&EPA
United States
Environmental Protection
Agency
Office of Water
Program Operations (WH-547)
Washington DC 20460
October 1978
EPA-430/9-78-006
Water
Report To Congress On
Control Of Combined
Sewer Overflow
In The United States
MCD - 50
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of Combined Sewer Overflow in the United States" (MCD-50)
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Please indicate the MCD number and title of publication.
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REPORT TO CONGRESS
ON
CONTROL OF COMBINED SEWER OVERFLOW
IN THE
UNITED STATES
Project Officer
Philip H. Graham
Facility Requirements Division
Office of Water Program Operations
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
Contract No. 68-01-3993
EPA Report No. 430/9-78-006
MCD Report No. 50
October 1, 1978
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^ .M
,5322
\
S UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
SEP 29 1978
THE ADMINISTRATOR
Honorable Walter F. Mondale
President of the Senate
Washington, D.C. 20510
Dear Mr. President:
Enclosed is the Environmental Protection Agency's (EPA's) report,
"Control of Combined Sewer Overflow in the United States," required
October 1, 1978, by section 516(c) of the Clean Water Act. This report
presents by State the status of awarded grants, requested grants, and
the estimated time required to achieve required control of combined
sewer overflow pollution. It also compares discharges of pollutants
from treated municipal effluent with combined sewer overflow and analyzes
alternative control technologies. Finally, it presents legislative
alternatives to control pollution from combined sewer overflow.
Combined sewers have been identified in about 1,300 communities,
and serve a population of 37,606,000 in an area of 2,248,000 acres. The
58 communities with greater than 10,000 acres of combined sewer area
account for 83 percent of the area and 81 percent of the population
served by combined sewers, and are distributed among 24 States.
Combined sewer systems are located in some of the most heavily
populated urban centers of our nation. Pollutant discharges are limited
to generally short reaches of receiving waters located near highly
concentrated population. Many millions of people observe and are exposed
to the receiving water impacts resulting from combined sewer overflow.
Grants for combined sewer overflow control have been awarded for
6.4 percent and requested for 16.8 percent of the total combined sewer
overflow control needs of an estimated $21.16 billion. Thus, grants
have been made or requested for a total of 24.2 percent of the estimated
needs.
The time required to provide needed funds to correct combined sewer
overflow problems varies widely among the States. The most sensitive
variables affecting this time are Federal allocation of construction
grant funds to the States, State allocation of funds to combined sewer
overflow control, and annual rate of construction cost increase.
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If the annual construction cost increase is matched by an increase
in Federal and State funding for combined sewers, average time to fund
correction for all States ranges between 8 and 14 years for the alternative
allocation funding formulae assumed in the report. The maximum time for
any State ranges from 14 to 40 years depending on the assumptions.
A comparison of the pollutant loads from only the national combined
sewer area shows that more than 80 percent of the total annual lead and
suspended solids loads are delivered to the receiving waters from combined
sewer overflows. More than 80 percent of the annual nutrient (phosphorus
and nitrogen) loads are delivered to the receiving waters from secondary
wastewater treatment plant effluent. Annual BOD5, (biochemical oxygen
demand) loads are split evenly between secondary wastewater treatment
plants' effluent and combined sewer overflow.
Five legislative alternatives are analyzed in the report. EPA
recommends the first alternative, to continue with the present law. The
success of this alternative in providing timely funding for control of
combined sewer overflow will depend principally on the amount of money
available to States with serious combined sewer problems, the proportion
of these funds assigned by the States to combined sewer projects, and
the annual rate of increase in construction costs.
We have based this report on the best available information, including
unpublished data we are gathering in the current "needs" survey for the
next report to Congress on the cost of needed publicly-owned treatment
works. The "needs" survey results, due February 10, 1979, will permit
us to refine the conclusions and recommendation in this report. The
"needs" survey results will, for example, provide a revised estimate by
State of the cost of controlling combined sewer overflow, and an analysis
of the impact of pollutant loads for combined sewers on receiving waters.
I would be pleased to discuss further the_ recommendations made in
this report at your convenience.
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. D.C. 20460
SEP 2 9 1978
THE ADMINISTRATOR
Honorable Thomas P. O'Neill, Jr.
Speaker of the House
of Representatives
Washington, D.C. 20515
Dear Mr. Speaker:
Enclosed is the Environmental Protection Agency's (EPA's) report,
"Control of Combined Sewer Overflow in the United States," required
October 1, 1978, by section 516(c) of the Clean Water Act. This report
presents by State the status of awarded grants, requested grants, and
the estimated time required to achieve required control of combined
sewer overflow pollution. It also compares discharges of pollutants
from treated municipal effluent with combined sewer overflow and analyzes
alternative control technologies. Finally, it presents legislative
alternatives to control pollution from combined sewer overflow.
Combined sewers have been identified in about 1,300 communities,
and serve a population of 37,606,000 in an area of 2,248,000 acres. The
58 communities with greater than 10,000 acres of combined sewer area
account for 83 percent of the area and 81 percent of the population
served by combined sewers, and are distributed among 24 States.
Combined sewer systems are located in some of the most heavily
populated urban centers of our nation. Pollutant discharges are limited
to generally short reaches of receiving waters located near highly
concentrated population. Many millions of people observe and are exposed
to the receiving water impacts resulting from combined sewer overflow.
Grants for combined sewer overflow control have been awarded for
6.4 percent and requested for 16.8 percent of the total combined sewer
overflow control needs of an estimated $21.16 billion. Thus, grants
have been made or requested for a total of 24.2 percent of the estimated
needs.
The time required to provide needed funds to correct combined sewer
overflow problems varies widely among the States. The most sensitive
variables affecting this time are Federal allocation of construction
grant funds to the States, State allocation of funds to combined sewer
overflow control, and annual rate of construction cost increase.
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If the annual construction cost increase is matched by an increase
in Federal and State funding for combined sewers, average time to fund
correction for all States ranges between 8 and 14 years for the alternative
allocation funding formulae assumed in the report. The maximum time for
any State ranges from 14 to 40 years depending on the assumptions.
A comparison of the pollutant loads from only the national combined
sewer area shows that more than 80 percent of the total annual lead and
suspended solids loads are delivered to the receiving waters from combined
sewer overflows. More than 80 percent of the annual nutrient (phosphorus
and nitrogen) loads are delivered to the receiving waters from secondary
wastewater treatment plant effluent. Annual BODg, (biochemical oxygen
demand) loads are split evenly between secondary wastewater treatment
plants' effluent and combined sewer overflow.
Five legislative alternatives are analyzed in the report. EPA
recommends the first alternative, to continue with the present law. The
success of this alternative in providing timely funding for control of
combined sewer overflow will depend principally on the amount of money
available to States with serious combined sewer problems, the proportion
of these funds assigned by the States to combined sewer projects, and
the annual rate of increase in construction costs.
We have based this report on the best available information, including
unpublished data we are gathering in the current "needs" survey for the
next report to Congress on the cost of needed publicly-owned treatment
works. The "needs" survey results, due February 10, 1979, will permit
us to refine the conclusions and recommendation in this report. The
"needs" survey results will, for example, provide a revised estimate by
State of the cost of controlling combined sewer overflow, and an analysis
of the impact of pollutant loads for combined sewers on receiving waters.
I would be pleased to discuss further^
this report at your convenience.
recommendations made in
re W yours,
s-M. Costle
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CONTENTS
Page
TABLES vi
FIGURES vii
ACKNOWLEDGMENTS viii
Executive Summary ES - 1
Chapter
1 INTRODUCTION 1-1
MANDATE 1-3
SCOPE 1-3
OVERVIEW OF OTHER URBAN WATER
RESOURCES NEEDS 1-5
THE 1978 NEEDS SURVEY 1-5
2 OUTLINE OF LEGISLATIVE ALTERNATIVES 2-1
ALTERNATIVE 1—CONTINUE WITH PRESENT
LAW 2-1
ALTERNATIVE 2—MODIFICATION OF
CURRENT LAW TO PROVIDE CONGRESSIONAL
FUNDING OF LARGER PROJECTS 2-1
ALTERNATIVE 3—MODIFICATION OF
CURRENT LAW TO PROVIDE FUNDING
FOR NONSTRUCTURAL CONTROL
TECHNIQUES 2-1
ALTERNATIVE 4—MODIFICATION OF
CURRENT LAW TO PROVIDE A SEPARATE
FUNDING FOR COMBINED SEWER OVERFLOW
PROJECTS 2-2
ALTERNATIVE 5--DEVELOPMENT OF A NEW
LAW TO PROVIDE FUNDING FOR
MULTIPURPOSE URBAN WATER
RESOURCES PROJECTS 2-2
REVIEW 2-2
3 CURRENT STATUS OF CSO PROJECTS 3-1
SOURCES OF DATA 3-1
DEVELOPMENT OF GRANT NUMBER FILE 3-2
PROCEDURE TO WRITE REPORT 3-2
QUALITY OF DATA 3-2
RESULTS 3-2
4 CSO NEEDS 4-1
PROCEDURE TO WRITE REPORT 4-1
QUALITY OF DATA 4-1
RESULTS 4-1
Vi i
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CONTENTS—Continued
Chapter Page
5 CSO CORRECTION TIME 5-1
OVERALL ESTIMATE OF TIME REQUIRED
TO FUND CSO POLLUTION CONTROL
PROJECTS 5-1
URBAN AREAS WITH MAJOR NEEDS 5-3
STATE-BY-STATE ESTIMATES OF TIME
REQUIRED TO FUND CSO POLLUTION
CONTROL PROJECTS 5-3
Allocation Formulas 5-7
Rate of Spending 5-7
6 COMPARISON OF ANNUAL POLLUTANT DISCHARGES 6-1
SUMMARY OF POLLUTANT DISCHARGE ANALYSIS 6-1
Drainage Areas and Populations
of the Study Sites 6-4
Procedure for Estimating
Pollutant Loads 6-4
RESULTS 6-9
Nationwide 6-9
15 Study Sites 6-12
7 TECHNOLOGICAL ALTERNATIVES FOR COMBINED
SEWER OVERFLOW CONTROL 7-1
INTRODUCTION 7-1
PROCESS DEFINITIONS 7-2
Source Controls 7-2
Collection System Controls 7-3
Treatment Facilities 7-5
COST EFFECTIVENESS 7-8
ENERGY USE 7-13
COMPARISON OF 25-MGD CSO TREATMENT
FACILITIES 7-16
8 DISCUSSION OF LEGISLATIVE ALTERNATIVES 8-1
ALTERNATIVE 1—CONTINUE WITH PRESENT
LAW 8-1
Advantages of Alternative 1 8-2
Disadvantages of Alternative 1 8-2
ALTERNATIVE 2—MODIFICATION OF CURRENT
LAW TO PROVIDE CONGRESSIONAL FUNDING
OF LARGER PROJECTS 8-4
Advantages of Alternative 2 8 - 5
Disadvantages of Alternative 2 8-5
ALTERNATIVE 3—MODIFICATION OF CURRENT
LAW TO PROVIDE FUNDING FOR
NONSTRUCTURAL CONTROL TECHNIQUES 8-5
Disadvantages of Alternative 3 8 - 6
Disadvantages of Alternative 3 8-6
VI11
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CONTENTS — Continued
Chapter Page
8 ALTERNATIVE 4 — MODIFICATION OF CURRENT
LAW TO PROVIDE A SEPARATE FUNDING FOR
COMBINED SEWER OVERFLOW PROJECTS 8-7
Advantages of Alternative 4 8-8
Disadvantages of Alternative 4 8-8
ALTERNATIVE 5 — DEVELOPMENT OF A NEW LAW
TO PROVIDE FUNDING FOR MULTIPURPOSE
URBAN WATER RESOURCES PROJECTS 8-8
Advantages of Alternative 5 8-9
Disadvantages of Alternative 5 8-10
SUMMARY OF ALTERNATIVES 8-10
RECOMMENDATIONS 8-11
Appendix
A CORRESPONDENCE A - 1
B COMPARISON OF POLLUTANT DISCHARGES
FOR 15 CITIES B - 1
C DESCRIPTION OF TECHNOLOGICAL ALTERNATIVES C - 1
IX
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TABLES
Table Page
1-1 Annual Cost of Construction and Operation
and Maintenance for Selected Urban Water
Facilities 1-6
3-1 Summary of Funded Grant Amounts for
CSO Pollution Control 3-4
4-1 Summary of Requested Grant Amounts for
CSO Pollution Control 4-2
5-1 SMSA's with Combined Sewer Service
Area Greater Than 10,000 Acres 5-4
5-2 State-by-State Estimates of Time Required
to Fund CSO Pollution Control Projects
for Six Funding Alternatives 5-9
6-1 Drainage Areas and Populations for 15
Study Site Pollutant Loading Comparisons 6-3
6-2 Drainage Areas and Populations for 18
Urbanized Areas Pollutant Loading
Comparisons 6-5
6-3 Summary of Combined Sewer Drainage Areas
and Populations 6-6
6-4 Stormwater Average Areal Load Equations 6-8
6-5 Secondary Wastewater Treatment Plant
Effluent Concentrations for the 1978
Needs Survey 6-10
6-6 BODs Ratios for Stormwater Loads 6-10
6-7 Nationwide Comparison of Annual Discharges
From Combined Sewer Overflow and Secondary
Wastewater Treatment Plant Effluent 6-11
6-8 Percentage of Sites Where Indicated Source
Contributes More Than 33% of the Total
Pollutant Discharge 6-13
7-1 Range of Feasibility and Unit Costs
for CSO Technological Alternatives 7-11
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TABLES—Continued
Table Page
7-2 Energy Use for Several CSO Control
Alternatives 7-14
7-3 Comparison of Seven 25-mgd CSO
Treatment Systems 7-17
XI
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FIGURES
Figure
1-1 Geographic Distribution of Population Served
by Combined Sewer Systems
5-1 Estimates of CSO Pollution Correction Times
6-1 Location of 15 Pollutant Loading Comparisons
6-2 BOD5 Discharge from Combined Sewer Overflow
versus Combined Sewer Area
6-3 Suspended Solids Discharge from Combined Sewer
Overflow versus Combined Sewer Area
6-4 Total Nitrogen Discharge from Combined Sewer
Overflow versus Combined Sewer Area
6-5 Phosphate Phosphorus Discharge from Combined
Sewer Overflow versus Combined Sewer Area
6-6 Lead Discharge from Combined Sewer Overflow
versus Combined Sewer Area
7-1 Unit Removal Cost for a Typical Combined Sewer
Service Area
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ACKNOWLEDGMENTS
This report was prepared by CH2M HILL, Inc. James E. Scholl
developed the pollutant loading comparisons and the evaluation
of technological alternatives. Michael J. Mara served as
project systems analyst and developed the CSO Funding Status
reports. Typing and editorial services were provided by
the Gainesville Office Word Processing Center. Ronald
L. Wycoff served as project manager.
Especially acknowledged is the leadership and review of
Philip H. Graham, Facilities Requirements Branch, Municipal
Construction Division, EPA, who was the Project Officer;
and Michael Cook, Chief, Facilities Requirements Branch,
EPA. Both of these individuals provided valuable guidance
and review throughout the project. Numerous other individuals
both within and outside of EPA provided significant
cooperation and direct participation in the preparation of
this report.
xm
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Executive Summary
CONTROL OF COMBINED SEWER OVERFLOW IN THE UNITED STATES
SUMMARY INFORMATION ON COMBINED SEWER AREAS
There are approximately 1,300 communities in the United
States which have a total combined sewer area of 2-1/4
million acres, serving a total of 38 million persons. Eighty
three percent of the combined sewer area and 81% of the
resident population served are concentrated in 58 cities
located in 24 states.
STATUS OF CONSTRUCTION GRANTS FOR CONTROL OF POLLUTION
FROM COMBINED SEWER OVERFLOW
Total national needs for control of pollution from combined
sewer overflow (CSO) were estimated by the 1976 Needs Survey
to be $18.26 billion in January 1976 dollars. Updating this
estimate to January 1978 dollars yields a total national
need of approximately $21.16 billion. Previously met needs
estimated and reported in Table 3-1 are approximately $1.36
billion based on 75% grant eligibility. Remaining unmet
needs are, therefore, approximately $19.81 billion.
Based on information provided by the FY 1978 project priority
list, as of 23 June 1978, construction grants have been
requested but are not yet funded for an additional $2.67
billion, as reported in Table 4-1. Based on 75% grant
eligibility, these construction grants would generate an
additional $3.56 billion in construction funds. From these
estimates, it may be concluded that approximately 6.4% of
national CSO pollution control needs have been met and that
an additional 16.8% of the national needs have been specifically
identified.
ESTIMATED TIME REQUIRED TO FUND COMBINED
SEWER OVERFLOW POLLUTION CONTROL PROJECTS
The overall time required to control pollution from combined
sewer systems is summarized in Figure 5-1.
This figure illustrates the importance of maintaining constant
buying power in the construction grants program if CSO
correction is to be achieved in a reasonable period of time.
Constant buying power is assured if the annual total construc-
tion grants allocation is increased each year by a percentage
equal to the percentage increase in construction costs
during the preceding year.
ES - 1
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Six estimates of the time required to fund CSO correction
projects by state are developed and are based on the assumption
that future buying power will remain constant (i.e., total
funding equals 5.0 billion January 1978 dollars annually).
The assumptions associated with each estimate are related to
the grant allocation formula and to the rate of state funding
for CSO control. The following grant allocation formulas
are considered.
1. Construction grant funds will be allocated to each
state under the present allocation formula.
2. Construction grant funds will be allocated to each
state under a new formula. This formula proportions
state allocations based on the ratio of state needs to
total national needs for combined sewer overflow control
(Category V) and on the ratio of state needs to total
national needs for all other municipal wastewater
control facilities (Categories I through IVB). The
weighting factors are 20% for Category V and 80% for
Categories I through IVB.
3. Construction grant funds will be allocated to each
state under a new formula. This formula is identical
to 2 above except that the weighting factors are changed
to 50% for Category V and 50% for Categories I through
IVB.
Once grant funds are allocated to each state, it is the
state's decision as to which projects are funded. This
decision is made based on a project's standing on the
state's project priority list. It is probable that, as
secondary wastewater treatment plant needs are met, combined
sewer overflow pollution abatement needs will receive higher
priority. The following two alternative assumptions were
made concerning the rate of spending by states with CSO
needs.
a. States with combined sewer systems will invest in CSO
control facilities at a uniformly changing rate until
a maximum of 50% of the annual allocation is invested
in CSO control. The transition from the present rate
of investment in CSO control facilities to the maximum
rate of 50% will require 5 years.
b. The second spending assumption is identical to No. 1
above except that the maximum spending rate is reduced
from 50% to 30%.
Assumptions which are common to each of the above funding
formula and spending alternatives are as follows.
ES - 2
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1. Funding level for construction grants is $4.25 billion
per year for current year and $5.0 billion per year
thereafter. Funds are expressed in January 1978 dollars
(i.e., constant buying power).
2. The current funding formula will be in effect from 1
October 1978 through 30 September 1981.
The allocation and spending alternatives are referenced to
an alphanumeric identifier, la, 2a, 3a, Ib, 2b, and 3b,
which represents all possible combinations of the three
allocation formulas and two spending rates. The average and
maximum times to fund CSO correction projects for each
allocation and spending alternative are summarized in the
following table. Individual estimates for each state are
reported in Table 5-2.
Summary of Time Required
To Fund CSO Correction Projects
Time in Years by Alternative
Maximum
Average
la
25
9.78
24
9
2a
.36
14
8
3a
.26
40
14
Ib
.20
38
13
2b
.64
21
11
3b
.84
The results of the analysis summarized above indicate that
the time to fund CSO correction projects will be highly variable
from state to state. Average times may vary from approximately
8.3 years to 14.3 years and maximum times may vary from
approximately 14 years to 40 years for the six alternatives
analyzed. It also appears that the rate at which states fund
CSO projects will have a greater influence on correction time
than would modification of the grants allocation formula.
It should be emphasized that these values represent time required
to fund CSO projects. The actual construction of the projects
will require an additional 2 to 5 years in each case.
Also, water pollution control facilities have an economic
life ranging from 10 to 15 years for mechanical equipment
and from 20 to 50 years for plants and collection systems.
Therefore, the process of facilities construction should be
realistically viewed as continuous.
ES - 3
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POLLUTANT DISCHARGE FROM COMBINED SEWER OVERFLOW
An important characteristic of CSO is its concentrated
location. Combined sewer systems are located in some of the
most heavily populated urban centers of our nation. Thus,
the pollutant discharge is limited to the generally short
reaches of the receiving water located near the highest
concentrations of population. Thus, many millions of people
observe and are exposed to the receiving water impacts
resulting from combined sewer overflow.
Combined sewer overflow can be a significant source of
pollution in certain cases. The relative importance of CSO
depends upon the ratio of combined sewer service area to
separate sewer service area. In general, combined sewers
are a major source of oxygen-demanding materials (BOD5) and
suspended solids (SS). Wastewater treatment plant effluent
is generally the major source of nutrients and urban stormwater
runoff is the major source of lead. Other constituents, such
as benzene and cadmium, were not considered in this investigation
because of a lack of generalized loading data for combined
sewer service areas.
Another important characteristic of CSO as demonstrated in
the site studies, is the intermittent nature of the discharge.
Combined sewer overflow occurs only during runoff-producing
rainfall events which, in general, range from 200 to 1,300
hours per year or from 2% to 15% of the time. Thus, pollutant
loading rates during runoff events may be extremely large.
Combined sewer overflow contains raw wastewater which may
contain disease organisms, is usually repugnant, and results
in unpleasant odors. During combined sewer overflow events,
heavier particulate organic material settles to the bottom of
the waterway and contributes to a benthic load which detri-
mentally impacts the receiving water, even during dry weather
periods. Floatable and soluble organic material can impact
the waterway with a shock pollution loading which can negate
any fishable or swimmable goals. The impact of a large
combined sewer overflow event on any viable aquatic biota
element in the receiving water can be extremely determinatal.
There are at least 2-1/4 million acres of combined sewer
service area in the United States today with an average
population density of 16.7 persons per acre. A comparison
of annual pollutant loads from the total national combined
sewer service area resulting from overflow and from secondary
WWTP effluent reveals:
1. Five-day biological oxygen demand (BOD5) discharge is
approximately the same for CSO and for secondary WWTP
effluent.
ES - 4
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2. Suspended solids (SS) discharge is approximately 15
times greater from CSO than from secondary WWTP effluent.
3. Total nitrogen (TN) discharge from CSO is only about
14% of the discharge from secondary WWTP effluent.
4. Orthophosphate (POO discharge from CSO is only about
27% of the discharge from secondary WWTP effluent.
5. Lead (Pb) discharge is approximately 4 times greater
from CSO than from secondary WWTP effluent.
In this report, pollutant loading comparisons are developed
for 18 urbanized areas served by a total of 727,000 acres of
combined sewer service area. These comparisons are developed
for combined sewer overflow, urban stormwater runoff, and
secondary WWTP effluent on an annual basis and on an average
runoff event basis. That is, pollutant discharges are
compared during the time span of 1 year and during the time
span of an average runoff event.
Since three pollutant sources are compared, a source is
termed major if it accounts for more than 1/3 of the pollutants
discharged during the time period of comparison. Results of
the 18 urbanized areas comparison on an annual loading basis
are:
1. Secondary WWTP effluent is the major source of BODs.
2. CSO and urban stormwater runoff are the major sources
of SS.
3. Secondary WWTP effluent is the major source of the
nutrients TN and P04.
4. Urban stormwater runoff is the major source of Pb.
Results of the 18 urbanized areas comparison on a average
runoff event basis are:
1. CSO and urban stormwater runoff are the major sources
of BOD5.
2. CSO and urban stormwater runoff are the major sources
of SS.
3. CSO and secondary WWTP effluent are the major sources
of the nutrients TN and P04.
ES - 5
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4. Urban stormwater runoff is the major source of Pb.
The reader should keep in mind that the above summary of
pollutant loading results is a composite summary and that
every combined sewer system, the urban area in which it is
located, and the receiving water into which it discharges
constitutes a unique system which requires individual analysis
TECHNOLOGICAL ALTERNATIVES AVAILABLE FOR CONTROL OF
POLLUTION FROM COMBINED SEWER OVERFLOW
There are many viable technological alternatives available
for control of pollution from combined sewer overflow.
There is, however, no single "best alternative" which can be
applied to all cases. The least cost solution in a given
case is a function of the degree of pollution removal required
and the physical and hydrologic characteristics of the
combined sewer service area. Each situation requires indivi-
dual planning and analysis.
CSO problems are unique to the given collection system. The
first objective of any combined sewer overflow pollution
control project should be to obtain an understanding of how
the existing collection system operates, including an
investigation of the existing regulator system. Collection
systems will not perform as designed unless they are operated
and maintained properly. If not maintained properly, overflow
of raw wastewater can occur during dry weather on a nearly
continuous basis.
The Office of Research and Development of the Environmental
Protection Agency has invested about $45 million in research
and demonstration projects for combined sewer overflow
control. The results of this research are published in the
Environmental Protection Technology Series and may be applied
to the planning and design of combined sewer overflow pollution
abatement facilities. Given the magnitude of the needs
which are on the order of $20 billion, it is clear that
investment in additional research would likely yield sub-
stantial net savings to the public. For example, if addi-
tional research resulted in development and demonstration of
technologies which are 5% more efficient than technologies
available today, $1 billion could be saved.
This report presents an analysis of the unit removal costs
expressed in dollars per pound of BOD5 removed from the
receiving water for a typical combined sewer watershed.
Unit removal costs are developed for nonstructural or low-
structural control alternatives such as street sweeping,
catch basin cleaning, and sewer flusing as well as for
structural or capital intensive controls which involve
ES - 6
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storage and/or treatment. The results of this analysis for
nonstructural or low-structural controls are:
1. Streetsweeping can be used to remove from 2% to 11% of
the watershed BOD5 load at a cost of from approximately
$3.00 to $7.50 pound of BOD5 removed.
2. Catch basin cleaning is not a viable alternative because
of low removal and high cost.
3. Sewer flushing can be used to remove from 20% to 50% of
the watershed BODs load at a cost of from less than $2
to approximately $14 per pound of BODs removed.
4. Swirl concentrators/regulators can be used to remove
from 30% to 55% of the watershed BOD5 load at a cost of
from $2 to $4 per pound of BODs removed.
The costs and effectiveness of storage/treatment systems
depend to a large extent upon the size of the area served.
Storage/treatment systems become more cost effective as the
area served by a given facility increases. For a small
watershed of 100 acres or less, sewer separations may be a
cost-effective control alternative. Sewer separation with
subsequent treatment at a secondary WWTP will remove approxi-
mately 65% of the total watershed BOD5 load at a unit cost
of approximately $24 per pound removed. For watersheds
greater than about 200 acres, storage/treatment systems will
become more cost effective than sewer separation. A typical
relationship between facility size percentage of BOD removal
and unit cost is illustrated on Figure 7-1 of this report.
The following comments pertain to storage/treatment systems.
1. In-line storage including real time control (RTC) of
the collection system is a viable alternative if the
existing collection system has a large interceptor
storage capacity. In-line storage with subsequent
treatment at a secondary WWTP will remove up to 45%
(possibly more in collection systems not yet investigated)
of the watershed BODs load at a cost of from $1.25 to
$4 per pound of BODs removed.
2. Off-line storage in a highly developed urban area is
expensive. In many cases, covered concrete storage
basins will be required to permit dual land use.
Therefore, economic optimization of all proposed storage/
treatment systems should be required before construction
funds are granted.
3. Storage/treatment systems are the only technologically
viable alternative for removal of more than about 65%
of the total annual watershed BODs load.
ES - 7
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4. For large watersheds greater than 2,000 acres in size,
the optimum storage/treatment system can be used to
remove from 30% to 80% of the watershed BOD5 load at a
cost of from $3 to $4 per pound of BOD5 removed.
The incremental cost of Advanced Wastewater Treatment (AWT)
is in the range of $1.90 to $7.00 per pound of BOD removed
depending upon the size of the plant and the final effluent
quality. These unit removal costs are comparable to available
CSO control unit removal costs. Therefore, there is no
clear economic advantage for CSO control over AWT. The
decision to construct AWT and/or CSO control facilities at
a given site must be based on individual economic and water
quality impact analysis.
The reader should remember that the discussions of pollutant
loadings and technological alternatives presented in this
Executive Summary and in the main body of the report represents
a summary of our understanding of the CSO pollution problem
as it exists today and that this understanding is ever-
changing. Much information has been developed in the last
few years, and it is probable that much more will be developed
in the future.
LEGISLATIVE ALTERNATIVES FOR FUNDING COMBINED SEWER
OVERFLOW POLLUTION ABATEMENT PROJECTS
Five basic legislative alternatives for funding CSO pollution
abatement projects are defined in Chapter 2 and discussed in
Chapter 8 of this report. They are:
1. Continue with present law.
2. Modification of present law to provide congressional
funding of larger projects.
3. Modification of present law to provide funding for
nonstructural control techniques.
4. Modification of present law to provide a separate
funding for combined sewer overflow projects.
5. Development of a new law to provide funding for multi-
purpose urban water resources projects.
The five legislative alternatives, including a brief discussion
of each, were submitted to various state agencies and munici-
palities as well as to EPA staff for comment and review.
Comments received by state and municipal officials are
presented in Appendix A.
ES -
-------
Alternative 1 "Continue with Present Law" appears to be one
of the most viable alternatives and would probably result in
minimum construction delays. Total time to correction would
remain an unknown since all projects would be subject to the
states' project priority system.
Alternative 2 "Modification of Current Law to Provide
Congressional Funding of Larger Projects" received little
support from local and state officials submitting comments.
This alternative is perceived as adding substantial delays
and uncertainty to the CSO pollution abatement process
without adding any quality to the end product.
Alternative 3 "Modification of Current Law to Provide Funding
for Nonstructural Control Techniques" does not at this time
appear viable because of its limited probable benefits and
the high risk of expanding the federal role in water quality
control far beyond current limits.
Alternative 4 "Modification of Current Law to Provide a
Separate Funding for Combined Sewer Overflow Projects" also
appears to be one of the most viable and workable solutions
to the problem of funding CSO pollution abatement projects.
In general, individuals located in areas of the country with
major combined sewer service areas who submitted comments
on the alternatives favored Alternative 4 with a national
fund (separate grants program) while individuals located in
areas of the country with few combined sewer systems who
submitted comments favored Alternative 1.
Alternative 5 "Development of a New Law to Provide Funding
for Multipurpose Urban Water Resources Projects" raises
questions of national urban water resources policy far
beyond the question of CSO pollution control. Most indi-
viduals who submitted comments questioned the workability of
such an approach, based in part upon anticipated substantial
construction delays.
It is recommended that Alternative 1 "Continue with Present
Law" be adopted as the funding method for future combined
sewer overflow pollution abatement projects. However, if
CSO pollution is to be corrected in a reasonable period of
time, states with substantial CSO needs must be willing to
spend a large share of their annual allocation on CSO
projects. Moreover, the relative size of the allocation to
these states would be increased if national appropriations
were allocated among the states based to a greater degree
on CSO needs.
It must be remembered that any increase in spending for
combined sewer overflow control needs (Category V) will
result in a decrease in spending for all other pollution
ES - 9
-------
control needs (Categories I-IV B). These tradeoffs must be
weighed carefully for any given municipality. It is believed
that this site-specific examination of pollution control
tradeoffs can best be accomplished in a timely fashion under
the present law.
This report is based on the best information available,
including unpublished data currently being gathered as part
of the 1978 Needs Survey for the report to Congress on cost
of needed publicly-owned treatment works. The Needs Survey
results, due 10 February 1979, will permit refinement of the
conclusions and recommendation in this report. The Needs
Survey results will, for example, provide a revised estimate,
by state, of the cost of controlling combined sewer overflow,
and an analysis of the impact of pollutant loads from combined
sewers on receiving waters.
ES - 10
-------
Chapter 1
INTRODUCTION
Combined sewers are defined as wastewater collection systems
designed to transport both sanitary wastes and stormwater
runoff in the same conduits. A separate sanitary sewer
system, on the other hand, is designed to transport only
sanitary wastewater while storm water is conveyed by separate
storm sewers.
During wet weather, combined sewer systems may overflow
directly to the receiving water and the combined sanitary
wastes and stormwater runoff are discharged without treatment.
Overflow points and treatment plant bypasses are provided,
by design, to prevent damage to the wastewater treatment
plant (WWTP) and to reduce local flooding during periods of
high flow. Combined sewer discharge can be a major source
of pollution during the period of overflow. Combined sewer
overflow can also be a source of long-term pollution in the
receiving water since solids are discharged which settle to
the bottom and form sludge deposits. These deposits exert
long-term oxygen demand which persist during periods of dry
weather.
Until the turn of the 20th century, constructing combined
sewer systems was accepted practice where population densities
were great enough to require both urban drainage and sanitary
wastewater transport. Small towns with less densely populated
areas were frequently drained by natural watercourses, and
thus only wastewater collection was required. In these
cases, separate sanitary sewers were constructed.
By the end of the 19th century, the need for wastewater
treatment became increasingly apparent. Therefore the
advantage of a separate collection system designed to
transport wastewater only also became apparent. For this
reason, nearly all wastewater collection systems constructed
after the turn of the century were separate systems.
Because of the period in which they were built, combined
sewer systems tend to be located in areas of the country
which experienced growth during the period from approximately
1850 through 1900. Major combined sewer service areas are
located along the upper east coast, in the upper midwest,
and in the far west. The geographic distribution of population
served by combined sewer systems is illustrated on Figure
1-1.
1-1
-------
Ratio of projected population served by combined
sewers to total sewered population, 1962.
I | 0%-10%
11%-2 5%
26%-50%
51%-75%
Over 75%
FIGURE 1-1. Geographic Distribution of Population Served by Combined Sewer Systems.
-------
There are at least 2-1/4 million acres of combined sewer
service area in the United States today located in 1,100 to
1,300 distinct collection systems. These systems serve
approximately 38 million people. However, about 83% of the
national total area is located in 58 major cities. Thus
these cities comprise most of the national needs for CSO
control.
MANDATE
Section 516 (c) of the 1977 Clean Water Act provides that:
"(c) The Administrator shall submit to the Congress by
October 1, 1978, a report on the status of combined
sewer overflows in municipal treatment works operations.
The report shall include (1) the status of any projects
funded under the Act to address combined sewer overflows,
(2) a listing by State of combined sewer overflow needs
identified in the 1977 State priority listings, (3) an
estimate for each applicable municipality of the number
of years necessary, assuming an annual authorization
and appropriation for the construction grants program
of $5,000,000,000 to correct combined sewer overflow
problems, (4) an analysis using representative munici-
palities faced with major combined sewer overflow
needs, of the annual discharges of pollutants from
overflows in comparison to treated effluent discharges,
(5) an analysis of technological alternatives available
to municipalities to correct major combined sewer
overflow problems, and (6) any recommendations of the
Administrator for legislation to address the problem of
combined sewer overflows, including whether a separate
authorization and grant program should be established
by the Congress to address combined sewer overflows."
This report, "Control of Combined Sewer Overflow in the
United States," responds to the above mandate.
SCOPE
The report addresses each of the six items outlined in
Section 516 (c) of the 1977 Clean Water Act. Chapter 2
presents a brief outline of the five basic legislative
alternatives for funding combined sewer overflow pollution
abatement projects considered in this study.
Chapter 3 discusses the current status of funded combined
sewer overflow pollution abatement projects by state. The
amount currently funded by state is compared to estimated
national needs as reported in the 1976 Needs Survey.
1-3
-------
Chapter 4 discusses the status of currently unfunded but
indentified projects. This total is also compared on a
state-by-state basis to estimated national needs as reported
in the 1976 Needs Survey.
Combined sewer overflow pollution abatement correction time
is discussed in Chapter 5. It is assumed that $5 billion
per year will be available for all municipal construction
grants. A relationship between overall correction time and
level of funding for combined sewer overflow pollution
abatement is presented. In addition, state-by-state estimates
of correction time are developed based on three alternative
grant allocation formulas, including the present formula.
Estimated annual pollutant discharge from combined sewer
overflow, wastewater treatment plant effluent, and urban
stormwater runoff generated by 15 different urban areas are
compared in Chapter 6. The pollutants considered are:
1. 5-day biochemical oxygen demand (BODs).
2. Suspended solids (SS).
3. Orthophosphate (PCK as PCK).
4. Total nitrogen (TN).
5. Total lead (Pb).
In addition to the annual loadings, relative loading rates
during runoff events are also estimated and compared.
There is a general lack of data regarding toxics in combined
sewer overflow and their receiving waters. A limited amount
of lead loading data are available and, therefore, estimates
of lead loadings are presented. However, background receiving
water lead data are rare and sampling intervals are long
(i.e., 4 samples per year). Therefore, receiving water
impact analysis is difficult. Other constituents, such as
benzene and cadimum, were not used in this analysis because
of a lack of generalized loading data.
A brief discussion of selected technological alternatives
for control of pollution from combined sewer overflow is
presented in Chapter 7. Advantages and disadvantages of
these techniques including unit cost treatment effectiveness
and energy use are presented in Chapter 7 and in Appendix C.
The final chapter is a discussion of the advantages and
disadvantages of the five legislative alternatives presented
in Chapter 2.
1-4
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OVERVIEW OF OTHER URBAN WATER RESOURCES NEEDS
The subject of this report is limited to the status of and
alternatives for the abatement of pollution resulting from
combined sewer overflow, which is a major urban water resources
need. However, it is only one part of a total urban pollution
control program and urban pollution control is only one part
of total urban water resources needs.
In 1971 the Office of Water Resources Research, U.S. Department
of the Interior published a report entitled "A National
Urban Water Resources Research Program." This report summarized
expected annual costs for construction and operation and
maintenance of selected urban water facilities including
facilities unrelated to pollution control. These estimates
for water supply and urban drainage are presented in Table 1-1
in order to provide a perspective or overview of nonpollution
control aspects of the urban water problem.
Inspection of Table 1-1 indicates that outlays for nonpollution
aspects of urban water resources management, particularly
urban drainage, are significant. The cost base for these
estimates was not given; however, if it is assumed that the
cost base is mid-1967 (approximate date of publication of
the original data) dollars, then the total annual outlay of
$7.66 billion becomes approximately $19 billion per year in
January 1978 dollars. Obviously urban water resources is a
subject which deserves the attention of federal as well as
state and local decision makers.
THE 1978 NEEDS SURVEY
At the time of this writing (August 1978), the 1978 Needs
Survey for Control of Pollution from Combined Sewer Overflow
and Urban Stormwater Runoff is under way. The results of
this survey will be available in February 1979.
There are two major elements of the ongoing Needs Survey
work which are related to this report. First, 10 of the 15
cities for which loading comparisons are developed in Chapter
6 are included as detailed site studies in the Needs Survey-
In addition to the estimated pollutant loadings presented
here, the Needs Survey will present a receiving water impact
analysis and an estimate of the improvement in receiving
water quality obtained by removing a portion of the total
load. Analysis of receiving water impacts of CSO, preferably
on a continuous basis, is necessary in order to plan effective
CSO control strategies.
Preliminary results of the Needs Survey site impact analysis
available to date indicate that CSO may have adverse impacts
1-5
-------
Table 1-1
Annual Cost of Construction and Operation and Maintenance
for Selected Urban Water Facilities
Service
Water distribution
Period for
Average
1967-1980
Annual Construction Cost
(million dollars)
Replacement
758
Growth
788
Annual O&M Cost
(million dollars)
2,319
Water treatment plants
1967-1980
253
264
776
Urban drainage (storm
sewers)
1966-1975
1,300
1,200
NA
Totals
Grant total $7.66 billion per year
2,311
2,252
3,095
Note: Data from "A National Urban Water Resources Research Program"—cost base not cited,
Includes nonconstruction capital outlays and debt service.
