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<pubnumber>833R04001</pubnumber>
<title>Report To Congress Impacts And Control Of CSOs And SSOs</title>
<pages>633</pages>
<pubyear>2004</pubyear>
<provider>NSCEP</provider>
<access>both</access>
<operator>mja</operator>
<scandate>03/03/09</scandate>
<origin>PDF</origin>
<type>single page tiff</type>
<keyword>ssos cso sewer csos water sso epa city control impacts system weather report treatment wastewater discharges order congress ofcsos state</keyword>
<author></author>
<publisher></publisher>
<subject></subject>
<abstract></abstract>

           United States
           Environmental Protection
           Agency
Office of Water (4203)
Washington, D.C. 20460
www.epa.gov/npdes
EPA 833-R-04-001
August 2004
v>EPA     Report to Congress
           Impacts and Control of CSOs and SSOs

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                              On   the  Cover
Large photo in background: Oklahoma City PVC sewer pipe stockpile. In response to problems from an aging sewer system
made up of more than 2,000 miles of pipe, Oklahoma City implementing a capital improvement planning program with the
goal of replacing sewer lines at the rate of 1 % per year. The City opted for replacing aging pipes with PVC pipes as a more
affordable, flexible and corrosion-resistant alternative. Photo courtesy of Julia Moore, Limno-Tech,lnc.

Top inset: Former Denny Way CSO outfall in Seattle, WA. The Denny Way outfall as shown was the largest volume CSO discharge
in the King County System.Through a joint effort of King Countyand the City of Seattle, the Denny Way/Lake Union CSO
Project was implemented to control over 600 million gallons of combined sewage from overflowing annually into Lake Union
and Elliott Bay. Under way since May 2000, construction is expected to be complete  in 2005. Progress to date includes the
demolition of the pictured outfall, restoration of the shoreline, and revitalization of the surrounding public park. Photo courtesy
of King County.


Second inset: Monitoring team responding to sewer overflow. Photo provided by ADS.

Third inset: City of Richmond,VA Canal Walk.The City of Richmond incorporated downtown revitalization, historical
interpretation, and combined sewer overflow planning as part of a large-scale redevelopment of their downtown riverfront
area.The riverfront redevelopment was made possible, in part, by the environmental improvements achieved by the Richmond
CSO Control Program.The resulting Canal Walk extends for more than a mile along the Haxall and Kanawha Canals and includes
under canal routing of combined sewage while providing a pathway of access to revitalized businesses, museums and new
outdoor public vistas and arenas.Photo courtesy of City of Richmond.

Fourth inset: Orange County, CA. Orange County Health Care Agency's Environmental Health Ocean Water Protection Program
administers a beach water quality monitoring program to ensure public recreational waters meet bacteriological water quality
standards for full body contact recreational activities such as swimming, surfing and diving. Beach closure or advisory signs are
posted at Orange County beaches  when high levels of bacteria are measured or when a sewage spill contamination of ocean or
bay waters occurs. Photo courtesy of OCHCA EH Ocean Water Protection Program.

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                        Table of Contents
Executive Summary—Report to Congress on the Impacts and Control of CSOs and SSOs    ES-1
Chapter 1 —Introduction     1-1

1.1   What are CSOs and SSOs?   1-2
     1.1.1    CSOs   1-2
     1.1.2    SSOs   1-3
1.2   How is this Report Organized?     1-3
Chapter 2—Background    2-1

2.1   What is the History of Sewer Systems in the United States?    2-1
     2.1.1    Combined Sewers and CSOs  2-3
     2.1.2    Sanitary Sewers and SSOs      2-4
2.2   What is the History of Federal Water Pollution Control Programs?  2-6
     2.2.1    Secondary Treatment   2-6
     2.2.2    Construction Grants   2-7
     2.2.3    Pretreatment  2-8
     2.2.4    Wet Weather   2-8
     2.2.5    Watershed-Based Permitting    2-9
2.3   What is the Federal Framework for CSO Control?    2-9
     2.3.1    CSO Case Law  2-9
     2.3.2    The National CSO Control Stategy and the MAG  2-10
     2.3.3    The CSO Control Policy    2-10
2.4   What is the Federal Framework for SSO Control?    2-10
2.5   What is the Wet Weather Water Quality Act?    2-11
Chapter 3—Methodology   3-1

3.1   What Study Objectives and Approach Did EPA Use to Prepare this Report?    3-1
3.2   What Data Sources Were Used?      3-2
     3.2.1    Federal Data Sources   3-2
     3.2.2    NPDES Authority and Other State Program Data Sources   3-3
     3.2.3    Community-Level Data Sources   3-3
     3.2.4    Non-Governmental Organization Data Sources     3-3
3.3   What Data Were Collected?     3-4
     3.3.1    Characterization of CSOs and SSOs  3-4
     3.3.2    Extent of Environmental Impacts Caused by CSOs and SSOs    3-5
     3.3.3    Extent of Human Health Impacts Caused by CSOs and SSOs     3-6
     3.3.4    Evaluation of Technologies Used by Municipalities to Address Impacts Caused by CSOs and SSOs  3-8

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Report to Congress on the Impacts and Control ofCSOs and SSOs
        3.3.5   Assessment of Resources Spent by Municipalities to Address Impacts Caused by CSOs and SSOs  3-8
  3.4   How Were Stakeholders Involved in the Preparation of this Report?   3-9
  3.5   What Data Considerations Are Important?     3-10
  3.6   What Quality Control and Quality Assurance Protocols Were Used?     3-11
  3.7   Summary     3-12


  Chapter 4—Characterization of CSOs and SSOs   4-1

  4.1   What Pollutants are in CSOs and SSOs?   4-2
        4.1.1    Microbial Pathogens    4-3
        4.1.2    BOD5   4-4
        4.1.3    TSS    4-5
        4.1.4    Toxics     4-6
        4.1.5    Nutrients  4-7
        4.1.6    Floatables 4-7
  4.2   What Factors Influence the Concentrations of the Pollutants in CSOs and SSOs?   4-8
        4.2.1    Factors Influencing Pollutant Concentrations in CSOs   4-8
        4.2.2    Factors Influencing Pollutant Concentrations in SSOs   4-9
  4.3   What Other Point and Nonpoint Sources Might Discharge These Pollutants to Waterbodies Receiving CSOs
        and SSOs?   4-9
        4.3.1    Wastewater Treatment Facilities    4-10
        4.3.2    Decentralized Wastewater Treatment Systems 4-11
        4.3.3    Industrial Point Sources   4-11
        4.3.4    Urban Storm Water  4-12
        4.3.5    Agriculture    4-12
        4.3.6    Domestic Animals and Wildlife  4-12
        4.3.7    Commercial and Recreational Vessels    4-13
  4.4   What is the Universe of CSSs?   4-13
  4.5   What are the Characteristics of CSOs?   4-16
        4.5.1    Volume of CSOs     4-17
        4.5.2    Frequency of CSOs  4-19
        4.5.3    Location of CSOs   4-19
  4.6   What is the Universe of SSSs?   4-20
  4.7   What are the Characteristics of SSOs?   4-20
        4.7.1    SSO Data Management System 4-20
        4.7.2    Statistical Technique Used to Estimate Annual National SSO Frequency and Volume    4-23
        4.7.3    Frequency of SSOs      4-24
        4.7.4    Volume of SSOs     4-25
        4.7.5    Location of SSOs   4-26
  4.8   How Do the Volumes and Pollutant Loads from CSOs and SSOs Compare to Those from Other Municipal
        Point Sources? .                                                                                    .. 4-29
  Chapter 5—Environmental Impacts of CSOs and SSOs      5-1

  5.1   What is EPAs Framework for Evaluating Environmental Impacts?    5-1
  5.2   What Overall Water Quality Impacts Have Been Attributed to CSO and SSO Discharges in National Assessments? .. 5-3
        5.2.1    NWQI 2000 Report    5-3

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                                                                                                    Table of Contents
      5.2.2    Analysis of CSO Outfalls Discharging to Assessed or Impaired Waters   5-6
      5.2.3    Modeled Assessment of SSO Impacts on Receiving Water Quality  5-8
5.3    What Impacts on Specific Designated Uses Have Been Attributed to CSO and SSO Discharges in National
      Asssessments?     5-10
      5.3.1    Recreation   5-10
      5.3.2    Shellfish Harvesting     5-13
5.4    What Overall Water Quality Impacts Have Been Attributed to CSO and SSO Discharges in State and Local
      Assessments?      5-15
      5.4.1    Water Quality Assessment in New Hampshire    5-15
      5.4.2    Water Quality Assessment of the Mahoning River Near Youngstown, Ohio     5-15
      5.4.3    Water Quality Assessment in Indianapolis, Indiana    5-16
      5.4.4    Water Quality Risk Assessment of CSO Discharges in King County, Washington   5-16
5.5    What Impacts on Specific Designated Uses Have Been Attributed to CSO and SSO Discharges in State and Local
      Assessments?      5-17
      5.5.1    Aquatic Life Support 5-18
      5.5.2    Recreation   5-21
      5.5.3    Shellfish Harvesting     5-25
5.6    What Factors Affect the Extent of Environmental Impacts Caused by CSOs and SSOs?     5-26
      5.6.1    Timescale Considerations     5-28
      5.6.2    Receiving Water Characteristics  5-28


Chapter 6—Human Health Impacts of CSOs and SSOs     6-1

6.1    What Pollutants in CSOs and SSOs Can Cause Human Health Impacts?     6-1
      6.1.1    Microbial Pathogens  6-2
      6.1.2    Toxics   6-4
      6.1.3    Biologically Active Chemicals    6-6
6.2    What Exposure Pathways and Reported Human Health Impacts are Associated with CSOs and SSOs?  6-7
      6.2.1    Recreational Water   6-7
      6.2.2    Drinking Water Supplies  6-10
      6.2.3    Fish and Shellfish   6-12
      6.2.4    Direct Contact with Land-Based Discharges    6-13
      6.2.5    Occupational Exposures   6-14
      6.2.6    Secondary Transmission   6-15
6.3    Which Demographic Groups Face the Greatest Risk of Exposure to CSOs and SSOs?    6-16
      6.3.1    Swimmers, Bathers, and Waders    6-16
      6.3.2    Subsistence and Recreational Fishers     6-16
      6.3.3    Wastewater Workers   6-17
6.4    Which Populations Face the Greatest Risk of Illness from Exposure to the Pollutants Present in CSOs and SSOs?  .. 6-17
      6.4.1    Pregnant Women   6-17
      6.4.2    Children 6-17
      6.4.3    Immunocompromised Groups     6-18
      6.4.4    Elderly      6-18
6.5    How are Human Health Impacts from CSOs and SSOs Communicated, Mitigated, and Prevented?  6-18
      6.5.1    Agencies and Organizations Responsible for Protecting Public Health  6-18
      6.5.2    Activities to Protect Public Health from Impacts  of CSOs and SSOs   6-22
6.6    What Factors Contribute to Information Gaps in Identifying and Tracking Human Health Impacts from CSOs
      and SSOs?     6-24
      6.6.1    Underreporting   6-24

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Report to Congress on the Impacts and Control ofCSOs and SSOs
        6.6.2    Use of Indicator Bacteria      6-25
  6.7   What New Assessment and Investigative Activities are Underway?  6-26
        6.7.1    Investigative Activities   6-26


  Chapter 7—Federal and State Efforts to Control CSOs and SSOs  7-1

  7.1   What are States and EPA Regions Doing to Control CSOs?  7-1
        7.1.1    Nine Minimum Controls  7-2
        7.1.2    Long-Term Control Plans    7-2
  7.2   What are States and EPA Regions Doing to Control SSOs?      7-3
        7.2.1    Application of Standard Permit Conditions to SSOs      7-3
        7.2.2    Electonic Tracking of SSOs     7-4
  7.3   What Programs Have Been Developed to Control SSOs?  7-5
        7.3.1    EPA Region 4's MOM Program 7-5
        7.3.2    Oklahoma - Collection System Program   7-6
        7.3.3    California - Record Keeping and Reporting of Events    7-7
        7.3.4    North Carolina - Collection System Permitting      7-8
  7.4   What Compliance and Enforcement Activities Have Been Undertaken?    7-8
        7.4.1    National Municipal Policy on POTWs 7-9
        7.4.2    Enforcement Management System      7-9
        7.4.3    Compliance and Enforcement Strategy (2000)     7-9
        7.4.4    Compliance Assistance  7-10
        7.4.5    Summary of Enforcement Activities  7-11


  Chapter 8—Technologies Used to Reduce the Impacts of CSOs and SSOs    8-1

  8.1   What Technologies are Commonly Used to Control CSOs and SSOs?   8-2
        8.1.1    Operation and Maintenance Practices    8-2
        8.1.2    Collection System Controls     8-5
        8.1.3    Storage Facilities     8-11
        8.1.4    Treatment Technologies     8-13
        8.1.5    Low-Impact Development Techniques  8-17
  8.2   How Do CSO and SSO Controls Differ?     8-20
        8.2.1    Common CSO Control Measures    8-20
        8.2.2    Common SSO Control Measures    8-21
  8.3   What Technology Combinations are Effective?     8-21
        8.3.1    Inflow Reduction or Low-Impact Development Coupled with Structural Controls    8-22
        8.3.2    Disinfection Coupled with Solids Removal   8-22
        8.3.3    Sewer Rehabilitation Coupled with Sewer Cleaning   8-22
        8.3.4    Real-Time Control Coupled with In-line or Off-line Storage Facilities  8-22
  8.4   What New Technologies for CSO and SSO Control are Emerging?     8-23
        8.4.1    Optimization of Sewer System Maintenance   8-23
        8.4.2    Information Management     8-23


  Chapter 9—Resources Spent Address the Impacts of CSOs and SSOs    9-1

  9.1   What Federal Framework Exists for Evaluating Resources Spent on CSO and SSO Control?    9-1
  9.2   What are the Past Investments in Wastewater Infrastructure? .                                             .. 9-2
IV

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                                                                                                  Table of Contents
9.3    What Has Been Spent to Control CSOs?     9-5
9.4    What Has Been Spent to Control SSOs?     9-6
9.5    What Does it Cost to Maintain Sewer Systems?     9-7
9.6    What are the Projected Costs to Reduce CSOs?     9-8
9.7    What are the Projected Costs to Reduce SSOs?     9-9
9.8    What Funding Mechanisms are Available for CSO and SSO Control?   9-10
      9.8.1     Self-financing  9-11
      9.8.2     State and Federal Funding for CSO and SSO Control   9-12

Chapter 10—Conclusions and Future Challenges    10-1
      Protecting Infrastructure     10-2
      Implementing the Watershed Approach   10-3
      Improving Monitoring and Information-Based Environmental Management   10-4
      Building Strategic Partnerships   10-5

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                                  List of Figures
  Figure ES.l—National Distribution of CSSs     ES-5
  Figure ES.2—National Distribution of SSSs     ES-6
  Figure ES.3—Sources of Pollution that Resulted in Swimming Beach Advisories and Closings  ES-8
  Figure 2.1—Typical Combined Sewer System  2-2
  Figure 2.2—Typical Separate Sanitary and Storm Sewer Systems  2-2
  Figure 2.3—National Distribution of Communities Served by CSSs    2-4
  Figure 2.4—National Distribution of Communities Served by SSSs    2-5
  Figure 4.1—Distribution of CSO Permits by Region and by State     4-14
  Figure 4.2—Distribution of CSO Outfalls by Region and by State    4-15
  Figure 4.3—Distribution POTW Facility Sizes Serving CSSs      4-17
  Figure 4.4—Distribution of SSSs with Wastewater Treatment  Facilities by Region and by State  4-21
  Figure 4.5—Distribution of Satellite SSSs by Region and by State      4-22
  Figure 4.6—States Providing Electronic Data on SSO Discharges     4-23
  Figure 4.7—Total Number of SSO Events Reported by Individual Communities, January 1, 2001 - December 31, 2002 ... 4-25
  Figure 4.8—Distribution of SSO Volume Reported Per Event      4-26
  Figure 4.9—Most Common Reported Causes of SSO Events      4-27
  Figure 4.10—Reported Causes of SSOs in Communities Reporting More than 100 SSO Events During a
              Single Calendar Year      4-28
  Figure 4.11—Reported Cause of Blockage Events     4-28
  Figure 5.1—NWQI 2000  Summary of Assessed Waters by Waterbody Type    5-4
  Figure 5.2—Sources  of Pollution that Resulted in Beach Advisories and Closings   5-11
  Figure 5.3—Sources  of Water Quality Impairment in New Hampshire      5-16
  Figure 5.4—Fish Species Found in the Chicago and Calumet River System,  1974 - 2001   5-22
  Figure 5.5—Sources  of Contamination Resulting in California Beach Closures in 2000   5-22
  Figure 5.6—Beach Closures in California During 2000 Attributed to SSOs    5-23
  Figure 5.7—Average Number Days per Year Coastal Municipalities in Connecticut Closed One or More Beaches  5-24
  Figure 5.8— Lake Michigan Beach Closures, 1998- 2002  5-25
  Figure 5.9— Movement of Bacteria Plume from SSO Discharge in Raritan Bay, New Jersey      5-27
  Figure 6.1—Microbial Pathogens Linked to Outbreaks in Recreational Waters, 1985 - 2000    6-8
  Figure 6.2—Microbial Pathogens Causing Outbreaks Linked to Drinking Water, 1985-2000      6-11
  Figure 9.1—Annual Capital Expenditures on Wastewater Projects, 1970 - 2000    9-3
  Figure 9.2—State and Local Expenditures on Wastewater O&M, 1970 - 2000    9-4
  Figure 9.3—CWSRF Annual Expenditures for CSO Projects, 1988  - 2002   9-5
  Figure 9.4—CWSRF Annual Expenditures for I/I and Sewer Replacement/Rehabilitation     9-6
  Figure 9.5—Changes in Estimated Needs Between 1996 and 2000 CWNS  9-10
  Figure 9.6—Revenue Sources for Municipal Wastewater Treatment     9-11
  Figure 9.7—State and Local Expenditures Under the CWSRF  Program for CSO Correction and SSO Capital Projects  ... 9-12
VI

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                                                                                                        Table of Contents
                                                 List of Tables
Table ES. 1—Comparison of Estimated Annual Discharge Volumes    ES-7
Table 4.1—Fecal Coliform Concentrations in Municipal Discharges 4-3
Table 4.2—6005 Concentrations in Municipal Discharges   4-5
Table 4.3—TSS Concentrations in Municipal Discharges    4-5
Table 4.4—Cadmium and Copper Concentrations in Municipal Discharges     4-6
Table 4.5—Lead and Zinc Concentrations in Municipal Discharges  4-6
Table 4.6—Nutrient Concentrations in Municipal Discharges   4-6
Table 4.7—Volume Reduction Estimates Based on Implementation of CSO Control Policy      4-18
Table 4.8—SSO Event Volume by Cause     4-27
Table 4.9—Estimated Annual Municipal Point Source Discharges    4-29
Table 4.10—Estimated Annual 6005 Load from Municipal Point Sources      4-29
Table 4.11—Estimated Annual TSS Load from Municipal Point Sources   4-30
Table 4.12—Estimated Annual Fecal Coliform Load from Municipal Point  Sources   4-30
Table 5.1—Pollutants of Concern in CSOs and SSOs Likely to Cause or Contribute to Impairment    5-3
Table 5.2—Pollutants and Stressors Most Often Associated with Impairment    5-6
Table 5.3—Leading Sources of Pollutants and Stressors Causing Water Quality Impairment      5-6
Table 5.4—Occurances of 305(b) Assessed Waters Within One Mile Downstream of a CSO Outfall      5-7
Table 5.5—Occurence of 303(d) Listed Waters Within  One Mile Downstream of a CSO Outfall    5-8
Table 5.6—Estimated Perentage of Time SSOs Would Cause Water Quality Standard Violations    5-9
Table 5.7—NMDMP Marine Debris Survey Results from 1996 to 2002      5-12
Table 5.8—Pollution Sources Reported for Harvest Limitations on Classified Shellfish Growing Waters in the 1990 and 1995
          National Shellfish Registers      5-14
Table 5.9—Harvest Limitations on Classified Shellfish  Growing Areas Within Five Miles of a CSO Outfall     5-15
Table 5.10—Relative Contributions of Pollutant Sources to Water Quality Problems in Indianapolis, Indiana   5-17
Table 5.11—Fish Kills Reported in North Carolina: 1997 - 2002   5-18
Table 5.12—Fish Kills Caused by Sewage Spills in North Carolina: 1997 - 2001    5-20
Table 5.13—Summary of Unauthorized Wastewater Discharges in Orange County, California, that
           Resulted in Beach Closures   5-25
Table 6.1—Common Pathogenic Bacteria Present in Sewage      6-3
Table 6.2—Common Enteric Viruses Present in Sewage      6-3
Table 6.3—Common Parasitic Protozoa Present in Sewage   6-4
Table 6.4—Concentration of Indicator Bacteria and Enteric  Pathogens Shed by an Infected Individual 6-5
Table 6.5—Participation in Water-Based Recreation in U.S. during July 1999 and January 2001     6-7
Table 6.6—Estimated Number of Illnesses per Year Attributed to CSOs and SSOs    6-10
Table 6.7—Association of CSO Outfalls with Drinking Water Intakes   6-12
Table 6.8—Examples of Secondary Transmission from Waterborne and Non-Waterborne Disease Outbreaks   6-15
                                                                                                                      VII

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Table 7.1—Summary of Electronic SSO Data by State    7-4
   Table 8.1—Summary of Operation and Maintenance Practices     8-3
   Table 8.2—Summary of Collection System Controls  8-6
   Table 8.3—Summary of Storage Facilities  8-12
   Table 8.4—Summary of Treatment Technologies  8-15
   Table 8.5—Summary of Low-Impact Development Techniques   8-18
   Table 9.1—Annual Budget Expenditures in Sanitary Sewer Systems   9-7
   Table 9.2—O&M Costs for Sewers .                                                                           .. 9-8
VIM

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                                                                                               Table of Contents
                                        List of Appendices
Appendix A  Statutes, Policies, and Interpretative Memoranda
Appendix B  Human Health Expert and Stakeholder Meeting Summaries
Appendix C  Documentation of State and Municipal Interviews
Appendix D  List of Active CSO Permits
Appendix E  GPRACSO Model Documentation
Appendix F  Analysis of CSO Receiving Waters Using the National Hydrography Dataset (NHD)
Appendix G  National Estimate of SSO Frequency and Volume
Appendix H  Estimation of SSO Impacts in Streams and Rivers
Appendix I  Human Health Addendum
Appendix J  Estimated Annual Illness Burden Resulting from Exposure to CSOs and SSOs at BEACH Survey Beaches
Appendix K  Summary of Enforcement Actions
Appendix L  Technology Descriptions
Appendix M  Financial Information
                                                                                                            IX

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               List  of  Acronyms
AIDS- Acquired Immune Disorder
Syndrome

AMSA- Association of Metropolitan
Sewerage Agencies

AO- Administrative Order

APO- Administrative Penalty Orders

APWA- American Public Works
Association

ASCE- American Society of Civil
Engineers

BAT- Best Available Technology
Economically Achievable

BCT- Best Conventional Pollutant
Control Technology

BEACH Program- Beaches
Environmental Assessment and
Coastal Health Program

BMP- Best Management Practice

BOD5- Biochemical Oxygen Demand
(measured over 5 days)

CAFO- Concentrated Animal Feeding
Operation

CATAD- Computer Augmented
Treatment and Disposal

CBO- Congressional Budget Office

CCTV- Closed Circuit Television
CDC- Centers for Disease Control
and Prevention

CFR- Code of Federal Regulations

cfs- Cubic Feet per Second

CIPP- Cured-in-place Pipe

CMOM- Capacity, Management,
Operation, and Maintenance

CSO- Combined Sewer Overflow

CSS- Combined Sewer System

CTP- Central Treatment Plant

CWNS- Clean Watersheds Needs
Survey

CWSRF- Clean Water State Revolving
Fund

ECD- Enforcement and Compliance
Docket

ENR- Engineering News Record

EPA- Environmental Protection
Agency

FEE- Flow Equalization Basins

FAC- Federal Advisory Committee

FOG- Fats, Oils, and Grease

FR- Federal Register

FY- Fiscal Year
FWPCA- Federal Water Pollution
Control Act

GAO- Government Accounting Office

CIS- Geographic Information System

GPRA- Government Performance and
Results Act

HUD-Housing of Urban
Development

I/I- Infiltration & Inflow

ISSC- Interstate Shellfish Sanitation
Conference

LGEAN- Local Government
Environmental Assistance Network

LID- Low Impact Development

LOV- Letter of Violation

LTCP- Long-Term Control Plan

MAG- Office of Water Management
Advisory Group

MDE- Maryland Department of the
Environment

MDEQ- Michigan Department of
Environmental Quality

MG- Million Gallons

mgd- Million Gallons per Day

ml- Milliliter
                                                                                     ACR-1

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Report to Congress on the Impacts and Control of CSOs and SSOs
MMSD- Milwaukee Metropolitan
Sewarage District

MOM- Management, Operation, and
Maintenance

MPN- Most Probable Number

MWWSSB- Montegomery Water
Works and Sanitary Sewer Board

MS4- Municipal Separate Storm
Sewer System

NCDENR- North Carolina
Department of Environmental and
Natural Resources

NEEAR Water Study- National
Epidemiological and  Environmental
Assessment of Recreational Water
Study

NIH- National Institutes of Health

NHD- National Hydrography Dataset

NJDEP- New Jersey Department of
Environmental Protection

NMC- Nine Minimum Controls

NMDSP- National Marine Debris
Survey Program

NMP-National Municipal Policy

NOAA-National Oceanic and
Atmospheric Administration

NPDES- National Pollutant Discharge
Elimination System

NRDC- Natural Resources Defense
Council

NURP- Nationwide Urban Runoff
Program
NWQI- National Water Quality
Inventory
WDR- Waste Discharge Requirements

WEF- Water Environment Federation
O&M- Operation and Maintenance
                                  WERF- Water Environment Research
ODEQ- Oklahoma Department of    Foundation
Environmental Quality
                                  WISE- Watershed Initiative for a Safe
OMB- Office of Management and     Environment
Budget
                                  WWTP- Wastewater Treatment Plant
ORD- Office of Research and
Development

PCBs- Polychlorinated biphenyls

PCS- Permit Compliance System

PL.- Public Law

POTW- Publicly Owned Treatment
Works

REAP- Rural Economic Assistance
Program

RWQCB- Regional Water Quality
Control Board

SRF- State Revolving Fund

SSO- Sanitary Sewer Overflow

SSS- Sanitary Sewer System

TKN- Total Kjeldahl Nitrogen

TMDL- Total Maximum Daily Loads

TSS- Total Suspended Solids

USGS- United States Geological
Survey

UV- Ultraviolet

WATERS- Watershed Assessment,
Tracking, & Environmental Results
ACR-2

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                                 Glossary
     This glossary includes a collection of the terms used in this manual and an explanation of each term. To the
     extent that definitions and explanations provided in this glossary differ from those in EPA regulations or other
     official documents, they are intended for use in understanding this manual only.
              A
Acute Toxicity- The ability of
    a substance to cause severe
    biological harm or death soon
    after a single exposure or dose.
    Also, any poisonous effect
    resulting from a single short-term
    exposure to a toxic substance.
               B
Bacteria- Microscopic, unicellular
    organisms, some of which
    are pathogenic and can cause
    infection and disease in animals
    and humans. Most often, non-
    pathogenic bacteria, such as fecal
    coliform and enterococci, are used
    to indicate the likely presence
    of disease-causing, fecal-borne
    microbial pathogens.

