater Runoff
on Urban Areas~of Sleep Slope," USEPA Report No. EPA-600/2-77- 168, NTIS
No. PB 272 755.
54. Kaufman, H.L., and Lai, F.H., Clinton Bogert Assoc., Fort Lee, NO,
"Conventional and Advanced Sewer Design Concepts for Dual Purpose Flood
and Pollution Control - A Preliminary Case Study, Elizabeth, NO," USEPA
Report No. EPA-600/2-78-090, NTIS No. PB 285 663.
55. Field, R., and Weisman, D.A., USEPA Storm and Combined Sewer Program,
Edison, NJ, "A Planning and Design Guidebook for Combined Sewer Overflow
Control," USEPA Report No. EPA7600/2-82-084, NTIS No. PB 82- 259 235.
56. Wuelschleger, R.E., et al.. Envirex Environmental Sciences Div.,
Milwaukee, WI, "Methodology for the Study of Urban Storm Generated
Pollution and Control," USEPA Report No. EPA-600/2-76-145, NTIS No. PB
258 243.
57. Dalrymple, R.J., etal., Beak bonsultants for American Public Works
Assoc., Chicago, IL, "Physical; and Settling Characteristics of
Particulates in Storm and Sanitary Wastewater," USEPA Report No. EPA-
670/2-75-011, NTIS No. PB 2 001.
58. Field, R., Storm and Combined Sewer Program, USEPA, Edison, NJ,
"Stormwater Pollution Control: A New Technology," 28 Minute Film
distributed by the General Services Administration (GSA), National Audio
Visual Center, Washington, DC ; 20409. ,
59. Lynard, W., etal., Matcalf & Eddy Engineers, Inc., Palo Alto, CA, "Urban
Stormwater Management and Technology: Case Histories," USEPA Report No.
EPA-600/8-80-035, NTIS No. PB 81-107 153.
i
60. Heaney, J.F., et al.. University of Florida, Gainesville, FL, "Stormwater
Management MDdel: Level I - Preliminary Screening Procedures,1 USEPA
Report No. EPA-600/2-76-275, NTIS No. PB 259 916.
42
-------
61. . Heaney, J.F., et al., University of Florida, Gainesville, FL, "Stormwater
Management Made!: Level I - Comparative Evaluation of Storage/Treatment
and Other Management Practices," USEPA Report No. EPA-600/2-77-083, NTIS
No. PB 265 671.
62. Moffa, Pi, and Karanik, J., Onondaga County, NY, "Methodology for
Evaluating the Impact and Abatement of Combined Sewer Overflows -,A Case
Study of Onondaga Lake, New York," USEPA Report No. EPA-600/8-80- 048,
NTIS No. PB 81-141 913.
63. Murphy, C.B., et al., O'Brien & Gere Engineers, Inc., Syracuse, NY,
,-Quinn, T.J., and Stewart, J.E., Monroe County Division of Pure,Waters, . ,
Rochester, NY, "Best Management Practices: . Implementation," USEPA Report
No. EPA-905/9-81-002, NTIS No. PB 82-169 210.
64. .Pitt, R.E., Woodward Clyde Consultants, San Francisco, CA, -
"Demonstration of Nonpoint Pollution Abatement Through Improved Street
Cleaning Practices,".USEPA Report No. EPA-600/2-79-161, NTIS No. PB
80-108 988.
65. Pitt, R.E., Consulting Environmental Engineer, Blue Mounds, WI,
"Characterization , Sources^ and Control of Urban Runoff by Street and
Sewerage Cleaning," USEPA Report No. Pending.
66. Pitt, R.E., Consulting Environmental Engineer, Blue Mounds, WI,
"Characterizationi Sources, and Control of Urban Runoff by,Street and
Sewerage Cleaning," USEPA Project Summary No. Pending.
67., Aronson, G.L.^ et al ., Environmental Design & Planning, Inc., Boston, MA,
"Evaluation of Catchbasin Performance for Urban Stormwater Pollution
Control," USEPA Report No. EPA-600/2-83-043, NTIS No. PB 83-217 745.
68. Aronson, G.L., et al., Environmental Design & Planning, Inc., Boston, MA,
"Evaluation of Catchbasin Performance for Urban Stormwater Pollution
Control," USEPA Report No. EPA-600/S2-83-043, NTIS No. PB 83-217 745.
69. Pisano, W.C., and Queriroz, C.S., Energy, and Environmental Analysis,
Inc., Boston, MAj "Procedures for Estimating Dry Weather Pollutant
Deposition, in Sewerage Systems," USEPA Report No. EPA-600/2-77-120, NTIS
No. PB 270 695.