-------
on the dissolved oxygen budget of the receiving water and
may be a major source of suspended solids. CSO is generally
not the major source of nutrients or lead except in cases
where the CSO service area is extensive compared to the
separate sewered service area. CSO is also a major source
of fecal coliform bacteria. Fecal coliform concentrations
are generally an order magnitude higher for CSO than for
separate urban stormwater runoff.
The second major element of the ongoing Needs Survey work
involves the establishment of a National Combined Sewer
System Data File. The objective of this portion of the
project is to assemble certain basic data on each combined
sewer system in the nation. These data include location,
sewer system characteristics, receiving water characteristics,
and the status of CSO correction planning. Preliminary
results of this data-gathering effort are used in part in
Chapter 5 to establish the location and size of the major
combined sewer systems in the United States.
1-7
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Chapter 2
OUTLINE OF LEGISLATIVE ALTERNATIVES
Five basic legislative alternatives for funding combined
sewer overflow pollution abatement projects have been
identified and are discussed in this report. The final
chapter of the report presents a summary discussion of each
alternative including advantages and disadvantages. The
five alternatives are defined here so that they may be
discussed in the subsequent chapters of the report.
ALTERNATIVE 1—CONTINUE WITH PRESENT LAW
Combined sewer overflow pollution abatement projects would
be funded under the existing provision of PL 92-500 as
amended in December 1977 by the Clean Water Act of 1977.
Combined sewer overflow control projects would be funded
under section 201 of the law.
ALTERNATIVE 2—MODIFICATION OF CURRENT LAW TO PROVIDE
CONGRESSIONAL FUNDING OF LARGER PROJECTS
Major combined sewer overflow pollution abatement projects
would be subject to funding on a case-by-case basis. Once
the planning process is complete, each project would be
presented to Congress. Congress would have a clear picture
of the costs likely to be incurred and the benefits likely
to accrue from the plan. The decision whether to fund all
of the project, a portion of the project, or none of the
project would rest with Congress.
ALTERNATIVE 3—MODIFICATION OF CURRENT LAW TO PROVIDE
FUNDING FOR NON5TRUCTURAL CONTROL TECHNIQUES
Combined sewer overflow pollution abatement projects may
include a mixture of both structural controls and management
practices. Management practices consist of those techniques
which require very few, if any, capital expenditures. Such
operation and maintenance costs are not grant eligible under
the current law-
2-1
-------
ALTERNATIVE 4—MODIFICATION OF CURRENT LAW TO PROVIDE
A SEPARATE FUNDING FOR COMBINED SEWER OVERFLOW PROJECTS
Combined sewer overflow pollution abatement projects would
be funded from amounts specifically earmarked by Congress
for this purpose. The funds could be made available either
from a national fund or as a set-aside within each State's
allotment of grant funds.
ALTERNATIVE 5—DEVELOPMENT OF A NEW LAW TO PROVIDE FUNDING
FOR MULTIPURPOSE URBAN WATER RESOURCES PROJECTS
The new legislation would provide for multipurpose urban
water resources projects planning and construction funding.
The objectives may include: (1) recreation, (2) urban
drainage, (3) point source pollution control, (4) control
of pollution from combined sewer overflows, (5) control of
pollution from urban storm-water runoff, (6) urban water
supply including water reuse, and (7) major flood control
projects. Funds for those portions of each project which
provide substantial benefits relative to costs could be
authorized by Congress on a case-by-case basis, or drawn
from existing programs such as those administered by EPA,
HUD, and EDA.
REVIEW
The five legislative alternatives as outlined above were
submitted to various state agencies and municipalities
as well as EPA staff for comment and review. Comments
received before 1 September 1978 from state and municipal
officials are presented in Appendix A. These comments
are presented in alphabetical order by (1) state agencies,
(2) interstate commissions, (3) councils of governments,
and (4) cities and wastewater authorities.
2-2
-------
Chapter 3
CURRENT STATUS OF CSO PROJECTS
The objective of this phase of the investigation was to
develop a status report for projects funded under PL 92-500,
which addresses combined sewer overflow pollution abatement.
SOURCES OF DATA
Two data files were used in developing the required infor-
mation: the EPA Combined Sewer System Data File which is
currently being developed and the EPA Grants Information and
Control System Data File. The data obtained from these
files were supplemented with information obtained from EPA
regional offices.
The Grants Information and Control System Data File (GIGS)
is an agencywide, computer-oriented management information
system that contains general purpose information on all EPA
grant programs, whether the program is administered through
headquarters or through a regional office. The GIGS file
contains information on federal grants awarded under
PL 84-660 as well as under PL 92-500.
The Combined Sewer System Data File (CSSD) is being developed
as part of the 1978 Needs Survey. It contains information
by authority facility number on combined sewer systems and
related CSO abatement projects.
The following variables from the GICS File were examined in
detail for each grant which provided funds for a combined
sewer service area.
1. Grant number.
2. Project step (i.e., planning, design, or construction).
3. Action step (i.e., currently funded or proposed).
4. Amount.
5. Description.
3-1
-------
DEVELOPMENT OF GRANT NUMBER FILE
The first step in the analysis consisted of development of a
master grant number file. This file was used with the GIGS
File to develop the required information. The grant number
file was developed from three sources of data: (1) the CSSD
File, (2) the state priority list, and (3) the GIGS File.
The state priority list was written using an existing EPA
Municipal Construction Division program and is a subset of
the GIGS File. The report descriptions were scanned and
grant numbers were noted for each record description that
mentioned combined sewer overflow pollution abatement.
Also, the GIGS File was examined for all grants which indicated
funding for combined sewer separation. All grant numbers
were then merged into a single master grant number file,
listing all grants related to combined sewer systems.
PROCEDURE TO WRITE REPORT
The grant file was matched against the GIGS File by grant
number. Project step, action step, grant amount requested
from EPA, and the first 40 characters of the project descrip-
tion were obtained from the GIGS File for each grant number
matched. If the project was previously funded, then the
record and grant amount were included in this report as a
current project or met need.
QUALITY OF DATA
Several problems were encountered in analyzing the data
generated by the above procedure. At present, there is no
way to determine how much if any of the dollar amount reported
is related to CSO pollution control. We know only that
combined sewers are involved to some degree in the grant.
Inspection of the detailed reports by state revealed that
many are not related to pollution abatement from CSO but are
construction grants for dry-weather flow facilities located
in combined sewered areas. Based on the project description,
a decision was made as to whether or not the grant was for
CSO correction. Each EPA regional office was contacted in
order to verify the list of CSO correction grants and amounts
identified. The final grant amounts reported here reflect
any modifications or additional information supplied by the
regional offices.
RESULTS
The total grant amounts by state and by step which were
determined to be for CSO pollution control are given in
3-2
-------
Table 3-1. Step 1 grants are for planning, Step 2 grants
are for design, and Step 3 grants are for construction.
Also reported in Table 3-1 are the CSO correction needs for
each state as estimated in the 1976 Needs Survey and updated
to January 1978 construction costs.
Funded grants total approximately $1.02 billion. Sixty-four
percent of the total funded grant amount for combined sewer
overflow control is for CSO projects in the Chicago
Metropolitan Sanitary District. Based on 75% grant eligibility,
these grants would generate approximately $1.36 billion in
actual needs met. Thus, only about 6-1/2% of total national
needs have been met.
3-3
-------
Table 3-1
Summary of Funded Grant Amounts for CSO Pollution Control
Funded Amounts
State
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
District
of Columbia
Florida
u> Georgia
, Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
Step 1
0
1,076
0
28,491
3,450,000
0
1,954,984
85,120
635,250
0
0
0
0
2,632,145
3,745,475
1,578,070
0
0
0
0
469,960
2,745,969
75,000
69,534
0
41,250
0
0
0
0
3,182,663
Step 2
; o
0
0
0
0
0
1,142,760
110,420
0
0
0
0
0
0
577,775
0
0
0
0
0
0
1,438,756
259,200
0
0
0
0
0
0
421,167
1,322,515
Step 3
0
2,250
0
7,731,119
33,123,750
5,273,100
0
1,592,170
0
0
0
0
0
650,611,130
29,142,392
0
0
0
0
0
1,033,200
20,130,148
187,507,710
0
0
81,220
0
0
0
5,046,950
1,986,785
Total
0
4,326
0
7,759,610
36,573,750
5,273,100
3,097,744
1,787,710
635,250
0
0
0
0
653,243,275
33,465,642
1,578 ,070
0
0
0
0
1,503,160
24,314,873
187,841,910
69,534
0
122,470
0
0
0
5,468,117
6,491,963
Estimated
Needs 1976
$ 0
3,499,021
0
54,263,221
446,348,285
3,903,512
448,900,403
46,050,547
173,035,223
579,500
349,120,934
0
9,931,471
2,996,603,772
1,429,021,502
105,225,610
0
153,201,256
0
558,921,955
55,006,140
1,015,479,871
1,561,701,504
258,917,123
0
1,497,568,239
0
169,347,285
16,995,576
356,925,640
701,102,280
-------
OJ
I
Ln
Table 3-1—Continued
State
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Guam
Puerto Rico
Virgin Islands
American Samoa
Pacific Trust
Territories
Total
Funded Amounts
Step 1
$ 0
0
0
0
1,493,400
0
0
36,070
225,000
0
0
0
0
0
15,240
0
470,407
190,500
3,353,925
0
0
0
0
0
0
Step 2
$ 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
97,270
1,185,150
0
0
0
0
0
0
Step
$
12,275
4,207
11,898
1,405
5,018
3,096
122
4,882
3
0
,492
0
0
,650
0
0
0
,303
0
,080
0
0
0
,047
,970
,628
0
,200
0
0
0
0
0
0
Total
$ 0
12,275,492
0
0
5,701,050
0
0
36,070
12,123,303
0
1,405,080
0
0
0
5,033,287
3,096,970
593,035
287,770
9,421,275
0
0
0
0
0
0
Estimated.
Needs 1976C
3,086,910
14
2,046
243
950
306
1
212
56
187
283
395
494
321
,878
,344
,947
,965
,217
,365
,537
,539
,435
,893
,840
,384
,291
26,195
0
,734
0
,083
,308
0
,479
,295
,072
0
,302
,420
,497
0
,798
,573
,224
,199
,026
0
0
,718
0
0
0
$26,479,529
$6,555,013 $986,168,260 $1,019,202,802
$21.17 Billion
From 1976 Needs Survey updated to January 1978 dollars.
-------
Chapter 4
CSO NEEDS
The objective of this phase of the investigation was to list
by state combined sewer overflow needs identified in the
1977 state priority listing. These are considered CSO needs
identified but not yet funded.
The sources of information and development of the grant
number file are the same as described in Chapter 3.
PROCEDURE TO WRITE REPORT
The procedures used to develop the required information were
the same as previously described in Chapter 4 with one
exception. Instead of listing projects which were previously
funded, only projects and their request grant amounts which
have not as yet been funded were reported. In this manner a
listing of identified but not yet funded (because of low
ranking on the state priority list) projects was developed.
QUALITY OF DATA
The same considerations expressed for the data in Chapter 3
are relevant here. Again, inspection of the detailed reports
by state revealed that many projects are not related to
pollution abatement from CSO but are construction grants for
dry-weather flow facilities located in combined sewered
areas. Based on the project description, a decision was
made as to whether or not the grant was for CSO correction.
Each EPA regional office was contacted in order to verify
the list of CSO correction grants and amounts requested.
The final requested grant amounts reported here reflect any
modifications or additional information supplied by the
regional offices.
RESULTS
The total requested grant amount by state and by step which
are considered to be for CSO pollution control are given in
Table 4-1. Step 1 grants are for planning, Step 2 grants
are for design, and Step 3 grants are for construction.
Also reported in Table 4-1 are the CSO correction needs for
each state as estimated in the 1976 Needs Survey and updated
to January 1978 construction costs.
4-1
-------
Table 4-1
Summary of Requested Grant Amounts for CSO Pollution Control
Requested Amounts Estimated
State Step 1 Step 2 Step 3 Total Needs 1976
Alabama $ 0$ 0$ 0$ 0$ 0
Alaska 00 0 0 3,499,021
Arizona 00 0 0 0
Arkansas 00 0 0 54,263,221
California 0 3,750,000 75,000,000 78,750,000 446,348,285
Colorado 0 21,000 1,635,000 1,656,000 3,903,512
Connecticut 1,250,000 9,610,000 461,656,000 472,516,000 448,900,403
Delaware 0 37,500 0 0 46,050,547
District
of Columbia 0 45,000,000 724,500,000 769,500,000 173,035,223
Florida 00 0 0 579,500
*> Georgia 0 0 41,900,000 41,900,000 349,120,934
i Hawaii 00 0 0 0
M Idaho 00 0 0 9,931,471
Illinois 108,750 3,764,511 696,254,369 700,127,030 2,996,603,772
Indiana 00 0 0 1,429,021,502
Iowa 00 0 0 105,225,610
Kansas 52,500 0 0 52,500 125,126,799
Kentucky 00 0 0 153,201,256
Louisiana 00 0 0 0
Maine 0 0 1,979,000 1,979,000 558,921,955
Maryland 0 433,600 4,807,500 5,241,100 55,006,140
Massachusetts 0 12,311,199 287,280,000 299,591,199 1,015,479,871
Michigan 0 1,590,000 43,280,000 44,870,000 1,561,701,504
Minnesota 00 0 0 258,917,123
Mississippi 00 0 0 0
Missouri 0 108,000 0 108,000 1,497,568,239
Montana 00 0 0 0
Nebraska 00 0 0 169,347,285
Nevada 00 0 0 16,995,576
New Hampshire 0 372,000 5,100,000 5,472,000 356,925,640
New Jersey 00 0 0 701,102,280
-------
I
OJ
Table 4-1 — Continued
State
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Guam
Puerto Rico
Virgin Islands
American Samoa
Pacific Trust
Territories
Step 1
$ 0
1,615,000
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
159,750
0
0
0
Requested Amounts
Step 2
$ 0
2,593,000
0
371,000
500,000
0
0
0
5,950,000
0
0
0
0
0
0
0
100,000
0
2,900,000
0
0
182,000
0
0
0
Step 3
$ 0
76,022,250
0
0
9,220,000
0
0
0
125,000,000
0
0
0
0
0
0
1,402,500
18,000,000
0
3,750,000
0
0
0
0
0
0
Total
$ o
80,230,250
0
371,000
9,720,000
0
0
0
130,950,000
0
0
0
0
0
0
1,402,500
18,100,000
0
6,650,000
0
0
341,750
0
0
0
Estimated
Needs 1976a
$ 0
3,086,910,734
0
14,878,083
2,046,344,308
0
243,947,479
950,965,295
306,217,072
0
1,365,302
212,537,420
56,539,497
0
187,435,798
283,893,573
395,840,224
494,384,199
321,291,026
0
0
26,195,718
0
0
0
Total
$3,186,000 $89,593,810 $2,576,786,619 $2,669,566,429 $21.17 Billion
From 1976 Needs Survey updated to January 1978 dollars.
-------
Requested grants total approximately $2.67 billion. Based
on 75% grant eligibility, these grants would generate
approximately $3.56 billion in actual needs met. Therefore,
approximately 17% of the national CSO pollution abatement
needs have been identified. However, the total of met and
identified needs accounts for only 23% of the total estimated
in the 1976 Needs Survey.
4-4
-------
Chapter 5
CSO CORRECTION TIME
Total national needs for control of pollution from combined
sewer overflow were estimated to be $18.26 billion in
January 1976 dollars. Updating this estimate to January
1978 dollars yields a total national need of approximately
$21.17 billion. Previously met needs estimated and reported
in Table 3-1 are approximately $1.36 billion based on 75%
grant eligibility. Remaining unmet needs are therefore
approximately $19.81 billion.
The time period required to correct pollution resulting from
combined sewer overflow under current funding procedures is
a function of the magnitude of the need which has been
estimated and the annual funding level. Present funding is
$4.5 billion per year for all municipal construction grants.
However, that portion of the total which is invested in CSO
pollution abatement is unknown since projects are funded
based on the respective state's priority system. States
that perceive CSO to be a major problem will give higher
priority to CSO projects than will states which do not
perceive the problem as major. Therefore, total correction
time for any individual combined sewer service area cannot
be predicted with certainty. However, correction time
estimates are developed in this report on an overall basis
and on a state-by-state basis. The overall estimate is
developed to illustrate the effect of level of funding on
CSO correction time, and the state-by-state estimates are
developed to illustrate the effect of various grant allocation
formulas and level of spending by the states on individual
CSO correction time.
OVERALL ESTIMATE OF TIME REQUIRED TO
FUND CSO POLLUTION CONTROL PROJECTS
The overall time required to fund CSO pollution control
projects is illustrated on Figure 5-1. This figure defines
two relationships between level of federal funding for CSO
control in billion dollars per year and time required to
fund present needs. The linear relationship is based on
funding in January 1978 dollars. That is, federal funding
is assumed to increase at a rate equal to the rate of
construction cost increase such that purchasing power remains
constant. The nonlinear relationship is based on the
assumption that federal funding for CSO pollution abatement
will remain constant regardless of increases in construction
5-1
-------
(1)
>-
0)
IX
13
cr
01
cc
30
25
20
15
10
0 '—
0.8
i 1
ASSUMPTIONS
1. Total Needs = $19.8 Billion (January 1978).
2. Construction Cost Increase = 7-1/2% per Year.
3. Grant Eligibility = 75% of Total Construction Cost
1.0 1.2 1.4 1.6 1.8 2.0
Federal Funding Level (billion dollars per year)
2.2
2-4
FIGURE 5-1. Estimates of CSO pollution correction times.
-------
costs. Thus, purchasing power will decrease with time.
The nonlinear relationship is also based on the assumption
that construction costs will increase at a constant rate of
7-1/2% per year.
Figure 5-1 illustrates the importance of maintaining constant
purchasing power if estimated needs are to be met in a
reasonable period of time. For example if 1.1 billion
January 1978 dollars per year of Federal Funds were allocated
to CSO correction total needs would be funded in approximately
14 years. However, if funding remains a constant 1.1 billion
dollars per year and if construction costs continue to
increase at a rate of 7-1/2% per year, then present needs
would never be met. That is, additional needs generated by
construction cost increases would always be greater than
needs met by actual construction in any given year.
URBAN AREAS WITH MAJOR NEEDS
Table 5-1 lists Standard Metropolitian Statistical Areas
(SMSA's) which contain combined sewer service areas greater
than 10,000 acres in size. Fifty-eight SMSA's meet this
criterion and account for approximately 1.867 million acres
of combined sewer service area or about 83% of the national
total. Population served by these 58 combined sewer service
areas totals approximately 30.7 million persons or 81% of
the total national population served by combined sewers.
Thus, the large majority of the CSO pollution problem is
located in relatively few major urban areas. The remaining
17% of the combined sewer service area is scattered throughout
the nation in hundreds of individual locations. The National
Combined Sewer System Data File which is currently under
development is a comprehensive attempt to locate and quantify
all combined sewer service areas nationwide.
Direct time estimates for funding CSO pollution control
projects on a city-by-city basis is not possible because
construction grant funds are allocated on a state-by-state
basis. However, inspection of Table 5-1 reveals that any
given state has a limited number of major combined sewer
service areas. Therefore, an estimate of funding time for
an individual state could logically be applied to each major
combined sewer system within that state.
STATE-BY-STATE ESTIMATES OF TIME REQUIRED
TO FUND CSO POLLUTION CONTROL PROJECTS
Estimates of the time required for each state to fund CSO
pollution control projects are developed under six sets of
assumptions. The variations in the assumed conditions are
related to the grant allocation formula and to the rate of
spending for CSO control.
5-3
-------
Table 5-1
SMSA's with Combined Sewer Service
Area Greater Than 10,000 Acres
State
SMSA Name
I
>£•
California
Connecticut
Connecticut
Dist. of Columbia
Georgia
Illinois
Illinois
Indiana
Indiana
Indiana
Indiana
Indiana
Indiana
Indiana
Indiana
Kansas
Kentucky
Maine
Massachusetts
Massachusetts
Michigan
Michigan
Michigan
Minnesota
Missouri
Missouri
Missouri
Nebraska
San Francisco
Hartford
New Haven
Dist. of Columbia
Albany
Chicago
St. Louis Metro
Anderson
Chicago Metro
Evansville
Fort Wayne
Indianapolis
Lafayette
Muncie
South Bend
Kansas City Metro
Louisville
Portland
Lawrence-Haverhill
Springfield
Detroit
Lansing
Saginaw
Minneapolis-St. Paul
Kansas City
St. Joseph
St. Louis
Omaha
Approximate
SMSA Combined Sewer
Number Service Area (Acres)
7360 28,550
5440 20,800
8880 16,700
8840 12,700
12,000
1600 248,263
7040 16,900
0400 20,000
2960 61,367
2440 15,800
2760 12,320
3480 34,000
3920 10,000
5280 13,686
7800 20,200
22,600
28,800
6400 15,300
4160 41,500
8000 32,900
2160 192,000
4040 10,867
6960 11,500
5120 26,000
3760 36,480
7000 14,200
7040 45,079
5920 25,201
Approximate
Population Served
By Combined Sewers Note
731,000 2
275,000 1
179,000 1
400,000 1
76,000 1
4,688,950 2
47,740 2
80,700 1
100,462 2
142,000 1
114,000 2
456,000 1
47,805 2
43,000 2
175,000 1
76,000 2
457,450 2
86,000 1
545,000 1
254,000 1
2,900,000 1
85,000 2
103,000 1
326,700 1
292,000 2
75,900 1
399,200 2
191,505 2
-------
Ln
I
U1
Table 5-1 — Continued
State
New Jersey
New Jersey
New Jersey
New Jersey
New York
New York
New York
New York
New York
New York
New York
Ohio
Ohio
Ohio
Ohio
Ohio
Ohio
Ohio
Oregon
Pennsylvania
Pennsylvania
Pennsylvania
Rhode Island
Tennessee
Virginia
Virginia
SMSA Name
Jersey City
New York City Metro
Newark
Philadelphia Metro
Albany
Binghamton
Buffalo
New York City
Rochester
Syracuse
Utica Rome
Akron
Cincinnati
Cleveland
Columbus
Lima
Toledo
Youngstown
Portland
Philadelphia
Pittsburgh
Scran ton
Providence
Nashville
Lynchburg
Richmond
SMSA
Number
3640
6040
5640
6160
0160
0960
1280
5600
8160
8680
0080
1640
1680
1840
4320
8400
9320
6440
6160
6480
4640
6760
Approximate
Combined Sewer
Service Area (Acres)
20,572
22,200
24,911
20,300
33,860
15,200
55,566
107,126
17,070
23,530
21,650
13,000
73,400
46,799
11,785
10,100
19,343
13,700
24,200
45,600
31,500
17,100
21,000
14,700
10,400
11,500
Approximate
Population Served
By Combined Sewers
444,098
1,204,000
547,577
201,000
290,456
145,000
1,154,728
5,783,000
328,000
488,086
228,857
54,200
778,000
151,600
174,914
70,000
204,000
172,000
316,000
1,926,176
667,000
148,000
333,000
180,000
70,800
200,000
Note
2
1
2
1
2
1
2
2
2
2
2
1
1
2
2
1
2
1
1
2
1
1
1
1
1
1
-------
U1
I
CTl
Table 5-1 — Continued
State
Washington
Washington
West Virginia
Wisconsin
Total
Notes : 1 . Data
2 . Data
SMSA Name
Seattle
Spokane
Huntington
Milwaukee
from 1976 Needs Survey.
from EPA Combined Sewer
SMSA
Number
7600
7840
3400
5080
System
Approximate
Combined Sewer
Service Area (Acres)
37,900
29,429
10,400
17,800
1,867,354
Data File.
Approximate
Population Served
By Combined Sewers
463,000
155,439
85,000
419,000
30,731,343
Note
1
2
1
1
-------
Allocation Formulas
The following three grant allocation formulas are considered.
1. Construction grant funds will be allocated to each
state under the present allocation formula.
2. Construction grant funds will be allocated to each
state under a new formula. This formula proportions
state allocations based on the ratio of state needs to
total national needs for combined sewer overflow
control (Category V) and on the ratio of state needs to
total national needs for all other municipal wastewater
control facilities (Categories I through IVB). The
weighting factors are 20% for Category V and 80% for
Categories I through IVB.
3. Construction grant funds will be allocated to each
state under a new formula. This formula is identical
to No. 2 above except that the weighting factors are
changed to 50% for Category V and 50% for Categories I
through IVB.
Rate of Spending
Once grant funds are allocated to each state, it is the
state's decision as to which projects are funded. This
decision is made based on a project's standing on the
state's priority list. It is probable that as secondary
wastewater treatment plant needs are met, combined sewer
overflow pollution abatement needs will receive higher
priority. The following two alternative assumptions were
made concerning the rate of spending by states with CSO
needs.
a. States with combined sewer systems will invest in CSO
control facilities at an uniformly changing rate until
a maximum of 50% of the annual allocation is invested
in CSO control. The transition from the present rate
of investment in CSO control facilities to the maximum
rate of 50% will require 5 years.
b. The second spending assumption is identical to No. 1
above except that the maximum spending rate is reduced
from 50% to 30%.
Assumptions which are common to each of the above allocation
and spending alternatives are as follows.
1. Funding level for construction grants is $4.25 billion
per year for current year and $5.0 billion per year
thereafter. Funds are expressed in January 1978 dollars,
5-7
-------
2. The current funding formula will be in effect from 1
October 1978 through 30 September 1981.
The allocation and spending alternatives are referenced to
an alphanumeric identifier, la, 2a, 3a, Ib, 2b, and 3b,
which represents all possible combinations of the three
allocation formulas and two spending rates. The estimated
time required to fund correction of CSO pollution for each
state under these six alternatives is reported in Table 5-2.
The results of the analysis summarized in Table 5-2 indicate
that CSO correction time will be highly variable from state
to state. Average time to fund correction of CSO may vary
from approximately 8.3 years to 14.3 years and maximum time
to correct may vary from approximately 14 years to 40 years
for the six alternatives analyzed. It also appears that the
rate at which states fund CSO projects will have a greater
influence on correction time than would modification of the
grants allocation formula.
It should be noted that the values reported in Table 5-2
represent time required to fund CSO projects. The actual
construction of these projects will require an additional 2
to 5 years in each case. Also, water pollution control
facilities have an economic life ranging from 10 to 15 years
for mechanical equipment and from 20 to 50 years for plants
and collection systems. Therefore, the process of facilities
construction for CSO pollution abatement should be realistically
viewed as continuous.
5 -
-------
Table 5-2
State-by-State Estimates of
Time Required to Fund CSO Pollution
Control Projects for Six Funding Alternatives
State
Funding Time in Years by Alternative
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Dist. of Columbia
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
la
0
3
0
4
5
0
15
6
19
0
8
0
4
11
18
5
7
6
0
25
3
13
11
7
0
21
0
12
5
15
9
0
12
0
5
13
0
9
10
2a
0
3
0
4
5
0
14
8
24
0
9
0
4
11
15
6
8
6
0
19
3
12
9
8
0
19
0
15
5
13
10
0
9
0
7
11
0
8
11
3a
0
3
0
4
5
0
11
8
14
0
9
0
4
9
12
6
8
7
0
13
3
11
9
8
0
13
0
12
5
11
9
0
9
0
7
10
0
8
10
Ib
0
3
0
4
5
0
23
9
30
0
12
0
4
16
27
7
10
8
0
40
4
20
17
10
0
33
0
18
5
23
13
0
18
0
6
19
0
12
14
2b
0
3
0
4
7
0
21
12
38
0
13
0
4
16
23
8
12
9
0
29
4
17
13
11
0
29
0
23
6
19
15
0
13
0
12
16
0
11
16
3b
0
3
0
4
7
0
17
12
21
0
13
0
5
12
17
8
12
10
0
19
4
15
13
11
0
19
0
18
6
16
14
0
13
0
12
15
0
12
15
5-9
-------
Table 5-2—Continued
Funding Time in Years by Alternative
State
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Am. Samoa
Guam
Puerto Rico
Trust Terr.
Virgin Islands
la
20
0
2
7
3
0
16
7
10
11
8
0
0
0
4
0
0
2a
14
0
2
8
3
0
15
8
8
9
8
0
0
0
4
0
0
3a
12
0
2
8
3
0
12
8
9
9
8
0
0
0
4
0
0
Ib
32
0
2
10
4
0
25
10
14
17
11
0
0
0
4
0
0
2b
22
0
2
11
4
0
24
12
12
13
11
0
0
0
5
0
0
3b
17
0
2
12
4
0
17
12
12
13
11
0
0
0
5
0
0
Maximum Correction
Time
Average Correction
Time (years)
25
24
14
40
38
Note: States with zero time to correct are
states without combined sewer systems.
21
9.78 9.36 8.26 14.20 13.64 11.84
5-10
-------
Chapter 6
COMPARISON OF ANNUAL POLLUTANT DISCHARGES
SUMMARY OF POLLUTANT DISCHARGE ANALYSIS
Pollutant loads at 15 combined sewer study sites were
estimated for five parameters (BOD5, suspended solids, total
nitrogen, phosphate phosphorus, and lead) from three sources
(combined sewer overflow, separate storm runoff, and waste-
water treatment plant effluent). Figure 6-1 is a map
locating all 15 study sites. Ten of these site studies are
included in the 1978 Needs Survey. These are: Rochester,
New York; Syracuse, New York; Philadelphia, Pennsylvania;
Washington, B.C.; Atlanta, Georgia; Milwaukee, Wisconsin;
Bucyrus, Ohio; Des Moines, Iowa; Sacramento, California; and
Portland, Oregon. Five additional sites were chosen for
this analysis to represent other major urban areas with
combined sewer overflow problems. These five sites are:
Boston, Massachusetts; New York, New York; Chicago, Illinois;
Detroit, Michigan; and San Francisco, California.
Fourteen of the 15 study sites are located in urbanized
areas as defined by the Bureau of the Census of the U.S.
Department of Commerce. The fifteenth site, Bucyrus, Ohio,
is not associated with a urbanized area. Nine of the 10
1978 Needs Survey sites (excluding Syracuse, New York) are
being analyzed on a watershed/receiving water basis by
simulation. The purpose of the ongoing simulations is to
evaluate the water quality response of the receiving water
considering all pollutant sources including combined sewer
overflow.
In general, two pollutant loading comparisons are presented
in Appendix B for each study site. The first is a comparison
of pollutants generated by the entire urbanized area.
Occasionally, two urbanized areas are applicable to a given
general location, such as New York City and New York Metro
New Jersey. In these cases, loading comparisons are presented
for both urbanized areas resulting in a total of 18 urbanized
area comparisons. Urbanized area pollutant loading estimates
are based on the method presented in EPA publication
No. EPA-600/2-76-275 entitled "Stormwater Management Model:
Level 1 Preliminary Screening Procedures."
The second loading comparison is based on 15 studies, 10 of
which are watersheds considered in the ongoing 1978 Needs
Survey. The remaining five are based on previously published
investigations, such as 208 studies. Generally, the 15 site
studies are located within the 18 urbanized areas studied.
The 15 study site data, reported in Table 6-1, are more
6-1
-------
PORTLAND=
DESMOfNES
" m
NEW YORK
PHILADELPHIA
SACRAMENTO
SAN FRANCISCO
WASHINGTON, D.C.
Ratio of projected population served by combined
sewers to total sewered population, 1962.
I J 0%-10%
51%-75%
Over 75%
11%-2 5%
26%-50%
FIGURE 6-1. Location of 15 pollutant loading comparisons.
-------
Table 6-1
Drainage Areas and Populations for 15
Study Site Pollutant Loading Comparisons
Approximate Drainage
Area (acres)
Approximate
Population (1970)
Study Site
Boston
New York
Rochester3
Syracuse
Philadelphia3
Washington, DCa
Atlanta3
Ch
, Chicago
00 Detroit
Milwaukee
Bucyrus
Des Moines
San Francisco
Sacramento
Portland3
Total
Total
24
205
11
13
110
202
149
555
92
33
2
49
24
70
51
1,595
,370
,000
,476
,900
,000
,521
,860
,000
,392
,200
,599
,018
,637
,000
,394
,367
Combined Sewer
24,
184,
11,
9,
50,
12,
9,
240,
92,
5,
2,
4,
24,
7,
5.1,
728,
370
615
476
000
000
396
060
000
392
800
000
018
637
000
394
158
Total
875,
7,614,
200,
175,
2,076,
4,000,
780,
5,500,
1,413,
441,
13,
255,
712,
494,
411,
24,962,
000
500
000
000
900
000
000
000
700
800
111
000
000
000
000
Oil
Combined
875
6,857
200
147
944
389
104
4,690
1,413
136
11
117
712
87
411
17,095
Sewer
,000
,000
,000
,000
,000
,000
,000
,000
,700
,400
,400
,700
,000
,500
,000
,700
Indicates site studies included in the 1978 Needs Survey.
Total Area PD = 15.65 persons/acre
Combined Sewer Area PD = 23.48 persons/acre
-------
recent and more detailed and, therefore, probably more
accurate than the data reported for the total urbanized
areas in Table 6-2.
The magnitude of pollutant loads were compared for two time
periods. First, the average load discharged from each
source during a year was calculated in pounds per year.
Second, the average annual loads were divided by the duration
of a year during which that source discharged to a receiving
water which gives the average event loading rate in pounds
per hour.
Drainage Areas and Populations of the Study Sites
The first survey of combined sewer systems in the United
States, conducted in 1967 by the American Public Works
Association (APWA), estimated that 3,029,000 acres were
served by combined sewers with an average population density
of 11.88 persons per acre. The most recent survey of combined
sewer systems in the United States, was reported in 1977 by
APWA and the University of Florida, estimated that 2,248,000
acres were served by combined sewers with an average popula-
tion density of 16.73 persons per acre. The 1977 survey was
based on the 248 urbanized areas defined by the Bureau of
the Census of the U.S. Department of Commerce in the 1970
census.
A statistical analysis of 106 urbanized areas reported in
the 1977 APWA Survey found that almost 150 million people
live in urbanized areas with a population density of 5.1
persons per acre. Approximately 53.8% of the urbanized area
is developed and 46.2% is undeveloped. That area which is
developed has an approximate land use distribution of 58.4%
residential, 14.8% industrial, 8.6% commercial, and 18.2%
other.
Drainage areas and populations of the 15 study sites and 18
urbanized areas considered by this study are shown in
Tables 6-1 and 6-2, respectively. The total combined sewer
population density of the 15 study sites is 23.48 persons
per acre and of the 18 urbanized areas is 25.18 persons per
acres. A comparison of the nationwide combined sewer data
base to the 15 study sites and 18 urbanized areas is shown
in Table 6-3. The 15 study sites comprise 32% of the total
combined sewer area and 44% of the total population served
by combined sewers. The 18 urbanized areas comprise 31% of
the total combined sewer area and 47% of the total population
served by combined sewers.
Procedure for Estimating Pollutant Loads
The magnitude of pollutant loads were compared for two time
periods. First, the average load discharged from each
6-4
-------
Table 6-2
Drainage Areas and Populations for
18 Urbanized Areas Pollutant Loading Comparisons
Approximate Drainage
(acres)
Urbanized
Area
Boston
New York City
New York Metro
(New Jersey)
Rochester
Syracuse
Philadelphia
Philadelphia
Metro (New Jersey)
Washington, DC
Washington
Metro (Virginia)
Atlanta
Chicago
Chicago Metro
(Indiana)
Detroit
Milwaukee
Des Moines
San Francisco
Sacramento
Portland
Total
Source: "Nationwide
Total
425,000
243,000
1,309,000
93,000
61,000
450,000
31,000
39,000
100,000
278,000
626,000
191,000
558,000
292,000
70,000
436,000
156,000
171,000
5,529,000
Evaluation
Combined
Sewer
21,200
108,300
6,200
14,300
13,200
10,900
20,300
12,700
1,500
9,500
204,900
32,300
166,200
17,800
4,000
24,637
5,600
24,200
697,737
of Combined
Approximate
Population (1970)
Total
2, 652,000
10,519,000 6
5,688,000
601,000
376,000
3,819,000
202,000
757,000
1,251,000
1,173,000
5,714,000 4
1,000,000
3,970,000 2
1,252,000
255,000
2,988,000
634,000
825,000
43,676,000 17
Sewer Overflows
Combined
Sewer
335,172
,764,418
203,608
240,669
159,192
159,031
200,970
398,780
24,000
108,680
,415,595
452,523
,474,718
418,656
117,680
712,000
69,944
316,052
,571,688
and Urban Stormwater Discharges, Volume II: Cost Assessments
and Impacts." EPA-600/2-77-064. March 1977.
Total Area PD - 7.90 persons/acre
Combined sewer area PD = 25.18 persons/acre
6-5
-------
CTl
Table 6-3
Summary of Combined Sewer Drainage Areas and Populations
Total Area Total Combined Combined
Studied Sewer Area Sewer
(acres) (acres) Population
APWA, 1967 6,529,300 3,029,000 36,000,000
APWA and UF, 1977 29,037,000 2,248,000 37,606,000
Combined Sewer
Population
Density
(persons/acre)
11.88
16.73
18 urbanized areas
(see Table 6-2) 5,529,000 697,737 17,571,688 25.18
15 study sites
(see Table 6-1) 1,595,367 728,158 17,095,700 23.48
-------
source during a year was calculated in pounds per year.
Secondly, the average annual loads were divided by the
duration of a year during which that source discharged to a
receiving water, yielding the average event load in pounds
per hour. In the case of WWTP effluent, the duration of
discharge is a continuous event for 8,760 hours per year,
while combined sewer overflow and storm runoff are inter-
mittent sources which discharge from 200 to 1,300 hours per
year.
Results of the average annual and event load calculations
are presented in the study site discussions reported in
Appendix B. In the discussion of study site results, any
pollutant source which contributes greater than 33% of the
total load during the period of comparison is termed major.
Average Annual Loads. As previously discussed, two
independent methods were used for estimating the magnitudes
of average annual pollutant loads. The first method is
presented in EPA publication No. EPA-600/2-76-275 entitled
"Stormwater Management Model: Level 1 Preliminary Screening
Procedures."
Average areal loading rates from intermittent urban runoff
and CSO in pounds per acre per year are based on urbanized
area population density data by sewer type, i.e., combined,
separate, or nonsewered, and average annual rainfall. The
equations used for these calculations are shown in
Table 6-4. The total average annual loading rate from
intermittent combined sewer overflow or urban runoff in
pounds per year is then found by multiplying the areal
loading rate times the drainage area of that source. Average
areal loading rates from continuous WWTP effluent in pounds
per acre per year are based on a municipal wastewater flow
of 100 gallons per capita per day, secondary wastewater
treatment plant effluent concentrations as defined in Table
6-5, and the urbanized area population density. The average
annual discharge from continuous WWTP effluent in pounds per
year is then found by multiplying the continuous source
areal loading rate times the urbanized area developed area.
The second method uses 1978 Needs Survey data or previously
published reports to estimate the average annual loads from
intermittent urban runoff and CSO. The 10 combined sewer
site studies included in the 1978 Needs Survey were simulated
using the Continuous Stormwater Pollution Simulation System
(CSPSS) which calculates a continuous trace of intermittent
urban runoff and generates annual loads tributary to the
relevant receiving water from combined sewer overflow and
urban storm runoff. Average annual loads for WWTP effluent
at these 10 site studies are based on the average daily flow
and an assumed level of secondary treatment effluent, as
6-7
-------
Table 6-4
Stormwater Average Areal Load Equations
Parameter
Combined Sewer Area
Separate or Nonsewered Area
t
oo
BOD 5
SS
TN
PB
0.54
M = (1.92)P(0.142 + 0.218 PD ) + (1.89)P
d
0.54
M = (39.25)P(0.142 + 0.218 PD, ) + (25.94)P
d
0.54
M = (0.315)P(0.142 + 0.218 PD^ ) + (0.28)P
d
0.54
0.54
M = (0.467)P(0.142 + 0.218 PD^ ) + (0.457)P
d
0.54
M = (9.52)P(0.142 + 0.218
+ (6.29)P
0.54
M = (0.0765)P(0.142 + 0.218 PDd ) + (0.068)P
0.54
M = (0.0812)P(0.142 + 0.218 PD ) + (0.071JP M = (0.0196)P(0.142 + 0.218 PD ) + (0.0172)P
0.54
M = (0.0126)P(0.142 + 0.218 PD ) + (0.0124)P
d
0.54
= (0.0126)P(0.142 + 0.218 PD^ ) + (0.0124)P
Source: Heaney, J. P. et al. Nationwide Evaluation of Combined Sewer Overflows and Urban Storm-water
Discharges, EPA-600/2-77-064. March 1977.