Best Available Technology
    Economically Achievable (BAT)-
    Technology-based standard
    established by the Clean Water Act
    as the most appropriate means
    available on a national basis for
    controlling the direct discharge
    of toxic and nonconventional
    pollutants to navigable waters.

Best Conventional Pollutant Control
    Technology (BCT)- Technology-
    based standard for the discharge
    from existing industrial point
    sources of conventional
    pollutants including BOD, TSS,
    fecal coliform, pH, oil and grease.
    The BCT is established in light of
    a two-part "cost reasonableness"
    test, which compares the cost
    for an industry to reduce its
    pollutant discharge with the cost
    to a POTW for similar levels of
    reduction of a pollutant loading.
    The second test examines the
    cost-effectiveness of additional
    industrial treatment beyond
    BPT. EPA must find limits, which
    are reasonable under both tests
    before establishing them as BCT.

Biochemical Oxygen Demand
    (BOD)- A measure of the
    amount of oxygen consumed
    by microorganisms from the
    decomposition of organic
   material in water over a specified
   time period (usually 5 days,
   indicated as BOD5). The
   BOD5 value is used for many
   applications, most commonly to
   indicate the effects of sewage and
   other organic wastes on dissolved
   oxygen in water.
              c
Chronic Toxicity- The capacity of
   a substance to cause long-term
   poisonous health effects in
   humans, animals, fish, and other
   organisms.

Clean Water Act- The Clean Water
   Act is an act passed by the
   U.S. Congress to control water
   pollution.  It was formerly
   referred to as the Federal Water
   Pollution Control Act of 1972 or
   Federal Water Pollution Control
   Act Amendments of 1972 (PL.
   92-500), 33 U.S.C. 1251 et. seq.,
   as amended by: PL. 96-483; PL.
   97-117; PL. 95-217, 97-117,
   97-440, and 100-04.
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Report to Congress on the Impacts and Control ofCSOs and SSOs
Combined Sewer Overflow (CSO)- A
    discharge of untreated wastewater
    from a combined sewer system at
    a point prior to the headworks of
    a publicly owned treatment works
    (POTW).

Combined Sewer System (CSS)- A
    wastewater collection system
    owned by a municipality (as
    defined by Section 502(4) of the
    Clean Water Act) that conveys
    domestic, commercial and
    industrial wastewater and storm
    water runoff through a single pipe
    system to a POTW.

Concentrated Animal Feeding
    Operation (CAFO)- New
    and existing animal feeding
    operations of a sufficient size
    that are required to develop
    and implement a nutrient
    management plan as a condition
    of a NPDES permit (defined at 40
    CFR 122.23).

Construction Grants Program-
    Federal assistance program
    authorized under Section 201
    of the Clean Water Act intended
    to assist with the development
    and implementation of waste
    treatment management plans and
    practices  that will achieve the
    goals of the Act.

Conventional Pollutants- As
    defined by the Clean Water Act,
    conventional pollutants include:
    BOD, TSS, fecal coliform, pH, and
    oil and grease.
               D
Dissolved Oxygen (DO)- The
    oxygen freely available in water,
    vital to fish and other aquatic
    life and for the prevention of
    odors. DO levels are considered
    a most important indicator of a
    water body's ability to support
    desirable aquatic life. Secondary
    and advanced waste treatment
    are generally designed to ensure
    adequate DO in waste-receiving
    waters.

Diurnal- Relating to or occurring
    in a 24-hour period, or daily. A
    pattern that repeats itself over a
    daily cycle.

Dry Weather CSO- An unauthorized
    discharge from a combined sewer
    system that occurs during dry
    weather conditions.

Dry Weather SSO- A sanitary sewer
    overflow that occurs during dry
    weather conditions, most often as
    a result of blockages, line breaks,
    or mechanical/power failures in
    the collection system.
               E
Effluent Limits- Restrictions
    established by a state or EPA
    on quantities, rates, and
    concentrations in municipal or
    industrial wastewater discharges.

Environmental Impact- Any change
    to the environment, whether
    adverse or beneficial, wholly
    or partially resulting from an
    organization's activities, products
    or services.

Eutrophic Condition- The presence
    of excess nutrients in a receiving
    water body. During the later
    stages of eutrophication the water
    body can become choked by
    abundant plant life due to higher
    levels of nutritive compounds
    such as nitrogen and phosphorus.
                F
Federal Advisory Committee- Any
    committee, board, commission,
    council, conference, panel, task
    force, or other similar group,
    or any subcommittee or other
    sub-group thereof (hereafter
    in this paragraph referred
    to as "committee"), which
    in— (A) established by statute
    or organization plan, or (B)
    established or utilized by the
    President; or (C) established or
    utilized by one or more agencies;
    in the interest of obtaining
    advise and recommendations
    for the President or one or more
    agencies or offices of the Federal
    Government, except that such
    term excludes (i) any committee
    that is composed wholly of full-
    time, or permanent part-time,
    officers or employees of the
    Federal Government, and (ii) any
    committee that is created by the
    National Academy of Sciences of
    the National Academy of Public
    Administration.

First Flush- The occurrence of higher
    concentrations of pollutants in
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                                                                                                       Glossary
    storm water or CSO discharges at
    the beginning of a storm.

Floatables and Trash- Visible buoyant
    or semi-buoyant solids including
    organic matter, personal hygiene
    items, plastics, styrofoam, paper,
    rubber, glass and wood.
                H
Headworks of a Wastewater Treatment
    Plant- The initial structures,
    devices and processes provided
    at a wastewater treatment plant
    including screening, pumping,
    measuring, and grit removal
    facilities.

Human Health Impacts- Damage
    to the health of an individual or
    individuals due to a given exposure
    or a series of exposures.

Indicator Bacteria- Bacteria that
    are common in human waste.
    Indicator bacteria are not harmful
    in themselves but their presence is
    used to indicate the likely presence
    of disease-causing, fecal-borne
    microbial pathogens that are more
    difficult to detect.

Infiltration- Storm water and
    groundwater that enter a sewer
    system through such means
    as defective pipes, pipe joints,
    connections, or manholes.
    (Infiltration does not include
    inflow).
Infiltration/Inflow (I/I)- The total
    quantity of water from both
    infiltration and inflow.

Inflow- Water, other than wastewater,
    that enters a sewer system from
    sources such as roof leaders,
    cellar drains, yard drains, area
    drains, foundation drains, drains
    from springs and swampy areas,
    manhole covers, cross connections
    between storm drains and sanitary
    sewers, catch basins, cooling
    towers, storm  waters, surface
    runoff, street wash waters, or
    other drainage. (Inflow does  not
    include infiltration).
                L
Long-Term Control Plan (LTCP)-
    Water quality-based CSO control
    plan that is ultimately intended
    to result in compliance with
    the Clan Water Act. Long-term
    control plans should consider the
    site-specific nature of CSOs and
    evaluate the cost effectiveness of a
    range of controls.
               M
Major Facility- Classification for
    wastewater treatment plants
    that are designed to discharge
    more than 1 mgd. Some facilities
    with smaller design flows are
    classified as major facilities
    when the NPDES authority
    deems it necessary for a specific
    NPDES permit to have a stronger
    regulatory focus.
Microbial Pathogens- Minute life
    forms including bacteria, viruses
    and parasites that can cause disease
    in aquatic biota and illness  or even
    death in humans.

Million Gallons per Day (mgd)- A
    unit of flow commonly used for
    wastewater discharges. One mgd is
    equivalent to a flow rate of 1.547
    cubic feet per second over a 24-
    hour period.

Minor Facility- A classification for
    wastewater treatment plants that
    are designed to discharge less than
    1 mgd.
                N
National Pollutant Discharge
    Elimination System (NPDES)- The
    national program for issuing,
    modifying, revoking and reissuing,
    terminating, monitoring and
    enforcing permits, and imposing
    and enforcing pretreatment
    requirements, under Sections 307,
    318, 402, and 405 of the Clean
    Water Act.

Nine Minimum Controls (NMC)-
    Technology-based CSO controls
    that do not require significant
    engineering studies or major
    construction.

Nutrient- Any substance assimilated by
    living things that promotes growth.
    The term is generally applied
    to nitrogen and phosphorus in
    wastewater, but is also applied to
    other essential and trace elements.
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Report to Congress on the Impacts and Control ofCSOs and SSOs
               o
Oxygen Depleting Substances-
    Materials including human waste
    and other organic matter that
    cause a loss of oxygen in water and
    wastewater, typically measured in
    treatment, recycling, and
    reclamation of municipal sewage
    or industrial wastes of a liquid
    nature. It also includes sewers,
    pipes, and other conveyances only
    if they convey wastewater to a
    POTW treatment plant [40 CFR
    §403.3].
    terms of BOD c
                P
Parasites- Animals or plants that live
    in and obtain nutrients from a
    host organism of another species.

Pathogenic- Capable of causing
    disease.

Point Source- Any discernible,
    confined, and discrete conveyance,
    including but not limited
    to any pipe, ditch, channel,
    tunnel, conduit, well, discrete
    fixture, container, rolling stock,
    concentrated animal feeding
    operation, landfill leachate
    collection system, vessel, or
    other floating craft from
    which pollutants are or may be
    discharged.

Primary Treatment- First steps in
    wastewater treatment wherein
    screens and sedimentation tanks
    are used to remove most materials
    that float or will settle.

Publicly Owned Treatment Works
    (POTW)- A treatment works,
    as defined by Section 212 of the
    Clean Water Act that is owned
    by a state or municipality. This
    definition includes any devices
    and systems used in the storage,
               Q
Sanitary Sewer Overflow (SSO)- An
    untreated or partially treated
    sewage release from a sanitary
    sewer system.

Sanitary Sewer System (SSS)- A
    municipal wastewater collection
    system that conveys domestic,
    commercial and industrial
    wastewater, and limited amounts
    of infiltrated ground water and
    storm water, to a POTW. Areas
    served by sanitary sewer systems
    often have a municipal separate
    storm sewer system to collect and
    convey runoff from rainfall and
    snowmelt.

Satellite Sewer Systems- Combined
    or separate sewer systems that
    convey flow to a publicly owned
    treatment works owned and
    operated by a separate entity.

Secondary Treatment-
    Technology-based requirements
    for direct discharging
    municipal sewage treatment
    facilities. Standard is based
    on a combination of physical
    and biological processes for
    the treatment of pollutants in
    municipal sewage. Standards
    are expressed as a minimum
    level of effluent quality in terms
    of: BOD^, suspended solids,
    and pH (except as provided
    for special considerations and
    treatment equivalent to secondary
    treatment).

State Revolving Fund Program- A
    federal program created by the
    Clean Water Act Amendments in
    1987 that offers low interest loans
    for wastewater treatment projects.
                T
Technology-Based Effluent Limit-
    Effluent limitations applicable to
    direct and indirect sources, which
    are developed on a category-by-
    category basis using statutory
    factors, not including water quality
    effects.

Total Suspended Solids  (TSS)- A
    measure of the filterable solids
    present in a sample of water or
    wastewater (as determined by the
    method specified in 40 CFR Part
    136).

Toxics- Materials contaminating the
    environment that cause death,
    disease, and/or birth defects in
    organisms that ingest or absorb
    them. The quantities and length of
    exposure necessary  to cause these
    effects can vary widely.
               w
Water Quality Standard- A law
    or regulation that consists of
    the beneficial use or uses of a
    waterbody, the numeric and
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                                                                                                         Glossary
    narrative water quality criteria that
    are necessary to protect the use or
    uses of that particular waterbody,
    and an antidegradation statement.

Water Quality-Based Effluent
    Limitations- Effluent limitations
    applied to dischargers when
    technology-based limitations
    insufficient to result in the
    attainment of water quality
    standards. Usually applied to
    discharges into small streams.

Waters of the United States- All waters
    that are currently used, were used
    in the past, or may be susceptible
    to use in interstate or foreign
    commerce, including all waters
    subject to the ebb and flow of the
    tide. Waters of the United States
    include but are not limited to all
    interstate waters and intrastate
    lakes, rivers, streams (including
    intermittent streams), mudflats,
    sand flats, wetlands, sloughs,
    prairie  potholes, wet meadows,
    play lakes, or natural ponds. [See
    40 CFR §122.2 for the complete
    definition.]

Watershed Approach- An initiative
    that promotes integrated
    solutions to address surface
    water, groundwater, and habitat
    concerns on a watershed basis.
    It is a decision-making process
    that reflects a common strategy
    for information collection
    and analysis and a common
    understanding of the roles,
    priorities and responsibilities of all
    stakeholders within a watershed.

Wet Weather Event- A discharge
    from a combined or sanitary
    sewer system that occurs in direct
    response to rainfall or snowmelt.

Wet Weather SSO- A sanitary sewer
    overflow that results from the
    introduction of excessive inflow
    and infiltration into a sanitary
    sewer system, such that the total
    flow exceeds conveyance capacity.
                                                                                                           GL-5

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          Executive  Summary
    Report to Congress on the Impacts
       and Control  of CSOs and  SSOs
     The U.S. Environmental
     Protection Agency (EPA or
     "the Agency") is transmitting
this Report to Congress on the extent
of human health and environmental
impacts caused by municipal
combined sewer overflows (CSOs)
and sanitary sewer overflows (SSOs),
including the location of discharges
causing such impacts, the volume of
pollutants discharged, the constituents
discharged, the resources spent
by municipalities to address these
impacts, and the technologies used
by municipalities to address these
impacts.
Overview and Background

Why is EPA Preparing this Report?
   In the Consolidated Appropriations
   Act for Fiscal Year 2001, PL. 106-
   554 (or "2000 amendments to the
Clean Water Act"), Congress requested
two reports and the development of
a technology clearinghouse. The first
report was transmitted to Congress in
December 2001 as Report to Congress-
Implementation and Enforcement
of the Combined Sewer Overflow
Control Policy (EPA 200la). This
second Report to Congress fulfills the
requirement that:

   Not later than 3 years after
   the date of enactment of this
   Act, the Administrator of the
   Environmental Protection Agency
   shall transmit to Congress a report
   summarizing-

   (A) the extent of human health
   and environmental impacts
   caused by municipal combined
   sewer overflows and sanitary
   sewer overflows, including the
   location of discharges causing such
   impacts, the volume of pollutants
   discharged, and the constituents
   discharged;

   (B) the resources spent by
   municipalities to address these
   impacts; and

   (C) an evaluation of the
   technologies used by municipalities
   to address these impacts.

Further, the technology information
compiled for this Report to
Congress will serve as a key element
in developing the technology
SSOs include untreated discharges from SSSs
that reach waters of the United States, as
well as overflows out of manholes and onto
city streets, sidewalks, and other terrestrial
locations.
                                                                                     ES-1

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     clearinghouse requested by P.L. 106-
                                     554.
                                     What are CSOs and Why are They a
                                     Problem?
                                     Two types of public sewer systems
                                     predominate in the United States:
                                     combined sewer systems (CSSs) and
                                     sanitary sewer systems (SSSs). CSSs
                                     were among the earliest sewer systems
                                     constructed in the United States and
                                     were built until the first part of the
                                     20th century. As defined in the 1994
                                     CSO Control Policy (EPA 1994a), a
                                     CSS is:

                                         A -waste-water collection system
                                         owned by a state of'municipality
                                         (as defined by Section 502(4)
                                         of the Clean Water Act)  that
                                         conveys domestic, commercial, and
                                         industrial waste-waters and storm
                                         water runoff through a single
                                         pipe system to a publicly-owned
                                         treatment works (POTW).

                                     During wet weather events (e.g.,
                                     rainfall or snowmelt), the combined
                                     volume of wastewater and storm water
                                     runoff entering CSSs often exceeds
                                     conveyance capacity. Most CSSs are
                                     designed to discharge flows that
                                     exceed conveyance capacity directly to
                                     surface waters, such as rivers, streams,
                                     estuaries, and coastal waters. Such
                                     events are called CSOs.

                                     A CSO  is defined as:

                                         The discharge from a CSS at
                                         a point prior to the POTW
                                         treatment plant.

                                     Some CSO outfalls discharge
                                     infrequently, while others discharge
                                     every time it rains. Overflow
                                     frequency and duration varies from
                                     system to system and from outfall to
outfall within a single CSS. Because
CSOs contain untreated wastewater
and storm water, they contribute
microbial pathogens and other
pollutants to surface waters. CSOs
can impact the environment and
human health. Specifically, CSOs
can cause or contribute to water
quality impairments, beach closures,
shellfish bed closures, contamination
of drinking water supplies, and other
environmental and human health
problems.

What are SSOs and Why are They a
Problem?
Since the first part of the 20*  century,
municipalities in the United States
have generally constructed SSSs.
For the purposes of this Report to
Congress, an SSS is:

    A municipal wastewater collection
    system that conveys domestic,
    commercial, and industrial
    wastewater, and limited amounts
    of infiltrated ground-water and
    storm -water, to a POTW.

SSSs are not designed to collect large
amounts of storm water runoff from
precipitation events. Areas served by
SSSs often have a municipal separate
storm sewer system (MS4) to collect
and convey runoff from rainfall and
snowmelt.

Untreated or partially treated
discharges from SSSs are commonly
referred to  as SSOs. SSOs  have a
variety of causes including blockages,
line breaks, sewer defects that allow
excess storm water and groundwater
to overload the system, lapses  in sewer
system operation and maintenance,
inadequate sewer design and
ES-2

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                                                                                               Executive Summary
construction, power failures, and
vandalism. An SSO is defined as:

    An untreated or partially treated
    sewage release from a SSS.

The discussion of SSOs in this
report, including national estimates
of SSO volume and frequency, does
not account for discharges from
points after the headworks of the
treatment plant, regardless of the
level of treatment, or backups into
buildings caused by problems in the
publicly-owned portion of the SSS.
EPA found that backups into buildings
are not widely tracked by permitting
authorities.

Generally speaking, SSOs can occur
at any point in an SSS, during dry
weather or wet weather. SSOs include
overflows that reach waters of the
United States. SSOs also include
overflows out of manholes and onto
city streets, sidewalks, and other
terrestrial locations. A limited number
of municipalities have SSOs that
discharge from fixed points within
their sewer system. SSSs can back
up into buildings, including private
residences. When sewage backups are
caused by problems in the publicly-
owned portion of an SSS, they are
considered SSOs.

SSOs can range in volume from
one gallon to millions of gallons.
The microbial pathogens and other
pollutants present in  SSOs can
cause or contribute to water quality
impairments, beach closures, shellfish
bed closures, contamination of
drinking water supplies, and other
environmental and human health
problems.
What Statutory and Regulatory
Framework Applies to CSOs and
SSOs?
With extensive and documented
stakeholder support, EPA issued
its final CSO Control Policy on
April 19, 1994 (59 FR 18688). The
CSO Control Policy "represents a
comprehensive national strategy to
ensure that municipalities, permitting
authorities, water quality standards
authorities, and the public engage in a
comprehensive and coordinated effort
to achieve cost-effective CSO controls
that ultimately meet appropriate
health  and environmental objectives."

When the CSO Control Policy was
released, many stakeholders, key
members of Congress, and EPA
advocated for it to be endorsed in
the Clean Water Act to ensure its full
implementation. In the Consolidated
Appropriations Act for Fiscal Year
2001, PL. 106-554, Congress stated
that:

    ...each permit, order, or decree
    issued pursuant to this Act after
    the date of enactment of this
    subsection for a discharge from a
    municipal combined storm and
    sanitary sewer shall conform to the
    CSO  Control Policy signed by the
    Administrator on April 11, 1994.

SSOs that reach waters of the United
States are point source discharges,
and, like other point source discharges
from municipal SSSs, are prohibited
unless  authorized by an National
Pollutant Discharge Elimination
System (NPDES) permit. Moreover,
SSOs, including those that do not
reach waters of the United States, may
be indicative of improper operation
and maintenance of the sewer system,
CSO outfalls were constructed in a wide
variety of shapes and sizes, including the
large box culvert shown here. In general, CSO
outfalls discharge directly to receiving waters.
        Photo: City of Wilmington, DE
                                                                                                           ES-3

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    and thus may violate NPDES permit
                                    conditions.

                                    What Methodology Did EPA Use
                                    for this Report to Congress?
                                    The basic study approach for this
                                    report was to divide the congressional
                                    request into a series of discrete study
                                    questions, then to identify and collect
                                    existing data appropriate to each study
                                    question. This effort entailed:

                                    •   Reviewing existing data collected
                                        by EPA and other federal agencies,
                                        state and local governments, and
                                        non-governmental organizations;

                                    •   Searching the existing literature
                                        for environmental and human
                                        health impacts attributable to
                                        CSOs and SSOs, as well as the cost
                                        and technologies used to control
                                        CSOs and SSOs;

                                    •   Organizing forums to work
                                        with EPA and external experts
                                        and stakeholders on the  specific
                                        questions addressed in this report;

                                    •   Updating, verifying, and
                                        establishing latitude and longitude
                                        coordinates for the inventory of
                                        CSO outfalls developed as part
                                        of EPAs 2001 Report to Congress-
                                        Implementation and Enforcement
                                        of the Combined Sewer Overflow
                                        Control Policy;

                                    •   Collecting SSO event information
                                        from those states that compile
                                        data on the volume, frequency,
                                        and cause of SSO events in
                                        electronic data management
                                        systems;

                                    •   Developing national estimates
                                        of the volume and frequency of
                                        CSOs and SSOs; and
•   Developing simple models to
    estimate environmental and
    human health impacts where there
    was an absence of direct cause-
    and-effect data.

EPA emphasized the collection,
compilation, and analysis of existing
data for this report. This effort allowed
the Agency to expand its knowledge
about CSOs and SSOs, and to identify
gaps in the existing data and in
current systems that provide such data.
This Report to  Congress recognizes
that EPA should and will continue
to investigate the environmental and
human health challenges posed by wet
weather.
Response to Congress

      EPAs response to the
      congressional request set forth
      in PL. 106-554 is presented
below, organized into five themes
addressing both CSOs and SSOs:

•   Characterization

•   Environmental impacts

•   Human health impacts

•   Control technologies

•   Resources spent

What are the Location, Volume of
Pollutants, and Constituents of
CSOs and SSOs?
Currently, 828 NPDES permits
authorize discharges from 9,348 CSO
outfalls in 32 states (including the
District of Columbia). As shown in
Figure ES.l, most CSSs are located in
the Northeast and Great Lakes regions.
ES-4

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                                                                                             Executive Summary
The estimated volume of CSO
discharged nationwide is 850 billion
gallons per year. The number of
CSSs and CSO permits has decreased
slightly since publication of EPA's 2001
Report to Congress-Implementation
and Enforcement of the Combined
Sewer Overflow Control Policy. Further,
the percentage of CSO long-term
control plans (LTCPs) that have been
submitted to permitting authorities
has increased from 34 to 59 percent.
This represents progress in controlling
CSOs in the United States.