70. Pisano, W.C., et al ., Northeastern University, Boston, MA, "Dry- Weather
Deposition and Flushing for Combined Sewer Overflow Pollution Control,"
USEPA Report No. EPA-600/2-79-133, NTIS No. PB 80-118,524.
43
-------
71. Kaufman, H.L., and Lai, F.H., Clinton Bogert Assoc., Ft. Lee, NJ, "Review
of Alternatives for Evaluation of Sewer Flushing Dorchester Area -
Boston," USEPA Report No. EPA-600/2-80-118, NTIS No. PB 81-1 648.
72. Chandler, R.W., and Lewis, W.R., Water Utilities Department, Dallas, TX,
"Control of Sewer Overflows by Polymer Injection," USEPA Report No.
EPA-600/2-77-189, NTIS No. PB 272 654.
73. Anerican Public Works Assoc., Chicago, IL, "Combined Sewer Regulator
Overflow Facilities," USEPA Report No. 11022DMU07/70, NO NTIS.
74. Anerican Public Works Assoc., Chicago, IL, "Combined Sewer Regulation and
Management: A Manual of Practice," USEPA Report No. 11022DMU08/70, NTIS
No. PB 195 676.
75. Freeman, P.A., Peter Freeman Assoc., Inc., Berlin, MD9 "Evaluation of
Fluidic Combined Sewer Regulators Under Municipal Service Conditions,"
USEPA Report No. EPA-600/2-77-071, NTIS No. PB 272 834.
76. Field, R., USEPA, Storm and Combined Sewer Program, Edison, NJ, "The
Dual-Functioning Swirl Combined Sewer Overflow Regulator/Concentrator,"
USEPA Report No. EPA-670/2-73-059, NTIS No. PB 227 182.
77. Field, R., and Masters, H.E., USEPA, Edison, NJ, "Swirl Device for
Regulating and Treating Combined Sewer Overflow," USEPA Report No.
EPA-625/2-77-012, EPA Technology Transfer Capsule Report, CERI
(Cincinnati) 2012.
78. Sullivan, R.H., et al., Anerican Public Works Assoc., Chicago, IL, "Swirl
and Helical Bend Pollution Control Devices: Design Manual," USEPA Report
No. EPA-600/8-82-013, NTIS No. PB 82-266 172.
79. Matthews, T.M., et al.. Snell Environmental Group, Akron, OH,
"Hydrobrakes Regulated Storage System for Stormwater Management," USEPA
Report No. EPA-600/2-83-097, NTIS No. PB 84-110 378.
80. Matthews, T.M., et al., Snell Environmental Group, Akron, OH,
"Hydrobrakes Regul ated Storage System for Stormwater Management, USEPA
Project Summary No. 600/S2-83-097, NTIS No. PB 84-110 378.
81. Field, R., USEPA, Storm and Combined Sewer Program, Edison, NJ, "An
Overview of the U.S. Environmental Protection Agency's Storm .and
Combined Sewer Program Collection System Research," Water Research.
Vol. 16, Pergamon Press Ltd., jpp. 859-870, 1982.
44
-------
81a. Driver, T. and 01 sen, M., Driver and 01 sen, Inc., Northbrook,, IU
"Demonstration of Sewer Relining by the Insituform Process, Northbrook,
IL," USEPA Report No. EPA-600/2-83-064, NTIS No. PB 83-245 878. -,,
82. Field, R., and Struzeski, E.J., USEPA, Storm and Combined Sewer Program,
Edison, NJ, "Management and Control of Combined Sewer Overflows," Journal
Water Pollution Control Federation, Washington DC, Vol> 44, No. 7., pp.
1393-1415, July 1972.~~ : .
83. Field, R., Storm and Combined Sewer Program, Edison, NJ; Lager, J.'A.,
Matcalf and Eddy, Inc., Palo Alto, CA, "Urban Runoff Pollution Control
State-of-the-Art," Journal of The Environmental Engineering Division,
American Society of Civil Engineers, Vol. 101, No. EE1, pp. 107-125,
February 1975.
84. Soderland, H., Kjessler & Mannerstrale AB, Swedish Council for Building
Research, Stockholm, Sweden, "Flow Balancing Method for Stormwater and
Combined Sewer Overflow," ISBN 91-540-3765-4: 017:1982, pp. 1-27, 1982.
85. Smith, William G., et al., Metcalf .& Eddy Engineers Inc., Palo Alto, CA,
"Storage/Sedimentation Facilities for Control of Storm and Combined Sewer
Overflows Design Manual," USEPA Report No. Pending, (USEPA Contract No.
68-03-2877).