Ib
Notes: M = Areal loading rate, acre-year.
P = Average annual rainfall, inches.
PD = Population density of the developed sewer area, capita/acre.
These equations are based on a typical developed land use distribution of 58.4% residential,
14.8% industrial, 8.6% commercial, 18.2% other, and 46.2% undeveloped.
-------
shown in Table 6-5 unless a higher quality effluent is known
to exist. Data for the additional five study sites not
included in the 1978 Needs Survey were taken from wastewater
management facilities plans or 208 studies that are referenced
in Appendix B. In the case where a particular annual
pollutant loading rate, e.g., lead, had not been estimated,
ratios of the particular parameter to BOD5 as shown in Table
6-6 were used to estimate the missing pollutant load.
Average Event Loads. Average event pollutant loading rates
were determined by dividing the average annual pollutant
discharge by the approximate average duration of runoff for
the watershed of interest. Thus, an intermittent event
factor, the reciprocal of the average annual runoff duration
in hours per year, is multiplied by the average annual load
in pounds per year to give the average intermittent event
loading rate in pounds per hour. WWTP effluent average
annual loads are multiplied by a continuous event factor,
which is the reciprocal of 8,760 hours per year, to give the
average continuous event loading rate in pounds per hour.
RESULTS
Nationwide
A nationwide comparison of annual pollutant discharges from
combined sewer overflow and secondary wastewater treatment
plant (WWTP) effluent is shown in Table 6-7. These estimates
of annual pollutant discharges were calculated using the
equations shown in Table 6-4 for an average annual rainfall
of 33.4 inches on the nationwide combined sewer area of
2,248,000 acres (3,512.7 square miles) with a population
density of 16.73 persons per acre, and on the total U.S.
urbanized area of 29,037,000 acres (45,370.3 square miles)
with a population density of 5.1 persons per acre. This
calculation does not give an exact estimate of the annual
pollutant discharges since site specific variations in
population density, rainfall, and land use distributions are
not considered. However, these estimates will give a
reasonable comparison of nationwide pollutant discharges.
The comparison in Table 6-7 shows that BOD5 annual discharges
are approximately the same from combined sewer overflow and
secondary WWTP effluent. The annual discharges of SS and Pb
are approximately 15 and 14 times higher from combined sewer
overflow than from secondary WWTP effluent. In addition,
the annual discharges of POi+ and TN from secondary WWTP
effluent are approximately 4 and 7 times the discharges from
combined sewer overflow, respectively.
6-9
-------
Table 6-5
Secondary Wastewater Treatment
Plant Effluent Concentrations
for the 1978 Needs Survey
Parameter
BOD 5
SS
TN
POit
Pb
Secondary
WWTP
Effluent
(mg/1)
30
30
30
4
0.04
Table 6-6
BOD5 Ratios for Stormwater Loads
Parameter
Combined sewer ratios
SS
TN
Ratio
Pb
Separate and nonsewer
ratios
SS
TN
Pb
17.24 BOD5
0.1646 BOD5
0.04085 BOD5
0.006564 BOD5
17.24 BOD5
0.1646 BOD5
0.04085 BOD5
0.027064 BOD5
Note: BOD5 Combined = 3.8816 =4.12
BOD5 Separate 0.941462
6-10
-------
Table 6-7
Nationwide Comparison of Annual
Discharges From Combined Sewer Overflow
and Secondary Wastewater Treatment Plant Effluent
0s!
i
Parameter
BOD 5
SS
TN
Pb
Combined Sewer Overflow
Average
Concentration
(mg/1)
115
370
9-10
1.9
0.37
Average Annual
Discharge
(million Ib/year)
306
5,310
48
12.
2.
3
01
Secondary Wastewater Treatment
Average Combined
Concentration Sewer Area
(mg/1)
30
30
30
4
0.04
(million Ib/year)
344
344
344
45.8
0.457
Plant Effluent
U.S. Urbanized
Area
(million
1,353
1,353
1,353
180
1.
Ib/year)
804
Note: Based on a total U.S. urbanized area of 29,037,000 acres (45,298 square miles) with
a population density of 5.1 persons per acre, a total combined sewer area of 2,248,000
acres (3,507 square miles) with a population density of 16.73 persons per acre, average
annual rainfall of 33.4 inches, and a municipal Wastewater flow of 100 gpcpd.
-------
A comparison of annual pollutant discharges nationwide does
not give adequate representation to the severity of combined
sewer overflow pollution. In densely populated urban areas,
combined sewer overflow is generally located on relatively
small reachs of a receiving water and the occurrence of CSO
eliminates water use where the most people live. In addition,
when flooding occurs in a combined sewer area, a public
health problem can result due to sewage flooding of streets
and basements. The fecal coliform content, and indication
that pathogenic organisms may also be present, can be several
thousand organisms per 100 ml of sample.
Short-term impacts of the combined sewer overflow on the
receiving water are generally caused by suspended solids
(SS), biochemical oxygen demand (BOD), and coliform bacteria,
while long-term impacts from combined sewer overflow are
generally caused by total nitrogen (TN) and phosphate-
phosphorus (POit). However, combined sewer overflow problems
are very site specific and require a detailed investigation
of the existing collection system, receiving water uses, and
receiving water impacts. Since combined sewer overflow
generally occurs between 2% and 15% of the time, there is a
significant potential for severe shock loading effects of
the receiving water.
15 Study Sites
A summary of annual and event discharges from 18 urbanized
areas with a combined sewer area of 697,737 acres (1,090.2
square miles) and a population density of 26.18 persons per
acre is shown in Table 6-8. Combined sewer overflow and
storm runoff are found to be a major source of annual SS and
Pb discharges, while secondary WWTP is shown to be a major
source of annual BOD5, TN, and PO^ discharges. On an event
basis, combined sewer overflow and storm runoff are found to
be a major source of BODS, SS, and Pb discharges, while
secondary WWTP is shown to be a major source of event TN and
PO^ discharges.
Appendix B presents results of the Stormwater Management
Model (SWMM) Level I analysis performed on 15 U.S. combined
sewer study sites including description of the combined
sewer problem, the annual and event pollutant discharges,
and sources of further information.
The relationship between relative combined sewer service
area and the percentage of total pollutant discharge
contributed by combined sewer overflow for the 18 urbanized
areas are shown in Figures 6-2 through 6-6. Although the
data represented by these curves were quite scattered, a
clear difference between event and annual discharges and
between the five pollutants is indicated. If the percentage
6-12
-------
GO
Table 6-8
Percentage
Contributes
Parameter
BOD 5
SS
TN
PO,
Pb
of Sites Where
More Than 33%
CSO
Annual
28
67
0
0
33
Indicated Source
of the Total Pollutant Discharge
Event
67
67
61
56
33
Storm
Annual
22
56
0
0
94
Runoff
Event
61
61
39
33
94
Secondary
Wastewater
Treatment
Plant Effluent
Annual Event
89 0
0 0
100 67
100 78
0 0
Note: Based on pollutant loading comparison for 18 urbanized areas.
-------
of the total area served by combined sewers is known, it is
possible to estimate the percentage of the annual discharge
(dashed lines) or event discharge (solid lines) contributed
by combined sewer overflow. For example, if 50% of an urban
drainage area is served by combined sewers, then approximately
40% of the annual BOD5 discharge and 80% of the event BOD5
discharge are contributed by combined sewer overflow (see
Figure 6-2) .
6-14
-------
o
O
-o
CD
C
!a
E
o
o
E
o
o
40-
30-
20-
10-
0
r
50 60 70 80
% of Total Area Served by Combined Sewers
90
100
FIGURE 6-2. BOD5 discharge from combined sewer overflow versus combined sewer area.
-------
100-1
o
g
01
C/5
E
o
CJ
E
o
20
30 4O 50 60 70 30
% of Total Area Served by Combined Sewers
90
100
FIGURE 6-3. Suspended solids discharge from combined sewer overflow versus combined sewer area.
-------
100-,
90-
80-
70-
0>
aj
CO
T3
OJ
C
6C-
8 50
E
o
30-
20-
10-
0
TOTAL
NITROGEN
i
10
20
Event Load
30 40 50 60 70 80
% of Total Area Served by Combined Sewers
90
100
FIGURE 6-4. Total nitrogen discharge from combined sewer overflow versus combined sewer area.
-------
o
OJ
CD
in
•a
a>
c
!Q
E
o
o
E
o
CD
•f-J
O
o
s?
100n
90-
80-
70-
60-
50-
40-
30-
20-
10-,
0
PHOSPHATE
PHOSPHORUS
Event Load
., Annual Load
.^———
10 20 30 40 50 60 70
% of Total Area Served by Combined Sewers
80
90
FIGURE 6-5. Phosphate phosphorus discharge from combined sewer overflow versus combined sewer area.
-------
o>
co
E
o
u
E
o
o
100-,
90-
80-
70-
60-
50-
40-
30-
20-
10-
Event Load
LEAD
of 1 1 1 1 1 1 1 1 1 1
10 20 30 40 50 60 70 80 90 100
% of Total Area Served by Combined Sewers
FIGURE 6-6. Lead discharge from combined sewer overflow versus combined sewer area.
-------
Chapter 7
TECHNOLOGICAL ALTERNATIVES FOR
COMBINED SEWER OVERFLOW CONTROL
INTRODUCTION
Alternatives for the control of combined sewer overflow must
be adaptable to highly variable operating conditions and/or
adaptable as dual wet- and dry-weather treatment facilities.
They must also be flexible to site-specific problems and
subject to reliable automatic operation. Funding for research,
development, and demonstration of combined sewer overflow
control technology during the past 10 years has been approxi-
mately $45 million which is less than 2/10 of 1% of the
total $21.16 billion of estimated needs for control of
combined sewer overflow.
Most of the information presented in this chapter was taken
from research reports published by the EPA Municipal Environ-
mental Research Laboratory, Office of Research and Development,
in the Environmental Protection Technology Series. Two EPA
compendium reportssummarizethe state-of-the-art in stormwater
control technology. They are entitled:
1. "Urban Stormwater Management and Technology: An Assessment."
EPA-670/2-74-040. December 1974.
2. "Urban Stormwater Management and Technology: Update
and User's Guide." EPA-600/8-77-014. September 1977.
Source control, collection system control, and treatment
alternatives for combined sewer overflow are defined in the
first section of this chapter. A detailed description of
each alternative including advantages, disadvantages, and
sources of additional information are presented in Appendix C.
This chapter provides cost-effectiveness data and the expected
range of feasible BOD removal for each control alternative.
Energy consumption in kilowatt hours per million gallons
treated is also presented for several treatment options.
The last section presents a comparison of cost effectiveness
for seven different combined sewer overflow treatment systems,
each with a design capacity of 25 mgd.
7-1
-------
PROCESS DEFINITIONS
Source Controls
Street Cleaning. The major objective of municipal street
cleaning is to enhance the aesthetic appearance of streets
by periodically removing the surface accumulation of litter,
debris, dust, and dirt. Common methods of street cleaning
are manual, mechanical broom sweepers, vacuum sweepers, and
street flushing. However, as currently practiced, street
flushing does not remove pollutants from stormwater but
merely transports them from the street into the sewers.
Sweeping streets in combined sewer watershed will have a
small impact on the BOD5 discharge since most of the BOD5
load is located in the sewers and not on the streets. As a
result, streetsweeping will be more effective from a BOD
removal viewpoint for a watershed served by separate sewers
than for a watershed served by combined sewers.
Combined Sewer Flushing. The major objective of combined
sewer flushing is to resuspend deposited sewage solids and
transmit these solids to the dry-weather treatment facility
before a storm event flushes them to a receiving water.
Combined sewer flushing consists of introducing a controlled
volume of water over a short duration at key points in the
collection system. This can be done using external water
from a tanker truck with a gravity or pressurized feed or
using internal water detained manually or automatically. A
recent feasibility study of combined sewer flushing indicates
that manual flushing using an external pressurized source of
water is most effective. Combined sewer flushing is most
effective when applied to flat collection systems. It may
also be applied in conjunction with upstream storage and
downstream swirl concentrators, followed by disinfection.
Catch Basin Cleaning. The major objective of catch basin
cleaning is to reduce the first flush of deposited solids in
a combined sewer system by frequently removing accumulated
catch basin deposits. Methods to clean catch basins are,
manual, eductor, bucket, and vacuum. Less than 45% of
municipalities in the United States uses mechanical methods.
The role of catch basins in newly constructed sewers is
marginal due to improvements in street surfacing and design
methods for providing self-cleaning velocities in sewers.
Catch basins should be used only where there is a solids-
transporting deficiency in the downstream sewers or at a
specific site where surface solids are unusually abundant;
however, many existing combined sewers have catch basins.
7-2
-------
Collection System Controls
Existing System Management. The major objective of collection
system management is to implement a continual remedial
repair and maintenance program to provide maximum trans-
mission of flows for treatment and disposal while minimizing
overflow, bypass, and local flooding. It requires an under-
standing of how the collection system works and patience to
locate unknown malfunctions of all types, poorly optimized
regulators, unused in-line storage, and pipes clogged with
sediments in old combined sewer systems.
The first phase of analysis in a sewer system investigation
is an extensive inventory of existing data and mapping of
flowline profiles. This information is then used to conduct
a detailed physical survey of regulator and storm drain
performance. This type of sewer system inventory and study
should be the first objective of any combined sewer overflow
pollution abatement project.
Flow Reduction Techniques. The major objective of flow
reduction techniques is to maximize the effective collection
system and treatment capacities by reducing extraneous
sources of clean water. Infiltration is the volume of
ground water entering sewers through defective joints;
broken, cracked, or eroded pipe; improper connections; and
manhole walls. Inflow is the volume of any kind of water
discharged into sewerlines from such sources as roof leaders,
cellar and yard drains, foundation drains, roadway inlets,
commercial and industrial discharges, and depressed manhole
covers. Combined sewers are by definition intended to carry
both sanitary wastewater and inflow. Therefore, flow reduction
opportunities are limited. Typical methods for reducing
sewer inflow are by discharging roof and areaway drainage
onto pervious land, use of pervious drainage swales and
surface storage, raising depressed manholes, detention
storage on streets and rooftops, and replacing vented manhole
covers with unvented covers.
Sewer Separation. Sewer separation is the conversion of a
combined sewer system into separate sanitary and storm sewer
systems. Separation of municipal wastewater from storm
water can be accomplished by adding a new sanitary sewer and
using the old combined sewer as a storm sewer, by adding a
new storm sewer and using the old combined sewer as a sanitary
sewer, or by adding a "sewer within a sewer" pressure system.
Swirl and Helical Concentrators. The major objective of
swirl and helical concentrators is to regulate both the
quantity and quality of storm water at the point of overflow.
Solids separation is caused by the inertia differential
which results from a circular path of travel. The flow is
7-3
-------
separated into a large volume of clear overflow and a concen-
trated low volume of waste that is intercepted for treatment
at the wastewater treatment plant. In addition to regulation
of combined sewer flow, they can provide high-rate primary
treatment for solids removal. A major attribute of the
swirl concentrator is the relatively constant treatment
efficiency over a wide range of flow rates (a fivefold flow
increase results in only about a 25% efficiency reduction)
and the absence of mechanical parts which use energy unless
input or output pumping is required. Swirl and helical bend
concentrators have been modeled and, in several cases,
demonstrated for various processes including treatment and
flow regulation, primary treatment, and erosion control.
Remote Monitoring and Control. The major objective of
remote monitoring and control on a combined sewer collection
system is to remotely observe the sewer and treatment capaci-
ties so that the most effective use of inline storage is
obtained with a minimum of severe overflow. A prerequisite
for this alternative is a large collection system with the
potential for inline storage. Three components are generally
added to the existing collection system: a data gathering
system for reporting rainfall, pumping rates, treatment
rates, and regulator positions; a central computer processing
center, and a control system to remotely manipulate gates,
valves, regulators, and pumps. The capital costs, operation
and maintenance costs, and effectiveness depend on the
hydraulic characteristics of the system of concern and thus
are very site-specific.
Fluidic Regulations. The major objective of fluidic combined
sewer overflow regulation is to provide dynamic control at
the site of overflow without a complex operational system.
They are self-operated by using a venturi pressure gradient
which senses the dry-weather interceptor sewer capacity
before allowing combined storm water to overflow. New
fluidic regulator capital costs are estimated to be 10%
greater than conventional static regulators.
Polymer Injection. The primary objective of polymer injection
to sewer flow is to increase the flow capacity of an existing
sewer by reducing the turbulent friction. It is most applica-
ble as an interim solution to infiltration problems of
sanitary sewers since they respond slowly over a long period
to rainfall-induced infiltration. A rapid short duration
flow increase, such as that occurring in combined sewers,
will generally exceed the capacity of polymer friction
reduction. Polymers used are water soluble, have a high
molecular weight and a large length-to-diameter ratio, and
are not toxic or harmful if swallowed.
7-4
-------
Treatment Facilities
Off-Line Storage. The major objective of off-line storage
is to contain combined sewer overflow for controlled release
into treatment facilities. Off-line storage provides a more
uniform constant flow and thus reduces the size of treatment
facilities required. Off-line storage facilities may be
located at overflow points or near dry-weather or wet-
weather treatment facilities. A major factor determining
the feasibility of using off-line storage is land availability.
Operation and maintenance costs are generally small, requiring
only collection and disposal costs for sludge solids, unless
input or output pumping is required.
Sedimentation. The major objective of sedimentation is to
produce a clarified effluent by gravitational settling of
the suspended particles that are heavier than water. It is
one of the most common and well-established unit operations
for wastewater treatment. Sedimentation also provides
storage capacity, and disinfection can be effected concurrently
in the same tank. It is also very adaptable to chemical
additives such as lime, alum, ferric chloride, and polymers
which provide higher suspended solids, BOD, nutrients, and
heavy metals removal.
Dissolved Air Flotation. The major objective of dissolved
air flotation(DAF)is to achieve suspended solids removal
in a shorter time than conventional sedimentation by attaching
air bubbles to the suspended particles. The principal
advantage of flotation over sedimentation is that very small
or light particles that settle slowly can be removed more
completely and in a shorter time. Capital costs for DAF are
moderate; however, operating costs are relatively high due
to the energy required to compress air and release it into
the flotation basin and due to the greater skill required by
operators. Chemical additives are also useful to improve
process efficiencies of BOD and SS removals and to obtain
nitrogen and phosphorus removals.
Screens. The major objective of screening is to provide
high-rate solids/liquid separation for combined sewer parti-
culate matter. Four basic screening devices have been
developed to serve one of two types of applications. The
microstrainer is a very fine screening device designed to be
the main treatment process of a complete system. The other
three devices, drum screens, rotary screens, and static
screens, are basically pretreatment devices designed to
remove coarse materials. BOD removal efficiencies are
approximately 15% for pretreatment screens and up to 50% for
microstrainers. For all screens, removal performance tends
to improve as influent suspended solids concentrations
increase due to the relatively constant effluent concentrations,
7-5
-------
In addition, screens develop a mat of trapped particles
which act as a strainer retaining particles smaller than the
screen aperture. Chemical additives can be used to improve
process removal efficiencies. The use of screens in series
does not show any advantage over the use of a single screen.
Microstrainers break up solid particles and expose greater
numbers of bacteria in the effluent to disinfection.
High-Rate Filtration. The major objective of high-rate
filtration (HRF)is to capture suspended solids and other
pollutants in a fixed bed dual media filter (a bed of anthra-
cite coal is usually above sand filter media). Filtration
is one step finer than screening. Solids are usually removed
by one or more of the following mechanisms: straining,
impingement, settling, and adsorption. Filtration has not
been used in wastewater treatment because of rapid clogging
due to compressible solids. Combined sewer overflow contains
a larger fraction of discrete, noncompressible solids which
can easily be washed from the filter media by periodic
backwashing. HRF has been developed over the past 15 years
for a variety of treatment applications, mainly for industrial
wastewater treatment.
High Gradient Magnetic Separation. The major objective of
high gradient magnetic separation (HGMS) is to bind suspended
solids to small quantities of a magnetic seed material (iron
oxide called magnetite) by chemical coagulation and then
pass them through a high gradient magnetic field for removal.
Magnetic separation techniques have been used since the 19th
century to remove tramp iron and to concentrate iron ores.
Solids are trapped in a magnetic matrix which must be cyclically
back-flushed like screens and filters.
Chemical Additives. The major objective of using chemical
additives is to provide a higher level of treatment than is
possible with unaided physical treatment processes (sedi-
mentation, dissolved air flotation, high rate filtration,
and high gradient magnetic separation). Chemicals commonly
used are lime, aluminum or iron salts, polyelectrolytes, and
combinations of these chemicals. There is no rational
method for predicting the chemical dose required. Jar tests
are used for design purposes; however, field control is
essential since the chemical composition of combined sewer
overflow is highly variable.
Carbon Adsorption. The major objective' of carbon adsorption
is to remove soluble organics as part of a complete physical-
chemical treatment system that usually includes preliminary
treatment, sedimentation with chemicals, filtration, and
disinfection. Carbon contacting can be done using either
granular activated carbon in a fixed or fluidized bed or
powdered activated carbon in a sedimentation basin. Periodic
7-6
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backwashing of the fixed bed must be provided, even if
prefiltration is used, because suspended solids will accumulate
in the bed. Application of carbon adsorption is well suited
to advanced waste treatment of sanitary sewage. However,
the feasibility of application to combined sewer overflow is
dependent upon the effluent quality objectives, the degree
of preunit flow attenuation, and the ability to obtain dual
dry- and wet-weather use of treatment facilities.
Biological Treatment. The major objective of biological
treatment is to remove the nonsettleable colloidal and
dissolved organic matter by biologically converting them
into cell tissue which can be removed by gravity settling.
Several biological processes have been applied to combined
sewer overflow treatment including contact stablization,
trickling filters, rotating biological contactors, and
treatment lagoons. Biological treatment processes are
generally categorized as secondary treatment processes.
These processes are capable of removing between 70% and 95%
of the BOD5 and suspended solids from waste flows at dry-
weather flow rates and loadings. An operational problem
when treating intermittent wet-weather storm events by
biological processes is maintaining a viable biomass.
Biological systems are extremely susceptible to overloaded
conditions and shock loads when compared to physical treatment
processes with the possible exception of rotating biological
contactors. This and the high initial capital costs are
serious drawbacks for using biological systems to treat
intermittent combined sewer overflow unless they are designed
as a dual treatment facility. Therefore, biological treatment
of combined sewer overflow is generally viable only in
integrated wet/dry-weather treatment facilities.
Disinfection. The major objective of disinfection is to
control pathogens and other microorganisms in receiving
waters. The disinfection agents commonly used in combined
sewer overflow treatment are chlorine, calcium or sodium
hypochlorite, chlorine dioxide, and ozone. They are all
oxidizing agents, are corrosive to equipment, and are highly
toxic to both microorganisms and people. Physical methods
and other chemical agents have not had wide usage because of
excessive costs or operational problems. The choice of a
disinfecting agent will depend upon the unique characteristics
of each agent, such as stability, chemical reactions with
phenols and ammonia, disinfecting residual, and health
hazards. Adequate mixing must be provided to force disin-
fectant contact with the maximum number of microorganisms.
Mixing can be accomplished by mechanical flash mixers at the
point of disinfectant addition and at intermittent points,
by specially designed contact chambers, or both.
7-7
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Sludge Disposal. As with all treatment processes, the
concentrated waste residue generated by combined sewer
overflow treatment must be disposed of properly.
It is estimated that treatment of CSO will generate 41.5
billion gallons of sludge per year, which is approximately
2.6 times the volume of raw primary wastewater treatment
plant sludge. However, the average solids concentration in
CSO sludge is about 1% compared to 2% to 7% in raw primary
sludge. This is due to the high volume, low solids residuals
generated by treatment processes employing screens. CSO
residuals have a high grit and low volatile solids content
when compared to raw primary sludge.
Preliminary economic evaluations indicate that lime stabi-
lization, storage, gravity thickening, and land application
is the most cost-effective disposal system. Application of
combined sewage sludges on land must meet required maximum
application rates for toxic metals, such as lead, zinc,
copper, nickel, and cadmium, as do sludges from separate
sanitary systems. Costs for overall CSO sludge handling
depend on the type of CSO treatment process, and volume and
characteristics of the sludge and the size of the CSO area,
among other considerations.
COST EFFECTIVENESS
The first objective of any combined sewer overflow control
project should be to obtain an understanding of how the
existing collection and treatment system is operating. A
cost-effective solution to a given CSO problem is not possible
unless the number of overflow points, malfunctioning regula-
tors, and separate sewer connections to combined sewers are
identified. In many cases, the dry-weather WWTP is an
integral part of the CSO control alternative, e.g., sewer
flushing, swirl concentrators, and storage, and must therefore
be included in the analysis.
The cost to remove BOD5 for several CSO control alternatives
is presented in Figure 7-1. Available capital cost data
were updated to January 1978 dollars. Annual costs were
developed based on an interest rate of 6-5/8% and an
appropriate economic life of the facility. Sludge pumping
and input or output pumping to a device are also included in
the estimated operation and maintenance costs.
A population density of 16.73 persons per acre and an
annual rainfall of 33.4 inches, which are national averages,
were assumed for the unit cost calculations. These assump-
tions yield an approximate BOD5 discharge of 136.2 pounds
per acre per year. Storage treatment calculations were
7-8
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60-,
Q
O
m
o
o
o
E
0)
QC
Q
O
CQ
50-
_ 40-
30-
20-
10-
JCatch Basin
^ Cleaning
ASSUMPTIONS
BODS YIELD = 136.2 Ib/ac/yr
POPULATION DENSITY = 16.7 persons/acre
ANNUAL RUNOFF = 16.5 inches
INTEREST = 6 5/8%
Level 4
Storage—Treatment
(200 acres)
Level 4
Storage—Treatment
(20 acres)
Sewer Separation
Optimized
Storage—Treatment
(2,000 acres)
Swirl Concentrator
—i r 1—
20 40
60
1 — — i - 1 —
80 100
% BOD5 Removal
FIGURE 7-1. Unit removal cost for a typical combined sewer service area.
-------
based on an annual runoff of 16.5 inches for 20-, 200-, and
2,000-acre combined sewer watersheds. Five different levels
of treatment were considered on the 2,000-acre watershed to
optimize the selected storage treatment system. The five
levels of treatment are defined in Table 7-1, each level
adds a new unit process to the previous level. The unit
processes are, storage, microscreening, sedimentation-
flocculation, high-rate filtration, and dissolved air
flotation. Treatment for the 200- and 20-acre combined
sewer watersheds was calculated using level 4 only.
Figure 7-1 can be used to approximate the range of BOD5
removal where a given control process is the least costly or
the most feasible alternative for the set of assumptions
previously outlined. Results of this analysis are shown in
Table 7-1. In general, source controls may be the most
feasible alternative to remove 10% to 30% of the BOD5
discharge from a small combined sewer drainage area.
Catchbasin cleaning is not a feasible alternative since a
maximum of 0.5% BOD5 removal is possible. Sewer flushing
appears to be the most promising source control of BOD5 in a
combined sewer watershed; however, the results will depend
on site-specific conditions of the existing system such as
sewer slope, overflow regulators, and WWTP facilities.
Streetsweeping can provide some control at low unit cost.
However, the maximum obtainable control is about 11% of the
total watershed BOD load. Streetsweeping would be more
competitive as a control technique on a separate sewer
watershed since all pollutants accumulate on the watershed
surface rather than in the collection system. Thus, a
greater portion of the total watershed pollutant load would
be available to the streetsweeper and the overall percent
removal would be greater.
Collection system controls appear to have a feasible range
of 30% to 60% removal of BOD5 from a combined sewer system.
Sewer separation may be a feasible control alternative for a
drainage area of 200 acres or less when 50% to 60% BOD5
removal is required. Swirl concentrators appear to be the
most feasible alternative to remove 32% to 56% at a cost
between $2.30 and $4.00 per pound of BOD5. In-line storage
with remote monitoring and control can be a cost-effective
alternative if storage capacity is available in the existing
system. An approximate cost is from $1.25 to $4.00 per
pound of BOD5, actually however, results are very site
specific. A preliminary calculation of- the cost to disconnect
roof drains from combined sewers indicates a removal cost
greater than $50.00 per pound of BOD5. A major problem with
roof drain disconnection and rooftop storage is obtaining
cooperation from building owners.
7-10
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Table 7-1
Range of Feasibility and Unit Costs
for CSO Technological Alternatives
Range of
Feasibility
(% Removal)
Source Controls
Streetsweeping 2-11
Catch basin
cleaning 0
Sewer flushing 18-32
Collection System Controls
Sewer separation 54-65
Swirl
concentrators 32-56
Remote control
in-line storage Site specific
Roof drain
disconnection Site specific
Storage/Treatment Systems
2, 000-acre
level 1 10-16
Level 2 16-35
Level 3 35-61
Level 4 61-87
Level 5 87-95
Range of
Costs
($/lb BOD 5)
3.00-7.50
>50.00
0.94-4.00
24.00
2.30-4.00
1.25-4.00
>50.00
4.70-6.00
3.40-4.70
3.10-3.40
3.10-4.20
4.20-14.00
Maximum
BOD 5 Removal
(%)
12
0.5
54
.65
56
Site specific
Site specific
25
50
79
90
95
7-11
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Table 7-1—Continued
Range of Range of Maximum
Feasibility Costs BOD5 Removal
(% Removal) ($/lb BOD5) (%)
200-acre
Level 3 56-90 8.00-13.00 90
20-acre
Level 3 65-90 30.00-41.00 90
Advanced Wastewater Treatment (AWT) (ADF = 5 to 25 mgd)
Effluent BOD
= 15 to 25 mg/1 — 1.90-2.60
Effluent BOD
= 10 mg/1 — 2.80-4.00
Effluent BOD
= 5 mg/1 — 4.90-7.00
Note: Assumptions common to all calculations:
Population density = 16.73/acre
BOD5 yield = 136.23 Ib/acre-year
Annual runoff = 16.5 inches
January 1978 dollars ENR = 2,672
Interest rate = 6-5/8%
Sludge pumping costs are included.
Storage/Treatment systems are based on runoff from a 2,000-acre
drainage basin unless otherwise stated. Treatment levels are
defined as follows.
Level 1 = Storage
Level 2 = Storage and microscreening
Level 3 = Storage, microscreening, and sedimentation-flocculation
Level 4 = Storage, microscreening, sedimentation-flocculation, and
high-rate filtration
Level 5 = Storage, microscreening, dissolved air flotation,
sedimentation-flocculation, and high-rate filtration
Advanced wastewater treatment costs are incremented costs incurred
above secondary treatment. Secondary treatment will remove
approximately 85% of the BOD5 from the dry-weather flow at a cost
of from $0.50 to $0.70 per pound of BOD5 removed. The unit costs
reported are those required to remove the remaining BOD5 from the
dry-weather flow.
7-12
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Treatment facilities for the storage and control of CSO
appear to be the most feasible control alternative for
drainage areas greater than 2,000 acres when removals greater
than 50% are required. A unit removal cost of $3.00 to
$4.00 per pound of BOD5 is maintained for 25% to 80% removal.
The cost of advanced wastewater treatment (AWT) for additional
treatment of dry-weather flow is also given in Table 7-1.
The AWT costs reported are incremental costs incurred above
secondary treatment. Secondary treatment will remove
approximately 85% of the dry-weather BOD5 load at a cost of
from $0.50 to $0.70 per pound of BOD5 removed. The unit
costs of AWT given in Table 7-1 represent the cost of removing
the remaining BOD5 from the dry-weather flow.
Often the pollution abatement choice in a combined sewer
watershed with existing secondary treatment facilities is
between additional treatment of the dry-weather flow (i.e.,
AWT) or treatment of the combined sewer overflow. The data
reported in Table 7-1 indicate that the proper choice is not
clear cut. The unit removal costs for AWT overlap the unit
removal costs for CSO control. Therefore, the choice must
be made based on individual analysis. It is clear, however,
that available CSO controls are economically competitive
with available AWT techniques.
It should be noted that this comparison is based on BOD5
removal costs. Often, AWT is required for control of nutrients
and not BOD. Since the major source of nutrients in a
combined sewer watershed is the secondary WWTP effluent (see
Chapter 6). AWT would have a clear economic advantage over
CSO control if removal of nutrients is the objective.
The results presented in Figure 7-1 and Table 7-1 are for a
typical combined sewer area and will not indicate the solution
to site-specific problems. However, the results strongly
indicate that large-scale integrated wastewater treatment
facilities will be required to control combined sewer overflow
pollution. The final combined sewer overflow control solution
will usually be a combination of the available alternatives
and must be tailored to the receiving water needs and uses.
In Appendix C, references are cited which contain detailed
information on the technical alternatives described in this
section.
ENERGY USE
The energy use of several CSO control alternatives is
presented in Table 7-2. Energy use is tabulated in units of
kilowatt hours (kWh) per million gallons (MG) treated. Data
in this table are taken from EPA report number EPA-430/9-77-
011 entitled "Energy Conservation in Municipal Wastewater
Treatment" (March 1977).
7-13
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Table 7-2
Energy Use for Several CSO
Treatment Process
Horizontal rotary screens
Vertical rotary screens
Vertical rotary screens
heating backwash water
Dissolved air flotation
High-rate filtration
Storage reservoirs
Sedimentation basins
Sludge pumping
Rapid mixing
Chlorine evaporation and
feed
Control Alternatives
Operating Parameters
Loading = 35 gpm/ft2
Loading =80 gpm/ft2
Backwash = 10 gpm @ 80 psi 160° F
Loading = 3,500 gpd/ft2
Pressurized flow = 15%
Loading = 15 gpm/ft2
Backwash =20 gpm/ft2
Detention time = 12 hours
3 gpm
Spray = 10 min ft2 reservoir walls
Loading = 1,000 gpd/ft2
Pumps run 10 min/hr
Sludge removal = 65%
G = 300/sec, Temperature = 15° C
Detention time = 1 min
Dosage =10 mg/1
Range of Energy Use
(kWh/MG)
10-16
20
30
750
7.5-15
0.4-1.9
0.8-1.0
5
10
3.5
-------
I
H-
01
Table 7-2—Continued
Range of Energy Use
Treatment Process Operating Parameters (kWh/MG) '_
Chlorine dioxide generation Dosage =1.2 mg/1 1.4-9.5
and feed
Hypochlorite generation Dosage = 10 mg/1 200
Source; "Energy Conservation in Municipal Wastewater Treatment." EPA-430/9-77-011.
March 1977.
For 10-mgd to 200-mgd treatment facilities.
-------
Energy use was calculated for a range of treatment capacities
from 10 mgd to 200 mgd. Dissolved air flotation has the
highest energy consumption (750 kWh/MG) due to the large
pumps required for operation. High-rate filtration (7.5
kWh/MG to 15 kWh/MG) and screens (10 kWh/MG to 20 kWh/MG)
have high energy uses relative to sedimentation basins (0.08
kWh/MG to 1.0 kWh/MG) . No data are available at this time
for high gradient magnetic separation.
Disinfection with hypochlorite requires much more energy
than chlorine or chlorine dioxide (200 kWh/MG versus 3.5
kWh/MG and 1.4-9.5 kWh/MG).
COMPARISON OF 25-mgd CSO TREATMENT FACILITIES
Seven different combined sewer overflow treatment systems,
each with a design capacity of 25 mgd, are presented in
Table 7-3. Data for capital costs, operating costs, land
area required, and SS and BOD5 removed are compared. Costs
exclude diversion structures, pumping stations, bar screens,
or sludge handling but include chlorination for disinfection.
Operating costs assume that CSO treatment operation is for
30 overflow events per year. Capital costs are based on an
Engineering News Record (ENR) construction cost index of
2672.
The swirl concentrator has a clear advantage in most columns,
the lowest unit removal costs per percent SS and BOD5
removed ($600 and $750, respectively) zero energy, and least
land. The microstrainer is next with a unit removal cost of
$2,090 for SS and $3,660 for BOD5. The highest unit removal
costs of SS and BOD5 are for dissolved air flotation at
$4,450 per percent SS removed and $6,230 per percent BOD5
removed.
7-16
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Table 7-3
Comparison of Seven 25-mgd CSO Treatment Systems
Land
Average Average Operating Area SS Unit BOD5 Unit
% Removal % Removal Capital Costs Required Removal Cost Removal Cost
Treatment System SS BOD5 Costs ($/yr) (acres) ($/% SS removed)($/% BOD5 removed)
High-rate filtration with
discostrainers 76
Flocculation-sedimentation
with grit chamber 75
Microstrainers (horizontal
shaft screens) 70
•^Dissolved air flotation
I with drum screens 70
h- •
^j Swirl concentrator with
degritter 50
Vertical shaft rotary
drum screens 40
High gradient magnetic
separation 95
45 $2,589,000 $41,600 0.081 $3,650.00 $6,170
60 2,600,000 74,200 0.964 4,160.00 5,210
40 1,250,000 31,800 0.057 2,090.00 3,660
50 2,690,000 64,700 0.528 4,450.00 6,230
40 143,000 16,800 0.028 600.00 750
35 1,060,000 24,400 0.052 3,040.00 3,470
92 2,850,000 73,600 0.275 3,530.00 3,650
.00
.00
.00
.00
.00
.00
.00
Note: Costs and energy usage exclude diversion structures, pumping stations, bar screens, or sludge handling but
include chlorination for disinfection. Operating costs assume CSO treatment operating for 30 CSO events per year.
Engineering News Record Construction Cost Index = 2672. (January 1978)
-------
Chapter 8
DISCUSSION OF LEGISLATIVE ALTERNATIVES
The five legislative alternatives for funding combined sewer
overflow pollution abatement projects, outlined in Chapter 2,
are discussed in this chapter. This discussion is based on
the information presented in the report and on comments
received from states, municipalities, planning agencies, and
EPA staff.
The alternatives are expanded somewhat from the outline form
of Chapter 2, and the advantages and disadvantages of each
are listed. Advantages and disadvantages are a subjective
topic since what may be an advantage to one group or interest
could well be a disadvantage to another. Advantages and
disadvantages presented herein are developed from the view-
point of maximizing the water quality benefits obtained from
investment of water pollution control dollars while maintaining
a controllable funding program which will solve the CSO
pollution problem in a timely fashion. This controllable
funding program should also be flexible enough to interface
with solutions to other urban water resources problems so
that overall, the least costly solutions can be obtained.
ALTERNATIVE 1—CONTINUE WITH PRESENT LAW
"Combined sewer overflow pollution abatement projects would
be funded under the existing provisions of PL 92-500 as
amended in December 1977, by the Clean Water Act of 1977.
Combined sewer overflow control projects would be funded
under section 201 of the law."
The procedure for project implementation would be the same
as it exists today and would consist of three major steps:
(1) facilities planning, (2) preparation of construction
documents (design), and (3) construction. The decisions
relating to the extent of federal participation in individual
CSO pollution abatement projects would be based on least
cost pollution control alternatives as well as on the project's
position on the State priority lists.
This alternative is flexible enough to allow some adjustment
in the present program if these adjustments can be achieved
by administrative rather than legislative action. For
example, existing EPA guidelines, such as PG-61 and PPJYI
No. 77-4, may be subject to change if deemed appropriate in
the future.