As shown in Figure ES.2, SSSs are
located across the country. EPA's
2000 Clean Watersheds Needs Survey
(CWNS) Report to Congress reported
15,582 municipal SSSs with wastewater
treatment facilities; an additional
4,846 satellite SSSs collect and
transport wastewater flows to regional
wastewater treatment facilities. SSOs
have the potential to occur in any of
these SSSs.

EPA estimates that between 23,000
and 75,000 SSO events occur per year
in the United States, discharging a
total volume of three to 10 billion
gallons per year. This estimate does
not account for discharges occurring
after the headworks of the treatment
plant or backups into buildings caused
by problems in the publicly-owned
portion of an SSS. The majority
of SSO events are caused by sewer
blockages  that can occur at any time.
The majority of SSO  volume appears
to be related to events caused by wet
weather and excessive inflow and
infiltration.
                   Figure ES.1
National Distribution
of CSSs

The majority of CSO permits are
held by communities located in
the Northeast and Great Lakes
regions.
                                                                                                          ES-5

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Report to Congress on the Impacts and Control ofCSOs and SSOs
  Figure ES.2
    National Distribution
    of SSSs

    SSSs are widely distributed
    across the United States, serving
    municipalities in all 50 states.
    Approximately 75 percent of SSSs
    are shown, where location data
    (latitude/longitude) were available
    from EPA's Permits Compliance
    System.
A comparison of the estimated annual
CSO and SSO discharge volume with
treated wastewater is presented in
Table ES.l.

CSOs and SSOs contain untreated
wastewater, and therefore the pollutant
concentration depends on the service
population, the characteristics of the
sewer system, weather conditions, any
treatment provided, and other factors.
The principal pollutants present in
CSOs and SSOs are:

•   Microbial pathogens

•   Oxygen depleting substances
•   Total suspended solids (TSS)

•   Toxics

•   Nutrients

•   Floatables and trash

Pollutant concentrations in CSOs
and SSOs vary substantially, not only
from community to community and
event to event, but also within a given
event. CSOs and SSOs contribute
pollutant loadings to waterbodies
where discharges occur. It is important
to note that waterbodies also receive
pollutants of the types found in CSOs
and SSOs from other sources such as
storm water runoff.
ES-6

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                                                                                             Executive Summary
  Treated wastewater3
  CSOb
  SSOC
                                            Annual Discharge Volume
                                                (billion gallons)
              11,425
               850
               3-10
                                                             Table ES.1
  a EPA 2000a
  b GPRACSO model, Section 4.5.1 of this report
  c Section 4.7.4 of this report
What is the Extent of
Environmental Impacts Caused by
CSOs and SSOs?
Pollutant concentrations in CSOs
and SSOs may be sufficient to cause a
violation of water quality standards,
precluding the attainment of one or
more of the designated uses (e.g.,
swimming, boating, fishing) for the
waterbody.

CSOs and wet weather SSOs discharge
simultaneously with storm water
runoff and  other nonpoint sources of
pollution. EPA recognizes that this can
make it difficult to identify and assign
specific cause-and-effect relationships
between CSOs, SSOs, and observed
water quality problems. In addition,
EPA found  that  the identification
and quantification of environmental
impacts caused by CSOs and SSOs
at the national level is difficult
because there is no comprehensive
national data system for tracking the
occurrence  and  impacts of CSOs and
SSOs.

Nevertheless, CSOs and SSOs can
by themselves affect the attainment
of designated uses and cause water
quality standards violations. Average
bacteria concentrations in CSOs and
SSOs may be several thousand times
greater than water quality standard
criteria, and waterbodies that receive
CSO and SSO discharges may lack
sufficient dilution or assimilative
capacity. Based on modeling analysis
conducted by EPA and summarized in
Table 5.6 of this report, water quality
standards are projected to be violated
frequently, even in the absence
of other sources of fecal coliform
pollution, where discharges from SSO
events include more concentrated
wastewater (e.g., SSOs with limited
I/I) or when SSOs discharge to smaller
receiving waters such as a stream or
small tributary.

As shown in Figure ES.3, CSOs were
responsible for 1 percent of reported
advisories and closings, and 2 percent
of advisories and closings that had
a known cause during the 2002
swimming season. SSOs were reported
to be responsible for 6 percent of
reported advisories and closings, and
12 percent of advisories and closings
having a known cause. Studies also
identify CSOs and SSOs as a cause
of shellfish harvesting prohibitions
and restrictions in classified shellfish
growing areas.

The environmental impacts of CSOs
and SSOs are most apparent at the
local level, and as the result of large
or recurrent discharges. Examples of
localized impacts due to CSOs and
SSOs include:
Estimated Annual
Discharge Volumes

On an annual basis,the volume
of CSO and SSO discharged is a
proportionally small amount
compared to the total flow
processed at municipal treatment
facilities.
                                                                                                          ES-7

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Report to Congress on the Impacts and Control ofCSOs and SSOs
  Figure ES.3
    Sources of Pollution
    Resulting in Swimming
    Beach Advisories and
    Closings (EPA 2003a)

    EPA's Beaches Environmental
    Assessment and Coastal (BEACH)
    Program conducts an annual survey
    of the nation's swimming beaches.
    During the 2002 swimming season,
    CSOs and SSOs (including sewer
    line blockages and breaks) were
    responsible for 1 and 6 percent of
    reported closings and advisories,
    respectively.

o
i/i
o
           cso

          POTW
   Boat discharge
    Septic system

           SSO

          Other

         Wildlife

Storm water runoff

       Unknown
                                     •  The City of Indianapolis assessed
                                        receiving waters in the city and
                                        ranked CSOs high in importance
                                        relative to other sources of
                                        pollution.

                                     •  The State of North Carolina has
                                        documented fish kills attributed to
                                        SSOs since 1997.

                                     •  The State of New Jersey closed
                                        over 30,000 acres  of classified
                                        shellfish growing  areas in the
                                        Raritan Bay area due to a large
                                        SSO in 2003.

                                     What is the Extent of Human
                                     Health Impacts Caused by CSOs
                                     and SSOs?
                                     Microbial pathogens and toxics can
                                     be present in CSOs and SSOs at levels
                                     that pose risks to human health.
                                     Human health impacts occur when
                                     people become ill due to contact with
                                     water or ingestion of water or shellfish
                                     that have been contaminated by CSO
                                     or SSO discharges. In addition, CSSs
                                     and SSSs can back up into buildings,
                                     including private residences. These
                                     discharges provide a direct pathway
                                     for human contact with untreated
                                     wastewater. Exposure to land-based
                                     SSOs typically occurs through the
                                     skin via direct contact. The resulting
                                     diseases are often similar to those
                                     associated with exposure through
                                     drinking water and swimming (e.g.,
                                     gastroenteritis), but may also include
                                     illness caused by inhaling microbial
                                     pathogens.

                                     Although it is clear that CSOs
                                     and SSOs contain disease-causing
                                     pathogens and other pollutants, EPA
                                     has limited information on actual
                                     human health impacts occurring as a
                                     result of CSO and SSO events. Further,
                                     CSOs and wet weather SSOs also tend
                                     to occur at times (e.g., storm events)
                                     when exposure potential may be lower.

                                     Identification and quantification
                                     of human health impacts caused
                                     by CSOs and SSOs at the national
ES-8

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                                                                                            Executive Summary
level is difficult due to a number of
factors, including under-reporting and
incomplete tracking of waterborne
illness, contributions of pollutants
from other sources, and the lack of a
comprehensive national data system
for tracking the occurrence and
impacts of CSOs and SSOs. As an
alternative to direct data on human
health impacts, EPA modeled the
annual number of gastroenteritis
cases potentially occurring as a result
of exposure to water contaminated
by CSOs and SSOs at BEACH survey
beaches. As shown in Table 6.6,
EPA found that CSOs and SSOs are
estimated to cause between 3,448 and
5,576 illnesses annually at the subset
of recreational areas included in the
analysis.

What Technologies Have
Municipalities Used to Reduce the
Impacts of CSOs and SSOs?
Municipalities have many options  in
selecting technologies to reduce the
impacts of CSOs and SSOs. These
technologies range from large-scale
structural projects (e.g., wet weather
storage facilities) to operation and
maintenance practices (e.g., sewer
cleaning). Technology selection is
determined by characteristics of the
sewer system, problems identified in
the sewer system, performance goals
established for the sewer system,
resources available, and other site-
specific considerations.

Municipalities employ a wide variety
of technologies and operating
practices to maintain existing
infrastructure, minimize the
introduction of unnecessary waste
and flow into the sewer system,
increase capture and treatment of
wet weather flow reaching the sewer
system, and minimize the impact of
any subsequent discharges on the
environment and human health. For
this Report to Congress, technologies
used to address CSOs and SSOs
have been grouped into five broad
categories:

•  Operation and maintenance
   practices

•  Collection system controls

•  Storage facilities

•  Treatment technologies

•  Low-impact development
   techniques

EPA, states, and municipalities have
made progress in developing tools and
strategies for reducing the frequency
and volume of CSOs and SSOs.
Much remains to be done, however,
to fully realize the objectives of the
Clean Water Act and the CSO Control
Policy. Municipalities have suggested
that limited resources prevent them
from acquiring and implementing
technologies as quickly as they and
regulatory agencies would prefer.

What Resources Have
Municipalities Spent to Address
the Impacts of CSOs and SSOs?
Municipal resources used to address
CSOs and SSOs are documented in
different ways. EPAs estimates  of
municipal CSO expenditures rely
on requests for Clean Water State
Revolving Loan Fund (CWSRF)
loans and on documents submitted
                                                                                                        ES-9

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    to EPA's CWNS, which include CSO
                                    LTCPs and other facility planning
                                    documents. In addition, EPA uses a
                                    cost curve methodology to estimate
                                    costs for communities with CSSs
                                    that do not submit documentation.
                                    In communities served by SSSs, SSO
                                    control expenditures are generally
                                    a combination of general operation
                                    and maintenance (O&M) and
                                    capital expenditures. In total, EPA
                                    documented expenditures of more
                                    than $6 billion on CSO control
                                    (through 2002) and at least $4 billion
                                    on SSO control (1998-2002). EPA's
                                    2000 CWNS estimated that at least an
                                    additional $50.6 billion is required to
                                    capture no less than 85 percent of the
                                    CSO by volume, and an additional
                                    $88.8 billion is required to  control
                                    SSOs over the next 20 years (EPA
                                    2003b).

                                    What Actions Should be  Taken to
                                    Reduce the Impacts of CSOs and
                                    SSOs?
                                    In its preparation of this report, EPA
                                    found that:

                                    Maintaining and improving the
                                    integrity of the  nation's wastewater
                                    infrastructure will protect the high
                                    level of environmental quality and
                                    public health enjoyed in the United
                                    States. Proper O&M of the nation's
                                    sewers is integral to ensuring that
                                    wastewater is collected, transported,
                                    and treated at POTWs; and to
                                    reducing the volume and frequency
                                    of CSO and SSO discharges. Many
                                    existing structural and non-structural
                                    technologies are well suited for
                                    CSO and SSO control. Emerging
                                    technologies and innovative practices
                                    hold promise for even greater
reductions in pollution. Municipal
owners and operators of sewer systems
and wastewater treatment facilities
need to manage their assets effectively
and implement new controls, where
necessary, as this infrastructure
continues to age.

The impacts of CSOs and SSOs are a
concern at the  local watershed level.
CSOs and SSOs are two among many
sources of pollutants that contribute
to urban water quality problems.
The watershed approach is central
to water quality assessments and the
identification of control strategies
must include all sources of pollution
affecting water quality. The presence
of sewer systems in most developed
watersheds nationwide underscores
the importance of considering
potential SSOs impacts on water
quality. Similarly, the presence of
CSOs in 32 states places them in
many watersheds across the country.
EPA, states, and municipalities should
strive toward better integration of
wet weather programs with other
NPDES, compliance assistance,
and enforcement activities. Better
integration of programs and activities
at the watershed level will provide
economies of scale with respect to
monitoring and reporting, protecting
water quality, and reducing the
impacts of CSOs and SSOs.

Improved monitoring and reporting
programs would provide better
data for decision-makers on CSO
and SSO control. Better tracking
of environmental impacts and the
incidence of waterborne disease would
increase national understanding of
the environmental and human health
impacts associated with CSOs, SSOs,
ES-10

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                                                                                             Executive Summary
and other sources of pollution. Use
of standardized reporting formats
for information on the occurrence
and control of CSOs and SSOs would
enable EPA, states, and others to track
pollutant loads and the performance
of controls. Recent EPA efforts such
as WATERS (Watershed Assessment,
Tracking, and Environmental
ResultS) work to unite national
water quality information that was
previously available only from several
independent and unconnected
databases. EPA will continue to work
to improve the information available.

The success that the nation has
achieved in improving water quality
since passage of the Clean Water Act is
due to the collective efforts of federal
and state agencies, municipalities,
industry, non-governmental
organizations, and citizens. Continued
cooperation among these groups
is essential to meet the challenges
to clean water that lie ahead. As
described in this Report to Congress,
numerous pollutant sources threaten
the environment and human health,
but establishing direct cause-and-
effect relationships is often difficult.
The information necessary to manage
water quality problems comes from
many sources. EPA recognizes the
value of working with stakeholders
and has pursued a strategy of extensive
stakeholder participation in its policy-
making on CSO and SSO issues.
Likewise, as communities continue
to implement CSO and SSO controls,
further cooperation with municipal,
industry, and environmental
organizations is essential to ensure
successful development and
implementation of environmental
programs.
                                                                                                        ES-11

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                               Chapter   1
                        Introduction
      This Report to Congress presents
      U.S. Environmental Protection
      Agency's (EPA or "the Agency")
most recent and comprehensive
characterization of combined sewer
overflows (CSOs) and sanitary sewer
overflows (SSOs), including the extent
of human health and environmental
impacts caused by CSOs and SSOs,
the resources spent by municipalities
to address these impacts, and the
technologies used by municipalities to
address these impacts. This report has
been prepared in direct response to  a
congressional mandate established in
December 2000 in the Consolidated
Appropriations Act for Fiscal Year
2001, PL. 106-554, which requires
that:

   Not later than 3 years after
   the date of enactment of this
   Act, the Administrator of the
   Environmental Protection Agency
   shall transmit to Congress a report
   summarizing—

    (A) the extent of human health
   and environmental impacts
   caused by municipal combined
   sewer overflows and sanitary
   sewer overflows, including the
   location of discharges causing such
   impacts, the volume of pollutants
   discharged, and the constituents
   discharged;

   (B) the resources spent by
   municipalities to address these
   impacts; and

   (C) an evaluation of the
   technologies used by municipalities
   to address these impacts.

EPA prepared this report between
March 2002 and July 2004. During this
time, EPA developed a methodology;
collected data from federal, state, and
local sources; performed analyses;
coordinated with stakeholders; and
wrote this report. Data collection was
completed in early fall 2003, and select
analyses were updated in mid-2004.
This report is the second Report to
Congress  required as part of PL. 106-
554. The first report was EPA's Report
to Congress-Implementation and
Enforcement of the Combined Sewer
Overflow Control Policy (EPA 833-R-
01-003).

PL. 106-554 also requires EPA to
develop and maintain a clearinghouse
of technologies for addressing the
impacts of CSO and SSO discharges.
In this chapter:
1.1  What are CSOs and
    SSOs?

1.2  How is this Report
    Organized?
 Typical CSO outfall discharge following a
 storm.
    Photo: NJ Department of Environmental Protection
                                                                                                   1-1

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     EPA expects that information
                                     provided in this Report to Congress
                                     will be the basis for the clearinghouse
                                     when it is developed.
                                     1.1 What are CSOs and SSOs?

                                        In the United States, two types of
                                        public sewer systems predominate:
                                        combined sewer systems (CSSs)
                                     and sanitary sewer systems (SSSs).

                                     A CSS is a wastewater collection
                                     system owned by a municipality (as
                                     defined by Section 502(4) of the Clean
                                     Water Act) that conveys domestic,
                                     commercial, and industrial wastewater
                                     and storm water runoff through a
                                     single pipe system to a publicly-owned
                                     treatment works (POTW).

                                     An SSS is a wastewater collection
                                     system owned by a municipality that
                                     conveys domestic, commercial, and
                                     industrial wastewater, and limited
                                     amounts  of infiltrated groundwater
                                     and storm water to a POTW. Areas
                                     served by SSSs often have a municipal
                                     separate storm sewer system (MS4) to
                                     collect and convey runoff from rainfall
                                     and snowmelt.

                                     1.1.1 CSOs
                                     The term "CSO" refers to a discharge
                                     from a CSS at a point prior to the
                                     POTW treatment plant. CSOs
                                     generally occur in response to wet
                                     weather events; that is, during and
                                     following periods when rainfall or
                                     snowmelt drain  to the CSS. Most CSSs
                                     are designed to discharge flows that
                                     exceed conveyance capacity directly to
                                     receiving waterbodies, such as rivers,
                                     streams, estuaries, and coastal waters.
CSSs can also back up into buildings,
including private residences. When
backups are caused by problems in
the publicly owned portion of a CSS,
they are considered unauthorized
discharges.

CSO discharges include a mix of
domestic, commercial, and industrial
wastewater, and storm water runoff.
As such, CSO discharges contain
human, commercial, and industrial
wastes as well as pollutants washed
from streets, parking lots, and other
surfaces. EPA's 1994 CSO Control
Policy (59 FR 18688) provides a
comprehensive national strategy
to ensure municipalities, NPDES
permitting authorities, water quality
standards authorities, EPA, and the
public to engage in a coordinated
planning effort to achieve cost-
effective CSO controls that ultimately
meet the requirements of the Clean
Water Act (EPA 1994a). The text of
the CSO Control Policy is provided
in Appendix A. In 2000, PL. 106-554
amended the Clean Water Act by
adding the following to Section 402:

    (q)(l) Each permit, order, or
    decree issued pursuant to this Act
    after the date of enactment of this
    subsection for a discharge from a
    municipal combined storm and
    sanitary sewer shall conform to the
    CSO Control Policy signed by the
   Administrator on April 11, 1994.

EPA's  Report to Congress-
Implementation and Enforcement
of the Combined Sewer Overflow
Control Policy identified CSSs in
32 states (including the District of
Columbia)  across nine EPA regions
(EPA  200la). As of July 2004, those 32
states had issued 828 permits to 746
communities.
1-2

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                                                                                         Chapter 1—Introduction
1.1.2SSOS
The term "SSO" refers to untreated or
partially treated sewage releases from
an SSS.

SSOs have a variety of causes,
including, but not limited to, severe
weather, blockages, line breaks,
power failures, lapses in sewer
system operation and maintenance,
inadequate sewer design and
construction, and vandalism. SSO
discharges typically contain a mix of
domestic, commercial, and industrial
waste. SSOs can pose challenging
public health and environmental
issues when they occur.

SSOs include those overflows that
reach waters of the United States, as
well as overflows out of manholes
and onto city streets, sidewalks, and
other terrestrial locations. A limited
number of municipalities have regular
SSO discharges from fixed points
within the sewer system. SSSs can back
up into buildings, including private
residences. When backups are caused
by problems in the publicly-owned
portion of an SSS, they are considered
SSOs.

SSOs that reach waters of the United
States are point source discharges,
and, like other point source discharges
from municipal SSSs, are prohibited
unless authorized by an National
Pollutant Discharge Elimination
System (NPDES) permit. Moreover,
SSOs, including those that do not
reach waters of the United States, may
be indicative of improper operation
and maintenance of the sewer
system, and thus may violate NPDES
permit conditions. EPA has  focused
on SSO problems with compliance
assistance and enforcement activities
in accordance with the Compliance
and Enforcement Strategy Addressing
Combined Sewer Overflows and
Sanitary Sewer Overflows, issued
April 27, 2000 (EPA 2000b). In
addition, EPA is evaluating options
for improving NPDES permit
requirements for SSOs and municipal
SSSs.

EPAs 2000 Clean Watersheds Needs
Survey Report to Congress reported
15,582 municipal SSSs providing
wastewater collection, conveyance,
and treatment are presently operating
within the 50 states and the District
of Columbia (EPA 2003b). EPA also
identified an additional 4,846 satellite
SSSs providing only collection and
conveyance. Not all of these hold
NPDES permits (EPA 2003b). If not
properly maintained, satellite systems
have the potential to have an SSO
or to cause an SSO in downsewer
systems.
1.2 How is this Report
     Organized?

       The purpose of this report is
       to respond to Congress with
       a current characterization of
the volume, frequency, and location
of CSOs and SSOs, the extent of
human health and environmental
impacts caused by CSOs and SSOs,
the resources spent by municipalities
to address these impacts, and the
technologies used to address these
impacts. The report contains 10
chapters; the content and purpose of
which are summarized below.
Since the passage of the Clean Water Act in
1972,all levels of government have made
substantial investments in the nation's
wastewater infrastructure.

          Photo: City of Chicago
                                                                                                           1-3

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Report to Congress on the Impacts and Control ofCSOs and SSOs
  Sewer separation is one of the most often
  used CSOcontrols.The separation project
  shown here is underway in Louisville,
  Kentucky.

   Photo: Louisville-Jefferson County Metropolitan Sewer District
Chapter 2 summarizes the history of
regulatory efforts to control CSOs
and SSOs. It describes federal water
pollution control legislation, paying
particular attention to Clean Water Act
requirements for secondary treatment
and pretreatment, the Construction
Grants Program, and amendments to
the Clean Water Act made by P.L. 106-
554.

Chapter 3 describes the methodology
used to develop this Report to
Congress. In order to report on
impacts, resources  spent to address
impacts, and the technologies
applied to control CSOs and SSOs,
EPA  designed and implemented a
comprehensive approach to gather
the necessary data and information.
This  effort included an extensive
literature search, site visits to EPA
regional offices and states, interviews
with state and local officials, an
experts workshop,  and outreach to
stakeholders.

Chapter 4 characterizes the pollutants
present in CSO and SSO discharges
and identifies other watershed sources
of these pollutants. This chapter
describes the universe of CSS and
SSS permittees under the NPDES
program. The  chapter also summarizes
information on the volume, frequency,
and location of CSOs and  SSOs, as
well as the most common causes of
SSOs.

Chapter 5 describes the types of
environmental impacts attributable
to CSO and SSO discharges in terms
of water quality standards  violations
and lost uses (i.e., closures of shellfish
beds and beaches). This chapter also
discusses the extent of environmental
impacts caused or contributed  to by
CSO and SSO discharges. National
data are used to describe the extent of
environmental impacts. State and local
data are used to illustrate site-specific
examples of impacts.

Chapter 6 describes waterborne
diseases and other potential human
health impacts associated with
exposure to the pollutants found
in CSO and SSO discharges. The
chapter summarizes mechanisms
at the federal, state, and local levels
for reporting and tracking these
impacts. In addition, the chapter
describes different techniques used to
communicate the risk associated with
exposure to CSO and SSO discharges
and how these risks can be minimized
or prevented.

Chapter 7 summarizes federal and
state activities to regulate CSOs and
SSOs to minimize impacts associated
with discharges. The chapter reports
on the issuance of permits and
other enforceable orders requiring
control of CSOs or elimination of
SSOs. This chapter also summarizes
technical assistance provided by
federal and state governments to assist
municipalities in controlling CSOs
and SSOs.

Chapter 8 surveys the technologies
most widely used to control CSO and
SSO discharges, including: operation
and maintenance practices, sewer
system controls, storage facilities,
treatment technologies, and low-
impact development techniques.
The chapter also describes effective
combinations of technologies as
well as emerging practices that show
particular promise in the control of
CSOs and SSOs.
1-4

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                                                                                        Chapter 1—Introduction
Chapter 9 provides information on
the resources spent by municipalities
to control CSO and SSO discharges,
including a discussion of the
national investment in wastewater
infrastructure. Specific information
from select municipalities on
expenditures related to CSO and SSO
control is presented. The chapter
summarizes projected financial needs
for municipalities to meet current
regulatory requirements for CSO and
SSO control and discusses available
sources of funding to address impacts
ofCSOsandSSOs.