86. Field, R., and Weisman, D.A., USEPA, Storm and Combined Sewer Program,
Edison, NJ, "A Planning and Design Guidebook for Combined Sewer Overflow
Control and Treatment," USEPA-600/2-82-084, NTIS No..PB 82- 259 235.
87. Maher, M.B., Crane Company, King of Prussia, PA, "Microstraining and
Disinfection of Combined Sewer Overflows - Phase III," USEPA Report No.
EPA-670/2-74-049, NTIS No. PB 235 771.
88. Drehwing, F.. et al., O'Brien & Gere Engineers, Inc., Syracuse, NY>
"Disinfection Treatment of Combined Sewer Overflows, Syracuse., New
York USEPA Report No. EPA-600/2-79-134, NTIS No. PB 80-113 459. .,'
89. Nebolsine, R., et al., Hydrotechnic Corp., New York, NY, "High-Rate
Filtration of Combined Sewer Overflows," USEPA Report No. 11023EY104/72,
NTIS No. 211 144. : , .
90. Innerfield, H., and Forndran, A., New York City Department of Water
Resources, New York, NY, "Dual Process High-Rate Filtration of Raw
Sanitary Sewage and Combined Sewer Overflows," USEPA Report No. EPA-
. 600/2-79-015, NTIS No. PB 296 626/AS.
45
-------
91. Gupta, M.K., etal., Envirex, Environmental Science Division, Milwaukee,
HI, "Screening/Flotation Treatment of Combined Sewer Overflows, Volume I
- Bench Scale and Pilot Plant Investigations," USEPA Report No.
EPA-600/2-77-069a, NT IS No. PB 272 834.
92. The Ecology Division, Rex Chainbelt, Inc., Milwaukee, WI,
"Screening/Flotation Treatment of Combined Sewer Overflows," USEPA
Report No. 11020FDC-01/72, NO NTIS.
93. f-feinholz, T.L., Envirex, Inc., Milwaukee, WI, "Screening/Flotation
Treatment of Combined Sewer Overflows - Volume II: Full Scale
Operation, Racine, WI," USEPA Report No. EPA-600/2-79-106a, NTIS No.
PB 80-130 693.
94. Shelley, G.J., et a!., George J. Shelley Consulting Engineers, Tamworth,
New South Wales, Australia, "Field Evaluation of a Swirl Degritter at
Tamworth N.S.W., Australia," USEPA Report No. EPA-600/2- 81-063, NTIS
No. PB 81-187 247.
95. Shelley, G.J. et al., George J. Shelley Consulting Engineers, Tamworth,
New South Wales, Australia, "Field Evaluation of a Swirl Degritter at
Tamworth N.S.W., Australia," USEPA Project Summary No.
EPA-600/S2-81-063, NTIS No. PB 81-187 247.
96. Benedict, A.H., and Roelfs, V.L., Whitely-Jacobsen and Assoc., Portland,
OR, "Joint Dry-Wet Weather Treatment of Municipal Wastewater at
Clatskanie, Oregon," USEPA Report No. EPA-600/2-81-061, NTIS No. PB
81-187 262. |
97. Benedict, A.H., and Roelfs, V.L., Whitely-Jacobsen and Assoc., Portland,
OR, "Joint Dry-Wet Weather Treatment of Municipal Wastewater at
Clatskanie, Oregon," USEPA Project Summary No. EPA- 600/S2-81-061, NTIS
No. PB 81-187 262.
98. Agnew, R.W., etal., Envirex, Milwaukee, WI, "Biological Treatment of
Combined Sewer Overflow at Kenosha, WI," USEPA Report No. EPA-670/2-
75-019, NTIS No. PB 2 107. ;
99. Field, R., et a!., USEPA, Storm and Combined Sewer Program, Edison, NJ,
"Proceedings of Workshop on Microorganisms in Urban Stormwater," USEPA
No. EPA-600/2-76-244, NTIS No. PB 263 030.
100. Glover, G.E., and Herbert, G.R., Crane Company, King of Prussia, PA,
"Micro-straining and Disinfection of Combined Sewer Overflows - Phase
II," USEPA Report No. EPA-R2-73-124, NTIS No. PB 219 879.
46
-------
101. Drehwing, f .J., et al.,-O'Brien & Gere Engineers, Inc., Syracuse, NY, ,
"Combined Sewer Overflow Abatement Program, Rochester, NY - Volume II
Pilot Plant Evaluations," USEPA Report No. EPA-600/2-79-031b, NTIS No.
PB 80-159 262. •-._,.-_
.Moffa, P;E., et al.,, O'Brien & Gere Engineers, Inc., Syracuse,. NY,
"Bench-Scale High-Rate-Disinfect ion of Combined Sewer Overflows with
Chlorine and Chlorine Dioxide," USEPA Report No. EPA-670/2-75-021, NTIS
No. PB 2 296. .