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Advantages of Alternative 1
The major advantage of the present program is that it is a
working program and that individuals involved in water
pollution control, including state agencies, municipalities,
and private design firms, are familiar with the program.
Another advantage of the present program is that it places
CSO pollution abatement projects in perspective with other
pollution control projects. Competition under the state
priority system allows for the comparison of pollution
reductions achieved by CSO projects with pollution reductions
achieved by other projects. Theoretically, this process
should result in placement of the project at the proper
location on the state priority list regardless of the source
of the pollutant. Therefore, the present system allows for
considerable input by the states regarding where and how
their share of the federal water pollution control grants
should be invested.
The ultimate objective of the current water pollution
control program is to remove pollutants from the receiving
water. Secondary treatment of municipal wastewater, advanced
waste treatment (AWT) of municipal wastewater, and combined
sewer overflow control are all tools which may be used to
meet this ultimate objective. Secondary wastewater treatment
is obviously the most cost-effective method by which pollutants
can be removed. However, once secondary treatment is achieved,
there is no clear economic advantage for AWT versus CSO
control or vice versa (See Chapter 7). The most economical
method for removing pollutants once secondary standards are
achieved will depend upon which pollutants are of interest,
the degree of additional removal required, and the physical
and hydrologic characteristics of the combined sewer watershed.
Under the current grants program, such tradeoffs in any given
municipality may be compared during the planning process,
which is a major advantage of the present program. This
competition between types of controls (i.e., AWT versus CSO
control) could be largely bypassed if a separate grants
program for CSO control were established.
Continuation of the present system for funding CSO pollution
control projects would also avoid the delays which would be
encountered if the present program is modified by legislative
action.
Disadvantages of Alternative 1
The present facilities planning process has not been applied
to combined sewer overflow abatement on a large scale
except for a few major projects. Past emphasis has been
placed on control of point source discharges, and only a
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small portion of existing CSO control needs have been
addressed in current plans. Thus, there exists today some
uncertainty on how best to apply the present construction
grants program to CSO abatement projects. However, this
uncertainty could probably be reduced to a great extent by
development of additional administrative guidelines rather
by legislative action. Also, funding of CSO control projects
is not generally delayed by the current construction grants
process but by low ranking on the state priority list. The
current program, including the state priority list system,
results in uncertainly in the time required to correct CSO
pollution as discussed in Chapter 5. The rate at which
states fund CSO projects will have a significant effect on
overall CSO correction time. This rate is indeterminate
under the present program.
A further disadvantage of the program as it exists under
present law is its single purpose nature. The objective of
the current water pollution abatement program is to identify
municipal pollution control needs and to provide federal
assistance for the construction of necessary facilities.
The single purpose of pollution abatement does not easily
lend itself to the examination of other urban water resources
benefits derived from construction of CSO pollution abatement
facilities, such as improved urban drainage and flood control.
The current law is designed to assist municipalities in
construction of needed water pollution control facilities.
Operation and maintenance costs are the responsibility of
the municipal owner. Therefore, proposed solutions may tend
to be skewed toward construction of treatment facilities
(capital improvements) since these are grant eligible rather
than toward implementation of management practices which are
not currently grant eligible. Thus, proposed solutions to
the CSO program developed under the present law may be
suboptimal from the standpoint of total urban water resources
management and may also be suboptimal for the single purpose
of pollution abatement because only selected portions of
pollution control needs (i.e., capital expenditures) are
grant eligible.
The overall cost savings which would result from funding
management practices may be more theoretical than actual.
The discussion of the unit cost of technological alternatives
for CSO control presented in Chapter 7 indicates that there
is no clear-cut cost advantage for known management practices
for CSO control. Streetsweeping and catch basin cleaning
have limited effectiveness at relatively high cost. Sewer
flushing can be quite competitive with other techniques,
from both a unit cost and effectiveness standpoint. However,
automatic sewer flushing systems can be designed which
- 3
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minimize operation and maintenance costs and maximize the
grant-eligible portion, which could make such systems
attractive to municipalities under the current eligibility
practices.
ALTERNATIVE 2—MODIFICATION OF CURRENT LAW TO
PROVIDE CONGRESSIONAL FUNDING OF LARGER PROJECTS
"Major combined sewer overflow pollution abatement projects
would be subject to funding on a case-by-case basis. Once
the planning process is complete, each project would be
presented to Congress. Congress would have a clear picture
of the costs likely to be incurred and the benefits likely
to accrue from the plan. The decision whether to fund all
of the project, a portion of the project, or none of the
project would rest with Congress."
Under this alternative, the basic framework of the existing
law is assumed to be adequate or nearly so. National CSO
pollution control construction needs are estimated to be
nearly $20 billion in January 1978 dollars. Based on 75% grant
eligibility, this would result in an expenditure of nearly
$15 billion in federal tax funds. Perhaps funding decisions
of this magnitude should be the responsibility of the legislative
rather than the executive branch of government. Therefore,
the purpose of Alternative 2 would be to transfer the final
decision to fund a given major project from the executive
branch of government to the legislative branch of government.
Theoretically, the above decision process could be applied
to all urban areas presently served by combined sewer systems.
However, the number of such communities is so large, approximately
1,300, that this alternative may be unmanageable on a nationwide
basis. Thus, a definition of "major combined sewer overflow
pollution abatement project" is required. A possible definition
could be similar to the criteria used to develop the list of
urban areas faced with major CSO control problems which is
presented in Table 5-1. This table lists 58 urban areas
located in SMSA's with combined sewer service areas equal to
or greater than 10,000 acres in size. This listing accounts
for approximately 83% of the total national combined sewer
service areas and for 81% of the total national population
served by combined sewers. These cities are likely to
account for at least 80% of the total national needs for CSO
control. Obviously, a large portion of the total problem is
concentrated in relatively few geographic locations which
may be termed major project areas.
Under Alternative 2, those projects which do not meet the
criteria for major projects would be funded through the
existing grants program.
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Advantages of Alternative 2
The advantage of Alternative 2 "Modification of Current Law
to Provide Congressional Funding of Larger Projects" is that
responsibility for funding a given major CSO pollution
control project is transferred from the executive branch of
government to the legislative branch of government. In this
manner, the costs and benefits of a given pollution control
project can be weighed against the costs and benefits of
other national needs which are known to the legislators.
The decision to spend limited federal funds for pollution
control or, for example, highway safety or education would
rest with elected officials.
Disadvantages of Alternative 2
There are several disadvantages of Alternative 2. First, it
would take some time to develop and pass such a law, which
would result in an equal period of construction delays.
Second, once a planning procedure was established and a
given plan and funding request was submitted to Congress for
action, an additional unknown period of time would elapse
before a decision is reached. During this entire period,
the municipality would be uncertain as to timing and level
of funding of their project. Overall CSO correction time
would be even less certain under Alternative 2 than it is
under the present program.
Another major disadvantage for Alternative 2 is that it
would effectively remove local and state authorities from
the decision-making process, which could result in an overall
adverse effect to a given state's water pollution control
program.
ALTERNATIVE 3—MODIFICATION OF CURRENT LAW TO
PROVIDE FUNDING FOR NONSTRUCTTJRAL CONTROL TECHNIQUES
"Combined sewer overflow pollution abatement projects may
include a mixture of both structural controls and management
practices. Management practices consist of those techniques
which require very few, if any, capital expenditures. Such
operation and maintenance costs are not grant eligible under
the current law."
Pollution from combined sewer overflow may be reduced by
several different techniques, as discussed in Chapter 7.
These techniques may be structural such as expansion of
existing treatment plants to treat a larger portion of the
flow, construction of storage basins to capture excess flow
for subsequent treatment, or physical separation of the
sewers. Each of the above may, under certain conditions, be
- 5
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grant eligible. On the other hand, techniques exist which
require very few, if any, capital expenditures. These are
termed management practices. In certain situations, it may
be more cost effective (i.e., less total cost per unit of
pollutant removed) to implement a nonstructural control than
to construct a structural control. However, federal aid is
available only in the form of construction grants, which may
tend to discourage the use of cost-effective nonstructural
alternatives. Modification of the existing law to allow
federal funding of management practices where they are shown
to be cost effective would be a step in the direction of
providing optimal pollution control strategies. However, as
discussed under Alternative 1, the potential cost savings
associated with implementation of management practices for
CSO control may be more theoretical than actual.
Advantages of Alternative 3
The major advantage of Alternative 3 is that it has the
potential for minimizing the overall unit cost of pollution
removal for CSO control projects.
Disadvantages of Alternative 3
Implementation of Alternative 3 would constitute a major
shift in federal involvement in water pollution control. To
date, federal involvement has been limited to construction
grants designed to aid municipalities with capital expendi-
tures. The responsibility for operating and maintaining the
completed facilities lies entirely with the owner. If any
operation and maintenance costs become grant eligible, the
precedent could be logically expanded to all operation and
maintenance costs including treatment plant operation, sewer
cleaning, streetsweeping, inflow correction, or any other
activity which results in removal of any pollutants from a
combined sewer watershed or separate sanitary collection
network. Thus, federal participation could expand into many
areas on a long-term basis, which are now clearly beyond the
scope of federal participation.
For example, if the operation and maintenance (O&M) portion of
streetsweeping and/or combined sewer flushing (which are
relatively ineffective pollution control practices compared
to secondary wastewater treatment) became grant-eligible, a
strong_argument could be made for treatment plant O&M eligibility.
Operation and maintenance of a secondary wastewater treatment
plant accounts for approximately 20% to 30% of the total
annual cost. Thus, if O&M grants as well as construction
grants were awarded for wastewater treatment, federal participation
could easily be expanded by 25% to 45% above current levels
due to WWTP O&M alone. Ultimately, the addition of O&M cost
in municipal grants could add several billion dollars per
year to the federal share.
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In addition, as previously discussed in Chapter 7 and under
Alternative 1, the most competitive of the available combined
sewer management practices appears to be sewer flushing.
Sewer flushing systems can be designed to minimize O&M costs
and to maximize the capital or grant-eligible portion (by
use of automatic flushing stations in lieu of manual flushing)
which should make such systems attractive under current
eligibility practices.
Other disadvantages include delays related to the development
and passage of enabling legislation and in a reevaluation of
plans previously approved.
ALTERNATIVE 4—MODIFICATION OF CURRENT LAW TO PROVIDE
A SEPARATE FUNDING FOR COMBINED SEWER OVERFLOW PROJECTS
"Combined sewer overflow pollution abatement projects would
be funded from amounts specifically earmarked by Congress
for this purpose. The funds could be made available either
from a national fund or as a set-aside within each State's
allotment of grant funds."
This approach would provide a certain annual allocation of
funds for the purpose of abatement of pollution from combined
sewer overflow. The set-aside percentage could be the ratio
of state CSO needs to total state allocation, or it could be
a national fund established as the ratio of national CSO
control needs to total national needs. If this approach
were utilized, then the problem will become one of determining
the optimum use of the available funds.
The planning process could be multipurpose, with funds
available for the water quality improvement portion of the
project. This alternative could be applied nationwide to
all urban areas served by combined sewers, or it could be
integrated with Alternative 2 to provide a planning and
funding vehicle for both major and minor projects.
Alternative 4, along with Alternative 1, received the most
favorable comments from states and municipalities submitting
replies, as reported in Appendix A. Most favorable responses
recommended a national allotment rather than an additional
state-by-state set-aside. Such an approach would in effect
establish a separate grants program for CSO control. Since
CSO control problems are substantially different from dry-
weather flow pollution control problems which require
different types of analysis, this alternative has intuitive
merit. However, fragmentation of the grants program could
result in suboptimum solutions to an individual municipalities
pollution abatement problem.
- 7
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Advantages of Alternative 4
The major advantage of this approach is that nationwide CSO
pollution correction effort would be known and that munici-
palities could plan on a long-term and orderly basis, since
there would be some assurance that construction funds would
be available during the year that construction is planned.
That is, an assured level of CSO control funding projected
over a realistic and predictable timetable would be provided,
This alternative would also reduce the uncertainities
associated with CSO correction time.
Disadvantages of Alternative 4
Because funding would be earmarked for a special category of
pollution control projects, these funds would be utilized
for that purpose regardless of the relative effectiveness in
reducing pollution. That is, the competition between types
of projects provided by the present program through the
state priority procedure would be largely bypassed under
Alternative 4.
Delays would also be encountered due to the time required to
develop and pass the enabling legislation. However, these
delays should not be as great as for Alternatives 2 and 3
since only the method of funding and not the basic decision
process or overall grant eligibility is in question.
ALTERNATIVE 5—DEVELOPMENT OF A NEW LAW TO PROVIDE
FUNDING FOR MULTIPURPOSE URBAN WATER RESOURCES PROJECTS
"The new legislation would provide for multipurpose urban
water resources projects planning and construction funding.
The objectives may include: (1) recreation, (2) urban drainage,
(3) point source pollution control, (4) control of pollution
from combined sewer overflows, (5) control of pollution from
urban stormwater runoff, (6) urban water supply including
water reuse, and (7) major flood control projects. Funds
for those portions of each project which provide substantial
benefits relative to costs could be authorized by Congress
on a case-by-case basis, or drawn from existing programs
such as those administered by EPA, HUD, and EDA."
A new law for multipurpose urban water resources planning
and construction offers the greatest potential for achieving
optimum investment of funds to achieve nationwide urban
water quality goals. It also offers perhaps the greatest
potential for diversion of funds to other objectives due to
the realities associated with growing water resources and
other national needs. While these may represent extremes,
it is probable that passage of new multipurpose legislation
is a higher risk approach to the achievement of urban water
-------
quality objectives than is the continuation or modification
of the present program.
National CSO pollution control needs could run into the tens
of billions of dollars. Single projects for large metropolitan
areas will cost hundreds of millions of dollars. Under the
present law, decisions regarding the federal portion of
these expenditures are the responsibility of the EPA Administrator
and, thus, the responsibility of the executive branch of
government.
If total multipurpose urban water resources needs are
considered including water supply and urban drainage, then
total expenditures for a single city could easily reach
several billions of dollars (See Chapter 1). When faced
with such a huge expenditure, the decision as to who pays
what portion of the cost becomes very important. Perhaps
decisions of this magnitude should be made by the legislative
branch of the government. Before such a decision can be
adequately addressed, the costs and benefits associated with
(or allocated to) each of the multipurpose objectives must
be known. Under Alternative 5, CSO control, along with
other major urban water resources needs, could be weighed
against national needs such as education and defense and
could be compared to our available limited resources.
Advantages of Alternative 5
Implementation of Alternative 5 would provide a needed
remedy for the present fragmentation of urban water resources
efforts which currently involve several federal agencies,
each with a limited role, the states, and the municipalities.
Elimination or reduction of this present fragmentation is
considered a major advantage of Alternative 5.
Another advantage of Alternative 5 is that funding for CSO
and other urban pollution control projects would be evaluated
against all other urban water resources projects; therefore,
the optimum investment of available funds would be known and
could be achieved if this flexibility were built into the
enabling legislation.
Congress would have a clear picture of the costs and benefits
not only of the water quality control portion of an urban
area's water resources needs, but also of all other water
resources needs of which water quality control may be only
a small part. Thus, an overview would be available before
the key decisions for a given project were made.
- 9
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Disadvantages of Alternative 5
Implementation of Alternative 5 would result in delays in
construction of CSO pollution control facilities much greater
than those delays likely to be encountered in any of the
other alternatives. These delays would be due to the fact
that Alternative 5 represents the most radical departure
from present practice and would require the cooperation and
coordination of several federal agencies as well as state
and local governments. Many comments received from state
and local officials questioned the practical workability of
such an approach.
A very flexible interpretation of Alternative 5 would
represent a significant departure from the philosophy of
PL 92-500, which is to control water pollution and to set
aside funds to be used for this single purpose. It is not
the intent of the present law to allow free competition
among multipurpose objectives for thse funds. Details of
this question would have to be addressed in the language of
the enabling legislation. Safeguards could be built in to
protect or modify the intent of PL 92-500 as deemed appropriate.
Alternative 5 does not address the question of CSO pollution
control outside of major urban areas. These combined sewer
systems would have to be handled under a separate program.
SUMMARY OF ALTERNATIVES
Alternative 1 "Continue with Present Law" appears to be one
of the most viable and would probably result in minimum
construction delays. Total time to correction would remain
an unknown since all projects would be subject to the states'
priority system.
Alternative 2 "Modification of Current Law to Provide
Congressional Funding of Larger Projects" received little
support from local and state officials submitting comments.
This alternative is preceived as adding substantial delays
and uncertainty to the CSO pollution abatement process
without adding any quality to the end product.
Alternative 3 "Modification of Current Law to Provide Funding
for Nonstructural Control Techniques" does not at this time
appear viable because of its limited probable benefits and
the high risk of expanding the federal role in water quality
control far beyond current limits.
Alternative 4 "Modification of Current Law to Provide a
Separate Funding for Combined Sewer Overflow Projects" also
appears to be one of the most viable and workable solutions
- 10
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to the problem of funding CSO pollution abatement projects.
In general, individuals located in areas of the country with
major combined sewer service areas who submitted comments on
the alternatives favored Alternative 4 with a national fund
(separate grants program) while individuals located in areas
of the country with few combined sewer systems who submitted
comments favored Alternative 1.
Alternative 5 "Development of a New Law to Provide Funding
for Multipurpose Urban Water Resources Projects" raises
questions of national urban water resources policy far
beyond the question of CSO pollution control. Most indi-
viduals who submitted comments questioned the workability of
such an approach, based in part upon anticipated substantial
construction delays.
RECOMMENDATIONS
It is recommended that Alternative 1, "Continue with Present
Law", be adopted as the funding method for future combined
sewer overflow pollution abatement projects. However, if
CSO pollution is to be corrected in a reasonable period of
time, states with substantial CSO needs must be willing to
spend a greater share of their annual allocation on CSO
projects. Moreover, the relative size of the allocation to
these states would be increased if annual appropriations
were alloted among the states based to a greater degree on
CSO needs.
It must be remembered that any increase in spending for
combined sewer overflow control needs (Category V) will
result in a decrease in spending for all other pollution
control needs (Categories I-IVB). These tradeoffs must be
weighted carefully for any given municipality. It is
believed that this site-specific examination of pollution
control tradeoffs can best be accomplished in a timely
fashion under the present law.
This report is based on the best available information,
including unpublished data currently being gathered for the
1978 Needs Survey. The Needs Survey results, due 10 February
1979, will permit refinement of the conclusions and recommen-
dations in this report. The Needs Survey results will, for
example, provide a revised estimate by state of the cost of
controlling combined sewer overflow and an analysis of the
impact of pollutant loads for combined sewers on receiving
waters.
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APPENDIX A
CORRESPONDENCE
-------
Bruce Babbitt, Governor
WBStS»«©£S*f S WS»or
SUZANNE DANDOY,M.D.,M.P.H.,Director
ARIZONA DEPARTMENT OF HEALTH SERVICES
Division of Environmental Health Services
July 21, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
Dear Mr. Cook:
This Department has reviewed your list of legislative alter-
natives for funding combined sewer abatement projects.
Although Arizona does not have a great amount of experience
with combined sewers, Alternative 1 appears to be the best
option; to continue to solve pollution problems from combined
sewers in priority order with all other projects.
Sincerely,
RLM:JWS:ca
Ronald L. Miller, Ph.D., Chief
Bureau of Water Quality Control
State Health Building
A - 2
1740 West Adams Street
Phoenix, Arizona 85007
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\TE OF CALIFORNIA—THE RESOURCES AGENCY
EDMUND G. BROWN JR., Govsrnor
; WATER RESOURCES CONTROL BOARD
IVISiON OF WATER QUALITY
!5 0. BOX 100 • SACRAMENTO 95801
(916) 445-7971
JUL 281978
In Reply Refer
to: 500:RW
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, B.C. 20460
LEGISLATIVE ALTERNATIVES FOR COMBINED SEWER PROJECTS
We have reviewed your subject memo dated July 3, 1978.
California has very few combined sewer systems. In fact, San
Francisco is the only city where work needed to deal with the
existing problems involves extremely large capital expenditures
Step 3 grants have been made to Sacramento, the next largest
city with combined sewers. The several remaining combined
sewer systems are rather small.
With respect to your alternatives for combined sewers, we
prefer No. 1 as it has been satisfactory for funding needed
projects in California. Our concern is that a system not be
developed which would introduce long delays in the San
Francisco combined sewer project which is partly in construc-
tion, partly in design, and partly in planning.
Your other alternatives, although not particularly attractive
as a way to complete San Francisco project, seem to be an
adequate base for a response to the law.
Thank you for the opportunity to comment on this subject.
w*
Ray Walsh
Assistant Division Chief
A - 3
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GOVERNMENT OF THE DISTRICT OF COLUMBIA
DEPARTMENT OF ENVIRONMENTAL SERVICES
ENVIRONMENTAL HEALTH ADMINISTRATION
WASHINGTON, D. C. 2OOO2
July 24, 1978
Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 "M" Street, S. W.
Washington, D. C. 20460
Subject: (Legislative Alternatives for Combined
Sewer Projects)
Dear Mr. Cook:
A review of the five legislative alternatives for funding
combined sewer abatement projects indicates your outline is
all inclusive and no additional legislative alternatives are
suggested. Furthermore, this office prefers alternative 3 -
"Modification of current law to provide funding for nons tructural
control techniques".
At this time , alternative 3 does not meet funding require-
ments under existing law. It is our suggestion that the law
should be modified to include funding for best management
practices because we believe this to be the most cost effective
of the five legislative alternatives.
Sincerely ,
ENVIRONMENTAL HEALTH ADMINISTRATION
BAILUS WALKER, Jr., Ph.D., M.P.H.
Environmental Health Scientist
Administrator
Robert Heckelman, Chief
Water Hygiene Division
Bureau of Air and Water Quality
A - 4
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of ^Natural
ENVI RONMENTAL PROTECTION DIVISION
JOE D. TANNER 270 WASHINGTON STREET. S.W
Commissioner ATLANTA. GEORGIA 30334
J. LEONARD LEDBETTER
Division Director
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S. W.
Washington, D. C. 20460
July 25, 1978
RE: Legislative Alternatives for
Combined Sewer Projects Proposal
Georgia EPD Review Comments
Dear Mr. Cook:
We appreciate the opportunity to comment on the proposed Combined Sewer
Overflow (CSO) Treatment Alternatives. In general the Georgia Environmental
Protection Division believes that the most appropriate and efficient manner
of funding Georgia's CSO Projects is through the present planning, design
and construction processes outlined in P.L. 92-500. CSO's are a major problem
in Georgia and the EPD is working towards the funding and mitigation of these
problems within the confines of the present grants system. Two City of Atlanta
projects are nearing completion of design with relatively few problems to date.
Both projects have been administered under the P.L. 92-500 grants program and
are excellent examples of the present system's ability to handle CSO projects.
Our specific item by item review comments are listed below:
1. Alternative 1 - Continue with present law
As stated above, funding CSO's treatment under the present grants'
system is considered the most workable situation presented by the
referenced Legislative Outline.
2. Alternative 2 - Modification of current law to provide Congressional
funding of larger projects
This proposal is not consistent with P.L. 92-500. Consideration on
a case-by-case basis by Congress would cause serious funding delays
and would remove local and State authorities from the decision making
process, which is unacceptable.
3. Alternative 3 - Modification of current law to provide funding for
nonstructural control techniques
This alternative is potentially acceptable but we reserve comment
until further development of it is complete.
A - 5
AN AFFIRMATIVE ACTION/EQUAL EMPLOYMENT OPPORTUNITY EMPLOYER
-------
Mr. Michael B. Cook
Page 2
July 25, 1978
4. Alternative 4 - Modification of current law to provide a separate
funding for combined sewer overflow projects
This alternative would possibly cause revisions of the present grants
program which is unacceptable. Also, serious delays in funding are
assured, as they are under Alternative 2, if Congressional action is
needed.
5. Alternative 5 - Development of a new law to provide funding for
multipurpose urban water resources projects
This proposed legislation would cause severe delays, misplaced
priorities and administrative problems within the existing systems
administered by EPA, HUD and EDA. There would be a bureaucratic
maze for each project to negotiate in order for it to receive funding.
Timely funding would be impossible. CSO projects should be evaluated
with other pollution control projects in order for a fair priority
to be established, but should not be evaluated against general water
resources projects.
We hope these comments are helpful. If you have any questions, feel free
to contact us.
Sincerely;
Harold F. Reheis, P.E., Chief
Water Quality Control Section
KFR:rb
A - 6
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iowa department of environmental quality
reply to: Darrell McAllister
phone: 515/281-8982
July 19, 1978
Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M. Street S.W.
Washington, D.C. 20460
RE: Alternatives for Combined Sewer Projects
Dear Mr. Cook:
EPA's memorandum of July 3, 1978 requesting comments on alternatives for
combined sewer projects has been reviewed by this office and would offer
the following suggestions.
The problem of combined sewer overflows exists both in large and small
cities. Your memorandum appeared to focus on larger cities and did not
provide an alternative that is trying to be implemented in Iowa. This
agency has been trying to get Regional EPA approval for Step 1 construction
grant funds to allow a limited study of the combined sewer problems. The
limited study would provide cost estimates for several alternatives and the
city would select an alternative, or the state water pollution control
agency would indicate an alternative, to be implemented. It would be the
responsibility of the city to implement the approved alternative without
Step 2 or 3 construction grant funds. In some cases, the abatement program
may be available for grant funds.
The Department feels this alternative would not require legislative action
as four of the five alternatives presented in the memo did. Also, implementation
of this alternative would allow EPA to gather needed information for making
decisions on funding of combined sewer abatement projects.
This Department appreciates the opportunity to comment and is available to
supply more information if you need it.
Sincerely,
CHEMICALS AND WATER QUALITY DIVISION
Darrell McAllister, Chief
Construction Grants Section
DMtmla
A - 7
Henry A. Wallace Bui/ding, Des Moines, Iowa 50319
-------
\ State of Kansas . . . ROBERT F. BENNETT,
DWIGHT F. METZLER, Secretary
Topeka, Kansas 66620
July 18, 1978
Mr. Michael B. Cook
Chief, Facilities Requirement Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
Dear Mike:
Mr. Rhett's memorandum of July 3, 1978 requests comments on "Legislative
Alternatives for Combined Sewer Projects". Our comments on the five basic
legislative alternatives are as follows:
1) There is considerable confusion as to the application of the present
law and/or the definition of combined sewers. It seems to me imper-
ative that these two items be addressed in the preamble to the study.
It is easy to define the traditional combined sewer system in which
a single set of pipes carries both sanitary and storm waste and
permits overflows whenever the total load exceeds the capacity of
the system. The situation is, however, radically different when the
community has attached a substantial sanitary sewer load at the
periphery of the combined sewer system. Under this configuration,
the combined sewers then serve a dual purpose i.e., a combined sewer
in the traditional sense, and an interceptor or transport sewer for
separated sewage. Discharges which occur from such a hybrid system
may result in massive bypassing of sanitary sewage. It is my opinion
that hybrid systems of this nature should be treated largely as a
sanitary sewer system.
There seems to be considerable confusion as to the meaning of the
present law. There are those who believe Congress passed a law which
required that all discharges be permitted under the NPDES and that a
minimum of secondary treatment be provided for all discharges by
July 1, 1977. There are others who take the position that Congress
did not intend either the permitting or minimum level of treatment
portions of the Act to apply to bypasses or to overflows from tradi-
tional combined systems. It is also our impression that there has
been considerable variation among Regional offices in approving funding
A - 8
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Michael B. Cook
July 18, 1978
page 2
for combined sewer projects. Under alternative one, it will be
necessary to clearly establish present law both in terms of
minimum level of treatment and NPDES responsibilities.
2) A problem may be associated with discharges into coastal waters.
Public Law 95-217 modified minimum treatment level requirements
for certain municipalities in coastal areas.
3) We believe that a sixth alternative should be included which would
provide for full or partial exemption of tradition or hybrid
combined systems from compliance with the minimum treatment and/or
NPDES requirements of Public Law 92-500. We do not necessarily
support such an alternative, but believe it should be considered.
A sub-option could provide for funding under any of the described
five options for those situations in which it could be established
that combined sewer overflows would «•£ result in significant
damage to receiving waters.
Sincerely yours,
°
Eugene^T. Jensen, Director
Bureau of Water Quality
ETJ:lm
A - 9
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NEIL SOLOMON. M.D., PH.D.
SECRETARY
DEPARTMENT OF HEALTH AND MENTAL HYGIENE
ENVIRONMENTAL HEALTH ADMINISTRATION
P.O. BOX 13387
201 WEST PRESTON STREET
BALTIMORE, MARYLAND 21203
PHONE • 301-383-2740
DONALD H, NOREN
DIRECTOR
July 26, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
U. S. Environmental Protection Agency
401 M Street, S.W.
Washington, D. C. 20460
Dear Mr. Cook:
RE: Legislative Alternatives
for Combined Sewer Projects
This letter is in response to Mr. John T. Rhett's memorandum of
July 3, 1978, in which he requested comments on legislative alternatives
to be studied in the EPA report on combined sewer overflows required by
Section 516(c) of the Clean Water Act.
We suggest that construction projects to alleviate combined sewer
overflows be funded under the present law. Such projects should be
subject to the State's approved Priority System and be ranked on the
State's Priority List along with all other treatment works' to be funded
under the Act. This will assure that available funds are utilized on
those projects which will be most effective in reducing water pollution
regardless of the source of pollution.
"Management practices" alleviate or eliminate combined sewer over-
flows should be made grant eligible through an amendment to the present
law, but funded through a separate appropriation. We believe Title II
of the present Act should be used exclusively for construction related
activities.
Note that our suggestions closely parallel your proposed
Alternatives 1 and 3. Alternative 2 is not recommended because of the
opportunity for it to become a "pork barrel" type program. Alternative 4
would direct funds to a specific class of projects regardless of their
A - 10
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Mr. Michael B. Cook
Page 2
effectiveness in reducing pollution and for this reason is not recommended.
Alternative 5 would require new, complex legislation and the extensive
interagency coordination required to implement it could serve to make it
ineffective.
We appreciate this opportunity to provide our comments on the
alternatives you plan to analyze in your report.
Noren, Director
Environmental Health Administration
DHN:dvs
cc: Mr. John Potosnak
The Honorable Neil Solomon
Dr. Benjamin D. White
A - 11
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Minnesota Pollution Control Agency
(612) 296-7301
AUG 16 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
U. S. Environmental Protection Agency
401 M Street Southwest
Washington, B.C. 20460
Re: Legislative Alternatives for Combined Sewer Projects
Dear Mr. Cook:
We have reviewed the referenced memorandum of July 3, 1978
pertaining to the U. S. Environmental Protection Agency (EPA)
report to Congress on funding combined sewer abatement projects,
and we wish to make the following comments.
We believe the five selected alternatives, as proposed, are viable
approaches, representative of the funding methodology which must
be considered for further detailed evaluation. Specific comments
are listed for the indicated alternatives and address mainly
clarification in the scope of the individual alternatives.
Alternative 1 - Continue with the present law. It is unclear
whether the Act will remain unchanged or whether the Regulations
and Program Memorandums will remain unchanged as well. An
evaluation should be made of how far EPA could proceed in changing
the program without changing the Act; i.e., shifting of priori-
ties and acceptable pollution abatement solutions.
Alternative 2 - Modification of current law to provide Congres-
sional funding of larger projects. The scope of this alternative
is unclear as to how smaller combined sewer overflow projects
would be addressed in this alternative; i.e., would the funding
be exclusive to larger projects?
Alternative 5 - Development of a new law to provide funding for
multipurpose urban water resources projects. This alternative
is broad in definition and should be given appropriate resource
allocation in its development. Another approach to Alternative
5 would be to divide the alternative into two subparts: One
A - 12
1935 West County Road B2, Roseville, Minnesota 55113
Regional Offices • Duluth/Brainerd / Fergus Falls/Marshall/Rochester/Roseville
Equal Opportunity Employer
-------
Mr. Michael B. Cook, Chief
Page Two
AUG 16 1978
alternative might be an evaluation of a comprehensive approach,
and a second alternative could be the evaluation of handling
the concept through existing programs; i.e., the 208 Program and
other water management programs.
We hope that these comments will be considered in developing
the report on funding legislation to Congress. Should any
questions arise concerning these comments, my staff will be
available tc offar assistance.
Sincerely,
San
Executi
SSGrsl
A - 13
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North Carolina Department of Natural
Resources &Community Development
James B. Hunt, Jr., Governor Howard N. Lee, Secretary
Division of Environmental Management
July 20, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch(WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
Dear Mr. Cook:
In response to Mr. John T. Rhett's July 3 memorandum, the North Carolina
Department of Natural Resources and Community Development, Division of Environmental
Management is pleased to offer the following comments for your consideration
relative to "Legislative Alternatives For Funding Combined Sewer Abatement
Projects". Our comments are brief, and address one general and two specific
areas of concern.
1. In all five(5) legislative alternatives, the prime consideration
for funding any combined sewer abatement project should be based
on the project's net economic benefits. Thus, any project not
proven to be cost-effective would not be funded.
2. Legislative alternative #5 is too broad in its coverage. We
suggest that the scope of this proposed legislation be limited
to: point source pollution control, control of pollution from
combined sewer overflows, control of pollution from urban storm
water runoff, and urban water supply including reuse. This
reduction in coverage will make the proposed legislation more
implementable and thereby much more effective in its effort to
reduce water pollution levels.
3. Finally, we believe evaluation of a sixth legislative alternative
is in order: discontinue funding of combined sewer abatement
projects and transfer these funds to construction grants and
non-point source pollution abatement projects. Nationally, this
transfer of funds should result in greater reduction of surface
water pollution and contribute significantly to the goal of
pollution-free waters.
A - 14
P. O. Box 27687 Raleigh, North Carolina 27611
An Equal Opportunity Affirmative Action Employer
-------
Mr. Michael B. Cook, Chief
July 20, 1978
Page 2
We appreciate this opportunity to offer our comments and we trust that
they will be of some value to you.
Sincerely yours,
A. F. McRorie
Director
A - 15
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Mr. Michael B. Cook, Chief July 26, 1978
Facility Requirements Branch (WH 547)
Environmental Protection Agency
401 M. Street, S.W.
Washington, Ohio 20460
Dear Mr. Cook:
We are responding pursuant to your request for comments on
proposed legislative alternatives for funding combined sewer
abatement projects. The 1976 Needs Survey identified costs
of approximately 1.8 billion dollars in Ohio for combined
sewer projects. Thus the Ohio EPA is extremely interested in
any program which increases the federal funding effort in
an area so critical to attainment of water quality standards.
It is our opinion that Alternative 4, modifying current law
to provide separate funding, is the most feasible and provides
the most positive approach to pollution abatement from combined
sewer overflows.
Under the present program (Alternative 1) most of the grant
monies have been directed to NPDES permit related activities.
For the most part these have been directed toward achieving
final effluent limitations based on meeting water quality
standards during dry weather. Very little has been done to
date under the present law to control combined sewer discharges
It was the intent of P.L. 95-217 to bring some stability to
the construction grant program by establishing a long term
funding program so the states and the grantees would have a
better expectation of future funding levels. It would appear
that Alternative 2 runs contrary to this philosophy as it
would leave funding entirely at the discretion of the Congress.
This has the potential for creating utter chaos in the waste-
water planning process.
Alternative 3, calling for nonstructural control techniques,
has the potential to significantly increase operation and
maintenance costs to local governments for a program with
questionable effectiveness. This alternative at a time when
local governments are attempting to limit increases in
personnel costs is not recommended.
A - 16
State of Ohio Environmental Protection Agency
Box 1049, 361 E. Broad St., Columbus, Ohio 43216 • (614) 466-8565
James A. Rhodes, Governor
Ned E.Williams, P.E., Director
-------
Mr. Michael B,
July 26, 1978
Page Two
Cook
The facility planning program, as presently developed, is
extremely complex requiring months if not years of effort
to achieve an end product. It would appear that from
Alternative 5, developing multipurpose projects, a program
could emerge which would be so unwieldy as to be totally
unworkable. In the meantime, progress on combined sewer
abatement projects could come to a standstill. Therefore
we do not recommend this alternative, either.
As stated previously, we feel that additional emphasis for
the combined sewer program is urgently needed and request
that it be implemented as expeditiously as possible.
Very truly yours,
Di rector
NEW/ds
cc: Ernie Rotering
A - 17
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DEPARTMENT OF ENVIRONMENTAL RESOURCES
POST OFFICE BOX 2063
HARRISBURG, PENNSYLVANIA 17120
August 16, 1978
In reply refer to:
File: 10-1.34
Mr. Michael Cook, Chief
Facility Requirements Branch (WH-547)
.Environmental Protection Agency
401 M Street, S.W.
Washington, D. C. 20460
Dear Mr. Cook:
This is in response to your request for comments on the legislative
alternatives for combined sewer projects.
We believe that Alternative 3 with certain modifications offers the
best course of action. Both structural controls and management practices
should be considered in planning such a project. However, the management
practice component of a project will not be seriously considered unless
there are incentives incorporated in the legislative package to share the
cost of operation and maintenance associated with these alternatives„ The
fact that capital expenditure gets subsidized by federal funding will
always tilt the scale in favor of capital-intensive measures at the expense
of management practices. One possible way to deal with the problem is
to subsidize operation and maintenance costs on an annual basis. Such
subsidy could take various forms: (a) the management entity (authority,
municipality, etc.) is reimbursed a fixed percent of the cost of operation;
(b) the management entity or political jurisdiction on behalf of the manage-
ment entity receives a block grant; (c) taxpayers in the management district
receive a tax credit on their individual tax return when they check that a
federally approved storm water management plan for the management district/
area has been implemented.
We realize there are shortcomings in each of the three forms. However,
any other appropriate mechanism to subsidize operation and maintenance
costs could be developed and included as a part of the recommended Alterna-
tive 3.
.cerely yonrs,
Daniel B. Drawbaugh, Chi
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STATE OF RHODE ISLAND AND PROVIDENCE PLANTATIONS
Department of Administration
STATEWIDE PLANNING PROGRAM
265 Melrose Street
Providence, Rhode Island 02907 July 11, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
Dear Mr. Cook:
I have reviewed Mr. John Rhett's memorandum of July 3 on
"Legislative Alternatives for Combined Sewer Projects." As the
agency responsible for preparation of long range and system plans
for Rhode Island and for conduct of the 208 project in this state,
we are directly concerned with correction of the problems created
by combined sewers. These exist in Providence, Pawtucket, Central
Falls, and Newport.
The five basic legislative alternatives which you outline
appear to cover the significant options available, however, only
two of these adequately address problems of the type experienced
with the combined sewer systems in Rhode Island as noted above.
These are Alternatives 1 and 4.
Alternative 1 appears to represent the most simple and direct
approach to these problems and to the achievement of the objectives
of P.L. 92-500. The problem with this alternative is the lack of
a clear policy on the part of EPA as to the availability of future
funds for combined sewer abatement projects. I believe that these
combined systems must be addressed under the objectives of P.L. 92-
500 and that a clarification of EPA's policy toward future funding
is urgently needed. If this is not possible, then Alternative 4,
which would establish a separate fund for combined sewer abatement
projects, could be workable. However, this appears to be more com-
plicated than the policy clarification suggested for Alternative 1.
The three remaining alternatives do not represent valid ap-
proaches to the correction of combined sewer systems. The adoption
of any one of these alternatives would require that the goals of
P.L. 92-500 be substantially modified. The goal of fishable, swim-
mable waters cannot be met under any of them.