Chapter 10 summarizes report
findings and key considerations for
EPA in shaping future regulations and
program activities aimed at CSO and
SSO control.
                                                                                                          1-5

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                              Chapter  2
                      Background
         Municipal sewer systems
         are an extensive and
         valuable part of the
nation's infrastructure. In 2000, 16,202
wastewater treatment facilities and
21,264 sewer systems (both CSS and
SSS) were in operation in the United
States. These systems serve about 208
million people in the United States,
as reported in EPA's Clean Watersheds
Needs Survey 2000 Report to Congress
(EPA 2003b). EPA estimates that
publicly-owned sewer systems account
for about 724,000 miles of sewer pipe
and approximately 500,000 miles
of privately-owned pipes deliver
wastewater into these systems.

Much of the nation's wastewater
infrastructure is aging. Components
of some sewer systems date back
over 100 years, as evidenced by wood
and brick sewers still in operation in
some cities. A survey of 42 wastewater
utilities indicated the age of sewer
system components ranged from new
to 117 years, with an average age of
33 years (ASCE 1999). Over time,
municipalities have used a wide variety
of materials, design and installation
practices, and maintenance and
repair procedures, which has led to
considerable variability in the current
condition of sewer infrastructure.

This chapter provides a brief history
of sewer systems and wastewater
treatment in the United States, using
context provided by the Clean Water
Act. Additional information on federal
and state efforts related to the control
of CSOs and SSOs is presented in
Chapter 7.
2.1 What is the History of
    Sewer Systems in the
    United States?
   In the pre-sewer era, human waste
   was dumped into privy vaults and
   cesspools, and storm water ran
into the streets or into surface drains.
Population increases during the 1800s,
particularly in urban areas, created
the need for more effective sanitary
systems. Between 1840 and 1880,
the percentage of Americans living
in urban areas rose from 11 percent
to 28 percent (Burian et al 1999).
This rapid urbanization resulted in
increased quantities of wastewater that
In this chapter:
2.1  What is the History of
    Sewer Systems in the
    United States?

2.2  What is the History of
    Federal Water Pollution
    Control Programs?

2.3  What is the Federal
    Framework for CSO
    Control?

2.4  What is the Federal
    Framework for SSO
    Control?

2.5  What is the Wet Weather
    Water Quality Act?
                                                                                                2-1

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Report to Congress on the Impacts and Control ofCSOs and SSOs
  Figure 2.1
    Typical Combined
    Sewer System
    Combined sewer systems are
    designed to discharge directly to
    surface waterbodies such as rivers,
    estuaries,and coastal waters
    during wet weather, when total
    flows exceed the capacity of the
    CSS or treatment plant.
   Figure 2.2
     Typical Separate
     Sanitary and Storm
     Sewer Systems

     Sanitary sewer systems are
     designed to collect and convey
     wastewater mixed with limited
     amounts of infiltration and inflow
     to a treatment plant. A separate
     storm sewer system is used in
     many areas to collect and convey
     storm water runoff directly to
     surface waterbodies.
overwhelmed privy vaults and cesspool
systems. Consequently, municipalities
began installing sewer systems to
protect public health and to address
aesthetic and flooding concerns
(Melosi 2000). Little precedent existed
for the construction of underground
sewer systems, however, and engineers
were reluctant to experiment with
expensive capital works (Tarr 1996).
In 1858, the first comprehensive sewer
system was designed for the city of
Chicago (Burian et al. 1999). Extensive
construction of municipal sewer
systems did not start until the 1880s.

In the United States, municipalities
installed sewer systems using two
predominant design options:
•   Combined sewer systems -
    domestic, commercial, and
    industrial wastewater, and storm
    water runoff are collected and
    conveyed in a single pipe system,
    as shown in Figure 2.1; or

•   Separate sanitary sewer and
    storm sewer systems - domestic,
    commercial, and industrial
    wastewater, and storm water
    runoff are collected and conveyed
    using two separate systems of
    pipe, as shown in Figure 2.2.

Combined sewer systems were less
expensive for municipalities that
needed both sanitary and storm
sewers, while SSSs were less expensive
2-2

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                                                                                         Chapter 2—Background
for municipalities that needed only a
wastewater collection system. Sanitary
sewers were sized to convey domestic,
commercial, and industrial wastewater,
and limited amounts of infiltrated
groundwater and storm water inflow.
Unlike CSSs, they were not intended
to collect large amounts of runoff
from wet weather events. In general,
large cities tended to construct CSSs,
given the flood control advantages
offered by such systems. By the end
of the 19   century, most of the large
urban areas with sewer systems had
CSSs. Smaller communities generally
pursued construction of separate
sanitary and storm sewers (Melosi
2000).

At the time, sanitary engineers
thought that both CSSs and SSSs
provided roughly equivalent health
protection, as neither design included
wastewater treatment (Tarr 1996).
This view was supported by an 1881
report to the National Board of
Health that recommended that design
choice be based on local conditions
and financial considerations (Hering
1977).

Construction of sewer systems greatly
improved local sanitary conditions
and in many cases reduced illness.
The direct discharge of untreated
wastewater to local receiving
waters, however, adversely impacted
downstream communities. During
the 1880s and 1890s, the rate of
typhoid deaths rose in cities with
drinking water intakes downstream
of untreated wastewater discharges.
Bacterial analysis confirmed the link
between sewage pollution in rivers
and epidemics of certain diseases
(Tarr 1996). Large outbreaks of
cholera, which claimed thousands
of lives, were also linked to sewage-
contaminated water supplies (Snow
1936). As a result, views on the safety
of discharging untreated wastewater
directly to receiving waters began
to shift toward the end of the 19*"
century.

As the need to provide wastewater
treatment was recognized, the  major
design difference between CSSs and
SSSs became apparent. Although
combined sewers offered an efficient
means of collecting and conveying
storm water and wastewater, they
made treatment more difficult due to
the large variation in flows between
dry and wet weather conditions.
Sanitary sewer systems simplified
and lowered the cost of wastewater
treatment, due to significantly
smaller volumes of wet weather flows
(Burian et al.  1999). Nonetheless,
municipalities with CSSs often
continued to utilize  and expand the
areas served by such systems (Tarr
1996).

Centralized municipal wastewater
treatment was still in its infancy in
the late  1800s (Burian et al. 1999). In
1892, only 27 municipalities treated
their wastewater; of these, 26 had SSSs.

2.1.1 Combined Sewers and CSOs

CSOs are primarily caused by wet
weather events (e.g., rainfall or
snowmelt), when the combined
volume of wastewater and storm
water entering the system exceeds the
capacity of the CSS or treatment plant.
When this occurs, combined systems
overflow directly to a receiving water.
Overflow frequency and duration
varies both from system to system and
Privy vaults and a water pump are located
side by side in this Pittsburgh neighborhood,
circa 1909.
        Photo: Paul Underwood Kellog
                                                                                                           2-3

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Report to Congress on the Impacts and Control ofCSOs and SSOs
  Figure 2.3
     National Distribution of
     Communities Served by
     CSSs

     CSSs are found throughout the
     United States, but are most heavily
     concentrated in the Northeast and
     Great Lakes regions.
from outfall to outfall within a single
CSS. Some CSO outfalls discharge
infrequently, while others activate
every time it rains. When constructed,
CSSs were typically sized to carry
three to five times the average dry
weather flow. Thus, there is usually
considerable conveyance capacity
within a CSS during dry weather.
Discharges from a CSS during dry
weather, referred to as dry weather
overflows, are infrequent and are
prohibited under the NPDES program.

State and local authorities generally
have not allowed the  construction of
new CSSs  since the first half of the
20*  century. As shown in Figure 2.3,
most of the communities served by
CSSs are located in the Northeast and
Great Lakes regions, while relatively
few are located in the Midwest,
Southeast, and Pacific Northwest.
Currently, 828 NPDES permits
authorize discharges from 9,348 CSO
outfalls in 32 states (including the
District of Columbia).

2.1.2 Sanitary Sewers and SSOs

SSOs include unauthorized discharges
from SSSs that reach waters of the
United States, as well as overflows out
of manholes and onto city streets,
sidewalks, and other terrestrial
locations. A limited number of
municipalities have SSO discharges
                     o»
2-4

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                                                                                           Chapter 2—Background
from fixed points within the sewer
system, similar to CSO outfalls.

SSOs, including those that do not
reach waters of the Unites States, may
be indicative of improper operation
and maintenance of the sewer system.
Causes of SSOs include, but are not
limited to:

•   Blockages

•   Structural, mechanical, or
    electrical failures

•   Collapsed  or broken sewer pipes

•   Insufficient conveyance capacity

•   Vandalism
In addition, high levels of infiltration
and inflow (I/I) during wet weather
can cause SSOs. Many SSSs that
were designed according to industry
standards experience wet weather
SSOs because levels of I/I may exceed
levels originally expected; removal
of I/I has proven more difficult and
costly than anticipated; or the capacity
of the system has become inadequate
due to an increase in service
population without corresponding
system upgrades. SSSs are located
across the country, as presented in
Figure 2.4. EPA believes that all SSSs
have the potential to  have occasional
SSOs.
                    Figure 2.4
National Distribution of
Communities Served by
SSSs
SSSs are located in all 50 states, but
are concentrated in the eastern
half of the United States and on the
west coast. SSSs are shown for ap-
proximately 75 percent of systems,
where locational  data (latitude/
longitude) were available from EPA's
Permit Compliance System.


                                                                                                            2-5

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   San Francisco's CSO Oceanside Water
   Pollution Control Plant treats an average
   of 17 million gallons per day (mgd) during
   dry weather and has 65 mgd of peak flow
   capacity.
      Photo: San Francisco Public Utilities Commission
2.2  What is the History of
     Federal Water Pollution
     Control Programs?

       The desire for a federal water
       pollution control program
       increased steadily through the
first half of the 20*  century. Congress
and the public became more aware
of the environmental and human
health impacts resulting from direct
discharges of untreated wastewater
to local receiving waters. Recognizing
the national interest in abating water
pollution for the benefit of water
supply and water resources, the 80*"
Congress stated:

    "The pollution of our water
    resources by domestic and
    industrial wastes has become an
    increasingly serious problem for
    the rapid growth of our cities
    and industries... Polluted waters
    menace the public health  through
    the contamination of water and
   food supplies, destroy fish and
   game life, and rob us of other
    benefits of our natural resources."
    (Senate Report No. 462 of the 80th
    Congress, 1948)

In 1948, Congress passed the
Federal Water Pollution Control Act
(FWPCA), P.L. 80-845, creating a
legislative  basis for water pollution
control in the United States. The
original FWPCA was amended many
times (in 1956, 1961, 1965, 1966,
1970, 1972, 1977, 1981, and 1987).
Notably, the 1972 Amendments (P.L.
92-500), commonly known as the
Clean Water Act, restructured the
authority for water pollution control
and consolidated that authority in the
Administrator of the EPA.  The Clean
Water Act provided a framework for:
•   Prohibition of point source
    discharges except as authorized by
    a permit;

•   Establishment of the National
    Pollutant Discharge Elimination
    System (NPDES), a regulatory
    program that requires "point
    source" dischargers, such as
    municipal wastewater collection
    and treatment plant operators,
    to obtain a permit and meet
    applicable regulations issued
    under the Clean Water Act;

•   Development of technology-
    based effluent limits, based on
    the pollutant reduction capacity
    of demonstrable treatment
    technologies, to be met by NPDES
    permit holders; and

•   Water quality standards and water
    quality-based effluent limitations,
    where technology-based limits
    are inadequate to meet  state water
    quality standards.

As a result of investment in wastewater
treatment, the United States has
realized major improvements in
environmental quality and human
health. Widespread epidemics of
typhoid fever and cholera that
killed thousands of people in the
19*  century and early 20*  century
were brought under control and
have remained under control due to
disinfection  of drinking water supplies
and advances in wastewater treatment.

2.2.1 Secondary Treatment

Many of the first wastewater treatment
facilities were designed to simply
separate solids and floating debris
from wastewater prior to  discharge;
this process is often referred to as
2-6

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                                                                                       Chapter 2—Background
primary treatment (Rowland and
Held 1976). This modest level of
treatment, however, was unable
to offset increased pollutant loads
associated with rapidly growing urban
populations and associated increases
in the volume of wastewater generated.
An additional level of treatment was
needed to protect the quality of the
nation's waters.

The 1972 Clean Water Act provided
the first statutory requirement for
achievement of effluent limits based
on secondary treatment by POTWs.
Specifically, Section 301 of the Clean
Water Act required POTWs to meet
limits based on secondary treatment
by July 1, 1977. EPA developed
limits based on secondary treatment
to include maximum allowable
concentrations of key parameters as
well as percent removal requirements.
Limits based on secondary treatment
include maximum acceptable
concentrations for biochemical
oxygen demand measured over five
days (BOD5), total suspended solids
(TSS), and pH. Percent removal
requirements for BOD5 and TSS were
also included. Adjustments to percent
removal requirements are available, on
a case-by-case basis, for POTWs with
less-concentrated influent that may
prevent compliance with the standard
requirements (EPA2000a).

2.2.2  Construction Grants

In addition to establishing effluent
limits for POTWs, the FWPCA and
its amendments brought about
substantial investment in wastewater
treatment between the  1940s and the
present. The 1956 Amendments (PL.
84-660) established the Construction
Grants Program for the construction
of wastewater treatment facilities and
provided $150 million in funding for
the program. Additional construction
grant funding was authorized with the
1961, 1965, and 1966 amendments.
With passage of the Clean Water Act
in 1972, funding for the Construction
Grants Program dramatically
increased. EPAs Construction Grants
Program distributed $100.7 billion
(2002 dollars) to communities
between 1970 and 1995 (EPA 2000a).
The 1987 amendments to the Clean
Water Act transformed the financial
assistance from a grant program to
a loan program. The Construction
Grants Program was phased out
by 1991 and replaced by the State
Revolving Fund (SRF) program.

Federal funding provided a strong
impetus for constructing and
upgrading wastewater infrastructure.
The level of treatment provided at
POTWs improved substantially over
the last 50 years (EPA 2000a):

•  30 percent of POTWs (3,529
   of 11,784) provided secondary
   treatment in 1950.

•  72 percent of POTWs (10,052
   of 14,051) provided secondary
   treatment in 1968.

•  99 percent of 16,024 POTWs
   provided secondary or greater
   treatment, or were "no-discharge
   facilities," in 1996.

High levels of compliance with
secondary treatment requirements
resulted in notable decreases in
pollutant loadings from POTWs, even
as the service population increased.
As an example, the amount of BOD5
discharged from POTWs declined by
                                                                                                        2-7

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Some municipalities promote storm drain
   stenciling as a storm water pollution
   prevention measure.
about 23 percent between 1968 and
1996, despite a 35 percent increase in
influent loadings to POTWs during
the same period (EPA 2000a).

2.2.3 Pretreatment

In the mid-1980s, more than one-
third of all toxic pollutants entering
the nation's waters were discharged
from POTWs (EPA 1986a). POTWs
are not typically designed to remove
toxic pollutants, and in some cases
constituents in industrial wastewater
can actually interfere with the
removal of conventional pollutants
such as BOD5 and TSS. To address
the discharge of toxic pollutants,
EPA, pursuant to Clean Water Act
Section 307, established the National
Pretreatment Program. The National
Pretreatment Program requires that
industrial and commercial dischargers
treat or control toxic pollutants in
their wastewater prior to discharge to
a municipal sewer system.

The General Pretreatment Regulations
require all large POTWs (i.e.,
those designed to treat flows of
more than 5 million gallons per
day (mgd)) and smaller POTWs
with significant industrial users to
establish local pretreatment programs.
These local programs implement
national pretreatment standards and
requirements in addition to any more
stringent local requirements necessary
to protect site-specific conditions.
More than 1,500 POTWs have
developed and are implementing local
pretreatment programs designed to
control discharges from approximately
30,000 significant industrial users.
The National Pretreatment Program
has made great strides  in reducing the
discharge of toxic pollutants to sewer
systems and to waters of the United
States (EPA 1999a).

2.2.4 Wet Weather

Initial implementation of the Clean
Water Act during the 1970s and 1980s
focused on discharges from traditional
point sources of pollution, such as
POTWs and industrial facilities.
Beginning in the late 1980s, attention
shifted to wet weather sources of
pollution. Under the NPDES program,
four program areas address wet
weather discharges: CSOs, SSOs, storm
water, and concentrated animal feeding
operations (CAFOs).

Storm Water
EPA published Phase I of the NPDES
Storm Water Program in 1990 (55
FR 47990). Phase I applies to large
dischargers; that is, those associated
with industrial activities, municipal
separate storm sewer systems
serving 100,000 people or more, and
construction projects disturbing
more than five acres of land.  In 1999,
EPA published the Phase II Final
Rule, which requires NPDES permit
coverage for storm water discharges
from smaller sources, including cities
and towns in urban  areas with separate
storm sewer systems serving fewer
than 100,000 people, and smaller
construction projects that disturb less
than five acres (64 FR 68722).

CAFOs
CAFOs are point sources, as defined
by Clean Water Act Section 502(14).
On February 12, 2003, EPA published
the Concentrated Animal Feeding
Operations Rule to ensure that manure
2-8

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                                                                                        Chapter 2—Background
and wastewater from CAFOs are
properly managed to protect the
environment and public health (68 FR
7175).

2.2.5 Watershed-Based
     Permitting

On December 17, 2003, EPA
published the Watershed-Based
NPDES Permitting Implementation
Guidance (EPA 2003c). Watershed-
based permitting under the NPDES
program emphasizes addressing
all stressors (including CSOs and
SSOs) within a watershed, rather
than individual pollutant sources on
a discharge-by-discharge basis. The
watershed-based permitting approach
is supported by EPA as a cost-effective
mechanism for improving water
quality and meeting watershed goals.
The approach builds on watershed
policy and guidance developed during
the 1990s: EPA's Watershed Strategy,
Watershed Framework, and  Clean
Water Action Plan (EPA 1994b, 1996a,
EPA and USDA 1998). In addition,
the approach fulfills commitments
articulated in recent initiatives such as
EPA's Trading Policy and Watershed-
Based Permitting Policy Statement
(EPA 2003d, 2003e).

Watershed-based permitting can
encompass a variety of activities
ranging from synchronizing NPDES
permits within a basin to developing
water quality-based effluent limits
using a multiple discharger modeling
analysis. Within a broader watershed
management system, the watershed-
based permitting approach is a tool
that can assist with implementation
activities such as monitoring,
reporting, and assessment.
2.3  What is the Federal
     Framework for CSO
     Control?

       CSOs are point source
       discharges and are subject to
       NPDES permit requirements.
CSOs are not subject to limits based
on secondary treatment requirements
otherwise applicable to POTWs.
Permits for CSOs must include
technology-based effluent limits,
based on the application of best
available technology economically
achievable (BAT) for toxic and
non-conventional pollutants and
best conventional pollutant control
technology (BCT) for conventional
pollutants. Additionally, like all
NPDES permits, permits authorizing
discharges from CSO outfalls must
include more stringent water  quality-
based requirements, when necessary,
to meet water quality standards. The
development of the federal framework
to address CSOs is described in detail
below.

2.3.1  CSO Case Law

In 1980, the U.S. Court of Appeals
for the D.C. Circuit accepted EPA's
interpretation of the Clean Water
Act that discharges at CSO outfalls
are not discharges from POTWs
and thus are not subject to the
limits based on secondary treatment
standards otherwise applicable to
POTWs (Montgomery Environmental
Coalition vs.  Costle, 46 F2d 568 (D.C.
Cir. 1980)). Following this decision,
EPA and states renewed their  focus
on permit requirements for CSO
discharges under the NPDES  program.
The sewer utility serving Louisville, Kentucky,
has restructured its organization to
coordinate CSO control needs with other
water quality improvement programs as part
of an effort to move toward watershed-based
permitting.
 Photo: Louisville-Jefferson County Metropolitan Sewer District
                                                                                                         2-9

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   A CSO outfall in Wilmington, Delaware.
       Photo: Wilmington Department of Public Works
2.3.2 The National CSO Control
     Strategy and the MAG

In 1989, EPA issued the National
CSO Control Strategy (54 FR
37371). The National CSO Control
Strategy encouraged states to develop
statewide permitting strategies to
ensure all CSOs were subject to an
NPDES permit and recommended six
minimum measures for CSO control;
additional controls could be required
as necessary. As EPA, states, and
municipalities worked to implement
the National CSO Control Strategy in
the early 1990s, the impacts of CSOs
(discussed in Chapters  5 and 6 of this
report) continued to receive national
attention. Environmental interest
groups pushed for further action, while
municipal organizations, concerned
that the National CSO Control Strategy
did not provide sufficient clarity,
sought a consistent national approach
to CSO control. In response to these
concerns, EPA formed a Management
Advisory Group (MAG) in 1992.
The MAG included representatives
from states, municipalities, industry
associations, and environmental
interest groups.

2.3.3 The CSO Control Policy

EPA published the CSO Control Policy
on April 19, 1994 (59 FR 18688). The
purpose of the CSO Control Policy was
twofold: 1) to elaborate on EPA's 1989
National CSO Control  Strategy; and
2) to expedite compliance with Clean
Water Act requirements. The policy
sought to minimize adverse impacts
from CSOs on water quality, aquatic
biota, and human health (EPA 1994a).

EPA's CSO Control Policy assigns
primary responsibility for its
implementation and enforcement
to NPDES authorities and water
quality standards authorities. This
policy also established objectives for
CSO communities: 1) to implement
the nine minimum controls (NMC)
and submit documentation on NMC
implementation; and 2) to develop
and implement a long-term control
plan (LTCP). Implementation status
of the NMC and LTCPs is presented
in Chapter 7. More information
on the CSO Control Policy is
provided in EPA's Report to Congress-
Implementation and Enforcement of
the Combined Sewer Overflow Control
Po/zcy(EPA2001a).
                                                                         2.4 What is the Federal
                                                                              Framework for SSO
                                                                              Control?
                                                                              SSOs that reach waters of the
                                                                              United States are point source
                                                                              discharges and, like other point
                                                                         source discharges from municipal
                                                                         SSSs, are prohibited unless authorized
                                                                         by an NPDES permit. Moreover, SSOs,
                                                                         including those that do not reach
                                                                         waters of the United States, may be
                                                                         indicative of improper operation and
                                                                         maintenance of the sewer system,
                                                                         and thus may violate NPDES permit
                                                                         conditions. In the 1989 National CSO
                                                                         Control Strategy, EPA explained that:
2-10

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                                                                                        Chapter 2—Background
"sanitary sewer systems must adhere
to the strict design and operational
standards established to protect the
integrity of the sanitary sewer system
and wastewater treatment facilities."

In 1994, a number of municipalities
asked EPA to establish  an SSO
Federal Advisory Committee
(FAC) of key stakeholders to make
recommendations on how the NPDES
program should address SSOs. The
municipalities indicated a desire for
greater national clarity, consistency
in NPDES requirements applicable
to SSOs, and a workable regulatory
framework. Five general stakeholder
groups were represented in the SSO
FAC: sanitary sewer system operators,
SSO-related health professionals,
state regulatory agencies, technical
professionals, and environmental and
citizen groups.

In 1995, EPA chartered an Urban Wet
Weather Flows FAC with stakeholder
representation to address cross-
cutting issues associated with wet
weather discharges (i.e., CSOs, SSOs,
and storm water). The  Urban Wet
Weather Flows FAC formed its SSO
Subcommittee by reconvening the
SSO FAC established in 1994. The
SSO Subcommittee was tasked with
developing a framework for addressing
SSOs and their impacts through
regulatory and non-regulatory actions.

Between 1995 and 1999, the SSO
Subcommittee held 12  meetings and
developed a number of documents,
including a series of issue papers
and a draft comprehensive guidance
document. In January 2001, EPA
prepared a notice of proposed
rulemaking related to SSOs, which
was withdrawn for review before it
was published in the Federal Register.
EPA is considering various options for
moving forward.
2.5 What is the Wet Weather
     Water Quality Act?

    In December 2000, as part of the
    Consolidated Appropriations Act
    for Fiscal Year 2001 (PL. 106-554),
Congress amended the Clean Water
Act by adding Section 402(q). This
amendment is commonly referred to
as the Wet Weather Water Quality Act
of 2000. Section 402(q) requires that
each permit, order, or decree issued
pursuant to the Clean Water Act after
the  date of enactment for a discharge
from a municipal combined sewer
system shall conform to the CSO
Control Policy. It authorized a $1.5-
billion grant program for controlling
CSOs and SSOs. Section 402(q) also
required EPA to issue guidance to
facilitate the conduct of water quality
and designated use reviews for CSO
receiving waters. EPA issued this
guidance on August 2, 2001 (EPA
2001b).
                                                                                                        2-11

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                             Chapter  3
                    Methodology
      This chapter documents the
      methodology EPA used
      to prepare this Report to
Congress. It presents EPA's study
objectives and analytical approach,
and summarizes the steps EPA has
taken to compile information on the
impacts and control of CSOs and
SSOs. This chapter describes EPA's
data sources, explains information
collection methods, and outlines the
steps EPA took to involve stakeholders
in the development of this report.
The chapter also summarizes data
considerations and quality assurance
measures used to enhance the  accuracy
and precision of results.
3.1 What Study Objectives and
    Approach Did EPA Use to
    Prepare this Report?
      The overall objective for
      this report is to respond
      to Congress with a current
characterization of the volume,
frequency, and location of CSOs and
SSOs; the extent of human health
and environmental impacts caused by
CSOs and SSOs; the resources spent
by municipalities to address these
impacts; and the technologies used to
address these impacts. Some new data
were obtained through interviews in
the development of this report, but
EPA did not undertake surveys or
field monitoring to characterize CSOs,
SSOs, and their impacts. Instead, EPA
primarily emphasized the collection,
compilation, and analysis of existing
data.