Maher, M.B., Crane Company, King of Prussia, PA, "Microstrainihg and
Disinfection of Combined Sewer Overflows - Phase III," USEPA Report No.
EPA-670/2-74-049, NTIS No. PB 235, 771. ,. ., : ,
Drehwing, F., et al., O'Brien & Gere Engineers, Inc., Syracuse, NY,
"Disinfection/Treatment of Combined Sewer Overflows, Syracuse, New
York," USEPA Report No. EPA-600/2-79-134, NTIS No. PB 80-113 459.
,. .. ... j . " - , "
Leitz, F.B., et al ., Ionics, Inc., Watertown, MA, "Hypochlorite
Generator for Treatment of Combined Sewer Overflows," USEPA Report No.
11023DAA03/72, NTIS No. PB 211 243.
Pontius, U.R., et al., Pavia-Byrne Engineering Corp., New Orleans, LA,
"Hypochchlorination of Polluted Stormwater Pumpage at New Orleans "
USEPA Report No. EPA-670/2-73-067, NTIS No. PB 228 581.
107. Connick, D.J., et al., Environmental Design & Planning, Inc., Allston
(Boston) MA, "Evaluation of a Treatment Lagoon for Combined Sewer '<
Overflow," USEPA Report No. EPA-600/S2-81-196, NTIS No. PB 82-105 214.
108. Gupta, M.K., et al., Envirex, Environmental Science Division, Milwaukee,
WI, "Handling and Disposal of Sludges from Combined Sewer Overflow
Treatment - Phase I (Characterization)," USEPA Report No.
EPA-600/2-77-053a, NTIS No. PB 270 212.
109. Huibregtse, K.R., et al., Envirex, Environmental Science Division,
Milwaukee, WI, "Handling and Disposal of Sludges from Combined Sewer
Overflow Treatment - Phase II (Impact Assessment)," USEPA Report No.
EPA-600/2-77-053b, NTIS No. PB 280.309.
110. Osantowski, R., et al., Envirex, Environmental Science Division,
Milwaukee, WI, "Handling and Disposal of Sludges from Combined Sewer
Overflow Treatment - Phase III (Treatability Studies)," USEPA Report No.
EPA-600/2-77-053C, NTIS No. PB 281 006.
102.
103.
104.
105.
106.
47}
-------
111. -Huibregtse, K.R., et al., Envirex, Environmental Science Division,
Milwaukee, WI, "Evaluation of Secondary Impacts of Urban Runoff
Pollution Control," USEPA Report No. EPA-600/2-82-045 NTIS Mo. PB 82-
230 319, 1982.
112. Homack, P., et al., E.T. Killiam Assoc., Inc., Millburn, NO,
"Utilization of Trickling Filters for Dual Treatment of Dry and Wet
Weather Flows," USEPA Report No. EPA-670/2-73-071, NTIS No. PB 231 251.
113. Welborn, H.L., Y-T-0 & Assoc., Walnut Creek, CA, "Surge Facility for
Wet-and Dry-Weather Flow Control," USEPA Report No. EPA-670/2-74-075,
NTIS No. PB 283 905.
j
114. Mahida, V.U., and DeDecker, F.J., Spalding DeDecker Assoc., Madison
Heights, MI, "Multi-Purpose Combined Sewer Overflow Treatment
Facility, Mt. Clemens, MI," USEPA Report No. EPA-670/2-75-010, NTIS
No. PB 2 914.
115. Field, R., and Fan, C-Y., USEPA, Edison, NJ, "Industrial Reuse of Urban
Stormwater," Journal of the Environmental Engineering Divisicm, ASCE,
Vol. 107, No. EE1, February 1981, pp. 171-189. ' "
116. Litwin, Y.J.. et al., Ramlit Associates, Inc., Berkeley, CA, "The Use of
Wetlands for Water Pollution Control," USEPA Report No. EPA-600/2-
82-086, NTIS No. PB 83-107 466.
117. Hickock, et al.. Eugene A. Hickock and Associates, Wayzata, MN, "Urban
Runoff Treatment Methods, Volume I - Non-Structural Wetland Treatment,"
USEPA Report No. EPA-600/2-77-217, NTIS No. PB 278 172.
4 8 -&V.S. GOVERNMENT PRINTING OFFICE: 1990 - 748-159/00375
-------
-------
0) O
s «»
m
cr>
CO
CO
r1 <
SS-
I!
>
3 r-*-
(D B>
OJ (0
NJ
O>
00
------- |