A - 19
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Mr. Michael B. Cook
July 11, 1978
Page 2
Each of these three latter alternatives presents a different
problem. Alternative 2 is simply unworkable from the standpoint
of the time and effort which would be required in negotiating fund-
ing for each project on a case by case basis. There seems to be
no problem in giving Congress a "clear picture" of the costs of
combined sewer abatement. Estimates of these costs should be
available from the water quality management (303) plans and area-
wide waste treatment (208) plans which are nearing completion
for virtually every combined system. The difficulty with Alter-
native 3 lies in the lack of feasible nonstructural control tech-
niques for any but the very largest combined systems. No satis-
factory nonstructural control techniques, for example, have been
identified in an intensive study of the combined system serving
Providence. Alternative 5 would make the available funding eligi-
ble for so many different activities, including some which have no
direct relationship to water quality or combined sewer abatement,
that little or nothing would be accomplished in solving the com-
bined system problem. Instead, these funds would be diverted to
recreation, urban water supply, or flood control projects, and
combined sewer abatement would be deferred for a few more decades.
I hope that this brief review provides the information that
you need. Please feel free to contact me if we can be of further
assistance.
Yours very truly,
Daniel W. Varin
Chief
DWV/rc
A - 20
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STATE OF RHODE ISLAND AND PROVIDENCE PLANTATIONS
DEPARTMENT OF ENVIRONMENTAL MANAGEMENT
75 Davis Street
Providence, R. I. 02908
19 July 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
U.S. Environmental Protection Agency
410 M Street S.W.
Washington, D. C. 20460
Dear Mr. Cook:
This office has reviewed the five proposed Legislative Alternatives
for Combined Sewer Projects. It is felt that Alternative #1 "Continue
with present law" is the only workable plan. Alternative #2 would only
increase the required paperwork, if Congress were needed to make final
decisions on each project. Alternative #3 appears to be opening the
door to a program which will be very difficult to control. The set
aside funds, as referred to in Alternative #4, should not be mandatory
and returnable for real location if not used by the State. Alternative
#5 again is too broad and would dilute this nation's pollution abatement
efforts.
This statement is brief and contains the reply requested. Please
notify me if any additional alternatives are analyzed.
Yours very truly,
JWF:ESS:mn /James W. Fester, Chief
Division of Water Resources
Department of Environmental
Management
A - 21
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TEXAS DEPARTMENT OF WATER RESOURCES
1700 N. Congress Avenue
Austin, Texas
^ £-=- Of
TEXAS WATER DEVELOPMENT BOARD
A. L. Black. Oluii-ni.m
Robert B. Gilmore, Vice Chairman
Milton T. Potts
John H. Garrett
George \V. McCleskey
Glen E. Ronev
TEXAS WATER COMMISSION
Joe D. Carrer,Cli.iir,,,;m
Dorsey B. Hardeman
Joe R. Carroll
Harvey Davis
Executive Director
July 14, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S .W.
Washington, D.C. 20460
Dear Mr. Cook:
Re: Proposed Legislative Alternative
for Combined Sewer Projects
In accordance with the Environmental Protection Agency letter of
July 3, 1978, subject referenced above, we have reviewed the proposed
alternatives and we request that we also be allowed to review the
draft study report on funding combined sewer abatement projects when
it is completed.
With reference to the alternatives proposed, we feel that combined
sewer abatement projects be funded with a national fund authorized
by Congress and not be funded with EPA construction grant funds
allotted to states.
An additional alternative should be considered as Alternative Number
6 for development of a new law for separate funding for combined
sewer overflow projects with multipurpose urban water resource
projects. This alternative would be the combination of Alternatives
4 and 5 except EPA construction grant funds for allocation to states
would not be used for such projects. Also the Corps of Engineers
could administer funds for projects associated with items 2, 5, 6
and 7 under Alternative 5.
A - 22
P.O. Box 13087 Capitol Station . Austin, Texas 78711 • Area Code 512/475-3187
-------
Mr. Michael-B. Cook, Chief
Page 2
July 14, 1978
If we may be of further service, please do not hesitate to let us
know.
Sincerely yours,
Emory G. Long, Director
Construction Grants and Water
Quality Planning
A - 23
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RAY BLANTON
GOVERNOR
Eugene W. Fowinkle, M.D., M.P.H.
Commissionw
STATE OF TENNESSEE
DEPARTMENT OF PUBLIC HEALTH
NASHVILLE 37219
621 Cordell Hull Building
July 26, 1978
Mr. Michael B. Cook, Chief
Facilities Requirement Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
Dear Mr. Cook:
The Outline of Legislative Alternatives attached to memorandum dated July 3,
1978 have been reviewed. It appears that the five alternatives cover all possible
and acceptable solutions.
We feel that possibly alternative 4 is the preferred alternative since it would
provide monies earmarked for the specific purpose and would not take money for
sewage treatment plants and interceptors. Alternative 2 would probably be too
slow to implement. I don't believe we would have much success with alternative 3
since funding is left to local government. Alternative 5 appears much too complex
and includes too many purposes.
If I can be of further service, please call.
Sincerely,
Nolon J/jaenson
Program Coordinator
Division of Water Quality Control
NJB/mk
A - 24
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STATE OF WEST VIRGINIA
DEPARTMENT OF NATURAL RESOURCES
CHARLESTON 25305
DAVID C. CALLAGHAN July 25, 1978
Director
CERTIFIED MAIL
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401M Street, S. W.
Washington, D. C. 20460
Dear Mr. Cook:
Section 516(c) of the Clean Water Act of 1977 requires that EPA sub-
mit by October 1, 1978 a report to Congress on combined sewer overflows.
We have just received a list of legislative alternatives that EPA proposes
to study in this regard. Our comments on each alternative are herein con-
tained for your consideration.
Alternative 1 - Continue with present law
"Combined sewer overflow pollution abatement projects would
be funded under the existing provisions of P.L. 92-500 as amended
in December, 1977 by the Clean Water Act of 1977. Combined sewer
overflow control projects would be funded under section 201 of the
law."
Under the existing law combined sewer overflow control projects
in West Virginia are reviewed and funded on a case-by-case basis with the
funding provided from the annual construction grant allocations. There
are many I/I analyses and sewer system evaluation surveys presently being
conducted in communities in the state. To date, we have had few combined
sewer overflow control projects proposed, therefore, only a small amount
of our construction grant dollars have been obligated toward these pro-
jects (not including I/I analyses and SSES studies). However, in the
immediate future as the SSES studies are completed and approved there will
be proposed more and more combined sewer overflow control projects that will
desire funding from our annual construction grant allocations. With the
great need in this state for adequate wastewater treatment and collection
facilities, we are reluctant to use our construction grant funds for "other"
projects such as combined sewer overflow control. Our comments on Alterna-
tives 3 and 4 to follow express our thoughts relative to the funding aspects
of these projects.
A - 25
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Page 2
Mr. Michael B. Cook Chief July 25, 1978
Facility Requirements Branch
EPA
Alternative 2 Modification of current law to provide Congressional
funding of larger projects
"Major combined sewer overflow pollution abatement projects
would be subject to funding on a case-by-case basis. Once the plan-
ning process is complete, each project would be presented to Congress.
Congress would have a clear picture of the costs likely to be incurred
and the benefits likely to accrue from the plan. The decision whether
to fund all of the project, a portion of the project, or none of the
project would rest with Congress."
The submission of major combined sewer overflow control projects
to Congress on a case-by-case basis for complete or partial approval and the
decision by Congress to fund all or part of these projects seems to be a
most undesirable alternative. A question in our minds is the EPA defini-
tion of "major" and how many projects in West Virginia, if any, would fall
into this category. The idea of submitting any individual projects to Con-
gress for approval and funding does not receive our endorsement at all.
Alternative 3 - Modification of current law to provide funding for
nonstructural control techniques"
"Combined sewer overflow pollution abatement projects may in-
clude a mixture of both structural controls and management practices.
Management practices consist of those techniques which require very few,
if any, capital expenditures. Such operation and maintenance costs are
not grant eligible under the current law."
We would support a modification of the existing law to provide
funding for nonstructural control techniques, although the implementation
of such a program might be difficult. These management practices being
grant eligible could assure the efficient use of funds for structural con-
trols. The funding source for these techniques should be a national fund
as identified in Alternative 4.
Alternative 4 Modification of current law to provide a separate
funding for combined sewer overflow projects'
"Combined sewer overflow pollution abatement projects would be
funded from amounts specifically earmarked by Congress for this purpose.
The funds could be made available either from a national fund or as a set-
aside within each state's allotment of grant funds."
We would approve a modification of the existing law to provide a
separate funding source for combined sewer overflow projects given the
following condition. A national fund for these projects would be most de-
sirable since this amount of money would be a "add-on" to our annual
A - 26
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Page 3 July 25, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch, EPA
construction grant allocation. We would not support another set-aside
within our annual allotment of construction grant funds for reasons that
were previously stated under Alternative 1. There are presently too
many set-asides already (i.e. Step 1 and Step 2 reserves, reserve for
cost-overruns, set-asides for innovative/alternative technologies, etc.)
that deplete funding for much needed projects during the course of a
fiscal year. However, we would support an additional funding allotment
that would be made available to each state for combined sewer overflow
control proj ects.
Alternative 5 Development of a new law to provide funding for
multipurpose urban water resources projects
"The new legislation would provide for multipurpose urban
water resources projects planning and construction funding. The objec-
tives may include: (1) recreation, (2) urban drainage, (3) point source
pollution control, (4) control of pollution from combined sewer over-
flows, (5) control of pollution from urban stormwater runoff, (6) urban
water supply including water reuse, and (7) major flood control projects.
Funds for those portions of each project which provide substantial bene-
fits relative to costs could be authorized by Congress on a case-by-case
basis, or drawn from existing programs such as those administered by EPA,
HUD and EDA."
Again projects authorized by Congress on a case-by-case basis
seems most unrealistic from our point of view. This alternative seems to
be an extension of alternative 2 in that multipurpose urban water resources
projects are now being considered with funding being provided by many
federal agencies. We would strongly disapprove of this alternative in the
same breath as alternative 2.
We hope that when you analyze these alternatives in your report
to Congress our comments will be given careful consideration.
Very truly yours,
WATER RESOURCES DIVISION
/-
Mike
•like Johriseri, Engineer
Construction Grants Section
Municipal Grants Branch
MJ/lt
c: Dave Robinson, Chief, WRD
Bern Wright, Ass't. Chief, WRD
Warren Means, Ass't. Chief-Munic. Grants Branch, WRD
A - 27
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State of Wisconsin \ DEPARTMENT OF NATURAL RESOURCES
Anthony S. Earl
Secretary
BOX 7Qoi
MADISON. WISCONSIN 53707
July 26, 1978 780
IN REPLY REFER TO:.
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
EPA
401 M Street, S.W.
Washington, B.C. 20460
Dear Mr. Cook:
We appreciate being given the opportunity to review the information
on Legislative alternatives for combined sewer projects. Although
the information is of a preliminary nature, we appreciate the
opportunity for input.
While we have no comments on the alternatives mentioned, we would
like to stress the impact that any choice could have on our state.
The current project now in the planning stages in Milwaukee is
estimated to have a cost of $634 million for the combined sewer
overflow abatement alone. Legislation affecting level of funding,
sources of funding and funding administration could have a great
effect on our grant program.
We would welcome the opportunity to comment on draft material in
the future as you begin to study the alternatives and make
recommendations. We would also appreciate being kept informed
as to the status of the report.
Sincerely,
Office of Intergovernmental Programs
Paulette Harder, Chief
Grant-in-Aid Section
cc: Paul Guthrie 14
A - 28
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State of Vermont
Department of Pish and Game
Department of Forest, Parks, and Recreation
Department of Water Resources
Environmental Board
Division of Environmental Engineering
Division of Environmental Protection
Natural Resources Conservation Council
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
AGENCY OF ENVIRONMENTAL CONSERVATION
Montpelier, Vermont 05602
Department of Water Resources
July 17, 1978
RE: Legislative Alternatives
for Combined Sewer Projects
Dear Mr. Cook:
We would like to comment on the proposed legislative alternatives for
combined sewer projects transmitted under John T. Rhett's July 3, 1978
Memorandum.
Alternative 1 - We endorse this alternative because the institutional
arrangements and personnel are currently in place to achieve program
accomplishments without reorganizing or refunding.
Alternative 2 - This alternative only discusses major combined sewer
overflow projects and leaves funding decisions to Congress. Projects needed
for water quality purposes will be subject to loss among other legislative
priorities or could be evaluated mostly from an overall government budgetary
view point instead of an environmental viewpoint. This alternative should
only be developed in conjunction with keeping non-major combined sewer over-
flow projects fundable under alternative 1.
Alternative 3 - Funding of only non-structural control techniques is only
Non-structural control techniques funding should augment
funding, not replace it. Continuing benefits from non-
techniques will require to a great extent continuing funding
a partial solution
structural control
structural control
to be continusouly effective.
Alternative 4 - This alternative is acceptable provided additional funding
is provided by Congress. We specifically oppose creation of further set-asides
of construction grant funds for specific purposes. The existing set-asides
make priority list management unnecessarily time consuming and difficult,
and detract from the states ability to use funds in priority areas of greatest
benefit to the states particular water quality needs.
A - 29
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Mr. Michael B. Cook
July 17, 1978
Page 2
Alternative 5 - This appears too complicated to apply to most projects
which have single purpose goals, as is frequently the case in small to medium
size communities. This appears to address only large urban areas with a
multiplicity of problems. Specific congressional approval would have all the
drawbacks mentioned in alternative #2.
I hope these comments have been of assistance to you. Please call us if
clarification is required.
Sincerely,
Reginald A. LaRps'a,/Director
Environmental Engineering
RAL/sec
A - 30
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vr&viiM& UMj2£tto1^^
607 BOYLSTON STREET
BOSTON
MASSACHUSETTS
02116
617-261-2365
DONALD B. STEVENS. CHAIRMAN
JOAN R. FLOOD. VICE-CHAIRMAN
GEORGE L. BURKE, TREASURER
ALFRED E. PELOQUIN, EXECUTIVE SECRETARY
July 25, 1978
CONNECTICUT
MAINE
MASSACHUSETTS
NEW HAMPSHIRE
NEW YORK
RHODE ISLAND
VERMONT
Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, D. C. 20460
Dear Mike :
I have reviewed the legislative alternatives to be studied
on funding combined sewer abatement projects as set forth in
Jack Rhett's memo of July 3, 1978 and find them all-inclusive.
No other alternatives come to mind at the moment. I assume that
sufficient flexibility will be maintained in the study to allow
for consideration of modified alternatives which may become
apparent as the study proceeds .
The Commission would greatly appreciate the opportunity of
reviewing the draft report prior to its finalization for Congress.
Sincerely,
AEP:jpc
LoquUn
Executive Secretary
A - 31
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LAND-OF-SKV REGIOIMAL COUNCIL
POST OFFICE BOX 217S • A S H E V I L I_ E . NORTH CAROLINA 28802
25 HERITAGE DRIVE • TELEPHONE (7O4) 234-S131
July 18, 1978
Mr. Michael D. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401M Street, SW
Washington, DC 20460
Dear Mr. Cook:
In response to the memorandum of July 3, 1978, from Mr.
John T. Rhett, I offer the following recommendations concerning
the five basic legislative alternatives outlined for combined
sewer overflows.
In general, I believe alternative #3: "Modification of
Current Law to Provide Funding for Non-Structural Control Techniques"
is a recommendation that should be carried out.
If you are to look at any additional alternatives, I would
suggest possibly combining the elements in Alternatives 3, 4,
and 5 so that there would be funding for non-structural control
techniques and additional funding for combined sewer overflows
with case by case funding available for multipurpose urban water
resource projects for large urban areas.
ours
RoberVA. Purcell
208 Project Director
RAP:ds
A - 32
SERVING REGION B: BUNCOMBE. HENDERSON, MADISON at TRANSYLVANIA COUNTIES
-------
Lane Council of Governments
NORTH PLAZA LEVEL PSB / 125 EIGHTH AVENUE EAST/ EUGENE, OREGON 374O1 / TELEPHONE C5O3) 637-4383
July 21, 1978
Mr. Michael Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M. Street, S.W.
Washington, D. C. 20460
Dear Mr. Cook:
We appreciate the opportunity to comment on the development of "Legis-
lative Alternatives for Combined Sewer Projects."
Our 208 Area has identified Urban Runoff Control as a serious problem
needing further attention, even though we are not in an area where
serious combined flows exist. Our major metropolitan area of some
150,000 population (sewered) employs separate systems, and only a few
surrounding communities have partially connected systems.
For these reasons, that is, because none of the other alternatives have
the flexibility or range to deal with situations such as ours, we feel
that Alternative 5 represents the best approach.
Urban waters, including streams receiving storm runoff, represent a
unique and fragile resource that has many more facets of concern in
terms of beneficial use than the subject of "combined sewers' is able to
address. It is felt in our area that urban streams and runoff are no
longer just a nuisance to be buried and forgotten.
Alternative 1 would be adequate as long as theualternative"funding
guidelines for 201 are applied and as long as other urban runoff control
projects are funded separately.
Alternative 2 has some benefits over #1 but still does not address the
smaller, but locally important, or noncombined sewer problems.
Alternative 3 is needed but does not seem to address the special funding
needs of combined sewer correction that cannot be avoided in all cases.
Alternative 4 seems to be much like #2 in actual impact on projects,
although different from an administrative standpoint. Although this
procedure reduces competition for funds, it does not particularly
support other problem solutions.
Alternative 5 represents the most comprehensive and balanced approach.
This is the only legislative approach that specifically addresses the
varied beneficial uses of urban water and runoff. Even so, it may still
A - 33
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Mr. Michael Cook
July 21, 1978
Page Two
be necessary to divide funding between "combined sewer" and "other"
project types and provide special funds for "combined sewer" correction
as well as incentives for nonstructural approaches.
Again, thank you for the opportunity to comment.
Sincerely,
Gerritt Rosenthal
208 Program Manager
GR:rl/Fl&2
A - 34
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GREATER PORTLAND
COUNCIL OF GOVERNMENTS
331 VERANDA STREET-PORTLAND, MAINE O41O3- 207-774-9891
iber
icipalities
Bridgton
•
ipe Elizabeth
•
Casco
•
;umberland
•
Falmouth
•
Freeport
•
Gorham
•
Gray
•
Maples'
•
Portland
•
Pownal
•
Scarborough
•
Sebago
•
outh Portland
•
Westbrook
•
Windham
•
Yarmouth
J
A
July 11, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch(WH-547)
Environmental Protection Agency
S.W.
.C. 20460
401 M Street,
Washington, D,
Dear Mr. Cook:
This letter is to provide comments on the combined sewer overflow
control legislative alternatives outlined in the attachment to
John Rhetts' memorandum of July 3, 1978. The comments are directed
principally at the structure of the proposal rather than at providing
advice as to the preferred approach.
A1t{#5
The alternatives proposed do not appear to represent a single
continuum of responses. One continuum appears to provide in-
creasing congressional control (Alt.#1 Altf#4 Alt.#2
Alternative #3 appears to define appoint on another cbntinuum
providing for a more open funding posture for non-structural con-
trols. The result is that the alternatives are not mutually
exclusive. This topic is complex, and I suggest that a presentation
which does not clearly identify the range of policy choices available
for each of the issues to be addressed will only further the problems
Congress obviously had with the program.
The two issues addressed in the alternatives outline are:
- congressional control
- funding for structural vs. funding for non-structural
pollution abatement
Other issues which occur to me are:
- funding for small, private source controls vs. funding
for larger, centralized, public controls
- seasonal vs. continuous permit requirements
I am sure that with national input the list of issues will grow.
The suggestion is to identify the significant issues in this program
and to define a continuum of responses for each and then to define
a process whereby Congress can pick an appropriate package of responses,
A - 35
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Page 2
Thank you for the opportunity to provide these comments.
Sincerely,
Eric A. Root, Director
Water Resources Planning
EAR/pi
Enclosure
cc: Bill Goodwin, City of Portland
Roy Spugnardi, City of South Portland
Ed Reidman, City of Westbrook
A - 36
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metropolitan Washington
COUNCIL OP GOVERNMENTS
1225 Connecticut Avenue, N.W., Washington, D. C. 2OO36 223-68OO
July 19, 1978
Mr. Michael E. Cook, Chief
Facility Requirements Branch (WH-547)
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
Dear Mr. Cook:
In response to request from Mr. John T. Rhett dated July 3, 1978, seeking
responses to the proposed Legislative Alternatives for Combined Sewer Project,
I would like to make the following comments:
1. Under Alternative 2, some limitation or definition of a "major"
project needs to be identified. This can be defined in terms of a
percentage of annual state allocation for Construction Grants or
in dollars.
2. Alternatives 3 and 4 would only perpetuate the need for more guide-
lines, regulations, and ensuing confusion by grant applicants and
administrators. Both of these alternatives should be included
in your Alternative 5.
Should you need clarification or expansion 'of any of the comments above,
please let me know. You may reach me by phone on Extension 386 at the above
number.
Sincerely,
K. Kenn«
Chief, Water Pollution Control
Department of Water Resources
A - 37
"ct of Columbia • Arlington County • Fairfax County • Loudoun County • Montgomery County » Prince George's County • Prince William County
Alexandria • College Park • Fairfax City • Falls Church • Gaithersburg • Greenbelt « Rockville • Takoma Park
-------
UN
Northwestern Indiana
Regional
Planning Commission
8149 Kennedy Avenue (219)923-1060
Highland, Indiana 46322 (312)731-2646
July 18, 1978
JACK R. CLEM - Chalrrran
PoiXM. County
N. ATTERSON SPANN - Vlce-Cha1rnan
Lube County CowKJA-tone/L
WILLIAM A. FISCHER - Secretary
VERNON SEGERT - Treasurer
Crown Po-tnt C-<-ty C
DONALD L. COPE - Executive Bd.
Town Boand Plt&., Pontw.
CLARK A. HETZ - Executive Bd.
Late County Councx&nan
WILLIAM S. TAHKE - Executive Bd.
Po'LteA County SuAvtyon.
GEORGE H. WILLIAMS - Executive Bd.
D-tAecfOT o£ PeveZopmenf
5 P&innuig, tU.y of, GOAIJ
ALEX DREMONAS - Executive Bd.
NWI RepT.oie.n-Ciiix.ue - Indiana
Coai-Ca-d Zone Management Plant.
RICHARD D. BELL
Tcwn SoaAtf, Hehfion
WILLIAM R. CARMICHAEL
PotfeA County CotnrtoliXJjneA
DANIEL M. COLBY
Tocwi Bound. G^dfrUh
OREAL J. CREPEAU
Aii ' t Co Paw-uient
Gene.ia£ tJ^-tce, In&md Stee^
RAYMOND R. FLACHBAflT
D.ctec£oi j(( Oept. 0|( Peye^pfnent
6 Pffl.nru.ng, CxJti/ 0^ Hanrwnd
ROBERT FREELANO, Jr.
Pieji^denf - &wy Cctt/ Council
TIMOTHY P. GALVIN, Jr.
HanAtifi
Calvin E. Green, Jr.
Mayo*, HoboAf
ROBERT E. COIN
Mai/oi, Po-ito^e
WILLIAM KURTIS
Town. Boand, Vvi-u
COLIN S. MACKENZIE
Oijdert Dunw
JOHN MELCHIORI
Town Son/id, Cfici-C
ROBERT A. PASTRICK
Ha.i/0 1, Eait C)w.cag
EDWARD J. RASKOSKY
GEORGE W. VAN TIL
T.-ufn 600. id. Hj^n
GORMAN E TUFFORD
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M. Street, S.W.
Washington, D.C. 20460
Subject: Comments on Legislative Alternatives for Combined
Projects
Dear Mr. Cook:
The Environmental Management Committee of the Northwestern
Indiana Regional Planning Commission and support staff have
reviewed, the CSO Alternatives and offers the following comments:
Alternative
Comment:
1 - Continue with present law.
Inadequate level of funding; no initiative
for states to concentrate on serious CSO
problems.
Alternative 2- Modification of current law to provide
Congressional funding of larger projects.
Comment: The concept would put the decision to fund
or not to fund in the hands of Congress.
This concept is a long drawn out process
and would tend to slow down plan implementation
of 208 WQM Plans and 201 P.P. recommending
CSO corrections.
Alternative 3 - Modification of current law to provide
funding for non-structural control
techniques.
Comment: While funding 0/M costs for non-structural
controls would be an improvement the alterna-
tive just does not go far enough to address
all the problems.
A - 38
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Michael B. Cook, Chief
Page Two
July 18, 1978
• Alternative 4 - Modification of current law to provide a
separate funding for combined sewer over-
flow projects.
Comment: This alternative has possibilities, however,
the alternative does not include urban storm
water projects. Funding should be at sufficient
levels to be meaningful.
• Alternative 5 •
Comment:
Development of a new law to provide funding
for multipurpose urban water resources projects.
This alternative has the greatest potential for
providing funding of sorely needed urban water
resource improvements. The authorization by
Congress on a case-by-case basis should be deleted.
Existing programs such as those administered by
EPA, HUD, and EDA should also include U.S. Army
Corps of Engineers, Water Resource Council, U.S.D.A.
and other Federal Agencies having programs dealing
with environmental issues. NOTE: Program require-
ments should not duplicate existing requirements,
but should build on past programs with the objec-
tives of improving and/or providing funding for
plan of study, design and construction where gaps
now exist. Consideration should also be given to
industrial waste water treatment and potential
funding.
In addition to the comments on proposed legislative changes, I call
your attention to NIRPC's 208 Water Quality Management Plan costs:
Municipal Waste Water Improvements
Combined Sewer Projects
Storm Sewers and Urban Runoff
Industrial Treatment Improvements
Non-Point Agricultural Runoff
$248 million
$217 million
$6.5 mill ion
$2.4 billion
$ 67 million
These improvements are proposed for only two (2) of Indiana's 92
counties. The current population is some 630,000 and land area of 915
square miles.
Future legislation should consider funding levels that would not
only enable improvements to be made, but at levels and time periods to
insure implementation of the Clear Water Act goals.
Should you have any questions, please contact John J. Janik, Chief,
Water Quality Management Planning at 219-923-1060.
Very truly yours,
WRC/JJJ/dkj
Wflliam R. Carmichael, Chairman
Environmental Management Committee
A - 39
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Soulheasf Michigan Council of Governments
8OO Book Building • Defroif, Michigan • 48226 • (313) 961-4266
July 20, 1978
Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, SW
Washington, D.C. 20460
Dear Mr. Cook:
We are writing pursuant to the request of John E. Rhett for comments
on the five basic legislative alternatives to be analyzed by EPA regarding
combined sewer overflows.
Firstly, we feel that a modification of the existing law would be
preferable to the development of a new law. Over the past three years
we have established an awareness in this region as to goals of the "Clean
Water Act" and the implication of "Section 208," "System 201," etc., and
it would be better to expand programs within this framework rather than
establish a new one.
Secondly, any modifications should definitely include funding a range
of non-structural control techniques which prove cost-effective vis-a-vis
major capital expenditures; (e.g., although it would not necessarily involve
combined sewer situations, we have found instances where the purchase and
relocation of structures would be the most cost-effective way of removing
a pollution problem as opposed to the construction of new facilities, but
we are unable to utilize 201 funds at present for such an option. This,
in effect eliminates this option since 100% local funding is not feasible.)
Thirdly, there is a need for the funding of multipurpose urban water
resource projects as suggested in your alternative five.
Your file alternatives cover all of the above, but we are perhaps sug-
gesting a sixth alternative that would amend the existing law to allow for
the funding of nonstructural and multipurpose projects under a new section.
Further, although allowing Congress to have final decision over individual
projects would have some political appeal, we question whether this would
be an effective way of choosing the best alternative to solving specific
DAVID H SHEPHERD. Chairperson
Mayor. City of Oak Park
ROBERT L BOV1TZ, Vice Chairperson
Mayor. City ol Trenton
A - 40
LAWRENCE R. PERNIOC Vice Chairperson
Commissioner. Oakland County
ROBERT E. SMITH. Vice Chairperson
President. Livingston
Intermediate School District
MICHAEL M. GLUSAC, Executive Director
MARY ELLEN PARROT, Vice Chairperson
Treasurer, Shelby Township
KATHLEEN M. FOJTIK. Vice Chairperson
Commissioner, Washtenaw County
-------
Michael B. Cook, Chief
July 20, 1978
Page Two
local pollution problems. Combined sewers are an integral part of the
overall water pollution problem in most metropolitan areas, and it is
preferable to have as few sources and methods of funding as possible.
Sincerely,
Michael M. Glusac
Executive Director
MMG/tb
A - 41
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VERMONT NATURAL RESOURCES
COUNCIL
July 11, 1978
Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, B.C. 20460
RE: Legislative Alternatives for Combined Sewer Projects
Dear Mr, Cook:
This letter is in response to John Rhett's memo of July 3
requesting comments on legislative alternatives for funding
combined sewer abatement projects. I have a few small comments
to share.
Alternative 2 fails to say anything about "minor" projects.
Would they be funded under existing provisions of Section 201,
or not funded at all? I think it is important to address
funding of minor projects as well as major ones, for what is
'minor" to EPA may
have a major impact in the community itself
Alternative 3 doesn't say whether it would take place
under Section 201 or through some other funding mechanism.
Personally, I think funding management practices would be an
excellent idea, but they might receive little serious consid-
eration under the 201 program as it is now conducted.
Alternative 5 fails to address the problem of rural
projects, I hope EPA realizes that combined sewer overflows
are as serious a problem in some rural communities as in
urban cities. Would this alternative be available to rural
towns, also?
On Alternative 5, I think you will need to be much more
specific about the process by which communities could use
funds "from existing programs such as those administered by
EPA, HUD, and EDA." I believe the success or failure of such
an approach would depend in large part on whether it increases
the "red tape" which towns would have to go through in order
to carry out projects.
Thank you for this opportunity to comment.
questions are helpful to you in your efforts.
I hope these
26 STATE STREET, MONTPELIER. VERMONT
Michele Frome , Director
-------
;HOLASJ.MELAS
PRESIDENT
Bart T. lynam
General Superintendent
751-5722
_ : r] '-: 1 - TH^
METROPOLITAN J
OF MIEATKK < UK A«iO
EASTISRHrE ST.*. CHICAGO.; ILLI-N'lffl 6Q&iMl J.i[
i.L,5.6OO
Trhl
JSL
BOARD OF COMMISSIONERS
JOANNE H. ALTER
JEROME A. COSENTINO
DELORIS M. FOSTER
WILLIAM A. JASKULA
NELLIE L JONES
JAMES C. KIRIE
CHESTER P. MAJEWSKI
NICHOLAS J. MELAS
RICHARD J. TROY
July 17, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
SUBJECT: Legislative Alternatives for Combined Sewer Projects
Dear Mr. Cook:
Per Mr. Rhett's request of July 3, 1978 on the subject topic, I have
reviewed the five alternatives proposed and have a couple of suggestions
relative thereto.
It is my opinion that Alternative 1 should be retained as the principal
mechanism for dealing with water pollution attributable to combined sewer
overflows. It places such projects in the proper perspective of PL/92-500
and the Clean Water Act of 1977. Competition for federal funding of such
projects under state priority guidelines assures that the pollution attri-
butable to such sources is compared with pollution from other sources and
placed at the proper priority level.
A modification of Alternative 5 which would provide a mechanism for co-
ordinating all other urban drainage and runoff control projects with the
pollution control aspects should be considered. Our experience in the
Chicago area indicates that achievement of pollution control aspects of
combined sewer overflows and other polluting discharges from urban areas
can provide cost savings at all levels of government. Funding provisions
which would allow resolution of other urban water management problems in
cooperation with water pollution control problems while retaining the
independence of the water pollution control projects is desirable. Re-
tention of the Alternative 5 as proposed would probably result in com-
bined projects being subjected to an overall cost/benefit analysis which
could override the necessity for eliminating water pollution as directed
by the Clean Water Act. Additionally, the relatively long period required
to obtain approvals of flood control and drainage projects could significantly
impede progress towards elimination of water pollution.
A - 43
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Mr, Michael B. Cook
-2-
July 17, 1978
We are critically aware of the lack of federal precedence for funding of
urban drainage projects and would therefore support a program which addresses
these problems with evaluation criteria and funding mechanism.
Very truly yours,
General Superintendent
cc:
:sbs
Mr. Ron Linton - AMSA
A - 44
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CLEVELAND REGIQIMAL SEWER DISTRICT
tiC1 ROCKWELL. • CLEVELAND OHIO .4^11-4 • TEL SIB 7P:-SEOG
AIMDREWT. UPJGAR
;R
July 25, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, D. C. 20460
Dear Mr. Cook:
Re: Legislative Alternatives for
Combined Sewer Projects
We have reviewed the July 3, 1978, list of legislative
alternatives. The list includes those options of relevance to
combined sewer overflow (CSO) projects. We believe EPA has a
unique opportunity to advise Congress about the varied and com-
plex pollution and drainage issues confronting residents of the
urban environment. The urban need for adequate storm drainage
and combined sewer overflow control facilities is well documented.
The central question is the source of funding to not only abate
pollution from CSO's, but also to alleviate storm water damages.
EPA can do much to focus Congressional interest in these problems.
We offer the following comments as issues which should be
considered during the analysis of the legislative alternatives:
ALTERNATIVE 1. Continue with present law.
We believe the present situation is undesirable, due to
the low priority assigned to CSO projects by many state priority
systems. Also, the guidance for funding CSO's has prescribed
limits which has served, in some cases, to defer needed wet weather
outlet sizing.
The present situation should not be viewed as acceptable
without increased EPA funding flexibility and improved priority
ranking for CSO projects. In essence, Alternative 4 is a more
desirable approach.
ALTERNATIVE 2. Modification of current law to provide Congressional
funding of larger projects.
A definition of "major combined sewer overflow pollution
abatement projects" is needed. We would assume that large cost
projects, including storm water handling elements would be included
in this definition.
A - 45
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Mr. Michael B. Cook, Chief
Page 2
July 25, 1978
A case-by-case project funding by Congress would clearly
show Federal interest and involvement in the urban drainage and
pollution issues.
A concern is that the historical EPA emphasis on rational
demonstration of the need for a project may become lost in such
a cumbersome decision-making process.
ALTERNATIVE 3. Modification of current law to provide funding
for nonstructural control techniques.
The funding of BMP will not alleviate the need for structural
CSO projects in most urban areas. It is our experience that imple-
mentation of BMP activities will not by itself significantly reduce
pollution from urban run-off, although BMP can serve an adjunctive
role in a structural pollution abatement program. We are concerned
that previous planning and design for CSO control would be signifi-
cantly delayed, while BMP requirements are studied. We believe that
BMP implementation would accrue only marginal results, while sub-
jecting necessary structural control projects to the significant
effects of inflation.
EPA should be vary cautious about recommending another set
of planning requirements which add little to the problem solving
process. Also, we are concerned that labor intensive programs,
such as BMP may be perceived by the taxpayer as a "luxury" program
when compared to other services and maintenance of existing struc-
tural facilities.
ALTERNATIVE 4. Modification of current law tojprovide a separate
funding for combined sewer overflow projects.
In an approach limited to the pollution abatement aspect of
the urban combined sewer problem, this alternative warrants the
most serious consideration. The merits of either a national fund
or a mandatory set-aside for state allotments seem equally subject
to debate. While the precedent for a set-aside exists and could
be easily implemented, we are concerned that such an approach could
be used to defer facing the magnitude of the CSO need element in
the swimmable, fishable goals of the Act. A separate national
fund represents a true commitment to abate CSO pollution, but may
conflict with Federal economy measures. EPA should point out
to Congress that the actual conflict is between CSO needs and the
goals of the Act. A compatible solution would be an assured level
A - 46
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Mr. Michael B. Cook, Chief
Page 3
July 25, 1978
of CSO control funding projected over a realistic timetable to
achieve the goals of the Act for this pollution source. We there-
fore recommend a minimum level setr-aside based upon the proportion
of CSO needs to the state allotment. Further, CSO compliance
scheduling should reflect the maximum time required to complete
construction based on the minimum level of annual CSO funding.
We also recommend that EPA reassess PRM 75-34, in order
to provide additional flexibility in those cases where an increase
in wet weather outlet capacity will achieve benefits in storm
water damage reduction.
ALTERNATIVE 5. Development of a new law to provide funding for
multipurpose urban water resources projects. While this may
ultimately become the method by which to resdlve urban water
resource problems, we are concerned that such an approach would
result in significant delays in the construction of those presently
designed CSO projects. We do not believe that the public's best
interest is served by deferring CSO pollution abatement until such
legislation is enacted and an implementing Federal structure is created
We believe that at the present time each Federal agency
involved in urban water resource problems has established an array
of complex regulations and mechanisms in an attempt to minimize
their roles in solving these serious problems. It is obvious that
a remedy for the present fragmentation of urban water resource efforts
is needed. However, we believe that additional study is required
before the roles of each Federal agency can be properly assessed, and
an effective program established. EPA can achieve much by reporting
to Congress on the present situation and by pointing out the need
for a comprehensive study.
We appreciate the opportunity to comment on the legislative
alternatives, and we are available to provide any of our information
which may be of use to you. We look forward to reviewing your
draft report, and we would appreciate being placed on your distri-
bution list for the CSO study documents.
Very truly yours,
Andrew T. Ungar, Director
CLEVELAND REGIONAL SEWER DISTRICT
ATU/inc
cc: AMSA
A - 47
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July 26, 1978 the Evergreen
CITY OF
everett
32OO CEDAR • 239-8821
EVERETT, WASHINGTON
Michael B. Cook, Chief S8Zo,
Facility Requirements Branch (WH-547) DEPARTMENT OF UTILITIES
Environmental Protection Agency
401 M Street, S. W.
Washington, B.C. 20460
LEGISLATIVE ALTERNATIVES FOR COMBINED SEWER PROJECTS
Dear Mr. Cook:
We suggest that a sixth alternative be considered for analysis in your report. This
alternative would be as follows:
Alternative 6 - Modification of current law to allow a lower level of
treatment for combined sewer overflows (concentrators
with post disinfection) and continue with present funding.
At the present time, many combined sewer overflow projects cannot be justified
under PG-61 requirements for funding. The result has been that all or nothing is
done. This alternative would allow for the construction of combined sewer over-
flow projects which do not meet secondary treatment standards but which provide
sufficient pollution control abatement and which are financially feasible under the
current funding program.
We hope that this suggestion will be given favorable review and we thank you for
this opportunity to comment.
Sincerely,
Marvin C. Haglund
Director of Utilities
cc: Craig Thompson, Sewer Superintendent
A - 48
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OF THE COUNTY OF MILWAUKEE
P.O. BOX 2079 MILWAUKEE, WISCONSIN 53201
PHONE 271-2403
Sewerage Commission of the City of Milwaukee • Metropolitan Sewerage Commission of the County of Milwaukee
July 17, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, B.C. 20460
Dear Mike:
I am writing in response to your request for comments on the
five basic legislative alternatives dealing with combined
sewer overflows. I believe that legislation to provide funding
for multi-purpose urban water resources projects will have the
greatest benefit not only to a community like Milwaukee, but
also other communities. As you know, here in Milwaukee we are
faced with a huge expenditure to deal with our combined sewer
overflows. However, the pollution entering the waterways
through this source is but a fraction of the total pollution
load received by the rivers and by Lake Michigan. For example,
the combined sewer pollution load entering the Milwaukee River
is only 25% of the total load coming into the Milwaukee River.
While we believe a significant improvement in water quality
can be achieved through interception of the combined sewer
overflows, it is obvious that the other sources must also be
dealt with to achieve further improvements in water quality.
In addition, there are problems of stormwater carrying a large
amount of pollutants which are not being dealt with, and with
pollutants entering the District from drainage outside of the
District. This is coupled with flooding problems which face us.
Our flood control channels system needs a great deal of planning
and improvements. A combination of these problems together with
our dry weather flow dictate a problem-solving approach that
includes an integration of all sources of drainage.