EPA used a two-tiered approach
to address the questions posed by
Congress. The first tier focused on
national assessments, drawing on
existing data collected by EPA and
other federal agencies to the fullest
extent possible. These data were
supplemented with select data from
non-governmental organizations
that were also national in scope.
The second tier focused on the use
of anecdotal data to provide site-
specific examples of impacts, costs,
and technology applications, and
to demonstrate the significance of
CSOs and SSOs at the local level. Site-
specific examples were largely drawn
from state and local interviews and
reports.
In this chapter:
3.1  What Study Objectives
    and Approach Did EPA
    Use to Prepare this
    Report?

3.2  What Data Sources Were
    Used?

3.3  What Data Were
    Collected?

3.4  How Were Stakeholders
    Involved in the
    Preparation of this
    Report?

3.5  What Data
    Considerations Are
    Important?

3.6  What Quality Control
    and Quality Assurance
    Protocols Were Used?

3.7  Summary
                                                                                              3-1

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Report to Congress on the Impacts and Control ofCSOs and SSOs
       Clean Watersheds Needs
       Survey 2000
       Report to Congress
3.2  What Data Sources Were
     Used?

      EPA developed a comprehensive
      list of potential data
      sources that could be used
to characterize CSOs and SSOs,
including environmental and human
health impacts from the discharges,
technologies used to control the
discharges, and the costs of the control
measures. This list included:

•   Federal data sources

•   NPDES authority and other state
    program data sources

•   Community-level data sources

•   Non-governmental organization
    data sources

The following sections describe
specific data sources EPA used to
develop this report.

3.2.1 Federal Data Sources
EPA researched its own files and
library of CSO- and SSO-related
documents for data that could be used
to characterize CSOs and SSOs. Data
and reports relevant to CSOs and
SSOs developed by EPAs permitting,
compliance and enforcement, research
and development, and water quality
assessment programs were among
those reviewed. Specific  EPA data
sources used in the analysis for this
Report to Congress include:

Beaches Environmental Assessment and
Coastal Health (BEACH) Program.
The BEACH Program focuses
on improving public health and
environmental protection programs
for beachgoers and providing the
public with information about the
quality of beach water.

Clean Watersheds Needs Survey
(CWNS). The CWNS summarizes
estimated capital costs for water
quality projects including projects to
control CSOs and SSOs.

Enforcement and Compliance Docket
(ECD). The ECD is the central archive
for all documents related to EPAs
enforcement and compliance activities.
It contains regulatory, case settlement,
and other policy related information.

EPAs 2001 Report to Congress-
Implementation and Enforcement of
the Combined Sewer Overflow Control
Policy. The 2001 Report to Congress
provides a comprehensive national
inventory of active CSO permits.

Government Performance and Results
Act (GPRA). EPA selected the CSO
program as a GPRA pilot program
for tracking programmatic benefits in
1997.

Municipal Technology Fact Sheets. EPA
maintains a series of more than 100
technology fact sheets, including more
than 20 with application to the control
of CSOs and SSOs.

National Water Quality Inventory
(NWQI). The biennial NWQI Report
to Congress is the primary vehicle for
informing Congress and the public
about general water quality conditions
in the United States.

Office of Research and Development
(ORD) projects. ORD works with
industry, universities, and other
agencies to develop technologies and
3-2

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                                                                                      Chapter 3—Methodology
techniques for protecting the nation's
freshwater and coastal resources and
human health.

Permit Compliance System (PCS). PCS
provides information on point sources
holding NPDES permits, including
permit issuance  and expiration
dates, discharge  limits, and discharge
monitoring data.

EPA also researched the programs
and files of other federal agencies to
ensure that relevant data from other
federal programs and activities were
assessed and included in this report,
as appropriate. The agencies consulted
included:

•   Centers for Disease Control and
    Prevention (CDC)

•   Congressional Budget Office
    (CBO)

•   Government Accounting Office
    (GAO)

•   National Institutes of Health
    (NIH)

•   National Oceanic and
    Atmospheric Administration
    (NOAA)

•   United States Geological Survey
    (USGS)

3.2.2 NPDES Authority and Other
     State Program Data Sources
Individual NPDES authorities and
associated state programs were the
primary sources of data on the
location of CSO outfalls as well as the
frequency, volume,  and cause of SSO
events. EPA conducted interviews with
states to assess the availability of data.
State program data and interviews
with program staff were also used to
identify site-specific CSO- and SSO-
related examples of environmental
and human health impacts such as fish
kills, beach closures, and outbreaks of
waterborne disease.

3.2.3 Community-Level Data
     Sources
EPA identified relevant community-
level data to supplement the national
data and drew on local planning
and monitoring studies, such as
CSO ETCPs, to illustrate site-specific
impacts and common technologies
used to control CSOs and SSOs.
Municipalities were interviewed
to obtain additional data to
characterize the volume, frequency,
and constituents of CSO and SSO
discharges; to identify the types of
controls implemented and results
achieved; and to quantify the resources
spent.

3.2.4 Non-Governmental
     Organization Data Sources
EPA also reviewed reports prepared by
non-governmental organizations that
contained national-level data relevant
to the objectives of this report. These
included:

•   American Public Works
    Association (APWA)

•   American Society of Civil
    Engineers (ASCE)

•   Association of Metropolitan
    Sewerage Agencies (AMSA)

•   The Ocean Conservancy

•   Water Environment Federation
    (WEF)

•   Water Environment Research
    Foundation (WERF)
                                                                                                        3-3

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    3.3  What Data Were Collected?

                                            Data collection involved
                                            identification and
                                            compilation of existing
                                    information. The primary data sources
                                    for this report were federal databases
                                    and reports as well as interviews with
                                    states and municipalities. In addition,
                                    EPA performed a comprehensive
                                    literature search and applied national
                                    assessment models, where appropriate.

                                    In compliance with the Paperwork
                                    Reduction Act, EPA prepared and
                                    submitted Information Collection
                                    Request 2063.01, which was approved
                                    by OMB on September 16, 2002
                                    (OMB No. 2040-0248).

                                    The following sections describe data
                                    collection and the key assessments
                                    carried out by EPA.

                                    3.3.1 Characterization of CSOs and
                                         SSOs
                                    This report characterizes CSOs and
                                    SSOs by addressing the following key
                                    questions:

                                    •   What pollutants are in CSOs and
                                        SSOs?

                                    •   What factors influence the
                                        concentrations of these pollutants in
                                        CSOs and SSOs?

                                    •   What other point and nonpoint
                                        sources might discharge these
                                       pollutants to waterbodies receiving
                                        CSOs and SSOs?

                                    •   What is the universe of combined
                                        sewer systems?

                                    •   What are the characteristics of
                                        CSOs?
•   What is the universe of sanitary
    sewer systems?

•   What are the characteristics of
    SSOs?

•   How do the volumes and loads from
    CSOs and SSOs compare to those
    from other municipal point sources?

To address these questions EPA used
NPDES permit files, state databases
for tracking CSO and SSO events, and
interviews with state and municipal
officials. Specific efforts included
updating data on the location of CSSs
and CSO outfalls from the 2001 Report
to Congress-Implementation and
Enforcement of the Combined Sewer
Overflow Control Policy (EPA 2001a),
and compiling SSO volume, frequency,
and cause data. This allowed
assessment of:

•   Pollutants found in CSOs and
    SSOs

•   Location of CSSs and individual
    CSO outfalls

•   Volume and frequency of CSOs
    and SSOs

•   Causes of SSOs

•   Comparison of pollutant loads
    from CSOs and SSOs with other
    municipal point sources

EPA relied on existing Agency data
systems wherever possible. These
include PCS, the CWNS, and NWQI.
EPA data systems were the principal
source of information used to locate
CSSs, CSO outfalls, and SSSs. Data
on the concentration of pollutants
found in CSO and SSO discharges
were developed from a number of
sources, including engineering and
scientific literature, EPA studies,
3-4

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                                                                                      Chapter 3—Methodology
municipal reports including CSO
LTCPs, and interviews with municipal
sewer system owners and operators.
EPA applied the GPPvACSO model
to calculate the annual volume
of CSOs. Documentation of the
GPRACSO model is included as
Appendix E of this report. EPA used
statistical techniques to develop
national estimates of the frequency
and volume of SSOs based on data
reported electronically by states.
Documentation of the statistical
techniques is included in this report as
Appendix G.

3.3.2 Extent of Environmental
     Impacts Caused by CSOs and
     SSOs
This report's analysis of the extent
of environmental impacts caused
by CSOs and SSOs addresses the
following key questions:

•   What is EPA's framework for
    evaluating environmental impacts?

•   What overall water quality impacts
    have been attributed to CSO
    and SSO discharges in  national
    assessments?

•   What impacts on specific designated
    uses have been attributed to CSO
    and SSO discharges in  national
    assessments?

•   What overall water quality impacts
    have been attributed to CSO and
    SSO discharges in state and local
    assessments?

•   What impacts on specific designated
    uses have been attributed to CSO
    and SSO discharges in state and
    local assessments?
•   What factors affect the extent of
    environmental impacts caused by
    CSOs and SSOs?

EPA used federal reports and data as
the primary bases for reporting on
environmental impacts from CSOs
and SSOs on a national level. The
assessment included identification
of water quality impairments and
environmental impacts associated with
CSOs and SSOs with respect to:

•   Impaired stream segments

•   Impaired lakes

•   Impaired estuaries

•   Impaired ocean shoreline

•   Impaired Great Lakes shoreline

•   Beach closures

•   Shellfish bed closures

EPA also  reviewed national resource
assessments from NOAA and non-
governmental organizations such as
the Ocean Conservancy.

CSS location and individual CSO
outfall information published
in the 2001 Report to Congress-
Implementation and Enforcement of
the Combined Sewer Overflow Control
Policy was updated for this Report to
Congress by contacting states and EPA
regions to confirm active CSO permit
data. The data system developed as
part of the 2001 report effort contains
latitude and longitude information for
over 90 percent of the CSO outfalls
currently permitted under the NPDES
program. Having the latitude and
longitude of the CSO outfalls allowed
individual permitted outfalls to be
associated with specific waterbody
segments (called "reaches") within
                                                                                                        3-5

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Water quality data from state 305(b) reports
   were used in gathering information on the
   environmental impacts of CSOs.
              Photo: P. Macneill
the National Hydrography Dataset
(NHD). The NHD is a comprehensive
set of digital spatial data of surface
water features that enables analysis
of water-related data in upstream
and downstream order. Associating
CSO outfall locations with the NHD-
indexed assessed waters allowed for
comparison of the outfalls to known
impairments reported by states, as
required under Clean Water Act
Sections 303(d) and 305(b), and to the
location of protected resources and
sensitive areas. Additional detail on the
CSO analysis using the NHD-indexed
assessed waters is documented in
Appendix F.

SSOs are generally considered
unpermitted discharges, and SSO
locations are not typically included
in NPDES permits. As described in
Chapter 4, SSOs occur for a variety of
reasons and at many locations within
the sewer system, including manholes,
roadways, and pump stations. Further,
some SSOs discharge to land and not
to waters of the United  States. For
these reasons, it was not possible to
conduct a parallel analysis for SSOs
using the NHD. EPA, however, did
develop a simple model for estimating
the likely impact of SSO events on
streams and rivers based on reasonable
assumptions about SSO event
duration, pollutant concentrations, and
waterbody characteristics. Additional
detail on the model is provided in
Appendix H.

National level assessments are unable
to convey the circumstances that
surround an individual CSO or SSO
event, the nature of site-specific
environmental impacts, and the
consequences with respect to water
quality criteria and designated uses.
To account for these localized impacts,
EPA used state and community-
level data to document site-specific
environmental impacts including
water quality standards violations,
shellfish bed closures, and fish kills.
These examples are not comprehensive
but are presented to illustrate the
potential of CSOs and SSOs to
cause  or contribute to impacts and
impairments.

3.3.3  Extent of Human Health
     Impacts Caused by CSOs and
     SSOs
This report's analysis of the extent of
human health impacts caused by CSOs
and SSOs addresses the following key
questions:

•   What pollutants are present in
    CSOs and SSOs that can cause
    human health impacts?

•   What exposure pathways and
    reported human health impacts are
    associated with CSOs and SSOs?

•   Which demographic groups face the
    greatest risk of exposure to CSOs
    and SSOs?

•   Which populations face the greatest
    risk of illness from exposure to the
    pollutants present in CSOs and
    SSOs?

•   How are human health impacts
    from CSOs and SSOs prevented,
    communicated, and mitigated?

•   What factors contribute to
    information gaps in identifying
    and tracking human health impacts
    from CSOs and SSOs?
3-6

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                                                                                       Chapter 3—Methodology
•   What new assessment and
    investigative activities are
    underway?

EPA began its effort to document
human health impacts from CSOs
and SSOs with a literature review. EPA
searched on-line databases including
PubMed, Toxline, LexisNexis, and
the Washington Research Libraries
Consortium for relevant reports and
articles. A series of waterborne disease
outbreak case studies developed from
published literature  is provided in
Appendix I. EPA gathered data on the
general incidence and characteristics
of waterborne diseases as well as on
other impacts associated with  the
pollutants found in  CSO or SSO
discharges. The primary source of
data on the incidence of waterborne
disease in the United States is a joint
surveillance system operated by the
CDC, EPA, and the Council of State
and Territorial Epidemiologists (CDC
2002). Summaries of data collected
by CDC are published periodically
and divided into waterborne-disease
outbreaks resulting from drinking
water, recreational waters, or, in some
cases, cruise ships. EPA also reviewed
reports from non-governmental
organizations for data related to
human health impacts.

EPA identified experts in the fields
of epidemiology, public health
policy, and waterborne  disease
research and invited them to attend
a workshop in August 2002. Experts
represented EPA, CDC, local health
departments, and academia. This
workshop did not constitute an
advisory committee under the Federal
Advisory Committees Act. Rather, it
solicited individual expert opinions
and provided a forum for information
exchange related to this Report to
Congress. EPA shared the results of its
initial data collection at this workshop,
received feedback on and refined the
study methodology, and sought to
ensure that gaps and redundancies in
the research effort did not exist. An
abstract of this workshop is provided
in Appendix B; the summary of this
workshop was published separately
(EPA2002b).

EPA also estimated the illness burden
resulting from exposure  to CSOs
and SSOs at beaches recognized by
state authorities using data from the
BEACH Program's annual survey
(BEACH Survey) and other sources.
EPA analyzed data from  responses
to the 1999-2002 BEACH Surveys
including the number of CSO and
SSO events, number of swimmers,
bacterial concentrations, and CSO
and SSO event duration. An illness
rate derived by Cabelli et al. (1983)
and Dufour (EPA 1984a) was applied
to estimate the number of swimmers
who contract gastrointestinal
illnesses. Additional details describing
this methodology are included in
Appendix J.

EPA also conducted interviews with
public health personnel, including
state or territorial epidemiologists and
local public health officials. States and
communities were selected from each
EPA region in an attempt to ensure
geographic, climatic, and population
variability among communities
interviewed. Nevertheless, the sample
is intentionally biased, targeting
communities that were likely to have
health data related to CSOs and SSOs,
or that employed noteworthy water
quality monitoring or waterborne
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    disease outbreak tracking techniques.
                                    The results of the interviews are
                                    provided in Appendix I.

                                    3.3.4 Evaluation of Technologies
                                          Used by Municipalities to
                                          Address Impacts Caused by
                                          CSOs and SSOs
                                    This report's evaluation of the
                                    technologies used by municipalities
                                    to address impacts caused by CSOs
                                    and SSOs addresses the following key
                                    questions:

                                    •   What technologies are commonly
                                        used to address CSOs and SSOs?

                                    •   How do CSO and SSO controls
                                        differ?

                                    •   What are effective technology
                                        combinations?

                                    •   What are emerging technologies for
                                        CSO and SSO control?

                                    EPA conducted a literature review
                                    and collected reports on CSO and
                                    SSO abatement efforts to evaluate
                                    technologies used by municipalities
                                    to address the impacts of CSO and
                                    SSO discharges. These data included
                                    existing EPA fact sheets, technical
                                    reports covering relevant research, and
                                    wet weather demonstration studies.
                                    EPA also reviewed technical guidance
                                    manuals developed by states, as well
                                    as documentation of local programs,
                                    including CSO LTCPs. The literature
                                    review was supplemented with
                                    discussions of CSO and SSO programs
                                    in interviews with municipal sewer
                                    system owners and operators.

                                    The analysis conducted by EPA
                                    included:
•   Development of 23 technology
    descriptions, included as
    Appendix L of this report, that
    summarize available technologies
    and the factors that influence their
    applicability and effectiveness.

•   Identification of common and
    promising technologies used by
    municipalities to control CSOs
    and SSOs.

EPA and non-EPA experts were
called upon to provide peer review
of technology descriptions, costs,
and performance. It is anticipated
that technology data gathered and
presented in this report's technology
descriptions will support development
of the technology clearinghouse
required by the Wet Weather Water
Quality Act of 2000 (P.L.106-554).

3.3.5 Assessment of Resources
     Spent by Municipalities to
     Address Impacts Caused by
     CSOs and SSOs
This report's assessment of resources
spent by municipalities to  address
impacts caused by CSOs and SSOs
addresses the following key questions:

•   What federal framework exists for
    evaluating resources spent on CSO
    and SSO control?

•   What are the past investments in
    wastewater infrastructure?

•   What has  been spent to control
    CSOs?

•   What has  been spent to control
    SSOs?

•   What does it cost to maintain sewer
    systems?
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                                                                                        Chapter 3—Methodology
•   What are the projected costs to
    reduce CSOs?

•   What are the projected costs to
    reduce SSOs?

•   What mechanisms are available for
    funding CSO and SSO control?

EPA used several of its own reports
and reviewed data from other federal
agencies (e.g., CBO, GAO, and
Census Bureau), states, and non-
governmental organizations to assess
the national investment in wastewater
infrastructure and future needs. EPA
also reviewed data collected for the
2000 CWNS (EPA 2003b). EPA used
a variety of reports to quantify the
resources spent by municipalities to
control CSOs and SSOs, including:

•   EPAs 1996 Clean Water Needs
    Survey (EPA 1997a) and 2000
    CWNS (EPA 2003b)

•   EPAs Clean Water and Drinking
    Water Infrastructure Gap Analysis
    (EPA 2002a)

•   Clean Water State Revolving Fund
    (CWSRF) records

•   Negotiated enforcement actions

•   Interviews with municipal owners
    and operators of sewer systems

•   CSO  LTCPs

•   Recent AMSA, ASCE, and WERF
    reports

EPA also  used a variety of sources
to  assess available mechanisms for
funding CSO and SSO control,
including:

•   EPAs Clean Water and Drinking
    Water Infrastructure Gap Analysis
    (EPA 2002a)
•   EPAs 2001 Report to Congress-
    Implementation and Enforcement
    of the Combined Sewer Overflow
    Control Policy (EPA 200la)

•   EPAs Fact Sheet: Financing Capital
    Improvements for SSO Abatement
    (EPA 200 Ic)

•   EPAs Combined Sewer Overflows:
    Guidance for Funding Options
    (EPA 1995a)

•   GAO reports

•   CSO LTCPs
3.4  How Were Stakeholders
     Involved in the Preparation
     of this Report?

      EPA consulted and worked with
      a broad group of stakeholders
      for this report. EPA conducted
site visits to several EPA regions
and six states; developed a series
of 23 technology descriptions in
cooperation with municipalities; and
sought review of sections  of the report
from experts internal and external
to EPA. States and municipalities
featured in this Report to  Congress
were provided the opportunity
to review information specifically
pertaining to them.

Throughout 2002 and 2003, EPA
met with representatives from key
stakeholder groups such as AMSA,
NRDC, and WEE During these
meetings, EPA presented an overview
of the congressional directive and the
Agency's planned response. EPA then
solicited feedback on its progress.
The comments and suggestions of the
stakeholder groups were incorporated
into the preparation of this report.
In 1999, North Bergen Municipal Utilities
installed numerous mechanical screen
bars and netting systems to control solids
and floatables in CSOs. The facilities cost
$3.3 million and annually cost $57,373 to
operate and maintain (2002 dollars).
            Photo: NJDEP
                                                                                                          3-9

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     As described in Section 3.3.3, EPA
                                     facilitated a workshop for public
                                     health experts in Arlington, Virginia.
                                     Experts represented EPA, CDC, local
                                     health departments, and academia.
                                     Observers of the workshop included
                                     representatives of many stakeholder
                                     groups.

                                     EPA also sponsored stakeholder
                                     meetings during development of
                                     this report in Washington, DC (June
                                     2003), and in Huntington Beach, CA
                                     (July 2003). Participants included
                                     representatives from EPA regions;
                                     states; municipal sewer system owners,
                                     operators, and consultants; national
                                     and local environmental organizations;
                                     professional associations; and public
                                     health experts. The purpose of these
                                     meetings was to:

                                     •   Provide a preliminary description
                                         of the report methodology and
                                         findings

                                     •   Discuss the implications of
                                         preliminary findings

                                     •   Describe data availability and
                                         limitations

                                     •   Solicit additional data on impacts,
                                         costs, and technologies

                                     EPA presented preliminary data on
                                     all aspects of the report, received
                                     comments on data  sources and
                                     data interpretation, and received
                                     input on the context within which
                                     these  findings should be viewed. A
                                     summary of the stakeholder meetings
                                     is provided in Appendix B of this
                                     report. EPA also made presentations
                                     at numerous national meetings and
                                     conferences to  provide progress
                                     reports and updates to stakeholders.
3.5  What Data Considerations
     Are Important?

       The information collection
       strategy used to support
       this report includes several
important data considerations. First
and foremost, EPA based this report
on the collection, compilation,
and analysis of existing data and
program information. No surveys
or field monitoring were conducted
to quantify pollutant concentrations
or environmental and human health
impacts. Similarly, EPA did not
undertake new research or analysis
in the assessment of technologies or
evaluation of costs.

Another important data consideration
is state-to-state differences in the
definition of "CSO event" and "SSO
event" related to threshold volumes
and duration of events that last
beyond midnight or for more than 24
hours. EPA also found that wastewater
backups into buildings, including
private residences, are not typically
tracked by or reported to NPDES
authorities.

A third consideration is that often
the pollutants present in CSOs and
SSOs have numerous sources within a
given watershed.  These sources include
municipal wastewater treatment plants,
storm water runoff, decentralized
wastewater treatment systems,
runoff from agricultural areas, and
wildlife and domesticated animals.
It can be difficult, if not impossible,
to differentiate environmental and
human health impacts caused by CSO
and SSO discharges from those caused
by these other sources.
3-10

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                                                                                       Chapter 3—Methodology
A fourth consideration is the potential
underreporting of waterborne disease
outbreaks. Existing systems for
tracking these outbreaks often lack
sufficient information on the cause
of the outbreak to establish whether
CSOs or SSOs are a suspected source.

A final data consideration is that
the nature of many CSO and SSO
control activities  makes it difficult
to separate their costs from routine
municipal wastewater infrastructure
expenditures. Further, local and state
governments currently fund the
majority of wastewater infrastructure
costs. Mechanisms for compiling
comprehensive national level
information  on expenditures on CSO
and SSO control  do not exist. The
CWSRF is the most comprehensive
source of information on state
and local spending on wastewater
projects. There are, however, several
important limitations to using data
from the CWSRF. First, operation
and maintenance (O&M) costs are
not reported. Second, many CSO
communities do  not participate in the
CWSRF. Third, the CWSRF has  no
separate accounting categories for SSO
control. Moreover, although many
communities and states are making
concerted efforts to report additional
needs for CSO and SSO control, very
few report the cost of implementing
technologies.

Although the above considerations
shaped the approach used to develop
this report, the basic objectives—to
respond to Congress with an accurate
characterization of the volume,
frequency, and location of CSOs and
SSOs; the extent of human health
and environmental impacts caused by
CSOs and SSOs; the resources spent
by municipalities to address these
impacts; and the technologies used to
address impacts—never varied.
3.6  What Quality Control
     and Quality Assurance
     Protocols Were Used?
      EPA applied a detailed data
      verification and interpretation
      process following data
collection. Federal and state data
sets were evaluated for missing and
inconsistent data. Follow-up phone
calls were made to data providers to
verify the accuracy and completeness
of EPAs records. Likewise, site-specific
examples of impacts and technology
application were reviewed by local
officials.

The data taken from reports prepared
by external sources, such as ASCE and
AMSA, were not obtained directly by
EPA and were used as reported. These
data were not subjected to the same
quality control as data collected and
compiled directly by EPA.
3.7  Summary
       Chapters 4 through 9 provide
       a detailed assessment of the
       data and materials collected
in support of this Report to Congress.
The compilation of existing data led to
development of several new analyses
that previously did not exist. These
include:

•  National estimates of the
   frequency and volume of SSOs
•  Analysis of causes of SSOs
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    •   National modeling of SSO events
                                        to estimate violations of water
                                        quality standards

                                    •   Updated CSO permit information
                                        with latitude and longitude for
                                        over 90 percent of CSO outfalls

                                    •   Analysis linking CSO outfall
                                        locations with impaired waters and
                                        sensitive areas through the NHD

                                    •   Modeling to estimate the number
                                        of gastrointestinal illnesses
                                        resulting from exposure to CSOs
                                        and SSOs at BEACH Survey
                                        beaches
3-12

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                             Chapter   4
               Characterization of
                   CSOs and SSOs
       Consistent with the
       congressional directive,
       this chapter provides a
comprehensive description of
CSOs and SSOs with respect to the
location of discharges, the frequency
and volume of discharges, and the
constituents discharged. Similarities
and differences in the character of
CSO and SSO discharges are noted
where they occur. Comparisons of
CSOs and SSOs to other sources of
pollution have been made where
appropriate. The CSO and SSO
characterization information provided
in this chapter is important for
assessing the environmental and
human  health impacts of CSOs and
SSOs.

For purposes of this Report to
Congress, the terms "wet weather" and
"dry weather" are used to distinguish
sewer overflows that are rainfall- or
snowmelt-induced from those that are
not caused by rainfall or snowmelt.
The discussion of CSOs in this report
is limited to wet weather CSOs. That
is, those CSOs that are rainfall- or
snowmelt-induced and occur at
permitted CSO outfalls. Dry weather
CSO discharges are prohibited under
the NPDES program.

SSOs can be induced by rainfall or
snowmelt when excess I/I causes the
conveyance capacity of the SSS to be
exceeded.  SSOs also occur as a result
of other, non-wet weather causes such
as blockages, line breaks, vandalism,
mechanical failures, and power failure.
The terms "wet weather SSOs" and
"dry weather SSOs" are used in this
report to differentiate these two
general types of SSOs because these
events have different characteristics
and respond to different control
strategies. The discussion of SSOs
in this report, including national
estimates of volume and frequency,
does not account for wet weather or
dry weather discharges occurring after
the headworks of the treatment plant,
regardless of the level of treatment,
or backups into buildings caused
by problems in the publicly-owned
portion of the SSS.
In this chapter:
4.1  What Pollutants are in
    CSOs and SSOs?

4.2  What Factors Influence
    the Concentrations of the
    Pollutants in CSOs and
    SSOs?

4.3  What Other Point and
    Nonpoint Sources Might
    Discharge These Pollutants
    to Waterbodies Receiving
    CSOs and SSOs?

4.4  What is the Universe of
    CSSs?

4.5  What are the
    Characteristics of CSOs?

4.6  What is the Universe of
    SSSs?

4.7  What are the
    Characteristics of SSOs?

4.8  How Do the Volumes
    and Pollutant Loads from
    CSOs and SSOs Compare
    to Those from Other
    Municipal Point Sources?
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     4.1  What Pollutants are in CSOs
                                          and SSOs?
                                     T
he principal pollutants present
in CSO and SSO discharges
include:
                                     •   Microbial pathogens

                                     •   Oxygen depleting substances
                                         (measured as BOD5)

                                     •   TSS

                                     •   Toxics

                                     •   Nutrients

                                     •   Floatables

                                     The pollutants in CSOs and SSOs
                                     come from a variety of sources.
                                     Domestic wastewater contains
                                     microbial pathogens, BOD5, TSS,
                                     and nutrients. Wastewater from
                                     industrial facilities, commercial
                                     establishments, and institutions can
                                     contribute additional pollutants such
                                     as fats, oils, and grease (FOG), and
                                     toxic substances including metals
                                     and synthetic organic compounds.
                                     Fungi do not have a major presence
                                     in wastewater (WERF 2003b). Storm
                                     water can also contribute pollutants to
                                     CSSs and, in some instances, SSSs. The
                                     concentration of pollutants in storm
                                     water is generally more dilute than in
                                     wastewater, but can contain  significant
                                     amounts of microbial pathogens,
                                     BOD5, TSS, toxics (notably metals and
                                     pesticides), nutrients, and floatables.
                                     Pollutant concentrations in CSOs and
                                     SSOs vary substantially, not  only from
                                     community to  community and event
                                     to event, but also within a given event.

                                     Descriptions of the pollutants in CSOs
                                     and SSOs are provided in the following
                                     subsections and include comparisons
                                     of concentration data for discharges
from different municipal sources. The
comparisons include, where available,
median pollutant concentrations
and ranges of concentrations found
in treated wastewater, untreated
wastewater, CSOs, wet weather
SSOs, dry weather SSOs, and urban
storm water. The origin and relative
availability of data on pollutant
concentrations in discharges were not
consistent for the different municipal
sources. In general, adequate data
were available to characterize treated
and untreated wastewater, CSOs, and
urban storm water. Monitoring data
to characterize actual wet and dry
weather SSO discharges, however, were
less readily available.

EPA compiled a limited dataset on
pollutant concentrations in wet
weather SSOs as part of municipal
interviews conducted for this Report
to Congress. EPA also identified a
study conducted by the Wisconsin
Department of Natural Resources
that quantified the concentration
of various constituents in wet
weather SSOs from a number of
federal and locally-sponsored studies
(WDNR 2001). The findings of
the WDNR study support the data
EPA collected on wet weather SSOs
for this Report to Congress. For
the purposes of this report, EPA
assumed that dry weather SSOs would
have the same characteristics and
pollutant concentrations as untreated
wastewater.

The descriptions of pollutants in CSOs
and SSOs include an overview of the
types of impacts  typically associated
with these pollutants. The presence of
pollutants in a CSO or SSO discharge
in and of itself is not indicative of
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                                                                       Chapter 4—Characterization of CSOs and SSOs
environmental or human health
impacts. The occurrence of actual
impacts depends on the concentration
of the pollutant present, the volume
and duration of the CSO or SSO
event, the location of the discharge,
the condition of the receiving water at
the time of the discharge, and, in the
case of human health, exposure. More
detailed discussions of environmental
and human health impacts of CSOs
and SSOs are presented in Chapters 5
and 6, respectively.

4.1.1 Microbial Pathogens
Microbial pathogens are
microorganisms that can cause disease
in aquatic biota and illness or even
death in humans. The three major
categories of microbial pathogens
present in CSOs and SSOs are
bacteria, viruses, and parasites. These
microbial pathogens are, for the most
part,  easily transported by water. A
brief  discussion of these pathogens,
including the concentrations present
in various municipal discharges, is
presented below. A more detailed
discussion of pathogens is presented in
Chapter 6 of this report.
Bacteria
The two broad categories of bacteria
associated with wastewater are
indicator bacteria and pathogenic
bacteria. Indicator bacteria are widely
used as a surrogate for microbial
pathogens in wastewater and water
quality assessments. Indicator bacteria
suggest the presence of disease-causing
organisms, but generally are not
pathogenic themselves. The principal
indicator bacteria used to assess water
quality are fecal coliform, E. coll, and
enterococcus. All three are found in
the intestines and feces of warm-
blooded animals.

Fecal coliform concentrations from
municipal sources are presented in
Table 4.1. As shown, concentrations of
fecal coliform found in CSOs and wet
weather SSOs are  generally less than
the concentrations found in untreated
wastewater and dry weather SSOs,
and greater than the concentrations
reported for urban storm water.

Pathogenic bacteria are capable
of causing disease. Examples of
pathogenic bacteria associated with
untreated wastewater, CSOs, and SSOs
Municipal Sources
Untreated wastewater/dry
weather SSOs
Wet weather SSOsa
CSOsb
Urban storm water0
Treated wastewater
Number of
Samples
-
-
603
1,707

Fecal Coliform (colonies/100 ml)
Range Median
1,000,000a-
1 ,000,000,000d
-
3 - 40,000,000
1 -5,230,000

-
500,000
215,000
5,081
<200e
                     Table 4.1
Fecal Coliform
Concentrations in
Municipal Discharges
                                                                               The presence of fecal coliform
                                                                               bacteria in aquatic environments
                                                                               indicates that the water has been
                                                                               contaminated with fecal material
                                                                               of humans or other warm-blooded
                                                                               animals.
aWDNR2001
 Data collected as part of municipal interviews
c Pitt etal. 2003
dNRC1996
e Limit for disinfected wastewater
                                                                                                            4-3

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     include Campylobacter, Salmonella,
                                     Shigella, Vibrio cholerae, and Yersina.

                                     Viruses
                                     More than 120 enteric (intestinal)
                                     viruses may be found in sewage (NAS
                                     1993). Concentrations of viruses
                                     reported in wastewater vary greatly
                                     and depend on the presence and
                                     amount of infection in the population
                                     served by a sewer system, season
                                     of the year, and the methods used
                                     for enumerating the virus counts.
                                     Examples of viruses associated with
                                     untreated wastewater, CSOs, and SSOs
                                     include poliovirus, infectious hepatitis
                                     virus, and coxsackie virus.

                                     Parasites
                                     The common parasites of human
                                     health concern in untreated
                                     wastewater are parasitic protozoa
                                     and helminths (NAS 1993).
                                     Parasitic protozoa include Giardia,
                                     Cryptosporidium, and Entamoeba.
                                     Giardia is the most common
                                     protozoan infection in the United
                                     States (NAS 1993). Giardia has been
                                     detected in treated and untreated
                                     wastewater at levels of 0.0002 to 0.011
                                     cysts per L and 2 to 200,000 cysts
                                     per L, respectively (Payment and
                                     Franco 1993; Yates 1994; NAS 1998;
                                     Rose et al. 200Ib). Cryptosporidium
                                     has also been  detected in treated
                                     and untreated wastewater at
                                     concentrations of 0.0002 to 0.042
                                     oocysts per L  and less than 0.3 to
                                     13,700 oocysts per L, respectively
                                     (Payment and Franco 1993; NAS 1998;
                                     Rose et al. 200la; McCurin and Clancy
                                     2004).

                                     Several recent studies have specifically
                                     investigated the presence of
Cryptosporidium and Giardia in CSOs.
Giardia concentrations ranging from
2 to 225 cysts per L were measured in
samples collected during two overflow
events at each of the six CSO outfalls
(EPA 2003f). A study conducted in
Pittsburgh also found Cryptosporidium
(0 to 30 oocysts per L) and Giardia
(37.5 to 1,140 cysts per L) in CSOs
(States et al. 1997). Given that both
CSOs and SSOs include untreated
wastewater, this suggests that CSOs
and SSOs are also likely to contain
significant concentrations of Giardia,
and possibly Cryptosporidium.

Helminths include roundworms,
hookworms, tapeworms, and
whipworms. These organisms are
endemic in areas lacking inadequate
access to hygiene facilities, including
toilets. Their transmission is generally
associated with untreated sewage and
sewage sludge. However, there is very
little documentation of waterborne
transmission of helminths (NAS
1993).

4.1.2 BOD5
BOD5 is widely used as a measure of
the amount of oxygen-demanding
organic matter in water or wastewater.
The organic matter in sewage is a
mix of human excreta, kitchen waste,
industrial waste, and other substances
discharged into sewer systems.
When significant amounts of BOD5
are discharged to a waterbody, the
dissolved oxygen can be depleted. This
occurs principally through the decay
of organic matter and the uptake of
oxygen by bacteria. The depletion
of dissolved oxygen in waterbodies
can be harmful or fatal to aquatic
life. Low levels of dissolved oxygen
are responsible for many of the fish
4-4

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                                                                           Chapter 4—Characterization of CSOs and SSOs

1 Municipal Sources
Untreated wastewater/dry
weather SSOsa
Wet weather SSOsb
CSOsb
Urban storm water0
Treated wastewater0*


BOD5 (mg/l)
Number of Samples Range
88-451

22 6-413
501 3.9 - 696
3,110 0.4-370



Median
    

42
43
8.6
30


^^^E
BOD5 Concentrations in
Municipal Discharges

concentrations are the same as
those for low dissolved oxygen:
aquatic organisms become stressed,
— suffocate and die



I







 a AMSA 2003a.85 facilities reported annual average BODs concentration data; each facility based its value on an
  unspecified amount of monitoring
 " Data collected as part of municipal interviews
 c Pitt etal. 2003
  Typical limit for wastewater receiving secondary treatment
kills reported and tracked by resource
agencies. BOD5 concentrations from
municipal sources are presented in
Table 4.2. As shown, the median
concentrations of BOD 5 in CSOs and
wet weather SSOs are typically five
times greater than concentrations
found in urban stormwater. Median
BOD5 concentrations in CSOs and
wet weather SSOs are typically 1.3 to
1.4 times greater than concentrations
found in treated wastewater.

4.1.3TSS

TSS  is a measure of the small particles
of solid pollutants that float on the
surface of, or are suspended in, water
or wastewater. TSS in wastewater
includes a wide variety of material,
such as decaying plant and animal
matter, industrial wastes, and silt.
High concentrations of TSS can
cause problems for stream health
and aquatic life. TSS can clog fish
gills, reduce growth rates, decrease
resistance to disease, and impair
reproduction and larval development.
The deposition of solids can damage
habitat by filling spaces between
rocks that provide shelter to aquatic
organisms. TSS can accumulate in
the immediate area of CSO and
recurrent SSO  discharges, creating
turbid conditions that smother the
eggs of fish and aquatic insects.
TSS concentrations from municipal
sources are presented in Table 4.3. As
shown, the median concentration of
TSS in CSOs and wet weather SSOs is
Municipal Sources
Untreated wastewater/dry
weather SSOsa
WetweatherSSOsb
CSOsb
Urban storm water0
Treated wastewaterd
Number of Samples
-
27
995
3,396

TSS (mg/l)
Range
118-487
1 0 - 348
1 - 4,420
0.5 - 4,800

Median
-
91
127
58
30
  a AMSA 2003a. 121 facilities reported annual average TSS concentration data; each facility based its value on an
  unspecified amount of monitoring
   Data collected as part of municipal interviews
  0 Pitt etal. 2003
  " Typical limit for wastewater receiving secondary treatment
                      Table 4.3
TSS Concentrations in
Municipal Discharges
                                                                                    Over the long-term, the deposition
                                                                                    of solids in the immediate area of
                                                                                    CSO and SSO discharges can
                                                                                    damage aquatic life habitat.
                                                                  ea of
                                                                                                                  4-5

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Table 4.4
    Cadmium and Copper
    Concentrations in
    Municipal Discharges

    For many municipalities, the largest
    source of copper in wastewater is
    corrosion of copper pipes (PARWQCP
    1999). Other sources include
    industrial discharges,copper-based
    root killers,and cooling water
    discharges.
   Table 4.5
    Lead and Zinc
    Concentrations in
    Municipal Discharges
    Municipal wastewater treatment
    facilities are reported to be the
    largest point source for zinc
    discharges to surface waters
    (WSDOH1996).
higher than concentrations in urban
storm water.

4.1.4 Toxics
Toxics are chemicals or chemical
mixtures that, under certain
circumstances of exposure, present an
environmental or human health risk.
Toxics include metals, hydrocarbons,
and synthetic organic chemicals.
Concentrations of toxics in wastewater
can be a concern in industrialized
areas or where monitoring data
indicate potential toxicity (Moffa
1997). Storm water contributions
to CSOs in urbanized areas can also
contain significant concentrations
of hydrocarbons and metals. Metals
concentrations from municipal sources
are presented in Tables 4.4 and 4.5.

In general, environmental problems
related to toxicity fall into two
categories: chronic or long-term
exposure to toxics causing reduced
growth and reproduction, and acute
Municipal
Sources
Untreated
wastewater/dry
weather SSOsa
Wet weather
SSOs
CSOsb
Urban storm
water0
Treated
wastewaterd
Cadmium (|Jg/l)
Number of Range Median
Samples

    


401
2,582
465

0.1 -101


0.16-30 2
0.04-16,000 1
0.01 - 3.0 0.04
Number of
Samples

~


346
2,728
596
Copper (|Jg/l)
Range

1 .8 - 322


10-1,827
0.6-1,360
2.8-16.0
Median

~


40
16
5.2
                                         a AMSA 2003a. 101 and 109 facilities reported annual average Cd and Cu concentrations, respectively; each facility
                                          based its value on an unspecified amount of monitoring
                                         "Data collected as part of municipal interviews
                                         c Pitt etal. 2003
                                         dWERF2000
Municipal
Sources
Untreated
wastewater/dry
weather SSOsa
Wet weather
SSOs
CSOsb
Urban storm
waterc
Treated
wastewaterd
Number of
Samples

~
-
438
2,954
21
Lead (|Jg/l)
Range Median

0.5 -250
-
5-1,013 48
0.2-1200 16
0.2 - 1 .4 0.6
Number of
Samples

~
-
442
3,016
530
Zinc(|Jg/l)
Range

9.7-1,850
-
1 0 - 3,740
0.1 - 22,500
20.0-57.5
Median

~
159
156
117
51.9
                                        a AMSA 2003a. 106 and 109 facilities reported annual average Pb and Zn concentrations, respectively; each facility based
                                         its value on an unspecified amount of monitoring
                                         Data collected as part of municipal interviews
                                        c Pitt etal. 2003
                                        d WERF 2000
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                                                                         Chapter 4—Characterization of CSOs and SSOs
or short-term exposure at higher
concentrations causing increased
mortality. Chronic effects are subtle
and difficult to identify, but can be
observed by lower productivity and
biomass (numbers of organisms),
bioaccumulation of chemicals, or
reduced biological diversity. Acute
effects can be observed as immediate
fish kills or  severely reduced biologic
diversity.

4.1.5 Nutrients
Nutrients is the term generally
applied to nitrogen and phosphorus.
Untreated wastewater contains
significant amounts of nitrogen
and phosphorus from domestic and
industrial sources. CSSs also receive
nutrients contained in urban runoff
from street  litter and chemical
fertilizers applied to landscaped
areas, lawns, and gardens. Nutrients
are essential to the growth of plants
and animals. Excess amounts of
nitrogen and phosphorus can cause
rapid growth of algae and nuisance
plants, as well as eutrophic conditions
that can lead to oxygen depletion.
Total phosphorus and total kjeldahl
nitrogen (a measure of ammonia
and organic nitrogen) concentrations
from municipal sources are presented
in Table 4.6. As shown for total
phosphorus, wet weather SSO
concentrations are roughly equivalent
to treated wastewater concentrations
and are approximately one-third of
untreated wastewater concentrations.
Total phosphorus concentrations
in CSO and urban stormwater are
generally less than those in wet
weather SSOs.

4.1.6 Floatables
Floatables is the term used to describe
the trash, debris, and other visible
material  discharged when sewers
overflow. In SSSs, floatables generally
include sanitary products  and other
wastes commonly flushed down a
toilet. In CSSs, floatables include litter
and detritus that accumulate on streets
and other paved areas that wash into
CSSs during rainfall or snowmelt
events. Floatables can have an adverse
impact on wildlife, primarily through
entanglement or ingestion. Floatables
Municipal
Sources
Untreated
wastewater/dry
weather SSOsa
Wet weather
SSOsb
CSOsc
Urban storm
waterd
Treated
wastewater3
Total Phosphorus
Number of Range
Samples
__

-
43
3,283
72

1.3-15.7

~
0.1 - 20.8
0.01 -15.4
0.07 - 6

(mg/l)
Median
5.8

2
0.7
0.27
1.65

Total Kjeldahl Nitrogen (mg/l)
Number of Range Median
Samples
59

~
373
3,199
64

11.4-61

~
0-82.1
0.05 - 66.4
0.5 - 32

33

~
3.6
1.4
3.95

                                                                                                      Table 4.6
                                                                                  Nutrient Concentrations
                                                                                  in Municipal Discharges

                                                                                  Nutrient additions can cause
                                                                                  increased algae or aquatic weed
                                                                                  growth that, in turn, can deplete
                                                                                  dissolved oxygen, reduce biologic
                                                                                  diversity, worsen aesthetics,and
                                                                                  impair use for water supply (Moffa
                                                                                  1997).
a AMSA2003a. 59 facilities reported annual average total PandTKN concentrations; each facility based its value on an
 unspecified amount of monitoring
bWDNR2001
c Data collected as part of municipal interviews
d Pitt etal. 2003
                                                                                                              4-7

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    can also contribute to aesthetic impacts
                                    in recreation areas.

                                    An extensive monitoring program
                                    conducted in New York City suggests
                                    that more than 90 percent of
                                    floatables in the city's CSOs originate
                                    as street litter (NYCDEP 1997). The
                                    monitoring program specifically found
                                    that street trash, including plastics,
                                    polystyrene, and paper, accounted
                                    for approximately 93 percent of the
                                    floatables discharged. Personal hygiene
                                    items and medical materials accounted
                                    for approximately one percent of all
                                    floatables discharged into New York
                                    Harbor through CSOs. The remaining
                                    six percent of floatable items included
                                    glass, metal, wood, and cloth.
                                    4.2 What Factors Influence
                                         the Concentrations of the
                                         Pollutants in CSOs and
                                         SSOs?
                                           The pollutant concentrations
                                           associated with CSO and SSO
                                           discharges are highly variable.
                                    Pollutant concentrations vary not
                                    only from site to site and event to
                                    event, but also within a given overflow
                                    event. Brief descriptions of some of
                                    the factors that influence pollutant
                                    concentrations in CSOs and SSOs  are
                                    described in the following subsections.

                                    4.2.1 Factors Influencing Pollutant
                                         Concentrations in CSOs
                                    The relative amounts of domestic,
                                    commercial, and industrial wastewater,
                                    and urban storm water carried by a
                                    CSS during specific wet weather events
                                    are the primary driver of pollutant
                                    concentrations in CSOs. Other factors
that contribute to the variability
include:

•   Elapsed time since the wet weather
    event began, with higher pollutant
    concentrations expected during
    the early stages of a CSO event
    (often termed the "first flush");

•   Time between the current
    and most recent wet weather
    events, with higher pollutant
    concentrations expected in CSOs
    occurring after lengthier dry
    periods; and

•   Intensity and duration of the wet
    weather event.

The sudden rush of flow into a CSS
brought on by rainfall, or in some
instances, snowmelt, can create a
first flush effect. The first flush effect
occurs when pollutants washed from
city streets and parking lots combine
with pollutants re-suspended from
settled deposits within the CSS.
This combination can produce
peak pollutant concentrations at
the beginning of the CSO event,
particularly if rainfall is intense. First
flush effects are typically observed
during the first 30 to 60 minutes of
a CSO discharge (Moffa 1997). They
are generally more pronounced after
an extended dry period and in sewer
systems with low gradients (slope).
Many CSO control programs have
been designed specifically to capture
the first flush.

4.2.2 Factors Influencing Pollutant
     Concentrations in SSOs
Wastewater flows generated by
domestic, commercial, and industrial
sources fluctuate on diurnal, weekend/
weekday, and seasonal cycles. Periods
4-8

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                                                                     Chapter 4—Characterization of CSOs and SSOs
of low and high flows are associated
with water demand and use. SSSs
carry varying amounts of I/I during
wet weather periods, when the ground
is saturated, and when the water table
is elevated. The amount of I/I entering
an SSS is influenced by:

•   Age and condition of SSS
    components

•   Local use of SSS for roof and
    foundation drainage

•   Location of sewer pipes relative to
    the water table

•   Characteristics of recent rainfall
    events

•   Soil type and antecedent soil
    moisture conditions

The amount of I/I, in turn, influences
the concentration of pollutants in SSO
discharges.