There is no question but that adequate funding for urban drainage
problems must be made available if we are serious about improving
A - 49
1974 Amer. Soc. of Civil Engrs. Landmark Award - 1974 Amer. Soc. of Civil Engrs. Wisconsin Engr. Achievement
-------
Metropolitan Sewerage District of the County of Milwaukee
Mr. Michael B. Cook
Page 2
July 17, 1978
the water quality in urban areas. Certainly, this is true here
in Milwaukee. I highly recrommend that the funds for this
program be administered by appropriate agencies rather than be
considered by Congress on a case-by-case basis. By its very
nature, the Congressional process is necessarily slow and will
result in major time delays.
Respectfully,
William J. Katz •
Director, Technical Services
WJK:sl
cc: J. Wesselman
D. G. Wieland
C. V. Gibbs
A - 50
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VENTURA REGIONAL
COUNTY SANITATION DISTRICT
JOHN A. LAMBIE
CHIEF ENGINEER
GENERAL MANAGER
IBER AGENCIES
TVRA COUNTY
ES
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Hueneme
Buenaventura
t Paula
Valley
'isand Oaks
CIAL DISTRICTS
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nty Water
mel Islands
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>rpark County
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View Sanitary
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tation
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amencan
on crete
association
July 31, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
U.S. Environmental Protection Agency
401 M Street, S.W., Room #1137
Washington, D.C. 20460
Dear Mike :
In reply to Jack Rhett's memorandum of July 3rd on "Legislative Alternatives for
Combined Sewer Projects," requesting comments on the proposed five basic alter-
natives, our Government Relations Committee met on July 24th and selected
"Alternative #1 - Continue With Present Law. "
Our selection of Alternative #1 was based on Doug Costle's response to Congress-
man Oberstar's question at the Oversight Hearing of July 13th, when he was asked
what the states would do with their funds after secondary treatment is fully imple-
mented . Administrator Costle stated that in order to avoid reallocation of their
funds , they would have to re-establish their priorities and that separation of com-
bined systems and additional sanitary needs would become even more necessary.
If the Administrator follows his statement of July 13th, then Alternative #1 appears
to be the logical choice since both Public Laws 92-500 and 95-217 reinforce these
eligibility categories .
If there are any additional meetings on this subject, prior to your submittal to
Congress by October 1st, we would appreciate your notifying us.
Very truly yours ,
/7
Cyril f. Malloy
Vice President of Government Relations
CIMrjb
cc: Burr Allegaert
John O . Wagner
A - 52
8320 old courthouse road • Vienna Virginia 22180 • (703) 821-1990
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THE JENNINGS-LAWRENCE COMPANY 555 Buttles Avenue Columbus, Ohio 43215 (614) 228-3846
August 3, 1978
Mr. Michael B. Cook, Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S. W.
Washington* D....-C. 20460
Dear Sir:
Re: Legislative Alternatives
Combined Sewer Projects
We have given some thought to the various alternatives in your Memo of July 3,
1978 and offer the following comments.
Alternative 5 seems to add yet another program with a new set of directives,
priorities and staff. We do not view this as an attractive solution.
Alternative 2 suffers from the need to define and then work around the title
"Major projects". This could well work to deliberately delay a job.
Alternative 1 may well be operable within present funding levels.
Alternative 3 is attractive,for we believe it entirely possible
that capital intensive projects might be initiated when maintenance would be more
cost-effective, if maintenance costs became eligible for permanent funding.
Alternative 4 is, in our opinion, the more desirable route, but not as a set-
aside. Overflow projects should be funded to the extent appropriations are made
for that purpose, not extracted from pollution control funds.
Yours truly,
THE JENNINGS-LAWRENCE COMPANY
CCW,Jr. :m Carl C. Walker,Jr./
A - 53
Estab!ished1917
-------
DEPARTMENT OF THE ARMY
OFFICE OF THE CHIEF OF ENGINEERS
WASHINGTON, D.C. 20314
REPLY TO
ATTENTION OF:
AUG1978
DAEN-CWE-BU
Mr. Michael B. Cook
Chief
Facility Requirements Branch (WH-547)
Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
Dear Mr. Cook:
We have reviewed the set of alternatives contained with the memorandum
"Legislative Alternatives for Combined Sewer Projects" dated 3 July 1978
We believe most alternatives have been included in the set presented;
however, one more should be added.
The set of alternatives that is evaluated should include those that
cover existing Federal programs. A combination of alternatives two
and five would describe our ongoing Urban Studies program and should
be added to the list. If desired, we can participate in further
development of this alternative or in evaluation of the total set.
When information described in the first five items of Section 516 (C)
of the Clean Water Act is available, a more thorough evaluation of
the set of alternatives will be possible.
Sincerely,
G. ROBINSON
Br'igadier General, USA
Deputy Director of Civil Works
A - 54
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APPENDIX B
COMPARISON OF POLLUTANT DISCHARGES FOR 15 CITIES
-------
Appendix B
COMPARISON OF POLLUTANT DISCHARGES FOR 15 CITIES
Comparison of pollutant discharges from three sources for 15
cities is presented in this appendix. The sources considered
are urban stormwater runoff, combined sewer overflow, and
secondary wastewater treatment plant effluent. Pollutant
loadings are compared on an average annual basis and on a
runoff event basis. Since three pollutant sources are
compared, a source is termed major if it accounts for more
than one-third of the pollutants discharged during the time
period of comparison. Conversely, a source is termed minor
if it accounts for less than one-third of the pollutants
discharged during the time period of comparison. The term
"Urbanized Area" refers to the definition used by the Bureau
of the Census of the U.S. Department of Commerce to establish
the location and extent of urban areas. A total of 279
Urbanized Areas were defined by the Bureau of the Census in
1975.
BOSTON, MASSACHUSETTS
Urban Characteristics
The Metropolitan Sewerage District of Boston serves 43
municipalities with a drainage area of 331,410 acres (517.8
square miles) and a 1970 population of 2,153,000. A waste-
water management plan for the Eastern Massachusetts
Metropolitan Area (EMMA) modeled a combined sewer drainage
area of 24,370 acres (38.1 square miles) in Boston which is
essentially 100% developed and has an average population
density of 35.9 people per acre. The total combined sewer
drainage area is approximately 28,000 acres (43.8 square
miles). Combined sewer overflow occurs approximately 60
times per year at over 100 locations on the Charles River,
Mystic River, and Chelsea River and into Boston Harbor and
Dorchester Bay. These overflow events cause beach closings
and restricted shellfishing in the receiving waters and are
documented to be the primary water pollution control priority
for the area. Two primary wastewater treatment plants
(WWTP) have a design capacity of 455 mgd and treat an average
daily flow of 402 mgd which is discharged into Boston Harbor.
In addition, two combined sewer overflow treatment facilities
provide detention and chlorination for a design flow of
390 mgd.
The average annual rainfall in Boston is 41.5 inches,
ranging from an average monthly low of 3.13 inches in June
to a high of 3.85 inches in March and November, as shown in
Figure B-l. Rainfall occurs for approximately 780 hours per
B - 2
-------
Average Annual Loads
100
90
80
70
CD
O 60
"5 50
§ "°
°- 30
20 X;Xj:
10 x-:'x
iiSig: Mt
rUJJJ- 8
BODS SS TN P04 Pb
Urbanized Area
100
80
70
-o
CD
° 60
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0>
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20
10
v';Xv
::::::x:
x-:-:
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;|;;|:
BODS SS TN P04 Pb
EMMA Study
100
90
80
70
Tl
O 60
— I
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§ 40
CD
^30
2o;ii;;;i;i
10 x$::i:::W:
BODS SJ
x ;:.- w: : :X;X
TN P04
S?
Pb
Average Event Loads
100_
90
80
70
CD
O 60
O 50
40
Urbanized Area
SS TN PO4 Pb
EMMA Study
LEGEND
BODS = 5-day Biochemical
Oxygen Demand
SS = Suspended Solids
TN = Total Nitrogen
PO4 = Phosphate Phosphorus
Pb = Lead
Illllllll Storm Runoff
Phosphorus ' -
6-
Sewers
off
uent «,4-
2-
1 -
Station: General
Logan Airport
j
F
M
A
M
J
J
A
S
0
N
D
Years of Record: 1871-1977 Monthly Rainfall Distribution
FIGURE B-1. Loading comparison for Boston, Massachusetts.
-------
year, causing overflow events for approximately 525 hours
per year or 5% of the time. The mean annual flows of the
Mystic River, Charles River, and Neponset River are 31 cfs,
294 cfs, and 46 cfs, respectively. Present receiving water
uses include boating, swimming, shellfishing, and navigation.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Boston, Massachusetts,
are shown in Figure B-l. Combined sewer overflow is a minor
source of average annual loads for all parameters; storm
runoff is a major source of lead (Pb), suspended solids
(SS), and BOD5, 88%, 70%, and 64%, respectively; and secondary
WWTP effluent is a major source of phosphate phosphorus
(P04) and total nitrogen (TN) loads, 92% and 91%, respectively.
Average annual loads in pounds per year from the combined
sewer area modeled by the EMMA Study are shown in Figure B-l.
Combined sewer overflow is a major source of Pb and SS
average annual loads, 91% and 69%, respectively; storm
runoff average annual loads are zero since the entire basin
modeled is served by combined sewers; and primary WWTP
effluent is a major source of PO4, TN, and BOD5 average
annual loads, 92%, 90%, and 88%, respectively.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Boston, Massachusetts,
are shown in Figure B-l. Combined sewer overflow is a minor
source of event loads for all parameters; storm runoff is a
major source of Pb, BOD5, SS, TN, and PO4 average event
loads, 91%, 71%, 71%, 45%, and 41%, respectively; and secondary
WWTP effluent is a major source of PO4 and TN average event
loads, 42% and 38%, respectively.
Average event loads in pounds per hour from the combined
sewer area modeled by the EMMA Study are shown in Figure B-l.
Combined sewer overflow is a major source of Pb, SS, BOD5,
TN, and P04 average event loads, 99%, 97%, 69%, 64%, and
59%, respectively. Storm runoff average event loads are
zero since the entire basin modeled is served by combined
sewers. Primary WWTP effluent is a major source of PO4 and
TN average event loads, 41% and 36%, respectively-
Sources of Information
1. Metcalf & Eddy, Inc. Wastewater Engineering and
Management Plan for Boston Harbor--Eastern Massachusetts
Metropolitan Area (EMMA) Study, Main Report for the
Metropolitan District Commission. March 1976.
B - 4
-------
2. Metcalf & Eddy, Inc. Wastewater Engineering and
Management Plan for Boston Harbor--Eastern
Massachusetts Metropolitan Area (EMMA) Study, Technical
Data, Volume 1_, Combined Sewer Overflow Regulation.
November 1975.
3. Personal communication: John R. Elwood, Supervising
Sanitary Engineer, Metropolitan District Commission,
Environmental Planning Office.
NEW YORK, NEW YORK
Urban Characteristics
The five boroughs of New York comprise a land area of
approximately 205,000 acres (320.3 square miles) with a
combined sewer drainage area of 184,615 acres (288.5 square
miles) and a 1970 population of 7,614,500. Population is
not expected to change during the next 20 years since 90% of
the City's area is presently developed. Combined sewer
overflow occurs approximately 100 times per year at over 700
locations on the Hudson River, in New York Harbor, and in
Long Island Sound. These overflow events cause bacterial
contamination of swimming beaches and shellfishing areas.
Twelve WWTP's provide primary treatment or better to a
design dry-weather flow of 1,030 mgd, and two additional
municipal service areas discharge 210 mgd of raw sewage into
New York Harbor.
The average annual rainfall in New York is 43.7 inches,
ranging from an average monthly low of 3.35 inches in
January to a high of 4.33 inches in August, as shown in
Figure B-2. Approximately 114 rainfall events occur each
year with an average duration per event of 6.33 hours.
Therefore, rainfall occurs for approximately 722 hours per
year causing runoff for approximately 433 hours per year or
4.9% of the time. Receiving water uses include navigation
and, in restricted areas, fishing, swimming, and other
recreational activities.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of New York are shown in
Figure B-2. Combined sewer overflow is a major source of SS
and Pb annual loads, 74% and 46%, respectively. Storm
runoff is a major source of the average annual load for Pb,
44%, and secondary WWTP effluent is a major source of PO4,
TN, and BOD5 average annual loads, 95%, 94%, and 65%,
respectively.
B - 5
-------
100
90
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JODS SS TN PO, Pb BODS SS TN PO4 Pb BODS SS TN PO4 Pb 7 n , n ' . ocr. -„-,-, r?
V.C. Urbanized Area N.Y. Metro, New Jersey N.Y.C. 208 g. Years of Record: 1869-1977
Urbanized Area
5- -5
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JFMAMJJASOND
Monthly Rainfall Distribution
BODS SS TN PO4 Pb BOD5 SS TN P04 Pb BODS SS TN P04 Pb BODS = 5-day Biochemical
N.YlC. Urbanized Area N.Y. Metro, New Jersey N.Y.C. 208 CSS3 Combined Sewers ss4u7S"s
Urbanized Area Illinill Storm Runoff TN = Total Nitrogen
PO4 = Phosphate Phosphorus
I I WWTP Effluent Pb = Lead
FIGURE B-2. Loading comparison for New York, New York.
-------
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of New York Metro New
Jersey are shown in Figure B-2. Combined sewer overflow is
a minor source of average annual loads for all parameters.
Storm runoff is a major source of Pb, SS, and BOD5 average
annual loads, 96%, 87%, and 39%, respectively; and secondary
WWTP effluent is a major source of PO4, TN, and BOD5 average
annual loads, 93%, 92%, and 58%, respectively-
Average annual loads in pounds per year from the area
modeled by the New York 208 for baseline conditions are
shown in Figure B-2. Combined sewer overflow is a minor
source of average annual loads for all parameters. Storm
runoff is a major source of the average annual load for Pb,
35%; and baseline WWTP effluent is a major source of total
kjeldahl nitrogen (TKN), BOD5, PO4, SS, and Pb average
annual loads, 88%, 85%, 82%, 72%, and 44%, respectively.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of New York are shown in
Figure B-2. Combined sewer overflow is a major source of
SS, BOD5, Pb, TN, and P04 average event loads, 81%, 74%,
51%, 47%, and 44%, respectively. Storm runoff is a major
source of the average event load for Pb, 49%; and secondary
WWTP effluent is a major source of PO4 and TN average event
loads, 46% and 42%, respectively-
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of New York Metropolitan
New Jersey are shown in Figure B-2. Combined sewer overflow
is a minor source of average event loads for all parameters.
Storm runoff is a major source of Pb, SS, BOD5, TN, and PO4
average event loads, 99%, 94%, 89%, 61%, and 57%, respectively;
and WWTP effluent is a major source of P04 and TN average
event loads, 40% and 36%, respectively.
Average event loads in pounds per hour from the area modeled
in the New York 208 for baseline conditions are shown in
Figure B-2. Combined sewer overflow is a major source of
PO4, BOD5, TN, SS, and Pb average event loads, 71%, 68%,
67%, 57%, and 36%, respectively. Storm runoff is a major
source of the average event load for Pb, 60%; and baseline
WWTP effluent is a minor source of the average event load
for all parameters.
Sources of Information
1. New York City Department of Environmental Protection,
Areawide Waste Treatment Management Planning Program,
Executive Summary. March 1978.
B - 7
-------
2. Hazen and Sawyer, Inc. NYC 208 Task 516/526, Volume
II. Tables 1-7, 1-8, 1-12A, and 1-13.
3. Personal communication: Mr. William Pressman, Chief,
Research and Development, New York City Department of
Environmental Protection.
ROCHESTER, NEW YORK
Urban Characteristics
The drainage area in Rochester modeled by the 1978 Needs
Survey is served entirely by combined sewers with an area of
11,476 acres (17.9 square miles) and a 1970 population of
200,000. Twenty-two percent of the combined sewer area is
open space. Combined sewer overflow occurs approximately 75
times per year at 20 locations on the Genesee River. These
overflow events cause violations of dissolved oxygen and
fecal coliform standards. One secondary WWTP has a design
capacity of 100 mgd and treats an average daily flow of 50
mgd which is discharged to Lake Ontario.
The average annual rainfall in Rochester is approximately
32.6 inches, from an average monthly low of 2.39 inches in
February to a high of 3.09 inches in July, as shown in
Figure B-3. Rainfall occurs for approximately 1,060 hours
per year causing runoff for approximately 437 hours per year
or 5% of the time. The mean annual flow and depth of the
Genesee River are 2,743 cfs and 15 feet, respectively.
Receiving water uses for the Genesee River are swimming and
recreation and, for Lake Ontario, city water supply, swimming,
fishing, boating, and recreation.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Rochester, New York, are
shown in Figure B-3. Combined sewer overflow is a major
source for the average annual load of SS, 57%. Storm runoff
is a major source of Pb and SS average annual loads, 70% and
36%, respectively; and secondary WWTP effluent is a major
source of P04, TN, and BOD5 average annual loads, 92%, 90%,
and 55%, respectively.
Average annual loads in pounds per year from the area modeled
by the 1978 Needs Survey are shown in Figure B-3. Combined
sewer overflow is a major source of SS, 38%. Storm runoff
average annual loads are zero since the entire basin modeled
is served by combined sewers; and secondary WWTP effluent is
a major source of TN, P04, Pb, BOD5, and SS average annual
loads, 99%, 91%, 84%, 77%, and 62%, respectively-
B -
-------
Average Annual Loads
80
70
-o
CD
O 60
BOD,
SS TN PO, Pb
Urbanized Area
100
90
70
T3
CD
° 60
O 50
H-J
§40
OJ
^30
20
10
0
3OD, SS TN PO4 Pb
1978 Needs Survey
100
90
80
70
50 ff-Kv ••
20 :':•'•.'•.'•:• '.
10 •::•.'•:•:'.•;.
&
BODS SS TN PO4 Pb
Urbanized Area
Average Event Loads
90
80
70
CD
°60
° 50
§40
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Q.
30
20
10
0
BODS SS TN PCX Pb
1978 Needs Survey
LEGEND
BOD5 = 5-dav Biochemical
Oxygen Demand
SS = Suspended Solids
TN = Total Nitrogen
POa = Phosphate Phosphorus
Pb= Lead
K-M'I'Xd Combined Sewers
illlllllO Storm Runoff
WWTP Effluent
Station: Rochester Monroe c
County Airport
Years of Record: 1829-1977
FMAMJJASON
Monthly Rainfall Distribution
FIGURE B-3. Loading comparison for Rochester, New York.
-------
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Rochester, New York, are
shown in Figure B-3. Combined sewer overflow is a major
source of SS and BOD5 average event loads, 61% and 57%,
respectively. Storm runoff is a major source of Pb, SS, and
BOB5 average event loads, 73%, 39%, and 37%, respectively;
and secondary WWTP effluent is a major source of the event
load for P04, 36%.
Average event loads in pounds per hour from the area modeled
by the 1978 Needs Survey are shown in Figure B-3. Combined
sewer overflow is a major source of SS, BOD5, Pb, and PO4
average event loads, 93%, 86%, 80%, and 65%, respectively.
Storm runoff average event loads are zero since the entire
basin modeled is served by combined sewers; and secondary
WWTP effluent is a major source of TN and PO4 event loads,
77% and 35%, respectively.
Sources of Information
1. Edman, Anthony & Assoc., Lozier Engineering, Inc., and
Seelye, Stevenson, Value and Knecht, Inc. Wastewater
Facilities Plan, Combined Sewer Overflow Abatement
Program, Rochester Pure Waters District, Monroe County,
New York. December 1976.
2. New York State Department of Environmental Conservation.
Water Quality Management Plan for the Genesee River
Basin. November 1976.
3. Personal communication: N. G. Kaul New York Department
of Environmental Conservation.
4. Personal communication: Jimmy Stewart Rochester Pure
Waters District, Division of Sewer Maintenance.
SYRACUSE, NEW YORK
Urban Characteristics
The combined sewer drainage area modeled by O'Brien and Gere
Engineers for the Syracuse 208 Study was 9,000 acres (14.1
square miles) out of a total 13,900 acres (21.7 square
miles) with a 1970 population of 175,000. Less than 5% of
the combined sewer drainage area of 9,000 acres is open
space. Combined sewer overflow occurs approximately 170
times per year at 87 locations on the three streams flowing
into Lake Onondaga. These overflow events eliminate all
water contact sports in Onondaga Lake and cause combined
B - 10
-------
sewer flooding into basements and streets. The only WWTP
discharging to Lake Onondaga presently provides primary
treatment to an average daily flow of 80 mgd at a design
flow of 60 mgd. The present sewer system is in poor condition
and is known to have a significant infiltration/inflow
problem.
The average annual rainfall in Syracuse is 37.0 inches,
ranging from an average monthly low of 2.68 inches in January
to a high of 3.63 inches in June, as shown in Figure B-4.
Rainfall occurs for approximately 1,244 hours per year,
causing runoff for approximately 746 hours per year or 8.5%
of the time. The mean residence time of Onondaga Lake is
150 to 200 days. Present receiving water uses include
boating, picnicing, and non-water contact recreation.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Syracuse, New York, are
shown in Figure B-4. Combined sewer overflow is a major
source of SS, BOD5, and Pb average annual loads, 66%, 37%,
and 34%, respectively. Storm runoff is a major source of
the average annual load of Pb, 62%, and secondary WWTP
effluent is a major source of PO4, TN, and BOD5 average
annual loads, 89%, 87%, and 46%, respectively.
Average annual loads in pounds per year from the combined
sewer drainage area modeled by the O'Brien and Gere 208 Study
are shown in Figure B-4. Combined sewer overflow is a major
source of the average annual load of SS, 52%. Storm runoff
annual loads are zero since the entire basin modeled is
served by combined sewers; and secondary WWTP effluent is a
major source of TN, PO4, BOD5, Pb, and SS average annual
loads, 99%, 95%, 86%, 83%, and 48%, respectively.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Syracuse, New York, are
shown in Figure B-4. Combined sewer overflow is a major
source of SS, BOD5, TN, PO4, and Pb average event loads,
69%, 65%, 44%, 41%, and 35%, respectively- Storm runoff is
a major source of the average event load for Pb, 64%; and
secondary WWTP effluent is a major source of P04 and TN
average event loads, 41% and 37%, respectively.
Average event loads in pounds per hour from the combined
sewer drainage area modeled in the O'Brien and Gere 208 Study
are shown in Figure B-4. Combined sewer overflow is a major
source of SS, Pb, BOD5, and P04 average event loads, 93%,
71%, 66%, and 40%, respectively. Storm runoff average event
B - 11
-------
Average Annual Loads
100
90
80
70
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Average Event Loads
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iw:-:
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BOD5 SS TN P04 Pb
Syracuse 208
LEGEND
BODS = 5-day Biochemical
Oxygen Demand
SS = Suspended Solids
TN = Total Nitrogen
PO4 = Phosphate Phosphorus
Pb= Lead
K-X-X-H Combined Sewers
111111111 Storm Runoff
WWTP Effluent
Station: Hancock
International Airport
Years of Record: 1902-1977
6-
5-
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2-
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Monthly Rainfall Distribution
FIGURE B-4. Loading comparison for Syracuse, New York.
-------
loads are zero since the entire basin modeled is served by
combined sewers; and secondary WWTP effluent is a major
source of TN, PC>4, and BOD5 average event loads, 92%, 60%,
and 34%, respectively.
Source of Information
1. Personal communication: Dwight A. MacArthur, O'Brien
and Gere Engineers, Inc., Box 4873, Syracuse, New York
13221.
PHILADELPHIA, PENNSYLVANIA
Urban Characteristics
The drainage area modeled in Philadelphia by the 1978 Needs
Survey is 110,000 acres (171.9 square miles) with a 1970
population of 2,076,900. The combined sewer drainage area
of 50,000 acres (78.1 square miles) is essentially 100%
developed. Combined sewer overflow occurs approximately 70
times per year at 176 locations on the Delaware River estuary.
These overflow events restrict water contact recreation and
cause extremely low dissolved oxygen concentrations in the
receiving water. Three primary WWTP's treat an average
daily flow of 714 mgd which is discharged to the Delaware
River estuary. Industrial effluent is an important wastewater
source from Philadelphia that is not included in this analysis.
The average annual rainfall in Philadelphia is approximately
41.2 inches, ranging from an average monthly low of 2.80 inches
in October to a high of 4.52 inches in August, as shown in
Figure B-5. Rainfall occurs for approximately 1,860 hours
per year causing runoff for approximately 1,116 hours per
year or 13% of the time. The mean annual flow and depth of
the Delaware River estuary are 16,800 cfs and 21 feet,
respectively. Present receiving water uses include water
supply, navigation, fishing, and recreation.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Philadelphia, Pennsylvania,
are shown in Figure B-5. Combined sewer overflow is a minor
source of average annual loads for all parameters. Storm
runoff is a major source of Pb and SS average annual loads,
93% and 80%, respectively; and secondary WWTP effluent is a
major source of PO4, TN, and BOD5 average annual loads, 94%,
93%, and 62%, respectively.
B - 13
-------
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90
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BOD, SS TN P0a Pb BODS SS TN PO,, Pb BOD, SS TN PO,
Philadelphia, Pa. Ph ladelphia Metro, New Philadelphia, F
Urbanized Area Jersey, Urbanized Area 1978 Needs Sur
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BOO, SS TN PO, Pb BOD, SS TN P04 Pb BOD, SS TN PO,
Philadelphia, Pa. Philadelphia Metro, New Philadelphia, 1
Urbanized Area Jersey, Urbanized Area 1978 Needs Sur
Pb 7-, Station: International ri
'a. Airport
vey 6" Years of Record: 1872-1977 '6
5- -5
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JFMAMJJASOND
Monthly Rainfall Distribution
::x;: LEGEND
^ ^XvX'H Combined Sewers Oxygen Demand
a- SS= Suspended Solids
V8V II III Illl Storm Runoff TN = Total Nitrogen
PO4 = Phosphate Phosphorus
| | WWTP Effluent Pb = Lead
FIGURE B-5. Loading comparison for Philadelphia, Pennsylvania.
-------
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Philadelphia Metro New
Jersey are shown in Figure B-5. Combined sewer overflow is
a major source of SS, Pb, and BOD5 average annual loads,
97%, 94%, and 71%, respectively. Storm runoff is a minor
source of average annual loads for all parameters; and
secondary WWTP effluent is a major source of PO4 and TN
average annual loads, 79% and 76%, respectively.
Average annual loads in pounds per year from the area modeled
by the 1978 Needs Survey are shown in Figure B-5. Combined
sewer overflow is a minor source of average annual loads for
all parameters. Storm runoff is a major source of the
average annual load for Pb, 33%, and secondary WWTP effluent
is a major source of TN, PO4, BOD5, SS, and Pb average
annual loads, 81%, 65%, 65%, 49%, and 39%, respectively.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Philadelphia, Pennsylvania
are shown in Figure B-5. Combined sewer overflow is a minor
source of average event loads for all parameters. Storm
runoff is a major source of Pb, SS, BOD5, and TN average
event loads, 96%, 86%, 72%, and 33%, respectively; and
secondary WWTP effluent is a major source of P04 and TN
average event loads, 66% and 62%, respectively-
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Philadelphia Metro
New Jersey are shown in Figure B-5. Combined sewer overflow
is a major source of SS, Pb, BOD5, TN, and P04 event loads,
99%, 97%, 95%, 71%, and 67%, respectively. Storm runoff and
secondary WWTP effluent are minor sources of the average
event loads for all parameters.
Average event loads in pounds per hour from the area modeled
in the 1978 Needs Survey are shown in Figure B-5. Combined
sewer overflow is a major source of BOD5, P04, SS, and Pb
average event loads, 51%, 51%, 46%, and 42%, respectively.
Storm runoff is a major source of Pb, SS, and TN average
event loads, 50%, 43%, and 37%, respectively; and secondary
WWTP effluent is a major source of the average event load
for TN, 36%.
Sources of Information
1. Urban Stormwater Quality/Land Use Characterization,
prepared by Philadelphia Water Department Research and
Development Division. November 1977.
B - 15
-------
Facility Plan, City of Philadelphia, Combined Sewer
Overflow Control, by Watermation, Inc., July 1976.
Thomann, R. V., Systems Analysis and Water Quality
Management, Environmental Research and Applications,
Inc. (now McGraw-Hill), 1972.
Personal communication: Dennis Blair, Philadelphia
Water Department.
WASHINGTON, D.C.
Urban Characteristics
The drainage area modeled by the 1978 Needs Survey for
Washington, D.C., is 202,521 acres (316.4 square miles) with
a 1970 population of 4,000,000. The combined sewer drainage
area of 12,396 acres (19.4 square miles) is essentially 100%
developed. Combined sewer overflow occurs approximately 55
times per year at five locations on the Potomac River estuary.
These overflow events result in the elimination of water
contact recreation and commercial fishing in the receiving
water. Six secondary WWTP's have a design capacity of 415
mgd and treat an average daily flow of 361 mgd which is
discharged to the Potomac River estuary.
The average annual rainfall in Washington, D.C., is approxi-
mately 39.9 inches, ranging from an average monthly low of
2.52 inches in February to a high of 4.68 inches in August,
as shown in Figure B-6. Rainfall occurs for approximately
1,050 hours per year, causing runoff for approximately 630
hours per year or 7% of the time. The mean annual flow and
depth of the Potomac River estuary are 10,000 cfs and 15 feet,
respectively. Receiving water uses include navigation,
sport fishing, and non-water contact recreation.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Washington, B.C., are
shown in Figure B-6. Combined sewer overflow is a major
source of SS and Pb average annual loads, 68% and 36%,
respectively. Storm runoff is a major source of the average
annual load for Pb, 58%; and secondary WWTP effluent is a
major source of P04, TN, and BOD5 average annual loads, 93%,
92%, and 57%, respectively.
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Washington, D.C. Metro
Virginia are shown in Figure B-6. Combined sewer overflow
B - 16
-------
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Washington, D.C. Washington, D.C. Metro, Va. Washington, D.C. National Airport
• •I • i * 111 • i A -,^-7,^*1 •/-% 6~'6arsoTn6cora.io/i-iy// -e
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is minor source of the average annual loads for all parameters.
Storm runoff is a major source of Pb and SS average annual
loads, 94% and 83%, respectively; and secondary WWTP effluent
is a major source of PO4, TN, and BOD5 average annual loads,
95%, 94%, and 68%, respectively.
Average annual loads in pounds per year from the area modeled
by the 1978 Needs Survey are shown in Figure B-6. Combined
sewer overflow is a major source of TN and PO4 average
annual loads, 48% and 38%, respectively. Storm runoff is a
major source of Pb, SS, and BOD5 average annual loads, 76%,
74%, and 44%, respectively, and secondary WWTP effluent is a
major source of PO4, TN, and BOD5 average annual loads, 55%,
44%, and 33%, respectively.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Washington, D.C., are
shown in Figure B-6. Combined sewer overflow is a major
source of SS, BOD5, PB, P04, and TN average event loads,
73%, 66%, 38%, 38%, and 37%, respectively. Storm runoff is
a major source of the average event load for Pb, 61%; and
WWTP effluent is a major source of PO4 and TN average event
loads, 47% and 46%, respectively.
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Washington, B.C. Metro
Virginia are shown in Figure B-6. Combined sewer overflow
is a minor source of average event loads for all parameters.
Storm runoff is a major source of Pb, SS, BOD5, TN, and P04
average event loads, 98%, 92%, 81%, 42%, and 38%, respectively;
and secondary WWTP effluent is a major source of P04 and TN
average event loads, 59% and 55%, respectively.
Average event loads in pounds per hour from the area modeled
in the 1978 Needs Survey are shown in Figure B-6. Combined
sewer overflow is a major source of TN, PO4, and BOD5
average event loads, 81%, 77%, and 33%, respectively. Storm
runoff is a major source of SS, Pb, and BOD5 average event
loads, 77%, 76%, and 64%, respectively; and secondary WWTP
effluent is a minor source of average event loads for all
parameters.
Sources of Information.
1. Water Resources Planning Board, Metropolitan Washington,
COG, Major Sewage Treatment Plants in the Washington
Metropolitan Area. 1976.
B - 18
-------
2. Ibid, The National Pollutant Discharge Elimination
System"April 28, 1977.
3. Personal communication: Ed Jones, Operator, Blue
Plains WWTP, Washington, B.C.
4. Personal communication: Ken Sujishiro, Metropolitan
Washington Council of Governments.
ATLANTA, GEORGIA
Urban Characteristics
The drainage area modeled in the 1978 Needs Survey for
Atlanta is the 149,860 acres (234.2 square miles) tributary
to the Chattahoochee River with a 1970 population of 780,000.
The combined sewer drainage area of 9,060 acres (14.2 square
miles) within this basin is essentially 100% developed.
Combined sewer overflow occurs approximately 90 times per
year at six locations on the Chattahoochee River. These
overflow events together with stormwater runoff cause the
dissolved oxygen concentration to fall below 2 mg/1 several
times each year. Five secondary WWTP's treat an average
daily flow of 120 mgd which is discharged to the Chattahoochee
River.
The average annual rainfall in Atlanta is approximately
48.6 inches, from a monthly low of 2.59 inches in October to
a high of 5.63 inches in March, as shown in Figure B-7.
Rainfall occurs for approximately 930 hours causing runoff
for approximately 667 hours per year or 7.6% of the time.
The mean annual flow and depth of the Chatahoochee River are
2,742 cfs and 6.5 feet, respectively. Present receiving
water uses include recreation and sport fishing.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Atlanta, Georgia, are
shown in Figure B-7. Combined sewer overflow is a minor
source of average annual loads for all parameters. Storm
runoff is a major source of Pb, SS, and BOD5 average annual
loads 90%, 71%, and 37%, respectively; and secondary WWTP
effluent is a major source of P04, TN, and BOD5 average
annual loads 91%, 89%, and 51%, respectively.
Average annual loads in pounds per year from the area modeled
by the 1978 Needs Survey are shown in Figure B-7. Combined
sewer overflow is a major source of the average annual load
for Pb, 44%. Storm runoff is a major source of the SS, Pb,
B - 19
-------
Average Annual Loads
70
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20
10
BOD5 SS TN PO« Pb
Urbanized Area
90
80
70
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-------
and BOD5 average annual loads, 81%, 51%, and 36%, respectively;
and secondary WWTP effluent is a major source of TN, P04,
and BOD5 average annual loads, 92%, 72%, and 43%, respectively.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Atlanta, Georgia, are
shown in Figure B-7. Combined sewer overflow is a minor
source of average event loads for all parameters. Storm
runoff is a major source of Pb, SS, BOD5, TN, and PO4
average event loads, 93%, 75%, 70%, 46%, and 43%, respectively;
and secondary WWTP effluent is a major source of PO4 and TN
average event loads, 43% and 39%, respectively.
Average event loads in pounds per hour from the area modeled
in the 1978 Needs Survey are shown in Figure B-7. Combined
sewer overflow is a major source of Pb and BOD5 average
event loads, 47% and 34%, respectively. Storm runoff is a
major source of SS, BOD5, P04, Pb, and TN average event
loads, 85%, 61%, 54%, 53%, and 36%, respectively; and secondary
WWTP effluent is a major source for the average event load
of TN, 47%.
Sources of Information
1. Black, Crow and Eidsness, Inc., and Jordan, Jones, and
Goulding, Inc. Nonpoint Pollution Evaluation, Atlanta
Urban Area. May 1975.
2. Black, Crow and Eidsness, Inc. Storm and Combined
Sewer Pollution Sources and Abatement, Atlanta, Georgia.
January 1971.
3. Personal communication: Phil Nungasser, City of
Atlanta Bureau of Pollution Control.
CHICAGO, ILLINOIS
Urban Characteristics
The Metropolitan Sanitary District of Greater Chicago (MSDGC)
serves a total area of 555,000 acres (867.2 square miles)
with a combined sewer drainage area of 240,000 acres (375
square miles) and a 1970 population of 5,500,000. The
district is approximately 15% open space. Combined sewer
overflow occurs approximately 100 times per year at 645
locations on the Chicago River, Calumet River, and the
sanitary and ship canal system. The ship canal system was
built during the 1890's to divert Chicago wastewaters away
from Lake Michigan, the source of drinking water for Chicago,
B - 21
-------
to the Illinois River. In addition to low dissolved oxygen
concentrations and significant benthal deposits in the
receiving waters, these overflow events cause a potential
public health hazard by flooding basements, streets, and
Lake Michigan (19 Lake Michigan floods have occurred since
1954). The MSDGC has seven WWTP's. Three provide secondary
treatment to a design flow of 1,753 mgd and four provide
tertiary treatment to a design flow of 40 mgd. A tunnel and
reservoir plan known as the TARP project has been designed
by MSDGC to capture and store most combined sewer overflow
for subsequent secondary treatment.
The average annual rainfall in Chicago is 33.6 inches, from
an average monthly low of 1.80 inches in February to a high
of 3.47 inches in June, as shown in Figure B-8. Rainfall
occurs for approximately 1,529 hours per year causing runoff
for approximately 917 hours per year or 10.5% of the time.
The mean annual flows of the Chicago North Branch, Grand
Calument, and Little Calumet Rivers are 117 cfs, 211 cfs,
and 240 cfs, respectively. Receiving water uses include
navigation, public water supply,- swimming, fishing, and
other recreational activities.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Chicago are shown in
Figure B-8. Combined sewer overflow is a major source of
SS, Pb, and BOD5 average annual loads, 77%, 48%, and 41%,
respectively. Storm runoff is a major source of the average
annual load for Pb, 48%; and secondary WWTP effluent is a
major source of PO4, TN, and BOD5 average annual loads, 90%,
89%, and 49%, respectively.
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Chicago Metro Indiana
are shown in Figure B-8. Combined sewer overflow is a major
source of SS and BOD5 average annual loads, 63% and 33%,
respectively. Storm runoff is a major source of the average
annual load for Pb, 65%; and secondary WWTP effluent is a
major source of P04, TN, and BOD5 average annual loads, 91%,
88%, and 50%, respectively.
Average annual loads in pounds per year from the area modeled
by the MSDGC facilities plan are shown in Figure B-8.
Combined sewer overflow is a major source of BOD5 and SS
average annual loads, 54% and 36%, respectively. No estimates
of the storm runoff average annual loads were made. Existing
WWTP effluent is a major source of TN, P04, Pb, SS, and BOD5
average annual loads, 95%, 92%, 76%, 64%, and 46%,
respectively.
B - 22
-------
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Chicago, III. Chicago Metro, Ind. MSDGC Facilities Pla
Urbanized Area Urbanized Area
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Chicago, III. Chicago Metro, Ind. MSDGC Facilities Pla
Urbanized Area Urbanized Area
Station: Midway Airport
n 71 Years of Record: 1871-1977 T
6- -6
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JFMAMJJASOND
Monthly Rainfall Distribution
LEGEND
i..i.i.. _ . . J BODs = 5-day Biochemical
n Kvr.Yil Combined Sewers Oxygen Demand
SS = Suspended Solids
"Hill" Storm Runoff TN = Total Nitrogen
PO^ = Phosphate Phosphorus
1 1 WWTP Effluent Pb = Lead
FIGURE B-8. Loading comparison for Chicago, Illinois.
-------
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Chicago are shown in
Figure B-8. Combined sewer overflow is a major souce of SS,
BOD5, Pb, TN, and P04 average event loads, 81%, 73%, 50%,
45%, and 42%, respectively. Storm runoff is a major source
of the average event load for Pb, 50%; and secondary WWTP
effluent is a major source of PO4 and TN average event
loads, 49% and 44%, respectively-
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Chicago Metro Indiana
are shown in Figure B-8. Combined sewer overflow is a major
source of SS, BOD5, TN and PO4 average event loads, 67%,
60%, 37%, and 34%, respectively. Storm runoff is a major
source of the average event load for Pb, 67%; and secondary
WWTP effluent is a major source of PO4 and TN average event
loads, 50% and 45%, respectively.
Average event loads in pounds per hour from the area modeled
in the MSDGC facilities plan are shown in Figure B-8.