Dry weather SSOs consist mainly of
domestic, commercial, and industrial
wastewater, with limited amounts
of I/I. Therefore, the pollutant
concentrations in dry weather SSOs
are  most heavily influenced by the
relative contribution from domestic,
commercial, and industrial customers
to the total flow.
4.3  What Other Point and
     Nonpoint Sources Might
     Discharge These Pollutants
     to Waterbodies Receiving
     CSOs and SSOs?
       CSOs and SSOs contribute
       to pollutant loadings where
       discharges occur. Waterbodies
also receive pollutants of the types
found in CSOs and SSOs from other
point and nonpoint sources including:

•  Wastewater treatment facilities
•  Decentralized wastewater
   treatment systems
•  Industrial point sources
•  Urban storm water
•  Agriculture
•  Domestic animals and wildlife
•  Commercial and recreational
   vessels
The contribution of pollutant loads
from CSOs and SSOs relative to
other point and nonpoint sources
varies widely depending on the
characteristics of the waterbody and
the volume, frequency, and duration
of CSO and SSO events. Each of these
sources is discussed briefly below.
 In 1999, the Augusta Sanitary District completed the first phase of a $40-million
 five-phase CSO Long Term Control Plan as part of an Administrative Order (AO).
 Phase One involved a $12.2-million upgrade of the wastewater treatment plant to
 increase the treatment capacity and to better treat excess wet weather flows from
 the CSS. Prior to the upgrade,excess wet weather flows received minimal treatment
 (sometimes bypassing primary and secondary treatment processes entirely) and
 were not disinfected prior to discharge. Since completion of the treatment plant
 upgrade, the District bypasses secondary treatment processes only during wet
 weather events, and has the capacity to provide primary treatment, chlorination,
 and dechlorination to the bypassed flows. Bypassing frequency has decreased by
 70 percent.
                                                 CSO-related Bypass at
                                        Wastewater Treatment Facility:
                                                          Augusta, ME
                                                                                                         4-9

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Report to Congress on the Impacts and Control ofCSOs and SSOs
 Wet Weather Bypass at
 Wastewater Treatment Facility
 Serving SSS:
 Jefferson County, AL
The Village Creek Wastewater Treatment Plant  in Jefferson County, Alabama,
routinely experienced peak wet weather flows greater than 10 times its annual
average flow of 40 mgd. Due to extreme peak wet weather flows in the system,
untreated wastewater was frequently diverted from the Village Creek plant and
discharged without treatment. Between 1997 and 2001, excess  wastewater flow
was diverted and discharged an average of 41 times  per year. Under a Consent
Decree issued in  1996, Jefferson Country initiated corrective actions to address
diversions of untreated wastewater from the Village Creek facility, as well as other
problems within the system.The total cost for the improvements are estimated to
approach $2.5 billion.
                                     4.3.1 Wastewater Treatment
                                          Facilities
                                     Wastewater treatment facilities
                                     are designed to receive domestic,
                                     commercial, and industrial wastewater,
                                     and to treat it to the level specified in
                                     an NPDES permit. Permits typically
                                     define  effluent concentration limits
                                     for BOD5 and TSS, and for indicator
                                     bacteria (typically fecal coliform, E.
                                     coli, or enterococci) when disinfection
                                     is required. Wastewater treatment
                                     facilities that discharge to impaired
                                     or sensitive waters may have more
                                     stringent effluent limits for BOD5,
                                     TSS, or additional parameters (e.g.,
                                     additional reduction of nutrients and
                                     metals).

                                     Wastewater treatment facilities in
                                     the United States are estimated to
                                     contribute to the impairment of
                                     four percent of the nation's assessed
                                     rivers and streams; five percent of
                                     the nation's assessed lakes, ponds,
                                     and reservoirs; and 19 percent of
                                     assessed estuaries (EPA 2002c). The
                                     concentrations of fecal coliform,
                                     BOD5, TSS, metals, and nutrients
                                     in treated and untreated wastewater
                                     can be compared using the tables in
                                     Section 4.1 of this report.
                                     Untreated and Partially Treated
                                     Discharges from Wastewater
                                     Treatment Facilities
                                     In CSSs and to a lesser degree in
                                     SSSs, flows to wastewater treatment
                                     facilities increase during periods of
                                     wet weather. Significant increases in
                                     influent flow caused by wet weather
                                     conditions (e.g., due to I/I into the
                                     sewer system) can create operational
                                     challenges for treatment facilities
                                     and can adversely  affect treatment
                                     efficiency, reliability, and control
                                     of treatment processes. Excess wet
                                     weather flows can  result in discharges
                                     of untreated or partially treated
                                     wastewater at the treatment facility.

                                     Treatment plants are sometimes
                                     designed to route peak wet weather
                                     flows that exceed capacity around
                                     secondary treatment units and then
                                     blend them with treated wastewater to
                                     meet permit limits. Volumes associated
                                     with wet weather discharges can be
                                     substantial.

                                     Treatment facilities serving CSSs
                                     may be allowed to discharge partially
                                     treated wastewater (e.g., wastewater
                                     having received primary treatment
                                     and disinfection, if necessary) during
                                     periods of wet weather, according to
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                                                                       Chapter 4—Characterization of CSOs and SSOs
the terms of their permit. Untreated
wet weather discharges at treatment
facilities serving CSSs are not
permitted and are required to be
reported to the NPDES authority
within 24 hours of their occurrence.

With rare exception, treatment
facilities serving SSSs are only
permitted to discharge wastewater that
has received appropriate treatment.
Discharges of untreated wastewater
at treatment facilities serving SSSs are
required to be reported to the NPDES
authority within 24 hours of their
occurrence.

4.3.2   Decentralized Wastewater
       Treatment Systems

Decentralized wastewater treatment
systems are on-site or clustered
wastewater systems used to treat and
dispose of relatively small volumes
of wastewater, generally from private
residences and businesses that are
located in  close proximity to each
other. These systems serve individual
residences as well as trailer parks,
recreational vehicle parks, and
campgrounds. They are commonly
referred to as septic systems, private
sewage systems, or individual
sewage systems. Some decentralized
systems are designed to have a
surface discharge. Approximately
25 percent of the total population
of the United States is served by
decentralized wastewater treatment
systems, and about 33 percent of
new  residential construction employs
this type of treatment (EPA 2003g).
The 2001 American Housing Survey
for the United States reported
that approximately 6 percent of
decentralized wastewater treatment
systems fail annually. Depending
on assumptions about persons per
household and water use, these failures
may result in improper treatment
of 180 to 396 million gallons of
wastewater daily, or 66 to 144 billion
gallons discharged annually. Failing
decentralized wastewater treatment
systems can contribute to pathogen
and nutrient contamination of surface
water and groundwater (Bowers 2001).

4.3.3 Industrial Point Sources
Industrial point sources include non-
municipal industrial and commercial
facilities that treat and discharge
wastewater, with attendant pollutants,
directly to receiving waters. Unlike
municipal wastewater treatment
facilities, the types of raw materials,
production processes, and treatment
technologies utilized by industrial
and commercial facilities vary
widely. Consequently, the pollutants
discharged by industrial point sources
vary considerably and are dependent
on specific facility characteristics (EPA
1996b). In addition to wastewater,
industrial point sources can also
collect and discharge  storm water
runoff generated at their facility.
Industrial point sources are regulated
under the NPDES point source
and storm water programs. Many
discharges are governed by industry-
specific effluent guidelines. Industrial
point sources can be a major source
of pollutants, particularly nutrients
and toxics, in waters receiving the
discharges.

4.3.4 Urban Storm Water
Urban storm water runoff occurs
when rainfall does not infiltrate into
the ground or evaporate. Urban storm
water runoff flows onto adjacent
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     land, directly into a waterbody, or
                                     is collected and routed through a
                                     separate storm sewer system. Urban
                                     storm water runoff is principally
                                     generated from impervious surfaces
                                     such as city streets and sidewalks,
                                     parking lots, and rooftops. In
                                     general, the degree of urbanization
                                     increases the variety and amount of
                                     pollutants carried by storm water
                                     runoff. Although concentrations of
                                     specific pollutants in urban storm
                                     water runoff vary widely, the most
                                     common pollutants include microbial
                                     pathogens from pet and wildlife
                                     wastes; TSS; metals, oil, grease, and
                                     hydrocarbons from motor vehicles;
                                     and nutrients, pesticides, and
                                     fertilizers from lawns and gardens
                                     (EPA2003h).

                                     Urban storm water discharges are a
                                     leading cause of impairment of the
                                     nation's surface waters (EPA 2002c).
                                     Storm water is estimated to contribute
                                     to the impairment of 5 percent of
                                     assessed river miles nationwide, 8
                                     percent of assessed lake acres, and 16
                                     percent of assessed estuarine square
                                     miles (EPA 2002). EPA has estimated
                                     that approximately 27.6 billion gallons
                                     of storm water runoff are generated
                                     daily from urbanized areas nationwide
                                     (EPA2002c).

                                     4.3.5 Agriculture
                                     Agriculture is a major source of
                                     pollution in the United States and
                                     the leading source of impairment
                                     in assessed rivers and streams, as
                                     well as in assessed lakes, ponds, and
                                     reservoirs (EPA 2002c). Agricultural
                                     sources that contribute pollutant
                                     loads to waterbodies include row
                                     crops, pastures, feed lots, and holding
                                     pens. Agricultural practices that add
pollution include over-application
of manure, other fertilizers, and
pesticides; tillage practices that leave
the earth exposed to erosion; and
pasture and range practices that
provide livestock with direct access
to waterways. These practices add
microbial pathogens, BOD 5, TSS,
toxics, and nutrients to runoff from
agricultural areas. More than 150
microbial pathogens found  in livestock
manure are associated with health
risks to humans. This includes the
microbial pathogens that account
for more than 90 percent of food
and waterborne diseases in humans
(EPA 2003i). These pathogens are
Campylobacter, Salmonella (non-
typhoid), Listeria monoctyogenes,
pathogenic E. coll, Cryptosporidium,
and Giardia.

4.3.6 Domestic Animals and
     Wildlife
Although livestock are believed to be
the greatest contributor of animal
waste to receiving waters, loads from
pets, wild birds, and other mammals
can be significant (EPA 200Id). This
is particularly true in urban areas
where there are no livestock, but pets
and wildlife are common. In addition,
the feces of waterfowl (e.g.,  geese
and ducks) can contribute significant
nutrient loads to waterbodies (Manny
et al. 1994).

Animal waste associated with pets,
wild birds, and small mammals can
present significant risk to humans.
Between 15 and 50 percent of pets and
10 percent of mice and rats may be
infected with Salmonella (NAS  1993).
In addition, many wildlife species are
reservoirs of microorganisms that can
be pathogenic to humans. Beaver and
4-12

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                                                                      Chapter 4—Characterization of CSOs and SSOs
deer are large contributors of Giardia
and Cryptosporidium, respectively
(EPA 200Id). Waterfowl such as geese,
ducks, and heron can also contaminate
surface waters with microbial
pathogens (Graczyk et al.  1998).

Bacteria source-tracking can be
employed to establish the  relative
contribution of human and non-
human sources to levels of indicator
bacteria measured in a given
waterbody. For example, watershed
studies in the Seattle, Washington
area found that nearly 20 percent of
bacteria in receiving water samples
were traceable to dogs (EPA 200Id). A
study of Four Mile Run in Northern
Virginia found that waterfowl
accounted for 37 percent,  humans
and dogs together accounted for 26
percent, and raccoons accounted for
15 percent of the bacteria. Deer and
rats contributed smaller percentages
(NVPDC2000).

4.3.7 Commercial and Recreational
     Vessels
Improper disposal of sewage by
commercial and recreational vessels
can spread disease, contaminate
shellfish beds, and lower oxygen levels
in receiving waters (CFWS 2003).
Improper disposal is also a problem
in marinas and harbors, despite
the prohibition on the discharge of
untreated sewage in the Great Lakes,
in all navigable rivers, and within
three miles of the U.S. coastline.
Improper disposal of sewage occurs
largely as a result of inadequate
facilities on-board vessels  and at
docks, and a lack of education about
safe handling and disposal of sewage.
Boaters often illegally dump or dispose
sewage improperly in marina toilets,
overloading them (Baasel-Tillis
1998). Impacts due to pollution from
commercial and recreational vessels
are highly localized.
4.4  What is the Universe of
     CSSs?

          Most CSSs are located in
          the Northeast and Great
          Lakes regions. Thirty-
two states (including the District of
Columbia) have permitted CSSs in
their jurisdiction. As of July 2004,
these 32 states had issued 828 active
CSO permits to 746 communities.
These permits regulate 9,348 CSO
discharge points. The distribution
of CSO permits and CSO outfalls in
each state are shown in Figures 4.1
and 4.2, respectively. About 46 million
people are served by CSSs, which
include an estimated 140,000 miles of
municipally-owned sewers.

CSO permits have been issued to the
owners and operators of two types of
CSSs:

•   CSSs owned and operated by
    the same entity that owns and
    operates the receiving POTW; and

•   CSSs that convey flows to a POTW
    owned and operated by a separate
    entity under a different permit.

Communities that operate and
maintain a sewer system but send
wastewater flows to a treatment plant
owned and operated by another entity
are referred to as "satellite systems."
The 828 active CSO permits include
616 combined systems with POTWs,
176 satellite systems, and 36 systems
that EPA has been unable to classify
due to insufficient data.
                                                                                                         4-13

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Report to Congress on the Impacts and Control of CSOs and SSOs
        Figure 4.1
          Distribution of CSO Permits by Region and by State

          More than half of the nation's 828 active CSO permits are held by communities in
          four states: Illinois, Indiana,Ohio,and Pennsylvania.
                Total Permits: 828
                                        108 107
                         11
                    AK OR WA
                                 SD
                                             46
                                                             68
                                        IL  IN Ml MN OH Wl
                    Region 10    Region 8
         Region 5
         NJ NY
        Region 2
                                                                       39
                        11    :ih;;
                                                                  CT MA ME NH Rl  VT
   Region 1
                    Region 9
Region 7
Region 4
                                                                           56





                                                               11-    3


                                                              DC DE MD PA VA WV
Region 3
4-14

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                                                                     Chapter 4—Characterization of CSOs and SSOs
                                                                                           Figure 4.2
                        Distribution of CSO Outfalls by Region and by State

                        Similar to the distribution of CSO perm its, CSO outfalls are also concentrated in the
                        Northeast and Great Lakes regions.
                                               1,378
                                                              Total Outfalls: 9,348
                                                              1,032
876
T-
224
86 1
!•! 1
2



262
h


255
I 1


278
207
1 40 76 62
1 . • •
AK OR WA SD IL IN Ml MN OH Wl NJ NY CT MA ME NH Rl VT
Region 10 Regions Regions Region 2 Region 1
        Region 9
IA KS MOaNE
 Region 7
GA KY IN
Region 4
DC DE MD PA VA WV
     Region 3
aSince the 2001 Report to Congress—Implementation and Enforcement of the Combined Sewer Overflow Control Policy, the Missouri Department
of Natural Resources has been working with its CSO communities to confirm the number of CSO outfalls for each NPDES permit.The significant
increase in the number of CSO outfalls in Missouri is a result of this effort.
                                                                                                              4-15

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     NPDES permittees are classified by
                                     regulatory authorities as "major"
                                     or "minor" dischargers. Facilities
                                     are classified as "major" when the
                                     wastewater treatment plant is designed
                                     to discharge more than 1 mgd.
                                     Facilities with flows less than 1 mgd
                                     may be classified as "major" when the
                                     NPDES authority determines that
                                     a specific permit needs a stronger
                                     regulatory focus. Classification as
                                     "major" is used to guide permitting,
                                     compliance, and enforcement activities
                                     to ensure that larger sources of
                                     pollutants are given priority. Major
                                     facilities are typically inspected
                                     annually and must report monthly
                                     effluent concentrations and loadings.
                                     Based on information available in
                                     EPA's PCS for the 828 active CSO
                                     permits, EPA found that 57 percent
                                     were classified as major facilities.
                                     Facilities classified as "minor" usually
                                     have design flows less than 1 mgd.

                                     The CSO Control Policy established
                                     a population threshold of 75,000 to
                                     define small jurisdictions that may
                                     be held to  less rigorous requirements
                                                                        in developing an LTCP for CSO
                                                                        control. EPA does not have population
                                                                        data by permit for CSSs. EPA has
                                                                        previously estimated that average daily
                                                                        wastewater flows are approximately
                                                                        100 gallons per capita per day (EPA
                                                                        1985). As a surrogate, plants treating
                                                                        7.5 mgd (75,000 x 100 gallons per
                                                                        capita per day) are used to define the
                                                                        upper limit of a small jurisdiction.

                                                                        EPA obtained flow data for 398 of
                                                                        the 616 permits for CSSs  that include
                                                                        a POTW. As shown in Figure 4.3, 73
                                                                        percent of CSO permits (with available
                                                                        flow data) are for POTWs with design
                                                                        flows less than 7.5 mgd, and therefore
                                                                        an estimated service population of less
                                                                        than 75,000.
                                                                        4.5  What are the
                                                                             Characteristics of CSOs?
                                                                               An accurate characterization
                                                                               of the frequency, volume, and
                                                                               location of CSO discharges,
                                                                        coupled with information on the
                                                                        pollutants present in the discharges, is
  Figure 4.3
   Distribution of POTW
   Facility Sizes Serving CSSs

    'OTWs serving CSSs are designed to
   treat flows ranging from 0.1 mgd to
   1,600 mgd, but most treat less than
    .5 mgd.
7
                                                      Distribution of POTW Treatment Capacities
                                            mgd
                                                                                                30%
                                                                        13%
                                                                                      24%
                                                                                                  Small
                                                                                               Jurisdictions
                                                                                                  73%
                                                                  9%
4-16

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                                                                       Chapter 4—Characterization of CSOs and SSOs
needed to fully evaluate the potential
for environmental and human health
impacts from CSOs. This section
describes the process EPA used to
characterize CSO discharges at the
national level.

4.5.1 Volume of CSOs
EPA applied the previously developed
GPRACSO model to estimate
the volume and pollutant loads
attributable to CSOs nationwide. A
summary of the GPRACSO model and
how it was used to derive the national
estimates presented in this report is
provided in Appendix E.

The GPRACSO model was applied to
estimate the CSO volume associated
with three planning-level scenarios.
Corresponding BOD5 loads associated
with the CSO volumes were also
estimated. The three scenarios
modeled are:

•   Baseline scenario (1992)
    representing CSO volumes and
    pollutant loads prior to issuance
    of the CSO Control Policy.
                  •   Current implementation scenario
                      (2002) representing estimates
                      of CSO volumes and pollutant
                      loads with CSO controls that are
                      currently in place.

                  •   Full CSO Control Policy
                      implementation scenario
                      representing future CSO volume
                      and pollutant loads assuming
                      full implementation of the CSO
                      Control Policy (e.g., four to six
                      untreated overflows per year).

                  The three scenarios are compared in
                  terms of CSO volume and pollutant
                  load reduction in Table 4.7. National
                  estimates of the annual volume of
                  combined wastewater generated and
                  treated are added for context. The
                  volume of combined wastewater
                  generated represents the volume of
                  domestic, commercial, and industrial
                  wastewater and storm water runoff
                  that enters CSSs across the nation
                  during wet weather periods under
                  annual average conditions. The
                  estimate  of combined wastewater
                  treated represents the amount of
                  combined wastewater that receives the
                  minimum treatment specified under
 Scenario
 Baseline, prior to
 CSO Control Policy
                             Annual Volume
                            (billion gallons/yr)
Combined
Wastewater
Generated
  4,250
Combined
Wastewater
 Treated
  3,180
Untreated
  CSO
Discharged
  1,070
    Annual Load
 (million pounds/yr)

BOD5 from Untreated CSO
     Discharges
        445
 Current level of CSO
 control
  4,230
  3,380
  850
 Full CSO
 Control Policy
 implementation
  4,230a
 4,070a
  160
        367
        159
 a Assumes that the areas and populations served by CSSs will remain relatively constant at current levels through full
 implementation of the CSO Control Policy.
Volume Reduction
Estimates Based on
Implementation of CSO
Control Policy

EPA's GPRACSO model was used to
evaluate the potential reduction  in
discharges of untreated CSO and
the attendant 6005 loads based
on current and future expected
implementation of CSO controls.
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    the CSO Control Policy (primary
                                    clarification or equivalent and
                                    disinfection, as necessary). The volume
                                    of combined wastewater treated under
                                    the three scenarios is not constant,
                                    as each reflects a different control
                                    condition.

                                    EPA took a conservative approach
                                    in using the GPRACSO model to
                                    estimate reductions in CSO volumes
                                    and BOD5 loads. Only structural CSO
                                    controls, such as expanded capacity at
                                    a wastewater treatment facility, were
                                    considered. Non-structural controls,
                                    such as enhanced pretreatment
                                    requirements, inflow reduction,
                                    and pollution prevention, were not
                                    simulated with the GPRACSO model.
                                    The fact that sewer separation can
                                    lead to increased storm water volumes
                                    and loads was not factored into this
                                    analysis.

                                    The GPRACSO model estimates
                                    that prior to issuance of the CSO
                                    Control Policy (baseline scenario)
                                    approximately 1,070 billion gallons
                                    of untreated CSO and 445 million
                                    pounds of BOD5 were discharged
                                    annually from CSSs. Under the
                                    current implementation scenario,
                                    the GPRACSO model estimates that
                                    approximately 850 billion gallons
                                    of untreated combined sewage and
                                    367 million pounds of BOD5 are
                                    discharged from CSSs annually. The
                                    GPRACSO  model estimates that the
                                    national CSO volume and associated
                                    BOD5 loads have decreased by 21
                                    percent and 18 percent, respectively,
                                    since issuance of the CSO Control
                                    Policy.

                                    The full CSO Control Policy
                                    implementation scenario assumes
                                    that all CSO communities have, at a
minimum, implemented the controls
necessary to reduce the frequency of
CSO events to an average of four to
six untreated CSO events per year. The
actual level of control needed to meet
water quality standards may require
measures beyond those needed for an
average of four to six events per year.
When full implementation is achieved
under this scenario, the GPRACSO
model predicts that approximately
160 billion gallons of untreated CSO
and 159 million pounds of BOD5
would be discharged annually from
CSSs. Reaching a full implementation
of CSO control will require
communities with CSSs to provide
the equivalent of primary clarification
and disinfection, as necessary, to
an estimated additional 690 billion
gallons of currently untreated CSO
discharges.

4.5.2 Frequency of CSOs
In the CSO Control Policy, a "CSO
event" is defined as a discharge from
one or more CSO outfalls in response
to a single wet weather event. The
frequency of CSO events in a given
community can range from zero
events to 80 or more per year. The
frequency of CSO events in a given
community can also vary considerably
from year to year depending on
weather conditions. The CSO Control
Policy specifies that the evaluation
of CSO control alternatives and
development of LTCPs should be
on a system-wide, annual average
basis. Annual average conditions  are
typically established by performing a
statistical analysis on local, long-term
precipitation records that consider the
number of precipitation events per
year, maximum rainfall intensity, and
average storm duration.
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                                                                      Chapter 4—Characterization of CSOs and SSOs
In addition to estimating national
CSO volumes and pollutant loads,
the GPRACSO model was used to
estimate the frequency of CSO events.
Under the baseline scenario, prior to
issuance of the CSO Control Policy,
the GPRACSO model estimates that
there were approximately 60,000 CSO
events per year nationwide. Under
the current implementation scenario
with the current level of CSO control,
the GPRACSO model estimates
there are 43,000 CSO events per year
nationwide, a reduction of 28 percent
since the issuance of the CSO Control
Policy.

4.5.3 Location of CSOs
A key EPA initiative undertaken
as part of this Report to Congress
was to update, verify, and digitally
georeference the inventory of
CSO outfalls documented as part
of EPAs 2001 Report to Congress-
Implementation and Enforcement of
the CSO Control Policy. This effort
resulted in establishing latitude and
longitude coordinates for more than
90 percent of CSO outfalls.

With this new information, EPA
was able to associate those CSO
outfalls with latitude and longitude
coordinates with specific waterbody
segments (reaches) identified in the
NHD. The NHD is a comprehensive
set of digital spatial  data of surface
water features that enables analysis
of water-related data in upstream
and downstream order. Associating
CSO outfall locations with the NHD-
indexed assessed waters allowed
analysis of the types of waterbodies
receiving CSO discharges. Through
 this analysis, EPA found:

•   75 percent of CSOs discharge to
    rivers, streams, or creeks;

•   10 percent of CSOs discharge to
    oceans, bays, or estuaries;

•   8  percent of CSOs discharge to
    waters that are unclassified or
    unidentified in the NHD;

•   5  percent of CSOs discharge to
    other types of waters (unnamed
    tributaries, canals, etc.); and

•   2  percent of CSOs discharge to
    ponds, lakes, or reservoirs.