Combined sewer overflow is a major source of BOD5, SS, Pb,
P04, and TN average event loads, 92%, 84%, 75%, 47%, and
35%, respectively. No estimates of the storm runoff average
event loads were made. The existing WWTP effluent is a
major source of TN and PO4 average event loads, 65% and 53%,
respectively.
Sources of Information.
1. Dale, J. R., Jr. Bottling Rainstorms—Chicago's Tunnel
and Reservoir Plan. J. Wat. Poll. Cont. Fed Monitor.
Volume 50, No. 8. August 1978. pp. 1888-1892.
2. General Accounting Office, Comptroller General Report
to the U.S. Congress. Metropolitan Chicago's Combined
Water Cleanup and Flood Control Program: Status and
Problems. No. PSAD-78-94. May 24, 1978.
3. Metropolitan Sanitary District of Greater Chicago.
Development of a Flood and Pollution Control Plan for
the Chicagoland Area, Summary of Technical Reports.
August 1972.
4. Metropolitan Sanitary District of Greater Chicago.
Facilities Planning Study MSDGC Update Supplement and
Summary. May 1977.
5. Personal communication: J. H. Irons, Supervising Civil
Engineer Tunnel and Reservoir Section, Metro. Sanitary
District of Greater Chicago (MSDGC).
B - 24
-------
DETROIT, MICHIGAN
Urban Characteristics
The Detroit Water and Sewerage Department (DWSD) serves 71
municipalities with a total drainage area of 312,692 acres
(488.6 square miles), a combined sewer drainage area of
154,700 acres (241.7 square miles), and a 1970 population of
2,982,000. A segmented facilities plan for the DWSD modeled
a combined sewer drainage area of 92,392 acres (144.4 square
miles) which is 95% developed and has an average population
density of 15.3 people per acre. Combined sewer overflow is
controlled by a remote monitoring system which utilizes in-
line storage to reduce the number of overflow events to
approximately 15 per year at 77 locations on the Rouge and
Detroit Rivers. These overflow events cause benthal sludge
deposits and occasional low dissolved oxygen concentrations
in the Rouge River. One WWTP provides a design capacity of
1,200 mgd primary and 600 mgd secondary and treats an average
daily flow of 650 mgd.
The average annual rainfall in Detroit is 31.5 inches,
ranging from an average monthly low of 2.05 inches in February
to a high of 3.32 inches in June, as shown in Figure B-9.
Rainfall occurs for approximately 515 hours per year, causing
runoff for approximately 309 hours per year and combined
sewer overflow for approximately 113 hours per year of 1.29%
of the time. The mean annual flows and depths of the Detroit
and Rouge Rivers are 190,800 cfs and 27 feet and 270 cfs and
15 feet, respectively. Present uses of the Detroit River
include water supply, cold water fishing, total body contact
recreation, and transportation. Present receiving water
uses of the Rouge River include industrial water supply,
limited body contact recreation, warm water fishing, and
transportation.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Detroit, Michigan, are
shown in Figure B-9. Combined sewer overflow is a major
source of SS, Pb, and BOD5 average annual loads, 75%, 45%,
and 40%, respectively. Storm runoff is a major source of
the average annual load for Pb, 50%; and WWTP effluent is a
major source of PO4, TN, and BOD5 average annual loads, 90%,
88%, and 49%, respectively.
Average event loads in pounds per hour from the area modeled
in the DWSD segmented facilities plan are shown in Figure B-9.
Combined sewer overflow is a major source of Pb and SS
average event loads, 60% and 46%, respectively. Storm
runoff is a minor source of annual loads for all parameters,
B - 25
-------
Average Annual Loads
100
90
80
70
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DWSD Facilities Plan
Average Event Loads
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Urbanized Area
~BODS SS TN PO4 Pb
DWSD Facilities Plan
LEGEND
BODS = 5-day Biochemical
Oxygen Demand
SS = Suspended Solids
TN = Total Nitrogen
PO4 = Phosphate Phosphorus
Pb = Lead
K-X-X-H Combined Sewers
II1111111 Storm Runoff
WWTP Effluent
Station: City Airport J F
Years of Record: 1871-1977
MAMJJASON
Monthly Rainfall Distribution
FIGURE B-9. Loading comparison for Detroit, Michigan,
-------
and WWTP effluent is a major source of TN, P04 , BOD5, SS,
and Pb average annual loads, 98%, 98%, 87%, 53%, and 39%,
respectively.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Detroit, Michigan, are
shown in Figure B-9. Combined sewer overflow is a major
source of SS, BOD5, TN, PO4, and Pb average event loads,
79%, 78%, 72%, 71%, and 47%, respectively. Storm runoff is
a major source of the average event load for Pb, 53%; and
secondary WWTP effluent is a minor source of event loads for
all parameters.
Average event loads in pounds per hour from the remote
controlled combined sewer area modeled in the DWSD segmented
facilities plan are shown in Figure B-9. Combined sewer
overflow is a major source of Pb, SS, TN, BOD5, and P04
average event loads, 98%, 95%, 91%, 89%, and 63%, respectively.
Storm runoff and WWTP effluent are minor sources of average
event loads for all parameters.
Sources of Information
1. Watt, T. R., Skrentner, R. G., and Davanzo, A. C.
Sewerage System Monitoring and Remote Control.
EPA-670/2-75-020. May 1975.
2. Giffels/Black & Veatch. Detroit Water and Sewerage
District (DWSD) Segmented Facilities Plan. June 1977.
3. Personal communication: D. G. Suhre, General Super-
intendent of Engineering, Detroit Water and Sewerage
Department.
MILWAUKEE, WISCONSIN
Urban Characteristics
The drainage area modeled for Milwaukee by the 1978 Needs
Survey was 33,200 acres (51.9 square miles) tributary to the
Milwaukee River with a 1970 population of 441,800. The
combined sewer drainage area of 5,800 acres (9.1 square
miles) is essentially 100% developed. Combined sewer overflow
occurs approximately 60 times per year at' 62 locations on
the Milwaukee River. These overflow events cause the
resuspension of accumulated sediment deposits which can
cause the dissolved oxygen concentration to reach zero for
several hours and kill many fish. The Jones Island WWTP has
a design capacity of 200 mgd and treats an average daily
flow of 137 mgd which is discharged to Lake Michigan.
B - 27
-------
The average annual rainfall in Milwaukee is approximately
30.3 inches, ranging from an average monthly low of 1.57 inches
in February to a high of 3.53 inches in June, as shown in
Figure B-10. Rainfall occurs for approximately 926 hours
per year, causing runoff for approximately 673 hours per
year or 7.7% of the time. The mean annual flow and depth of
the Milwaukee River are 381 cfs and 6 feet, respectively.
Present receiving water uses include industrial water supply,
fish survival, swimming, and recreation.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Milwaukee, Wisconsin,
are shown in Figure B-10. Combined sewer overflow is a
major source of the average annual load for SS, 41%. Storm
runoff is a major source of Pb and SS average annual loads,
81% and 51%, respectively; and secondary WWTP effluent is a
major source of TN, P04, and BOD5 average annual loads, 93%,
93%, and 60%, respectively.
Average annual loads in pounds per year from the Milwaukee
River watershed area modeled by the 1978 Needs Survey are
shown in Figure B-10. Combined sewer overflow is a major
source of the average annual load for Pb, 60%. Storm runoff
is a major source of the average annual load for SS only,
36%; and secondary WWTP effluent is a major source of TN,
P04, BOD5, and SS average annual loads, 98%, 94%, 84%, and
46%, respectively. It should be noted, however, that the
WWTP effluent is discharged directly to Lake Michigan and
not to the Milwaukee River.
Average Event Loads
Estimated percentages of the average event loads in pounds,
per hour from the Urbanized Area of Milwaukee, Wisconsin are
shown in Figure B-10. Combined sewer overflow is a major
source of SS and BOD5 average event loads, 44% and 38%,
respectively. Storm runoff is a major source of Pb, SS, and
BOD5 average event loads, 84%, 55%, and 51%, respectively;
and secondary WWTP effluent is a major source of PO4 and TN
average event loads, 52% and 48%, respectively-
Average event loads in pounds per hour from the Milwaukee
River watershed area modeled in the 1978 Needs Survey are
shown in Figure B-10. Combined sewer overflow is a major
source of Pb and BOD5 average event loads, 74% and 54%,
respectively. Storm runoff is a major source of the average
event load for SS, 63%; and secondary WWTP is a major source
of TN, and P04 average event loads, 80%, and 56%, respectively.
B - 28
-------
Average Annual Loads
100
90
80
60
50
30
20
10 :
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1978 Needs
PO, Pb
Survey
Average Event Loads
100
80
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100
90
80
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20
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BOD5 SS TN PO4
1978 Needs Survey
Pb
LEGEND
BODS = 5-day Biochemical
Oxygen Demand
SS = Suspended Solids
TN = Total Nitrogen
PO4 = Phosphate Phosphorus
Pb= Lead
K*>X*M Combined Sewers
Ulllllll Storm Runoff
WWTP Effluent
Station: General
Mitchell Field
J F MAMJJASON
Years of Record: 1871-1977 Monthly Rainfall Distribution
FIGURE B-10. Loading comparison for Milwaukee, Wisconson.
-------
Sources for Information
1. State of the Art of Water Pollution Control in
Southeastern Wisconsin, Vol. 1, Point Sources, Prepared
by Stanley Consultants, Inc. July 1977.
2. State of the Art of Water Pollution Control in
Southeastern Wisconsin, Vol. 3, Urban Storm-Water
Runoff, Prepared by Stanley Consultants, Inc. July
1977.
3. Water Quality and Flow of Streams in Southeastern
Wisconsin, prepared by the Southeastern Wisconsin
Regional Planning Commission. November 1966.
4. Personal communication: William A. Kneutzberger,
Envirex, Inc., Milwaukee, Wisconsin.
BUCYRUS, OHIO
Urban Characteristics
The drainage area modeled by the 1978 Needs Survey is
2,599 acres (4.1 square miles) with a 1970 population of
13,111. The combined sewer drainage area of 2,000 acres
(3.1 square miles) is 15% open space. Combined sewer overflow
occurs approximately 140 times per year at 24 locations on
the Sandusky River. These overflow events cause consistently
low dissolved oxygen concentrations that often go to zero at
night due to accumulated sludge deposits. One secondary
WWTP has a design capacity of 4.2 mgd and treats an average
daily flow of 2.6 mgd which is discharged to the Sandusky
River.
The average annual rainfall in Bucyrus is 33.6 inches,
ranging from an average monthly low of 1.73 inches in October
to a high of 3.70 inches in May, as shown in Figure B-ll.
Rainfall occurs for approximately 930 hours per year causing
runoff for approximately 548 hours per year or 6.3% of the
time. The mean annual flow and depth of the Sandusky River
are 108 cfs and 1 foot, respectively. Receiving water uses
include recreation and downstream water supply.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the City of Bucyrus, Ohio, are shown in
Figure B-ll. Combined sewer overflow is a major source of
SS, Pb, and BOD5 average annual loads, 94%, 80%, and 71%,
respectively. Storm runoff is a minor source of average
annual loads for all parameters; and secondary WWTP effluent
B - 30
-------
Average Annual Loads
100
90
80
70
-o
CD
O 60
"S 50
§ "f
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°- 30
20
10
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"::::
ijiiijiji:
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City of Bucyrus
100
90
80
70
CD
0 60
0 50
§ 40
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20
10
0
*i*i*
X'X'X
|:*i*i
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11
3ODS SS TN PO4 Pb
1978 Needs Survey
Average Event Loads
Mlll_
1 1 1 nj^
I II 111
sSsi
BODS SS TN PO, Pb
City of Bucyrus
90
80
70
TJ
CD
_° 60
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CD
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30
20
10
0
*'£*'
:;>:*:
•:•:•:•:•:•
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3ODS SS TN PO4 Pb
1978 Needs Survey
LEGEND
BOD5 = 5-day Biochemical
Oxygen Demand
SS = Suspended Solids
TN = Total Nitrogen
PO4 = Phosphate Phosphorus
Pb= Lead
K'X':-:-:j Combined Sewers
Ulllllli Storm Runoff
I I WWTP Effluent
Station: Lahm
Municipal Airport "JFMAMJJASON
Years of Record: 1960-1977 Monthly Rainfall Distribution
FIGURE B-11. Loading comparison for Bucyrus, Ohio.
-------
is a major source of P04 and TN average annual loads, 77%
and 74%, respectively.
Average annual loads in pounds per year from the area
modeled by the 1978 Needs Survey are shown in Figure B-ll.
Combined sewer overflow is a major source of SS and Pb
average annual loads, 88% and 83%, respectively. Storm
runoff is a minor source of the average annual loads for all
parameters; and secondary WWTP effluent is a major source of
TN, BODs and P04 average annual loads, 94%, 70%, and 69%,
respectively.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the City of Bucyrus, Ohio, are shown in
Figure B-ll. Combined sewer overflow is a major source of
SS, BOD5, Pb, TN, and P04 average event loads 96%, 93%, 83%,
81%, and 79%, respectively. Storm runoff and secondary WWTP
effluent are minor sources of the average event loads for
all parameters.
Average event loads in pounds per hour from the area modeled
in the 1978 Needs Survey are shown in Figure B-ll. Combined
sewer overflow is a major source of SS, Pb, BOD5, P04, and
TN average event loads, 99%, 99%, 88%, 88%, and 51%,
respectively. Storm runoff average event loads are zero
since the entire 2,599 acres were modeled as a combined
sewer basin, and secondary WWTP effluent is a major source
of the average event load for TN only, 49%.
Sources of Information
1. Floyd G. Browne and Assoc. Ltd. Facilities Plan for
Wastewater Treatment Plant Improvement and Appurtenances
City of Bucyrus, Ohio. 1976.
2. Floyd G. Browne and Assoc. Ltd. Infiltration/Inflow
Analysis Report, City of Bucyrus, Ohio. 1974.
3. Burgess and Niple Ltd. Final Report, Land Use,
Transportation, Parks and Open Space. Columbus, Ohio.
1974.
4. Burgess and Niple Ltd. Stream Pollution and Abatement
from Combined Sewer Overflow. Columbus, Ohio. 1969.
5. Personal communication: Garry Cole, Floyd G. Browne &
Assoc. Ltd., Marion, Ohio.
B - 32
-------
DES MOINES, IOWA
Urban Characteristics
The drainage area modeled in Des Moines by the 1978 Needs
Survey was 49,018 acres (76.6 square miles) with a 1970
population of 255,000. The combined sewer drainage area of
4,018 acres (6.3 square miles) is essentially 100% developed.
Combined sewer overflow occurs approximately 105 times per
year at eight locations on the Des Moines River. These
overflow events together with the urban stormwater runoff
cause low dissolved oxygen concentrations during the summer
months. One secondary WWTP has a design capacity of 35 mgd
and treats an average daily flow of 39 mgd which is discharged
to the Des Moines River.
The average annual rainfall in Des Moines is approximately
31.5 inches, ranging from an average monthly low of 1.12 inches
in January to a high of 4.66 inches in June, as shown in
Figure B-12. Rainfall occurs for approximately 630 hours
per year, causing runoff for approximately 367 hours per
year or 4.2% of the time. The mean annual flow and depth of
the Des Moines River are 4,280 cfs and 5.8 feet, respectively.
Present receiving water uses include fishing, recreation,
and upstream water supply (Raccoon River).
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Des Moines, Iowa, are
shown in Figure B-12. Combined sewer overflow is a major
source of the average annual load for SS, 46%. Storm runoff
is a major source of Pb and SS average annual loads, 79% and
48%, respectively; and secondary WWTP effluent is a major
source of PO4, TN, and BOD5 average annual loads, 92%, 91%,
and 55%, respectively.
Average annual loads in pounds per year from the area
modeled by the 1978 Needs Survey are shown in Figure B-12.
Combined sewer overflow is a minor source of average annual
loads for all parameters. Storm runoff is a major source of
SS, Pb, and BOD5 average annual loads, 87%, 86%, and 57%,
respectively; and secondary WWTP effluent is a major source
of TN, PO4, and BOD5 average annual loads, 84%, 64%, and
36%, respectively.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Des Moines, Iowa, are
shown in Figure B-12. Combined sewer overflow is a major
source of SS, BOD5, and TN average event loads, 49%, 45%,
B - 33
-------
Average Annual Loads
90
80
70
-o
CO
° 60
O 50
8 40
CD
°- 30
20
10
$
w*%
x^
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1
BOD, SS TN P04 Pb
Urbanized Area
100
90
80
70
O 60
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§40
CD
°~ 30
20
10
fjlvKv •!
h
I
••••iliiinl...v.i
BOD5 SS TN P04 Pb
1978 Needs Survey
Average Event Loads
100
90
80
70
•o
CD
O 60
O 50
8 40 S;:;: Ji jg:;:
£ 3°ll;i|
20 vi'X*'. •'.•'•.'•I-
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Urbanized Area
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0)
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0)
CL
30
20
10
0
"BOD, SS TN PO4 Pb
1978 Needs Survey
LEGEND
BODS = 5-day Biochemical
Oxygen Demand
SS = Suspended Solids
TN = Total Nitrogen
PO4 = Phosphate Phosphorus
Pb- Lead
Ulllllll
Combined Sewers
Storm Runoff
WWTP Effluent
Station: Municipal
Airport
JFMAMJJASON
Years of Record: 1877-1977 Monthly Rainfall Distribution
FIGURE B-12. Loading comparison for Des Moines, Iowa.
-------
and 33%, respectively. Storm runoff is a major source of
Pb, ss, BOD5, TN, and PO4 average event loads, 82%, 51%,
50%, 37%, and 35%, respectively; and secondary WWTP effluent
is a major source of PO4 average event loads, 33%.
Average event loads in pounds per hour from the area modeled
by the 1978 Needs Survey are shown in Figure B-12. Combined
sewer overflow is a minor source of average event loads for
all parameters. Storm runoff is a major source of SS, Pb,
BOD5, P04, and TN average event loads, 93%, 88%, 86%, 82%,
and 68%, respectively; and secondary WWTP effluent is a
minor source of average event loads for all parameters.
Sources of Information
1. Henningson, Durham & Richardson. Combined Sewer
Overflow Abatement Plan, Des Moines, Iowa. EPA
R2-73-170. April 1974.
2. Iowa Department of Environmental Quality. Iowa Water
Quality Management Plan, Des Moines River Basin.
Draft. July 1975.
3. Personal communication: Mr. Leadington, Iowa Department
of Environmental Quality, Des Moines, Iowa.
SAN FRANCISCO, CALIFORNIA
Urban Characteristics
The City of San Francisco is served completely by combined
sewers with a combined sewer drainage area of 24,637 acres
(38.5 square miles) and a 1970 population of 712,000.
Except for parks, military reservations, and mountain slopes,
the area is 100% developed. Combined sewer overflow occurs
at 39 locations on San Francisco Bay to the east and the
Pacific Ocean to the west for nearly all rainfall events.
These overflow events cause beach closings due to bacterial
contamination of coastal waters. Three primary WWTP's have
a design capacity of 100 mgd and treat an average daily flow
of 105 mgd with 84 mgd discharged to San Francisco Bay and
21 mgd to the Pacific Ocean.
The average annual rainfall in San Francisco is approximately
20.3 inches, ranging from an average monthly low of 0.02 inches
in July to a high of 4.59 inches in January. About 40% of
the annual rainfall occurs in December and January.
Approximately 55 rainfall events occur each year with an
average duration per event of 6 hours. Rainfall occurs for
approximately 330 hours per year causing runoff for
approximately 198 hours per year or 2.3% of the time.
B - 35
-------
Present receiving water uses include commercial and sport
fishing, recreation, and navigation.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of San Francisco, California,
are shown in Figure B-13. Combined sewer overflow is a
major source of the average annual load for SS, 34%. Storm
runoff is a major source of Pb and SS average annual loads,
80% and 52%, respectively; and secondary WWTP effluent is a
major source of TN, P04, and BOD5 average annual loads, 96%,
96%, and 74%, respectively.
Average annual loads in pounds per year from the area
modeled by CH2M HILL for the wastewater facilities ocean
outfall design are shown in Figure B-13. Combined sewer
overflow is a minor source of average annual loads for all
parameters. Storm runoff annual loads are zero since the
entire city is served by combined sewers. Existing WWTP
effluent is a major source of P04, TN, BOD5, Pb and SS
average annual loads, 93%, 92%, 90%, 70%, and 69%,
respectively.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of San Francisco, California,
are shown in Figure B-13. Combined sewer overflow is a
major source of SS and BOD5 average event loads, 39% and
36%, respectively- Storm runoff is a major source of Pb,
SS, BOD5, TN, and PO4 average event loads, 98%, 60%, 59%,
41%, and 38%, respectively; and secondary WWTP effluent is a
major source of average event loads for all TN average event
loads, 34%.
Average event loads in pounds per hour from the area modeled
by CH2M HILL for the wastewater treatment facilities outfall
design are shown in Figure B-13. Combined sewer overflow is
a major source of SS, Pb, BOD5, and TN average event loads
95%, 95%, 83%, and 80%, respectively. Storm runoff average
event loads are zero since the entire city is served by
combined sewers, and the existing WWTP effluent loads are a
major source of the average event loads for P04 76%.
Sources of Information
1. Department of Public Works City and County of San
Francisco, and J. B. Gilbert & Assoc. Overview
Facilities Plan August 1975. San Francisco Master Plan
Wastewater Management.
B - 36
-------
Average Annual Loads
90
80
70
TJ
TO
O 60
O 60
C
g 40
0)
°~ 30
20
10
0
H
:::*::: :::
1 1 1 .Vf . .
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::
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•*•'• '•
BODs SS TN P04 Pb
Urbanized Area
55555
55555
;•:•:§•••
&:::5
:XvS
•S-S:;
BOD5 SS TN PO, Pb
Outfall Design
Average Event Loads
100
90
80
70
"S
O 60
O 50
+-•
§ 10
°- 30 ::;•::::;: W
20 •:•:;:•:•: •:•:•:•
10 •:•:•:•:•: ;:•:•:•
IfflB
SS TN PO4 Pb
Urbanized Area
100
90
80
70
•o
to
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5l5i5
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"BOD, SS TN P04 Pb
Outfall Design
LEGEND
BODS = 5-day Biochemical
Oxygen Demand
SS = Suspended Solids
TN = Total Nitrogen
PO4 = Phosphate Phosphorus
Pb= Lead
Combined Sewers
Ulllllll Storm Runoff
I I WWTP Effluent
6-
5-
V.4-
I
Station: Federal
Office Building " J F
Years of Record: 1850-1977
M A M J J A S O N
Monthly Rainfall Distribution
FIGURE B-13. Loading comparison for San Francisco, California.
-------
2. Engineering Science, Inc. Characterization and
Treatment of Combined Sewer Overflows. Submitted by
the City and County of San Francisco Department of
Public Works. November 1967.
3. Personal communication: Harold C. Coffee, Hydrology
Section Engineer, City and County of San Francisco
' Department of Public Works.
4. Personal communication: Dick Meighan, CH2M Hill, San
Francisco, California.
SACRAMENTO, CALIFORNIA
Urban Characteristics
The drainage area modeled by the 1978 Needs Survey for
Sacramento, California, is 70,000 acres (109.4 square miles)
with a 1970 population of 494,000. The combined sewer
drainage area of 7,000 acres (10.9 square miles) is approxi-
mately 3% open space. Combined sewer overflow occurs
approximately 40 times per year at two locations on the
Sacramento River. These overflow events have little impact
on the receiving water. Twenty-two secondary WWTP's have a
design capacity of 148 mgd and treat an average daily flow
of 98 mgd which is discharged to the Sacramento River, a
tributary to San Francisco Bay. The mean annual flow and
depth of the Sacramento River are approximately 24,000 cfs
and 22 feet, respectively. Receiving water uses include
water supply, navigation, recreation, and fishing.
The average annual rainfall in Sacramento is approximately
16.9 inches, from an average monthly low of 0.03 inches in
July to a high of 3.50 inches in January, as shown in
Figure B-14. Rainfall occurs for approximately 492 hours
per year, causing runoff for approximately 288 hours per
year or 3.3% of the time.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Sacramento, California,
are shown in Figure B-14. Combined sewer overflow is a
minor source of average annual loads for all parameters.
Storm runoff is a major source of Pb and SS average annual
loads, 86% and 63%, respectively; and secondary WWTP effluent
is a major source of TN, P04, and BOD5 average annual loads,
96%, 96%, and 73%, respectively.
Average annual loads in pounds per year from the area
modeled by the 1978 Needs Survey are shown in Figure B-14.
B - 3!
-------
Average Annual Loads
100
90
80
70
T3
CD
_° 60
O 50
C
g 40
°~ 30
20
10
0
•:•:• J444L
UUH :•;•
BODS SS TN P04 Pb
Urbanized Area
Average Event Loads
90
80
70
T
cc
C 60
O 50
§ 40
OJ
°- 30
20 • •:•:•:•:• •:
10 ••:•:•:•:••:
'00
90
80
70
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d>
°-30
20
10
S:W: %
•:•:• JIIIH
vM*X '.''
BODj SS TN PO, Pb
Urbanized Area
BOD5 SS TN P04 Pb
1978 Needs Survey
100
90
80
70
CD
°60
M- I
0 50|
C
03 „ J
CD
20 ;
10 [xjjj
BODS SS TN PO, Pb
1978 Needs Survey
LEGEND
BODS = 5-day Biochemical
Oxygen Demand
SS = Suspended Solids
TN = Total Nitrogen
PO4 = Phosphate Phosphorus
Pb= Lead
Combined Sewers
II 1 1 1 1 1 1 1 Storm Runoff
WWTP Effluent
Station: Executive
Airport " J F
Years of Record: 1940-1977
MAMJJASOND
Monthly Rainfall Distribution
FIGURE B-14. Loading comparison for Sacramento, California.
-------
Combined sewer overflow is a minor source of average annual
loads for all parameters. Storm runoff is a major source of
Pb and SS average annual loads, 62% and 51%, respectively;
and secondary WWTP effluent is a major source of TN, BOD5,
and SS average annual loads, 95%, 73%, and 36%, respectively.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hours from the Urbanized Area of Sacramento, California,
are shown in Figure B-14. Combined sewer overflow is a
minor source of average event loads for all parameters.
Storm runoff is a major source of Pb, SS, BOD5, TN and PO4
average event loads, 92%, 73%, 68%, 43%, and 40%, respectively;
and secondary WWTP effluent is a major source of PO4 and TN
average event loads, 46% and 42%, respectively.
Average event loads in pounds per hour from the area modeled
in the 1978 Needs Survey are shown in Figure B-14. Combined
sewer overflow is a major source of BOD5 and PO4 average
event loads, 42% each. Storm runoff is a major source of
Pb, SS, BOD5, P04, and TN average event loads, 86%, 78%,
50%, 50%, and 36%, respectively; and secondary WWTP effluent
is a major source of average event loads for TN, 40%.
Sources of Information
1. U.S. EPA. Environmental Impact Statement, Sacramento
Regional Wastewater Management Program. April 1975.
2. U.S. EPA. Urban Storm Runoff and Combined Sewer
Overflow Pollution, Sacramento, California. December
1971.
3. Sacramento Area Consultants. Storm-water Control
System, Sacramento Regional Wastewater Management
Program. August 1975.
4. J. B. Gilbert & Assoc. Feasibility Study, Elimination
of Wastewater Bypassing, City of Sacramento. September
1973.
5. Personal communication: Karen O'Hare, Sacramento Area
Planning Council.
6. Personal communication: Bill Hetland, Sacramento City
Sewer District.
B - 40
-------
PORTLAND, OREGON
Urban Characteristics
The drainage area modeled by the 1978 Needs Survey for
Portland, Oregon, is served entirely by combined sewers with
an area of 51,394 acres (80.3 square miles) and a 1970
population of 411,000. Only 6% of this area is open space.
Combined sewer overflow occurs approximately 149 times per
year at 43 locations on the Willamette River. These overflow
events contribute to low dissolved oxygen concentrations and
significant benthal deposits in the receiving water. Four
secondary WWTP's have a design capacity of 9 mgd and treat
an average daily flow of 7 mgd which is discharged to the
Willamette River.
The average annual rainfall is approximately 37.6 inches,
from an average monthly low of 0.49 inches in July to a high
of 6.24 inches in December, as shown in Figure B-15.
Rainfall occurs for approximately 1,496 hours per year,
causing runoff for approximately 898 hours per year or 10%
of the time. The mean annual flow and depth of the Willamette
River are approximately 24,000 cfs and 25 feet, respectively.
Receiving water uses include navigation, fishing, recreation,
and swimming.
Average Annual Loads
Estimated percentages of the average annual loads in pounds
per year from the Urbanized Area of Portland, Oregon, are
shown in Figure B-15. Combined sewer overflow is a major
source of the average annual load for SS, 59%. Storm runoff
is a major source of lead and SS average annual loads, 70%
and 36%, respectively; and secondary WWTP effluent is a
major source of PO4, TN, and BOD5 average annual loads, 89%,
87%, and 54%, respectively.
Average annual loads in pounds per year from the hydrologic
unit modeled by the 1978 Needs Survey are shown in Figure B-15
Combined sewer overflow is a major source of Pb, SS, BOD5,
P04 and TN average annual loads, 95%, 91%, 83%, 83%, and
63%, respectively. Storm runoff average annual loads are
zero since the entire basin modeled is served by combined
sewers. Secondary WWTP effluent is a major source of the
average annual load for TN, 37%.
Average Event Loads
Estimated percentages of the average event loads in pounds
per hour from the Urbanized Area of Portland, Oregon, are
shown in Figure B-15. Combined sewer overflow is a major
source of SS, BOD5, TN, and P04 average event loads, 62%,
B - 41
-------
Average Annual Loads
100
90
80
70
•D
ro
o so
O 50
^
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m
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BODS
Urbanized Area
100
90
80
70
m
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10
0
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BODS SS TN PC, Pb
1978 Needs Survey
Average Event Loads
80
70
•o
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c
S 40 $£#.
fe v:::-:;:::
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BODs SS TN PO4 Pb
Urbanized Area
90
80
70
CD
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" BODS SS TN
1978 Needs
PO4 Pb
Survey
LEGEND
BODS = Bnday Biochemical
Oxygen Demand
SS = Suspended Solids
TN = Total Nitrogen
POd = Phosphate Phosphorus
Pb = Lead
EvX'Xi Combined Sewers
milllll Storm Runoff
WWTP Effluent
Station: International
Airport J
Years of Record: 1941-1977
M A M J J A S O
Monthly Rainfall Distribution
N D
FIGURE B-15. Loading comparison for Portland, Oregon.
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42%, 37%, and 34%, respectively. Storm runoff is a major
source of Pb, BOD5, and SS average event loads, 72%, 47%,
and 38%, respectively; and secondary WWTP effluent is a
major source of PO4 and TN average event loads, 45% and 41%,
respectively.
Average event loads in pounds per hour from the area modeled
in the 1978 Needs Survey are shown in Figure B-15. Combined
sewer overflow is a major source of Pb, SS, BOD5, PO4, and
TN average event loads, 100%, 99%, 98%, 98%, and 94%,
respectively. Storm runoff average event loads are zero
since the entire basin modeled is served by combined sewers,
and secondary WWTP effluent is a minor source of average
event loads for all parameters.
Sources of Information
1. CH2M HILL. Proposed Plan Areawide Waste Treatment
Management Study, Volume !L. Columbia Region Assoc. of
Governments. November 15, 1977.
2. CH2M HILL. Portland 208 Plan, Technical Supplement No.
!_, Planning Constraints. Columbia Region Assoc. of
Governments. November 15, 1977.
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APPENDIX C
DESCRIPTION OF TECHNOLOGICAL ALTERNATIVES
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Appendix C
DESCRIPTION OF TECHNOLOGICAL ALTERNATIVES
Much of the information contained in Appendix C was abstracted
from EPA reports published by the Municipal Environmental
Research Laboratory Office of Research and Development in
the Environmental Protection Technology Series. This series
describes research performed to develop and demonstrate
instrumentation, equipment, and methodology to repair or
prevent environmental degradation from point and nonpoint
sources of pollution. Specific reports consulted are listed
for each technological alternative described in this appendix.
SOURCE CONTROLS
Management practices to control the accumulation of pollutants
on an urban watershed cannot be considered as independent
pollution control alternatives. They are part of a total
pollution control plan and will play an increasingly important
role in water pollution control as combined sewer overflow
is reduced.
To control pollutants at their source, management practices
must be applied where pollutants accumulate. For combined
sewers, dry-weather deposition of sewage solids in the
collection system is the major source of BOD5, TN, PO4 and
coliform bacteria. Therefore, source control techniques
such as sewer flushing, which operate in the collection
system can be expected to be more effective than source
control techniques such as street cleaning, which operate on
the land surface for BODs nutrients and coliform bacteria.
On the other hand, lead is a pollutant which is associated
with automobile use and accumulation is predominantly on the
street surface. Therefore, if removal of lead is of concern
in a combined sewer watershed, street cleaning can be expected
to be more effective than sewer flushing to achieve the
given objective.
Consideration of urban watersheds served by separate storm-
water and wastewater collection systems is beyond the scope
of this report. However, source controls which operate on
the land surface or which affect pollution accumulation such
as street cleaning, trash removal, and air pollution controls
will generally be more effective on separate watersheds than
on combined sewer watersheds, because the majority of the
pollutants accumulate on the land surface rather than in
the collection system.
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Since BOD5 is a major pollutant generated by combined sewer
overflow and since data on the cost and effectiveness of
BODS removal are generally available, the unit removal cost
of BOD, expressed in terms of dollars per pound removed, is
used to compare the cost-effectiveness of the technological
alternatives discussed in this report. If other pollutants
are of interest in a given case, the relative cost-
effectiveness of the various alternatives may change.
Street Cleaning
Process Description. The major objective of municipal
street cleaning is to enhance the aesthetic appearance of
streets by periodically removing the surface accumulation of
litter, debris, dust, and dirt. Common methods of street
cleaning are manual, mechanical broom sweepers, vacuum
sweepers, and street flushing. However, as currently
practiced, street flushing does not remove pollutants from
storm water but merely transports them from the street into
the sewers.
Streetsweeping has received a great deal of attention during
the last few years as a potential water quality control
management practice. It has the major advantage of being
applicable to highly developed, established urban areas. It
also controls pollutants at the source and will improve
general urban aesthetics as well as water quality. Street-
sweeping is a relatively inefficient control alternative for
removing BOD5 in a combined sewer watershed since only a
small portion of the total BOD5 load is located in or near
street gutters. Therefore, Streetsweeping will be more
effective for watersheds served by separate sewers than for
watersheds served by combined sewers.
Streetsweeping effectiveness is a function of sweeper
efficiency, frequency of cleaning, number of passes, equipment
speed, pavement conditions, equipment type, fraction of
streets swept, litter control programs, and street parking
restrictions.
Streetsweeping is a feasible control alternative for removal
of between 2% and 11% of the BOD5 discharge from a combined
sewer watershed at a cost of $3.00 to $11.60 per pound of
BOD5 removed.
Advantages.
1. Source control of pollution may, in some cases, be
cheaper than treatment.
2. Aesthetically better living conditions are provided.
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3. Flexible to changing community needs.
4. Stimulates local employment. Approximately 65% to 70%
of the annual cost is for labor and supervision.
5. Ease of application to highly developed urban areas.
Disadvantages.
1. Streetsweeping is applicable only to streets with curb
and gutters.
2. Parking restrictions may be required for streetsweeping
to be effective.
3. Streetsweepers consume approximately 1 gallon of gasoline
for every 6 miles swept at a speed of 6 miles per hour.
Sources of Information.
1. "Areawide Assessment Procedures Manual, Volume III,
Appendix G, Urban Stormwater Management Techniques:
Performance and Cost," EPA-6009-76-014. MERL Office of
Research and Development, U.S. EPA, Cincinnati, Ohio.
July 1976.
2. Sartor, J. D. and Boyd, G. B. "Water Pollution Aspects
of Street Surface Contaminants," U.S. EPA No. EPA-R2-
72-081. NTIS No. PB 214 408. Office of Research and
Monitoring, Washington, D.C. November 1972.
3. American Public Works Association. "Water Pollution
Aspects of Urban Runoff." EPA-R2-72-081. NTIS No. PB
215 532. U.S. EPA. January 1969.
4. Levis, A. H. "Urban Street Cleaning," EPA-670/2-75-
030. NTIS No. PB 239 327.
5. Amy, G. et al. "Water Quality Management Planning for
Urban Runoff." U.S. EPA No. EPA 440/9-75-004. NTIS
No. PB 241 689. December 1974.
6. Adimi, R. et al. "An Evaluation of Streetsweeping
Effectiveness in the Control of Nonpoint Source Pollution."
The Catholic University of America. April 1976.
(Unpublished paper prepared under the direction of G.
K. Young, Ph.D.).
Combined Sewer Flushing
Process Description. The major objective of combined sewer
flushing is to resuspend deposited sewage solids and transmit
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these solids to the dry-weather treatment facility before a
storm event flushes them to a receiving water. Combined
sewer flushing consists of introducing a controlled volume
of water over a short duration at key points in the collection
system. This can be done using external water from a tanker
truck with a gravity or pressurized feed or using internal
water detained manually or automatically.
Combined sewer flushing is most effective when applied to
flat collection systems. It may also be applied in conjunction
with upstream storage and downstream swirl concentrators,
followed by disinfection. Procedures are available to
estimate the quantity and distribution of dry-weather
deposition in sewers and for locating the optimum sites for
sewer flushing. A recent feasibility study of combined
sewer flushing indicates that manual flushing using an
external pressurized source of water is most effective. No
significant gain in the fraction of load removed was achieved
by repeated flushing, and 70% of the flushed solids will
quickly resettle. Therefore, repeated flushing in a down-
stream sequence is probably necessary to achieve significant
pollutant reductions. Process efficiency is dependent upon
flush volumes, flush discharge rate, sewer slope, length,
diameter, wastewater flow rate, and efficiency of the waste-
water treatment device receiving the resuspended solids.
Combined sewer flushing is a feasible control alternative for
removal of between 18% and 32% of the BOD5 discharge from a
combined sewer watershed at a cost of 0.94 to 4.00 per
pound of BOD5 removed.
Advantages.
1. Implementation of sewer flushing requires a complete
knowledge of how the existing system is operating.
2. Increases the sewer transport and storage capacity.
3. Flexible to the needs and characteristics of a specific
site.
4. Flexible to changes in facility capacities.
Disadvantages.
1. Experience with large-scale combined sewer flushing is
limited.
2. A continuous operation and maintenance program is
required.
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Sources of Information.
1. Pisano, W. C. and Queiroz, C. S. "Procedures for
Estimating Dry Weather Pollutant Deposition in Sewerage
Systems." EPA-600/2-77-120. July 1977.
2. FMC Corporation. "A Flushing System for Combined Sewer
Cleansing." EPA 11020 DNO 03/72. March 1972.
3. Process Research, Inc. "A Study of Pollution Control
Alternatives for Dorchester Bay." Commonwealth of
Mass. Metro. District Commission. Volumes 1, 2, 3, and
4. 23 December 1974.
4. Smith, S. F. "Statement for the Record—Subcommittee
on Investigations and Review—Committee on Public Works
and Transportation--!!. S. House of Representatives—On
Oversite Hearings on Municipal Construction Grants
Program." 3 August 1978.
Catch Basin Cleaning
Process Description. The major objective of catch basin
cleaning is to reduce the first flush of deposited solids in
a combined sewer system by frequently removing accumulated
catch basin deposits. Methods to clean catch basins are,
manual, eductor, bucket, and vacuum. Less than 45%
municipalities in the United States uses mechanical methods.
The role of catch basins in newly constructed sewers is
marginal due to improvements in street surfacing and design
methods for providing self-cleaning velocities in sewers.
Catch basins should be used only where there is a solids-
transporting deficiency in the downstream sewers or at a
specific site where surface solids are unusually abundant;
however, many existing combined sewers have catch basins. A
national survey of catch basin cleaning indicates that the
average cleaning frequency of 2.3 times/year has the potential
for removing approximately 2% of a combined sewer watershed
BOD5 load with a unit removal cost of greater than $50 per
pound of BOD. Therefore, catch basin cleaning cannot be
considered a feasible pollution control alternative for
combined sewer systems.
Advantage.
1. Site-specific combined sewer deposition and flushing
problems can be controlled.
Disadvantage.
1. Low overall removal efficiency.
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Sources of Information.
1. Lager, J. A., Smith, W. G., and Tchobanoglous, G.
"Catchbasin Technology Overview and Assessment." EPA-
600/2-77-051. May 1977.
COLLECTION SYSTEM CONTROLS
Existing System Management
Process Description. The major objective of collection
system management is to implement a continual remedial
repair and maintenance program to provide maximum transmission
of flows for treatment and disposal while minimizing overflow,
bypass, and local flooding. It requires an understanding of
how the collection system works and patience to locate
unknown malfunctions of all types, poorly optimized regulators,
unused in-line storage, and pipes clogged with sediments in
old combined sewer systems.
The first phase of analysis in a sewer system study is an
extensive inventory of data and mapping of flowline profiles.
This information is then used to conduct a detailed physical
survey of regulator and storm drain performance. In a
detailed study at Fitchburg, Massachusetts, Pisano (May
1978) found that minor repairs of four overflow structures
and several small alterations of storm sewer piping obtained
a 43.9% reduction of the present BOD load due to combined
sewer overflow at a cost of $26,500. An additional 23% BOD
reduction was obtained at a cost of $4,678,000 using sewer
flushing, streetsweeping, inflow correction and storage.
This type of sewer system inventory and study should be the
first objective of any combined sewer overflow pollution
abatement project.
Advantages.
1. Requires a thorough analysis of the existing sewer
system which will result in an understanding of how the
collection system operates before control alternatives
are chosen.
2. Regulator modification and storm drain repiping can be
very cost-effective.
3. Application is very flexible to site-specific conditions.
Disadvantages.
1. No general cost-effectiveness data are available since
the results are very site-specific.
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Sources of Information.
1. Pisano, W. C. "Analyzing the Existing Collection
System." Paper presented at a seminar on combined
sewer overflow assessment and control procedures.
Windsor Locks, Connecticut. May 1978.
Flow Reduction Techniques
Process Description. The major objective of flow reduction
techniques is to maximize the effective collection system
and treatment capacities by reducing extraneous sources of
clean water. Infiltration is the volume of ground water
entering sewers through defective joints; broken, cracked,
or eroded pipe; improper connections; and manhole walls.
Inflow is the volume of any kind of water discharged into
sewerlines from such sources as roof leaders, cellar and
yard drains, foundation drains, roadway inlets, commercial
and industrial discharges, and depressed manhole covers.
Combined sewers are by definition intended to carry both
sanitary wastewater and inflow. Therefore, flow reduction
opportunities are limited. Typical methods for reducing
sewer inflow are by discharging roof and areaway drainage
onto pervious land, use of pervious drainage swales and
surface storage, raising depressed manholes, detention
storage on streets and rooftops, and replacing vented manhole
covers with unvented covers.
It appears that the disconnection of roof drains from
combined sewer systems would have limited effectiveness
since very little of the pollutant load accumulates on
roofs. Therefore, total annual pollutant yield would be
largely unaffected. However, the frequency of overflow may
be reduced since total runoff would be reduced somewhat.
Advantages.
1. Application is very flexible to site-specific conditions
2. Requires a thorough analysis of the existing sewer
system before alternatives are chosen.
3. Maximizes the effective capacities of collection
system and treatment works.
Disadvantages.
1. No general cost-effectiveness data are available since
the results are very site-specific.
2. Extraneous flow problems are not simple to solve, and
opportunities are limited in combined sewers.
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3- Detention storage on streets has the potential of
disrupting traffic and business activity.
4. Rooftop storage and roof drain disconnection require
the cooperation of building owners.
Sources of Information.
1. Sullivan, R. H. et al. "Sewer System Evaluation,
Rehabilitation and New Construction, A Manual of Practice."
EPA-600/2-77-Ol7d.
2. Cesareo, D. J. and Field, R. "Infiltration-Inflow
Analysis." J. Env. Eng. Div. ASCE. Vol. 101, No. 5,
pp. 775-784. October 1975.
3. Respond, F. J. "Roof Retention of Rainfall to Limit
Urban Runoff." National Symposium on Urban Hydrology,
Hyd. and Sed. Control, July 26-29, 1976. Kentucky
Univ. Office Resident Eng. Service Bull. N III 115.
1976.
4. Poertner, H. G. "Detention Storage of Urban Stormwater
Runoff." APWA Reporter. 40, 5:14. 1973.
5. Poertner, H. G. "Better Storm Drainage Facilities at
Lower Costs." Civil Eng. 43, 10:67. 1973.
6. Peters, G. L. and Troemper, 0. P. "Reduction of Hydrualic
Sewer Loadings by Downspout Removal." JWPCF 41, 4:63-
81. 1969.
Sewer Separation
Process Description. Sewer separation is the conversion of
a combined sewer system into separate sanitary and storm
sewer systems. Separation of municipal wastewater from
storm water can be accomplished by adding a new sanitary
sewer and using the old combined sewer as a storm sewer, by
adding a new storm sewer and using the old combined sewer as
a sanitary sewer, or by adding a "sewer within a sewer"
pressure system. If combined sewers are separated it must
be remembered that storm sewer discharges may contribute a
significant pollutant load relative to secondary wastewater
treatment plant effluent and, therefore, may require some
type of control even after the sewer systems are separated.
Sewer separation is a feasible control alternative for small
combined sewer systems. Sewer separation will remove between
0% and 65% of the BOD5 discharge from a combined sewer
watershed at a cost of approximately $24.00 per pound of
BOD5.
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Advantages.
1. All municipal wastewater is treated prior to discharge.
2. Wastewater treatment plants operate more efficiently
under the relatively stable sanitary flow conditions.
3. Increased construction employment.
4. By definition, combined sewer overflow is eliminated.
Disadvantages.
1. Traffic and business activity is disrupted during a
long construction period.
2. It is difficult to eliminate all sanitary connections
to storm sewers.
3. Sewer separation is not flexible to changing water
pollution control needs.
Sources of Information.
1. American Society of Civil Engineers. "Combined Sewer
Separation Using Pressure Sewers." EPA 110020 EKO.
October 1969.
2. C-E Maguire, Inc. "Storm Water—Wastewater Separation
Study, City of Norwich, Connecticut." Engineering
Report. May 1976.
3. Albertson, Sharp and Backus, Inc. "City of Norwalk,
Connecticut, Facilities Plan Update for Sewerage System."
Engineering Report. June 1977.
Swirl and Helical Concentrators
Process Description. The major objective of swirl and
helical concentrators is to regulate both the quantity and
quality of storm water at the point of overflow. Solids
separation is caused by the inertia differential which
results from a circular path of travel. The flow is separated
into a large volume of clear overflow and a concentrated low
volume of waste that is intercepted for treatment at the
wastewater treatment plant. In addition to regulation of
combined sewer flow, they can provide high-rate primary
treatment for solids removal. A major attribute of the
swirl concentrator is the relatively constant treatment
efficiency over a wide range of flow rates (a fivefold flow
increase results in only about a 25% efficiency reduction)
and the absence of mechanical parts which use energy unless
input or output pumping is required.
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Swirl and helical bend concentrators have been modeled and,
in several cases, demonstrated for various processes including
treatment and flow regulation, primary treatment, and erosion
control. Swirl concentrators have been operated in Syracuse,
New York, from 1974 to present, in Rochester, New York, from
1975 to 1977, and in Toronto, Ontario, Canada, from 1975 to
1977. Helical bends have been operated in Lasalle, Quebec,
Canada, and Nantwich, England.
Swirl concentrators are a feasible control alternative to
remove between 33% and 56% of the BOD5 discharge from a
combined sewer watershed at a cost of $2.30 to $3.00 per
pound of BOD5. These cost estimates include pumping.
Advantages.
1. Operation and maintenance costs are low.
2. Operates well under intermittent shock loading conditions.
3. Very flexible and stageable to site-specific needs.
4. Requires no energy except that needed to recover hydraulic
head losses through the system, or for pumping through
the concentrator.
Disadvantages.
1. Experience with full-scale operation of swirl concen-
trators is limited.
2. Swirl concentrators do not remove dissolved pollutants.
Sources of Information.
1. Sullivan, R. H. et al. "The Helical Bend Combined
Sewer Overflow Regulator." EPA-600/2-75-062. December
1975.
2. "The Swirl Concentrator as a Grit Separator Device."
EPA-670/2-74-026.
3. Sullivan, R. H. et al. "Relationship Between Diameter
and Height for the Design of a Swirl Concentrator as a
Combined Sewer Overflow Regulator." EPA-670/2-74-039.
4. Sullivan, R. H. et al. "The Swirl Concentrator for
Erosion Runoff Treatment." EPA-600/2-76-271. September
1975.
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Remote Monitoring and Control
Process Description. The major objective of remote monitoring
and control on a combined sewer collection system is to
remotely observe the sewer and treatment capacities so that
the most effective use of inline storage is obtained with a
minimum of severe overflow. A prerequisite for this alter-
native is a large collection system with the potential for
inline storage. Three components are generally added to the
existing collection system: a data gathering system for
reporting rainfall, pumping rates, treatment rates, and
regulator positions; a central computer processing center,
and a control system to remotely manipulate gates, valves,
regulators, and pumps. The capital costs,
operation and maintenance costs, and effectiveness depend on
the hydraulic characteristics of the system of concern and
thus are very site-specific. Remote monitoring and control
of combined sewer flow is presently used to reduce overflow
in Detroit, Michigan, and Seattle, Washington.
Remote monitoring and control is a feasible control alternative
only if a significant in-line storage volume exists. Available
site-specific data indicate that a 20% to 45% removal of the
BOD5 discharge from a combined sewer watershed is possible
at a cost of $1.25 to $4.00 per pound of BOD5.
Advantages.
1. Utilizes the in-line storage capacity of the existing
system.
2. Low unit removal costs are possible.
3. Attenuation of peak flows is achieved.
4. The first flush is captured.
Disadvantages.
1. Limited to sites with large collection systems and
large interceptors which can be used for storage.
2. Requires highly trained operators and computer facilities.
3. There is no easy method of removing settled solids;
they may be bypassed to receiving waters during high
flows.
4. Devices to provide in-line storage may restrict peak
sewer capacity.
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Sources of Information.
1. Leiser, C. P. "Computer management of a combined sewer
system by METRO SEATTLE." EPA-670/2-74-022.
2. Metropolitan Sewer Board—St. Paul, Minnesota. "Dispatch-
ing System for Control of Combined Sewer Losses." EPA
Report No. 11020FAQ03/71. March 1971.
3. Watt, T. R. et al. "Sewerage System Monitoring and
Remote Control." EPA-670/2-75-020. May 1975.
4. Smith, S. F. "Statement for the Record—Subcommittee
on Investigations and Review—Committee on Public Works
and Transportation—U.S. House of Representatives—On
Oversite Hearings on Municipal Construction Grants
Program." 3 August 1978.
Fluidic Regulations
Process Description. The major objective of fluidic combined
sewer overflow regulation is to provide dynamic control at
the site of overflow without a complex operational system.
They are self-operated by using a venturi pressure gradient
which senses the dry-weather interceptor sewer capacity
before allowing combined storm water to overflow. New
fluidic regulator capital costs are estimated to be 10%
greater than conventional static regulators. A fluidic
regulator demonstration program operated in Philadelphia,
Pennsylvania, from February 1971 to March 1975.
Advantages.
1. Provides dynamic control of combined sewer overflow
without complex operational systems.
2. Reliability of operation and low maintenance.
3. Subject to real time control operation.
Disadvantages.
1. Experience with in-system operation is limited.
2. Higher capital costs than conventional regulators.
Sources of Information.
1. Freeman, P. A. "Evaluation of Fluidic Combined Sewer
Regulators Under Municipal Service Conditions." EPA-
600/2-77-071. August 1977.
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Polymer Injection
Process Description. The primary objective of polymer
injection to sewer flow is to increase the flow capacity of
an existing sewer by reducing the turbulent friction. It is
most applicable as an interim solution to infiltration
problems of sanitary sewers since they respond slowly over a
long period to rainfall-induced infiltration. A rapid short
duration flow increase, such as that occurring in combined
sewers, will generally exceed the capacity of polymer friction
reduction. Polymers used are water soluble, have a high
molecular weight and a large length-to-diameter ratio, and
are not toxic or harmful if swallowed.
Advantages.
1. Can reduce sanitary sewer overflow and flooding problems
due to rainfall-induced infiltration.
2. Low-cost solution to sanitary sewer infiltration problems.
Disadvantages.
1. Polymer lumping and injection failures.
2. Increased sanitary sewer flows may exceed the wastewater
treatment plant capacity.
3. Polymer injection will have little impact on combined
sewer overflow.
Sources of Information.
1. Chandler, R. W. and Lewis, W. R. "Control of Sewer
Overflows by Polymer Injection." EPA-600/2-77-189.
September 1977.
TREATMENT FACILITIES
Offline Storage
Process Description. The major objective of offline storage
is to contain combined sewer overflow for controlled release
into treatment facilities. Offline storage provides a more
uniform constant flow and thus reduces the size of treatment
facilities required. Offline storage 'facilities may be
located at overflow points or near dry-weather or wet-
weather treatment facilities. A major factor determining
the feasibility of using offline storage is land availablity.
Operation and maintenance costs are generally small, requiring
only collection and disposal costs for sludge solids, unless
input or output pumping is required. Many demonstration
projects have included storage of peak storm-water flows.
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These include Chipewa Falls, Wisconsin, Boston, Massachusetts,
Milwaukee, Wisconsin, and Columbus, Ohio.
Offline storage is a feasible control alternative to remove
between 2% and 22% of the BOD5 discharge from a combined
sewer watershed at a cost of $1.60 to $5.60 per pound of
BOD5. However, the primary objective of offline storage is
to capture the runoff waters for subsequent treatment by a
separate wet-weather treatment plant or combined wet/dry
weather treatment facility.
Advantages.
1. Reduces the size of required treatment facilities by
equalizing combined sewer overflow.
2. Flexible operation and adapts well to staged construction.
3. Can provide multipurpose services (recreational or
aesthetic designs).
4. Simple in design and operation.
5. Storage alone may remove up to 30% of the BOD captured
depending upon detention time.
Disadvantages.
1. Suitable land area must be available.
2. Additional treatment facilities are usually required.
3. Standing water may provide an environment that breeds
mosquitoes and results in odor and algae problems.
Sources of Information.
1. Liebenow, W. R. and Bieging, J. K. "Storage and Treatment
of Combined Sewer Overflow." EPA-R2-72-070. October
1972.
2. Commonwealth of Massachusetts, Metropolitan District
Commission. "Cottage Farm Combined Sewer Detention and
Chlorination Station." EPA-600/2-77-046. November
1976.
3. City of Milwaukee, Wisconsin, and Consoer, Townsend,
and ASSO. "Detention Tank for Combined Sewer Overflow,
Milwaukee, Wisconsin, Demonstration Project." EPA-
600/2-75-071. December 1975.
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4. Dodson, Kinney, and Lindbolm. "Evaluation of Storm
Standby Tank, Columbus, Ohio." EPA No. 11020FAL03/71
March 1971.
Sedimentation
Process Description. The major objective of sedimentation
is to produce a clarified effluent by gravitational settling
of the suspended particles that are heavier than water. It
is one of the most common and well-established unit operations
for wastewater treatment. Sedimentation also provides
storage capacity, and disinfection can be effected concurrently
in the same tank. It is also very adaptable to chemical
additives such as lime, alum, ferric chloride, and polymers
which provide higher suspended solids, BOD, nutrients and
heavy metals removal. Many demonstration projects have
included sedimentation. These include Dallas, Texas, New
York City, New York, Saginaw, Michigan, and Mt. Clemens,
Michigan.
Advantages.
1. The process is familiar to design engineers and operators.
2. Simple in design and operation.
3. Flexible operation and adapts well to staged construction.
4. Disinfection can be effected concurrently with sedi-
mentation in the same tank.
5. Storage is provided in conjunction with sedimentation.
6. Chemical additives can be used to improve process
removal efficiencies.
7. Energy requirements are usually low.
Disadvantages.
1. High land requirement.
2. Some manual basin cleaning must be provided between
storm events.
3. Removal performance is sensitive to the duration of
peak combined sewer overflow rates.
Sources of Information.
1. Mahida, V. U. and DeDecker, F. J- "Multi-Purpose
Combined Sewer Overflow Treatment Facility, Mount
Clemens, Michigan." EPA-670/2-75-010. May 1975.
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2. Metcalf and Eddy, Inc. Wastewater Engineering. McGraw-
Hill, 1972.
3. Wolf, H. W. "Bachman Treatment Facility for Excessive
Storm Flow in Sanitary Sewers." EPA-600/2-77-128.
4. Feurstein, D. L. and Maddaus, W. O. "Wastewater
Management Program, Jamaica Bay, New York, Volume I:
Summary Report." EPA-600/2-76-222a. September 1976.
5. Process Design Manual for Suspended Solids Removal.
EPA Technology Transfer. EPA 625/l-75-003a. January
1975.
Dissolved Air Flotation
Process Description. The major objective of dissolved air
flotation (DAF) is to achieve suspended solids removal in a
shorter time than conventional sedimentation by attaching
air bubbles to the suspended particles. The principal
advantage of flotation over sedimentation is that very small
or light particles that settle slowly can be removed more
completely and in a shorter time. Capital costs for DAF are
moderate; however, operating costs are relatively high due
to the energy required to compress air and release it into
the flotation basin and due to the greater skill required by
operators. Chemical additives are also useful to improve
process efficiencies of BOD and SS removals and to obtain
nitrogen and phosphorus removals. DAF demonstration facilities
were operated in Milwaukee, Wisconsin, from 1969 to 1974, in
Racine, Wisconsin, from 1973 to present, and in San Francisco,
California, from 1970 to present.
Advantages.
1. Chemical additives can be used to improve the process
removal efficiencies.
2. High rate intermittent operation is reliable.
3. Smaller sludge volumes and basin than for sedimentation.
4. Land requirements are smaller than for conventional
sedimentation.
Disadvantages.
1. Operating costs are relatively high.
2 Energy needs are much higher than for conventional
sedimentation.
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3. Greater skill is required for operation.
Sources of Information.
1. Bursztynsky, J. A. et al. "Treatment of Combined Sewer
Overflow by Dissolved Air Flotation.1' EPA-600/2-75-
033. September 1975.
2. Rex Chainbelt, Inc. "Screening/Flotation Treatment of
Combined Sewer Overflows." EPA 11020FDC. January
1972.
3. White, R. L. and Cole, T. G. "Dissolved Air Flotation
for Combined Sewer Overflows." Public Works. Vol. 104
No. 2, pp. 50-54. 1973.
4. Gupta, M. K. et al. "Screening/Flotation Treatment of
Combined Sewer Overflow, Volume 1 Bench Scale and Pilot
Plant Investigations." EPA-600/2-77-069a. August
1977.
Screens
Process Description. The major objective of screening is to
provide high-rate solids/liquid separation for combined
sewer particulate matter. Four basic screening devices have
been developed to serve one of two types of applications.
The microstrainer is a very fine screening device designed
to be the main treatment process of a complete system. The
other three devices, drum screens, rotary screens, and
static screens, are basically pretreatment devices designed
to remove coarse materials. BOD removal efficiencies are
approximately 15% for pretreatment screens and up to 50% for
microstrainers. For all screens, removal performance tends
to improve as influent suspended solids concentrations
increase due to the relatively constant effluent concentra-
tions. In addition, screens develop a mat of trapped particles
which act as a strainer retaining particles smaller than the
screen aperture. Chemical additives can be used to improve
process removal efficiencies. The use of screens in series
does not show any advantage over the use of a single screen.
Microstrainers break up solid particles and expose greater
numbers of bacteria in the effluent to disinfection.
Microstrainers have operated at Mt. Clemens, Michigan from
1972 to 1975, at Philadelphia, Pennsylvania, from 1969 to
1974, at Rochester, New York, from 1975 to 1976, at Oil
City, Pennsylvania, from 1976 to present, and several projects
are now under construction. Rotary, disc, and drum screens
have operated at Cleveland, Ohio, from 1970 to 1971, at
Milwaukee, Wisconsin, from 1969 to 1974, and at New York
City, New York, from 1975 to present.
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Microscreening is a feasible control alternative for removal
of between 22% and 43% of the BOD5 discharge from a combined
sewer watershed at a cost of $1.70 to $2.40 per pound of
BOD5.
Advantages.
1. Capable of treating highly varying flows under inter-
mittent conditions.
2. Flexible to site-specific operation needs by providing
pretreatment or main treatment.
3. Suspended solids removals of up to 70% are achievable.
4. The concentrated waste solids flow is usually less than
1% of the total flow, and the sludge is amenable to
dewatering.
5. Small land requirement.
6. Adaptable to automatic operation.
7. Microstrained effluent is more easily disinfected due
to solids breakup.
Disadvantages.
1. Removes only particulate matter.
2. Optimal use of chemical additives is not always possible
due to widely varying influent characteristics.
3. Operational problems include screen binding due to oil
and grease buildup and biological growth on the screen
panels.
4. High-impact velocities tend to break up solids and
floes if chemical additives are used.
Sources of Information.
1. Gupta, M. K. et al. "Screening/Flotation Treatment of
Combined Sewer Overflow, Volume l--Bench Scale and
Pilot Plant Investigations." EPA-600/2-77-069a.
August 1977.
2. Maher, M. B. "Microstraining and Disinfection of
Combined Sewer Overflow—Phase III." EPA-670/2-74-049.
August 1974.
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3. Clark, M. J. et al. "Screening/Flotation Treatment of
Combined Sewer Overflow, Volume II: Full-Scale Demon-
stration." U.S. EPA Demonstration Grant No. 11023 FWS.
Draft Report. April 1975.
4. Prah, D. H. and Brunner, P- L. "Combined Sewer Stormwater
Overflow Treatment by Screening and Terminal Ponding at
Fort Wayne, Indiana." U.S. EPA Demonstration Grant No.
11020 GYU. Volumes 1 and 2. Draft Report. June 1976.
5. Neketin, T. H. and Dennis, H. K. Jr. "Demonstration of
Rotary Screening for Combined Sewer Overflow." EPA No.
11023 FDD 07/71. July 1971.
High-Rate Filtration
Process Description. The major objective of high-rate
filtration (HRF) is to capture suspended solids on a fixed
bed of anthracite coal and on sand filter media. Periodic
backwashing of the filter bed must be provided even if
prefiltration is used because suspended solids will clog the
filter. HRF has been developed over the past 15 years and
is used in a variety of treatment applications, mainly for
industrial wastewater treatment. A pilot plant study of HRF
at the New York City Newton Creek Wastewater Treatment Plant
found that chemical additives improved HRF performance;
however, above 25 mgd, the extra cost of chemicals was
higher than the increased removals. Estimated unit treatment
costs in dollars per million gallons treated at the Newtown
Creek HRF were reduced approximately 80% when the HRF was
used as a dual treatment process. HRF demonstration facilities
were operated in Cleveland, Ohio, from 1970 to 1971, in
Rochester, New York, from 1975 to 1976, and in New York City
from 1975 to 1978.
Advantages.
1. Well suited to automatic operation.
2. Flexible in capacity to site-specific needs.
3. Backwash volume is usually less than 6% of the treated
flow, and sludge is amenable to dewatering.
4. Adaptable to dual treatment, i.e., dry-weather sanitary
sewage and combined sewer overflow, which reduces
annual costs by approximately 80%.
5. HRF in dual functions increases the capacity of over-
loaded dry-weather treatment plants.
6. Land requirements for HRF units are only 7% to 10% of
that needed for primary clarifiers of the same capacity.
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Disadvantages.
1. HRF operation is hindered by the accumulation of
compressible organic solids on the filter media.
2. Pretreatment is required to remove coarse solids.
3. Limited full-scale experience.
4. HRF does not remove dissolved pollutants.
5. Moderately high energy use.
Sources of Information.
1. Nebolsine, R. N. et al. "High Rate Filtration of
Combined Sewer Overflow." EPA 11023 EY 104/72. April
1972.
2. Innerfeld, H. et al. "Dual Process High-Rate Filtration
of Raw Sanitary Sewage and Combined Sewer Overflow."
U.S. EPA Grant No. S 803271. Draft Report. July 1978.
3. Drehwing, F. J. et al. "Combined Sewer Overflow Abatement
Program, Rochester, N.Y. Pilot Plant Evaluations."
U.S. EPA Grant No. Y005141. Draft Report. 1977.
4. Hickok, E. A. et al. "Urban Runoff Treatment Methods
Volume II—High-Rate Pressure Filtration." U.S. EPA
Grant No. S-802535. At Press. 1977.
5. Murphy, C. B. et al. "High Rate Nutrient Removal for
Combined Sewer Overflow." U.S. EPA Grant No. S-802400.
At Press. 1977.
High Gradient Magnetic Separation
Process Description. The major objective of high gradient
magnetic separation (HGMS) is to bind suspended solids to
small quantities of a magnetic seed material (iron oxide
called magnetite) by chemical coagulation and then pass them
through a high gradient magnetic field for removal. Magnetic
separation techniques have been used since the 19th century
to remove tramp iron and to concentrate iron ores. Solids
are trapped in a magnetic matrix which must be cyclically
back-flushed like screens and filters. Research on the
application of HGMS to combined sewer overflow pollutant
removal has been performed since July 1975 by Sala Magnetics,
Inc., in Cambridge, Massachusetts.
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Advantages.
1. Well suited to automatic operation.
2. Flexible to large variations in flow rate and influent
character without substantial changes in effluent
quality.
3. Estimated capital costs are approximately 40% lower
than comparative physical-chemical treatment.
4. Estimated operation and maintenance costs are approx-
imately 20% lower than comparative physical-chemical
treatment.
5. Adaptable as a dual function treatment facility for CSO
and dry-weather sanitary sewage.
6. Land requirements for magnetic separation are small.
7. Lower chlorine demand for disinfection.
8. BOD5 removals higher than 92% are possible with a
detention time of only 3 minutes.
9. Provides nutrient and heavy metals removals.
10. Reduced sludge dewatering costs.
Disadvantages.
1. No full-scale facilities have been constructed to treat
CSO or sanitary sewage.
2. Proper alum-polyelectrolyte flocculation is essential
to high gradient magnetic separation.
3. The ratio of magnetite seed to suspended solids is
critical for effective operation.
Sources of Information.
1. Allen, D. M., Sargent, R. L. and Oberteuffer, J. A.
"Treatment of Combined Sewer Overflow by High Gradient
Magnetic Separation." EPA-600/2-77-015. March 1977.
2. Kolm, H., Oberteuffer, J. A. and Keeland, D. "High
Gradient Magnetic Separation." Scientific American,
233(5):46-54, 1975.
3. Oder, R. R. and Horst, B. I. "Wastewater Processing
with High Gradient Magnetic Separators (HGMS)." Presented
at the 2nd National Conference on Complete Water Reuse,
Chicago. May 1975.
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4. Bitton, G. et al. "Phosphate Removal by Magnetic
Filtration." Water Research, 8:107. 1974.
5. Bitton, G. and Mitchell, R. "Removal of E. coli
Bacteriophage by Magnetic Filtration." Water Research
8:548. 1974.
Chemical Additives
Process Description. The major objective of using chemical
additives is to provide a higher level of treatment than is
possible with unaided physical treatment processes (sedi-
mentation, dissolved air flotation, high rate filtration,
and high gradient magnetic separation). Chemicals commonly
used are lime, aluminum or iron salts, polyelectrolytes, and
combinations of these chemicals. There is no rational
method for predicting the chemical dose required. Jar tests
are used for design purposes; however, field control is
essential since the chemical composition of combined sewer
overflow is highly variable. The major advantage of using
chemical additives with physical treatment is the increased
pollutant removals including removal of dissolved parameters.
The major disadvantages of using chemical additives are the
higher energy and treatment costs, greater sludge volumes,
and the necessity of experienced personnel to monitor the
application of chemicals. Many full-scale physical treatment
facilities use chemical additives.
Advantages.
1. Well suited to automatic control.
2. It can significantly increase pollutant removals,
including removal of heavy metals, by physical processes
3. It can provide removal of dissolved pollutants.
4. Lime sludge can be recalcined for lime recovery if this
proves economical.
Disadvantages.
1. increased volumes of sludge.
2. Higher energy needs.
3. Higher treatment costs.
4 Experienced personnel are required to monitor the
application of chemicals.
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Sources of Information.
1. Weber, W. J. Jr. Physicochemical Processes for Water
Quality Control. Wiley--Interscience. 1972.
Carbon Adsorption
Process Description. The major objective of carbon adsorption
is to remove soluble organics as part of a complete physico-
chemical treatment system that usually includes preliminary
treatment, sedimentation with chemicals, filtration, and
disinfection. Carbon contacting can be done using either
granular activated carbon in a fixed or fluidized bed or
powdered activated carbon in a sedimentation basin. Periodic
backwashing of the fixed bed must be provided, even if
prefiltration is used, because suspended solids will accumulate
in the bed. A physicochemical treatment system utilizing
powdered activated carbon, coagulated with alum, settled
with polyelectrolyte addition, and in some cases, passed
through a trimedia filter was demonstrated in Albany, New
York, during 1971 and 1972, to treat combined sewer overflow.
Application of carbon adsorption is well suited to advanced
waste treatment of sanitary sewage. However, the feasibility
of application to combined sewer overflow is dependent upon
the effluent quality objectives, the degree of preunit flow
attenuation, and the ability to obtain dual dry- and wet-
weather use of treatment facilities.
Advantages.
1. Well suited to automatic control under intermittent
conditions.
2. High quality effluent (BOD removal efficiencies greater
than 94%) at a detention time of 50 minutes or less.
3. Adaptable as a dual-function treatment facility for
combined sewer overflow and dry-weather sanitary sewage.
4. It can provide removal of dissolved pollutants.
Disadvantages.
1. Increased volumes of sludge.
2. Higher energy needs.
3. Higher treatment costs.
4. Full-scale application to combined sewer overflow is
recent.
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Sources of Information.
1. Swindler-Dressier Co. "Process Design Manual for
Carbon Adsorbtion." EPA 17 020 GNR. October 1971.
2. Shuckrow, A. J., Dawson, G. W. and Bonner, W. F.
"Physical-Chemical Treatment of Combined and Municipal
Sewage." EPA-R2-73-149. February 1973.
3. Weber, W. J., Jr. Physicochemical Processes for Water
Quality Control. Wiley-Interscience. 1972.
Biological Treatment
Process Description. The major objective of biological
treatment is to remove the nonsettleable colloidal and
dissolved organic matter by biologically converting them
into cell tissue which can be removed by gravity settling.
Several biological processes have been applied to combined
sewer overflow treatment including contact stablization,
trickling filters, rotating biological contactors, and
treatment lagoons. Biological treatment processes are
generally categorized as secondary treatment processes.
These processes are capable of removing between 70% and 95%
of the BOD5 and suspended solids from waste flows at dry-
weather flow rates and loadings. An operational problem
when treating intermittent wet-weather storm events by
biological processes is maintaining a viable biomass.
Biological systems are extremely susceptible to overloaded
conditions and shock loads when compared to physical treatment
processes with the possible exception of rotating biological
contactors. This and the high initial capital costs are
serious drawbacks for using biological systems to treat
intermittent combined sewer overflow unless they are designed
as a dual treatment facility. Therefore, biological treatment
of combined sewer overflow is generally viable only in
integrated wet/dry-weather treatment facilities. Biological
treatment of combined sewer overflow was demonstrated in
Kenosha, Wisconsin, Milwaukee, Wisconsin, and New Providence,
New Jersey.
Advantages.
1. Biological treatment processes are well established and
familiar to design engineers and operators.
2. High process removal efficiencies are possible.
3 Integration of wet- and dry-weather into dual treatment
facilities may be achieved.
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Disadvantages.
1. Limited ability of biological processes to handle
fluctuating flow rates and pollutant loads.
2. Storage/detention facilities preceding the biological
processes are required.
3. Enclosed facilities are necessary in cold climates.
4. High initial capital costs unless integrated as a dual
use facility for treating both wet- and dry-weather
flows.
Sources of Information.
1. Agnew, R. W. et al. "Biological Treatment of Combined
Sewer Overflow at Kenosha, Wisconsin." EPA-670/2-
75-019. April 1975.
2. Welsh, F. L. and Stucky, D. J. "Combined Sewer Overflow
Treatment by the Rotating Biological Contactor Process."
EPA-670/2-74-050. June 1974.
3. Hamack, P. et al. "Utilization of Trickling Filters
for Dual-Treatment of Dry- and Wet-Weather Flows."
EPA-670/2-73-071. September 1973.
4. Parks, J. W. et al. "An Evaluation of Three Combined
Sewer Overflow Treatment Alternatives." EPA-670/2-
74-079. December 1974.
5. Metcalf and Eddy, Inc. Wastewater Engineering. McGraw-
Hill, 1972.
Disinfection
Process Description. The major objective of disinfection is
to control pathogens and other microorganisms in receiving
waters. The disinfection agents commonly used in combined
sewer overflow treatment are chlorine, calcium or sodium
hypochlorite, chlorine dioxide, and ozone. They are all
oxidizing agents, are corrosive to equipment, and are highly
toxic to both microorganisms and people. Physical methods
and other chemical agents have not had wide usage because of
excessive costs or operational problems. The choice of a
disinfecting agent will depend upon the unique characteristics
of each agent, such as stability, chemical reactions with
phenols and ammonia, disinfecting residual, and health
hazards. Adequate mixing must be provided to force disin-
fectant contact with the maximum number of microorganisms.
Mixing can be accomplished by mechanical flash mixers at the
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point of disinfectant addition and at intermittent points,
by specially designed contact chambers, or both. Chlorine
may enhance aftergrowth of microorganisms in the receiving
water by cleaving large protein molecules into small proteins,
peptides, and other amino acids. Disinfection of combined
sewer overflow is included at many locations including
Boston, Massachusetts, from 1971 to present, Rochester, New
York, from 1975 to present, and Syracuse, New York, from
1974 to present.
Advantages.
1. Water contact and shellfishing of receiving waters is
possible with the disinfection of combined sewer overflow.
2. Contamination of public water supplies with pathogenic
organisms is reduced.
Disadvantages.
1. Disinfection residuals may be toxic.
2. Disinfection may enhance microorganism aftergrowth in a
receiving water.
3. Direct measurement of pathogenic organisms is difficult
and may result in a gross overdesign or underdesign of
disinfection facilities for intermittent and changing
combined sewer overflow characteristics.
Sources of Information.
1. Olivieri, V. P., et al. "Microorganisms in Urban
Stormwater." EPA-600/2-77-087. July 1977.
2. Moffa, P. E., et al. "Bench-Scale High-Rate Disinfection
of Combined Sewer Overflow with Chlorine and Chlorine
Dioxide." EPA-670/2-75-021. April 1975.
3. Weber, J. F. "Demonstration of Interim Techniques for
Reclamation of Polluted Beachwater." EPA-600/2-
76-228. 1976.
4. Pontius, U. R. et al. "Hypochlorination of Polluted
Stormwater Pumpage at New Orleans." EPA-670/2-73-067.
September 1973.
5. Maher, M. B. "Microstraining and Disinfection of
Combined Sewer Overflow—Phase III." EPA-670/2-74-049.
August 1974.
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SLUDGE DISPOSAL
As with all treatment processes, the concentrated waste
residue generated by combined sewer overflow treatment must
be disposed of properly. An EPA report entitled "Handling
and Disposal of Sludges from Combined Sewer Overflow Treatment,
Phase II—Impact Assessment," EPA-600/2-77-0536, December
1977, presents the results of a study completed in February
1976 which assessed the impact of sludge volumes generated
by full-scale treatment of CSO in the United States.
It is estimated that treatment of CSO will generate 41.5
billion gallons of sludge per year, which is approximately
2.6 times the volume of raw primary wastewater treatment
plant sludge. However, the average solids concentration in
CSO sludge is about 1% compared to 2% to 7% in raw primary
sludge. This is due to the high volume, low solids residuals
generated by treatment processes employing screens. CSO
residuals have a high grit and low volatile solids content
when compared to raw primary sludge. Regarding the effect
of toxic materials in combined sewage sludges affecting
its suitability for application on agricultural lands,
an EPA report entitled "Municipal Sludge Management:
Environmental Factors," EPA 430/9-77-004, October 1977
presents total amount in pounds per acre of sludge metals
allowed on agricultural land for lead, zinc, copper, nickel,
and cadmium. These amounts cannot be exceeded for sludges
from either separate sanitary or combined sewer areas.
Preliminary economic evaluation indicated that lime stabi-
lization, storage, gravity thickening, and land application
is the most cost-effective disposal system. Costs for
overall CSO sludge handling depend on the type of CSO treatment
process, and volume and characteristics of the sludge, and
the size of the CSO area, among other considerations.
Estimates indicate that first investment capital costs range
from $181 to $4,129 per acre and annual operating costs
range from $56 to $660 per acre. The report recommends that
the use of grit removal, lime stabilization, and gravity
thickening plus dewatering be further investigated to establish
specific design criteria for CSO sludge disposal.
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U.S. GOVERNMENT PRINTING OFFICE 1978—677-384
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA 430/9-78-006
3. RECIPIENT'S ACCESSION NO.
TITLE ANDSUBTITLE
Control of Combined Sewer
Overflow in the United States
5. REPORT DATE
October 1Q7B
6. PERFORMING ORGANIZATION CODE
AUTHOR(S) "
Ronald L. Wycoff, James E. Scholl
and Michael J. Mara
'. PERFORMING ORGANIZATION NAME AND ADDRESS
CH2M HILL SOUTHEAST, INC.
(Formerly Black, Crow & Eidsness, Inc.)
7201 N.W. llth Place
Gainesville, FL 32602
8. PERFORMING ORGANIZATION REPORT NO.
MCD-50
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-01-3993
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Municipal Construction Division
Office of Water Program Operations
Washington, DC 20460
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
700/02
15. SUPPLEMENTARY NOTES
Project Officer: Philip H. Graham
16. ABSTRACT
Section 516 (c) of the 1977 Clean Water Act provides that:
"(c) The Administrator shall submit to the Congress by October 1, 1978, a
report on the status of combined sewer overflows in municipal treatment works
operations. The report shall include (1) the status of any projects funded
under the Act to address combined sewer overflows, (2) a listing by State of
combined sewer overflow needs identified in the 1977 State priority listings,
(3) an estimate for each applicable municipality of the number of years
necessary, assuming an annual authorization and appropriation for the
construction grants program of $5,000,000,000 to correct combined sewer overflow
problems, (4) an analysis using representative municipalities faced with major
combined sewer overflow needs, of the annual discharges of pollutants from
overflows in comparison to treated effluent discharges, (5) an analysis of
technological alternatives available to municipalities to correct major combined
sewer overflow problems, and (6) any recommendations of the Administrator for
legislation to address the problem of combined sewer overflows, including
whether a separate authorization and grant program should be established by
the Congress to address combined sewer overflows."
This report, "Control of Combined Sewer Overflow in the Uriited__S_tia±e_s_, " responds tn
17.
the above mandate«
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Combined Sewers
Construction Grants
Water Pollution Control
Cost Effectiveness
Rainfall
Runoff
Water Quality
b. IDENTIFIERS/OPEN ENDED TERMS
Drainage Systems
Storm Runoff
Urban Hydrology
Combined Sewer Overflow
COSATI Field/Group
13B
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURI I Y CLASS (This Repot
Unclassified
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-7
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