Further, associating CSO outfall
locations with  the NHD-indexed
assessed waters allowed comparison
with impairments reported by states
in the 303(d) program (waters not
meeting water  quality standards  or not
supporting their designated uses), and
the location of protected resources
and sensitive areas. These analyses are
discussed in more detail in Section
5.3  of this report. Additional detail on
the CSO analysis using the NHD is
presented in Appendix F.
4.6  What is the Universe of
     SSSs?
      EPAs 2000 CWNS reported
      15,582 municipal SSSs with
      wastewater treatment facilities
across the nation (EPA 2003b). EPA
has also identified an additional  4,846
satellite SSSs that collect and transport
wastewater to regional treatment
facilities (EPA 2003b). The number
of SSSs with wastewater treatment
facilities and the number of satellite
systems are shown for each state in
Figures 4.4  and 4.5, respectively.
                                                                                                         4-19

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                           Figure 4.4
                              Distribution of SSSs with Wastewater Treatment Facilities by EPA
                              Region and by State
                              SSSs are located in all 50 states. EPA's 2000 CWNS reported 15,582 municipal SSSs with
                              wastewater treatment facilities across the nation.
                                                    100
200   300
400   500
600
700   800
                                  Region 1
                                                                                                         1500
                                                                                                     1,363
                                                                                                   ^^
                                  Region 10
4-20

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                                                              Chapter 4—Characterization of CSOs and SSOs
                                                                       Figure 4.5
  Distribution of Satellite SSSs by Region and by State

  EPA identified 4,846 satellite SSSs that collect and transport flows to regional wastewater
  treatment facilities; such systems exist in all states, with the exception of Hawaii.
Region 1
Region 2
Region 3
Region 4
Region 5
                    100
                 200
300
400
500
600
700
800
 CT
MA
ME
 NH
 Rl
 VT
 NJ
 NY
 DE
MD
 PA
VA
WV
 AL
 FL
GA
 KY
MS
 NC
 SC
 TN
 IL
 IN
ME
 Ml
OH
 Wl
                                                                                                   4-21

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Report to Congress on the Impacts and Control ofCSOs and SSOs
 Figure 4.6
 States Providing
 Electronic Data on SSO
 Discharges
    
 EPA identified 25 states in which
 the NPDES authority is using an
 electronic data system to track the
 volume, frequency, location, and
 cause of SSO discharges within its
 jurisdiction. Data from these states
 were used to develop national
 estimates of SSO frequency and
 volume.
EPA estimates that 164 million people
are served by municipal SSSs. EPA
estimates that SSSs contain 584,000
miles of municipally-owned sewer
pipes and that approximately 500,000
miles of privately-owned pipes deliver
wastewater into SSSs (EPA 2003b).

As described in Section 4.4, NPDES
permittees are commonly classified
by NPDES authorities as "major"
or "minor" dischargers. Based on
information available in PCS for
permits issued to SSSs with wastewater
treatment facilities, EPA found that
80 percent were classified as minor
facilities, with average daily discharges
less than 1 mgd.
4.7  What are the
     Characteristics of SSOs?
       An accurate characterization
       of the frequency, volume, and
       location of SSO discharges,
coupled with information on the
pollutants present in the discharges, is
needed to fully evaluate the potential
for environmental and human health
impacts from SSOs. Currently, there
are no federal systems in place to
compile data on the frequency,
volume, and location of SSO
discharges. This section describes the
processes EPA used to characterize
SSOs.
4-22

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                                                                     Chapter 4—Characterization of CSOs and SSOs
4.7.1 SSO Data Management
     System
For the purposes of this report, EPA
identified 25 states where the NPDES
authority is using an electronic data
system to track the volume, frequency,
location, and cause of SSO discharges
within its jurisdiction. As shown in
Figure 4.6, these 25 states are spread
across the nation.

EPA collected the individual state
datasets and compiled them in a single
SSO data management system. In its
collection of SSO data from the states,
EPA found that the definition of an
"SSO event" varied. For example,
some states include incidents such as
secondary treatment bypasses which
exceed NPDES permit limits by more
than 50  percent at the main outfall,
and spills from septic haulers as SSO
events in their data systems. EPA also
found that backups into buildings
caused by problems in the publicly-
owned portion of an SSS are not
tracked by states.

SSOs are untreated or partially treated
releases  from an SSS. The discussion
of SSOs in this report does not
include  discharges occurring after the
headworks of the treatment plant,
regardless of the level of treatment;
or backups into buildings caused
by problems in the publicly-owned
portion  of an SSS. Datasets for each
state were screened using these
qualifiers. SSO events that did not
meet the above criteria were omitted
from the SSO data management
system and from the analyses of
SSO frequency, volume, and cause
presented later in this chapter.
Additional information on the data
management system is provided in
Appendix G of this report.

4.7.2Statistical Technique Used
     to Estimate Annual National
     SSO Frequency and Volume
National estimates of SSO frequency
and volume were generated using
reported data on 33,213 SSO events
in 25 states that occurred in calendar
years 2001, 2002, and 2003, combined
with basic information describing
the sewered universe in each state
from the 2000 CWNS. This basic state
information included:

•  Total number of sewer systems
   by state (combined and separate
   sanitary);

•  Number of SSSs by state; and

•  Population served  by SSSs by state.

To account for the uncertainty in the
data reported by states, two separate
scenarios were evaluated:

•  The first scenario assumed that
   SSO events tracked in the state's
   data system include all of the SSO
   events that occurred statewide
   during the reporting period.

•  The second scenario assumed that
   SSO events tracked in the state's
   data system include SSO events
   from only those communities that
   chose to report and are therefore
   a fraction of SSO events that
   occurred statewide during the
   reporting period.

Regression  analyses demonstrated that
the frequency of SSO events in a  state
is correlated both to the total number
of SSSs as well as to the population
served, although neither parameter
                                                                                                        4-23

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Figure 4.7
    Total Number of SSO
    Events Reported by
    Individual Communities,
    January 1,2001 -
    December 31,2003
    Nearly 70 percent of the
    communities in the 25 states
    reported between one and four
    SSO events during the three-year
    reporting period.
                                    is a perfect predictor. To account for
                                    the uncertainty as to which provides
                                    the better national estimate of SSO
                                    frequency, two additional sub-
                                    scenarios were analyzed:

                                    •  Estimating SSO event frequency
                                        for non-reporting states based on
                                        total number of SSSs in each state;
                                        and

                                    •  Estimating SSO event frequency
                                        for non-reporting states based
                                        on the total population served by
                                        SSSs in each state.

                                    National estimates of SSO volume
                                    were generated using the following
                                    five-step procedure:

                                    1.  Tabulate the total number of
                                        events and SSO volume for each
                                        of the reporting states.
                                    2.  Estimate the total number of SSO
                                        events per year for each non-
                                        reporting state based on a) the
                                        number of SSSs in the state, and
                                        b) the population served by SSSs
                                        in the state.

                                    3.  Divide the total number of events
                                        in each non-reporting state into
       different categories describing the
       cause of the SSO event, accounting
       for observed regional differences
       from the 25 reporting states.

   4.  Calculate SSO volume for each
       cause category in each non-
       reporting state, accounting for
       observed regional differences.

   5.  Calculate national estimates
       by summing the total number
       of events by state and the total
       volume across all states.

   A detailed explanation of the statistical
   techniques applied to the SSO data
   provided by the 25 states is presented
   in Appendix G.

   4.7.3 Frequency of SSOs
   Between January 1, 2001, and
   December 31, 2003, 33,213 SSO
   events were reported by individual
   communities in the 25 states.
   During this three-year period, 2,663
   communities reported one or more
   SSO discharges. The number of
   SSO discharges reported by each
   community is presented in Figure
   4.7. As shown, most of the 2,663

Percent Reported

VI
o
I/I
•a
Si
I
0)
ce
"o
0)
01
E
flj
OC



1
2-4
5-7
8-10
11-20
21-30
31-40
41-50
51-75
76-100
>100


^H
7%
^H 3%
H 2%
• 1%
H 2%
•
• 2%
4-24

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                                                                      Chapter 4—Characterization of CSOs and SSOs
communities reported between one
and four SSO events during the
three-year reporting period. One
community reported more than 1,300
SSOs over the three years.

Using the statistical techniques
described previously, and in Appendix
G, SSO frequency information in
the SSO data management system
was extrapolated into a national
estimate. This analysis suggests that
between 23,000 and 75,000 SSO
events per year occur in the United
States. EPA evaluated the SSO
frequency information in the SSO
data management system for regional
trends and found only marginal
regional effects for overall event
frequency. Therefore, EPA did not
make adjustments to the estimated
number of SSO events in non-
reporting states based on geographic
location.
                                    4.7.4 Volume of SSOs
                                    Estimated SSO volumes were reported
                                    and available for 28,708 (86 percent)
                                    of the 33,213 events included in
                                    the SSO data management system.
                                    Between January 1, 2001, and
                                    December 31,2003, a total of 2.7
                                    billion gallons of SSO was reported
                                    discharged in the 25 states. The
                                    reported volume for individual SSO
                                    events ranged from one gallon to 88
                                    million gallons. The distribution of
                                    reported SSO volumes for these events
                                    is presented in Figure 4.8. As shown:

                                    •  More than half of the reported
                                       SSOs were less than 1,000 gallons;

                                    •  More than 80 percent of the SSOs
                                       were less than 10,000 gallons; and

                                    •  Approximately 2 percent of the
                                       SSOs were greater than 1  million
                                       gallons.

                                    Further, the 1,000 largest SSO events
                                    (3 percent of reported events)
                                    accounted for almost  90 percent of the
                                    total SSO volume reported.
 01
 o
 in
 in
          1 -100
          gallons

       101 -1,000
          gallons

      1,001-10,000
          gallons

    10,001 -100,000
          gallons

  100,001 -1,000,000
          gallons

1,000,001 -10,000,000
          gallons

      > 10,000,000
          gallons
                           Distribution of SSO Volume Reported
                                            17%
                                                           29%
                                    12%
                             5%
                                                                                                  Figure 4.8
        Distribution of SSO
        Volume Reported Per
36%     Event

        Estimated SSO volumes were
        available for 86 percent of events in
        the SSO data management system.
        The reported volumes for individual
        SSO events ranged from one gallon
        to 88 million gallons.
                      1%
                                                                                                          4-25

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     Using the statistical techniques
                                     described in Appendix G, data on the
                                     volume discharged during individual
                                     SSO events were extrapolated into
                                     a national estimate of the annual
                                     volume of SSO discharged. This
                                     analysis suggests that the total SSO
                                     volume discharged annually is
                                     between three and 10 billion gallons.

                                     In an unpublished EPA report
                                     supporting a draft rulemaking on
                                     SSOs, EPA previously estimated that
                                     the national volume of SSO discharges
                                     caused by wet weather totaled 311
                                     billion gallons per year. That estimate
                                     was derived from a model designed
                                     to predict the relationship between
                                     the frequency of wet weather SSO
                                     events and the required national
                                     investment in SSO control measures.
                                     The model was based on variables
                                     such as sewer system capacity, acreage
                                     served by SSSs, and the percentage
                                     of rainfall that became I/I. Values
                                     assigned to each of these variables
                                     were based on very little empirical
                                     data, and the output of the model was
                                     not verified. EPA has a much higher
                                     degree of confidence in the national
                                     SSO volume estimates  presented in
                                     this Report to Congress because the
                                     new estimates are based on a much
                                     larger empirical data set and rely on a
                                     simplified approach for extrapolating
                                     to a national estimate.

                                     4.7.5 Location of SSOs
                                     SSOs can occur at any  location in the
                                     SSS, including: manholes, cracks and
                                     other defects in sewer lines, emergency
                                     relief outlets, and elsewhere. Reports
                                     of SSO events often include street
                                     addresses where the spill occurred.
                                     Because SSO events can occur at so
                                     many locations, gathering latitude and
longitude for SSOs at a national level
is impractical. Rather, it is more useful
to look at the cause of the events,
which is often linked to the type of
location where it occurs. EPA grouped
the reported SSO events into five
broad cause categories:

•   Blockages

•   Wet weather and I/I

•   Power and mechanical failures

•   Line breaks

•   Miscellaneous (e.g., vandalism,
    contractor error)

In general, SSOs attributed to
wet weather and I/I are caused by
insufficient sewer system capacity,
while the other types of spills are
attributable to  sewer system operation
and maintenance.

Cause information was available for
77 percent of the SSO events included
in the SSO data management system.
As shown in Figure 4.9, 48 percent
of all SSO events with a known cause
were the result of the complete  or
partial blockage of a sewer line, and
26 percent of SSO events were caused
by wet weather and I/I. In general, the
communities reporting large numbers
of SSO events have programs that
place a strong emphasis on tracking.
As a result, EPA believes that these
communities are likely to identify
additional low-volume SSO  events
(e.g., SSOs resulting from blockages)
that have the potential to go unnoticed
or unreported  in other jurisdictions.

EPA evaluated  the reported causes
of SSO events in the SSO data
management system for regional
trends and found significant
4-26

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                                                                      Chapter 4—Characterization of CSOs and SSOs
Causes of SSO Events
Percent
v ^y7 Blockages 48%
\ ^
V
/ v
r T
Total
Wet weather and I/I
Mechanical or power failures
Line breaks
Miscellaneous

26%
11%
10%
5%
100%
                                                                                                   Figure 4.9
                                                                              Most Common Reported
                                                                              Causes of SSO Events

                                                                              Nearly 50 percent of all SSO events
                                                                              with a known cause were the result
                                                                              of complete or partial blockage of
                                                                              a sewer line.
differences in the cause of SSO events
between EPA regions. Specifically,
EPA found that nearly three-quarters
of SSO events in the arid Southwest
were caused by blockages, while more
than half of SSO events in Great
Lakes states were attributed to wet
weather and I/I. Therefore, average
regional distributions for SSO cause
were developed and applied in the
estimation of SSO volume in non-
reporting states. More information
on regional trends in SSO cause is
presented  in Appendix G.

EPA found that individual SSO event
volumes show a strong correlation
with cause, with the smallest events
attributed to blockages and the largest
events occurring as a result of wet
weather or excessive I/I. As shown
in Table 4.8, the average volume of
SSO events caused by wet weather or
excessive I/I is much greater than the
average volume for any other type of
SSO event.

Additional analysis was performed
on the cause of SSO events in those
communities reporting more than
100 events during a calendar year
(either 2001 or 2002); this analysis
was done to determine whether the
distribution of causes was markedly
different in municipalities reporting
higher numbers of SSO events. As
shown in Figure 4.10, EPA found
that communities reporting higher
numbers of SSO events attributed
a significantly higher percentage of
their SSO  events to blockages and a
correspondingly lower percentage of
SSO events to wet weather and I/I.

More detailed information on cause
was available for approximately 80
percent of the more than 12,000 SSO
events attributed to the complete or
Cause Average SSO Median SSO Total Volume
Event Volume Event Volume (million gallons)
(gallons) (gallons)
Blockages
Wet weather and I/I
Mechanical or power
failures
Line breaks
Miscellaneous
5,900
360,000
63,000
172,000
260,000
500
14,400
2,000
1,500
1,200
69
1,860
157
239
199
Percent
of Total
Volume
3
74
6
9
8
                                                                                                  Table 4.8
                                                                              SSO Event Volume by
                                                                              Cause

                                                                              Although wet weather and I/I
                                                                              was listed as the cause for one-
                                                                              quarter of SSO events, these events
                                                                              account for nearly three-quarters of
                                                                              the total SSO volume discharged.
                                                                                                         4-27

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Report to Congress on the Impacts and Control ofCSOs and SSOs
  Figure 4.10
    Reported Causes of
    SSOs in Communities
    Reporting More than
    100 SSO Events During a
    Single Calendar Year

    EPA found that communities
    reporting higher numbers of SSO
    events (>100 per year) attributed a
    significantly higher percentage of
    their SSO events to blockages.
Causes of SSO Events
V
V
V
V
T
Total
Blockages
Wet weather and I/I
Line breaks
Mechanical or power failures
Miscellaneous

Percent
74%
14%
7%
3%
2%
100%
                                    partial blockage of a sewer line. As
                                    shown in Figure 4.11, grease from
                                    restaurants, homes, and industrial
                                    sources is the most common cause
                                    of reported blockages. Grease is
                                    problematic because it solidifies,
                                    reduces conveyance capacity, and
                                    blocks flow. Grit, rocks,  and other
                                    debris that find their way into the
                                    sewer system account for nearly a
                                    third of the reported blockages. Roots
                                    are responsible for approximately
                                    one quarter of reported blockages.
                                    Roots are problematic because they
                                    penetrate weaknesses in sewer lines
                                    at joints and other stress points, and
                                    cause blockages.
4.8  How Do the Volumes and
     Pollutant Loads from
     CSOs and SSOs Compare
     to Those from Other
     Municipal Point Sources?
   A   s described in Section 4.3,
  L\  waterbodies receive pollutant
-/.  AJoads of the types found in
CSOs and SSOs from other urban and
rural sources. Responsibility for two of
these sources—wastewater treatment
plants and urban storm water
runoff—belongs almost exclusively
to municipalities. Comparing
information on annual discharges
from municipal sources gives context
  Figure 4.11
    Reported Cause of
    Blockage Events

    Grease-the most common cause
    of blockage-solidifies, reduces con-
    veyance capacity,and can eventu-
    ally block flow in sewers.
Causes of Blockage Events
V
V
V
V
Total
Grease
Grit, rock, and other debris
Roots
Roots and grease

Percent
47%
27%
22%
4%
100%
4-28

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                                                                        Chapter 4—Characterization of CSOs and SSOs
to the magnitude of CSO and SSO
discharges. At a national level, as
shown in Table 4.9, the volume of
CSOs and SSOs discharged is one to
two orders of magnitude less than
the total flow processed at wastewater
treatment plants. The volume of urban
storm water runoff generated annually
is nearly equivalent to the volume of
treated wastewater.
                   In addition to considering the volumes
                   discharged by various municipal
                   sources, it is also informative to
                   consider their relative contributions
                   in terms of pollutant loads at the
                   national level. The comparisons of
                   BOD5, TSS, and fecal coliform loads
                   presented in Tables 4.10, 4.11, and 4.12
                   are based on the volumes presented in
 Source
Treated wastewater3
CSOb
SSOC
Urban storm water runoffd
a EPA 2000a
b GPRACSO model, Section 4.5.1
c High estimate, Section 4.7.4
         Average Discharge Volume
                   (billion gallons)
                                               11,425
                                                             Percent of Total
                                                        Municipal Discharges
                       Annual Discharge  Median BOD5  Total BOD5   % of Total
                               Volume Concentration        Load   Municipal
                         (billion gallons)        (mg/L)   (Ibs.xlO8)  BOD5 Load
 Treated wastewater
 :so
 SSO
 Urban storm water runoff
                                        7.2
                                                                       19%
                                                                                                     Table 4.9
                                                             Estimated Annual
                                                             Municipal Point Source
                                                             Discharges
                                                             On an annual basis,the volume
                                                             of CSO and SSO discharged is a
                                                             proportionally small amount of the
                                                             total flow processed at municipal
                                                             wastewater treatment facilities.
                                                                                                     Table 4.10

                                                             Estimated Annual BOD5
                                                             Load from Municipal
                                                             Point Sources

                                                             CSOs and SSOs contribute to a
                                                             relatively low percentage of the
                                                             total municipal 6005 load disharged
                                                             annually.
 1 BODr concentrations taken from the GPRACSO model vary with time, as described in Appendix E.
 Source
 Treated wastewater
 SSO
 Urban storm water
 runoff
Annual Discharge     Median TSS  Total TSS Load   % of Total
        Volume  Concentration      (IbsxIO8)   Municipal
  (billion gallons)         (mg/L)                  TSS Load
          11,425
            850
             10
          10,068
                                                30
                                               127
                                                91
                                                58
28.5
48.6
 33%
 10%
< 1%
 56%
                                                                                                     Table 4.11
Estimated Annual TSS
Load from Municipal
Point Sources
Storm water discharges account for
nearly 60 percent of the municipal
TSS load discharged annually.
                                             it for
                                             ipal
 Source
 Treated wastewater
Annual Discharge     Median FC   Total FC Load   % of Total
        Volume  Concentration   (MPNxlO14)   Municipal
  (billion gallons)     (#7100 ml)                   FC Load
          11,425
a Assumes wastewater treatment includes disinfection
                                                             865
                                                          69,172
                                                           1,892
                                                           19,362
            1%
           76%
            2%
                                                   21%
                                                                                                     Table 4.12
          Estimated Annual Fecal
          Coliform Load from
          Municipal Point Sources
                                                                                CSOs appear to be the most
                                                                                significant source of fecal coliform
                                                                                when compared to other municipal
                                                                                point sources on an annual basis.
                                                                                                            4-29

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     Table 4.9, and on the concentrations
                                     presented in Tables 4.1, 4.2, and 4.3.
                                     As shown, CSOs and SSOs contribute
                                     a relatively low percentage of the
                                     total municipal BOD5 and TSS load
                                     discharged annually. CSOs, however
                                     appear to be the most significant
                                     municipal source of fecal coliform.
                                     Further, as shown earlier in Figure 4.1,
                                     most CSSs are located in the Northeast
                                     and Great Lakes regions. Therefore,
                                     the fraction of discharge volume and
                                     pollutant load attributed to CSOs in
                                     states with many CSSs and locally in
                                     communities with CSSs is likely to be
                                     much higher. Similarly, communities
                                     experiencing frequent and/or high
                                     volume SSO events are  likely to
                                     attribute a larger percentage of the
                                     discharge volume and pollutant load
                                     to SSOs.

                                     BOD5 , TSS, and fecal coliform loads
                                     from several important watershed
                                     sources of pollutants identified in
                                     Section 4.3 of this report, including
                                     agricultural practices and animal
                                     feeding operations, domestic animals
                                     and wildlife, and decentralized
                                     wastewater treatment systems, are not
                                     reflected in these comparisons. It is not
                                     practical to estimate the contributions
                                     of these various sources to the total
                                     annual load of BOD5, TSS, or fecal
                                     coliform on a national level; however,
                                     local examples provide some context.
  Relative Contribution of CSOs
  to Bacterial Loads:
  Rouge River, Ml
A recent study on Michigan's Rouge River (a river with a long history of CSOs and
pollution problems) assessed the relative contributions of CSOs to overall bacterial
indicator loads in the river (Murray and Bona 2001). This study conducted sampling
for fecal coliform and fecal streptococci bacteria at 28 sites within the watershed.
The results of the study suggest that CSOs contribute 10 to 15 percent of the total
bacterial load  in the watershed. The authors acknowledge the contributions of
a variety of other sources, including  non-CSO municipal sources  and nonpoint
sources. The nonpoint sources mentioned as other contributors included wildlife,
domestic animals,  rural  runoff, contaminated  groundwater, and  faulty  septic
systems.
  Relative Contribution of CSOs
  to Bacterial and 6005 Loads:
  Washington, D.C.
The District of Columbia Water and  Sewer Authority quantified pollutant loads
to receiving waters as part of its modeling analysis to support development of
a CSO LTCP (DCWASA 2002). The CSO contribution to the tidal Anacostia River in
Washington, D.C.,was estimated to be 61 percent for fecal coliform and 14 percent
for 8005. Similarly, the CSO contribution to Rock Creek was estimated to be 41
percent for fecal coliform and 6 percent for 8005. Storm water from Washington,
D.C., and suburban areas in Maryland as well as other upstream nonpoint sources
accounted for the remaining loads in both watersheds.
4-30

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                             Chapter   5
         Environmental Impacts of
                   CSOs and SSOs
      This chapter describes the
      extent to which CSOs and
      SSOs cause or contribute to
environmental impacts. The chapter
first discusses EPA's framework for
evaluating environmental impacts
from CSOs and SSOs, using water
quality standards. The chapter then
summarizes environmental impacts
from CSOs and SSOs as reported in
national assessments and presents
the results of new analyses completed
by EPA. Next, site-specific examples
are presented to illustrate the types
of impacts that CSOs and SSOs have
at the local watershed level. Lastly,
the factors that affect the extent of
environmental impacts caused by CSO
and SSO discharges are described.

In conducting data collection
and research for this report, EPA
found that CSOs and SSOs cause
or contribute to environmental
impacts that affect water quality and
the attainment of designated uses.
Pollutant concentrations in CSOs and
SSOs alone may be sufficient to cause
a violation of water quality standards.
Impacts from CSOs and SSOs are
often compounded by impacts from
other sources of pollution such as
storm water runoff, decentralized
wastewater treatment systems, and
agricultural practices. This can make
it difficult to identify and assign
specific cause-and-effect relationships
between CSO or SSO events and
observed water quality impacts and
impairments.

For the purpose of this report,
environmental impacts do not include
human health impacts. The extent of
human health impacts due to CSOs
and SSOs is discussed in Chapter 6.
5.1 What is EPA's Framework
    for Evaluating
    Environmental Impacts?
     EPA's water quality standards
     program provides a framework
     for states and authorized tribes
to assess and enhance the quality of
the nation's waters. Water quality
standards define goals by designating
uses for the water (e.g., swimming,
boating, fishing) and setting pollutant
In this chapter:
5.1  What is EPA's Framework
    for Evaluating
    Environmental Impacts?

5.2  What Overall Water
    Quality Impacts Have Been
    Attributed to CSO and SSO
    Discharges in National
    Assessments?

5.3  What Impacts on Specific
    Designated Uses Have
    Been Attributed to CSO
    and SSO Discharges in
    National Assessments?

5.4  What Overall Water
    Quality Impacts Have Been
    Attributed to CSO and SSO
    Discharges in State and
    Local Assessments?

5.5  What Impacts on Specific
    Designated Uses Have
    Been Attributed to CSO
    and SSO Discharges
    in State and Local
    Assessments?

5.6  What Factors Affect the
    Extent of Environmental
    Impacts Caused by CSOs
    and SSOs?
                                                                                             5-1

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     limits (criteria) necessary to protect
                                     the uses.

                                     Attainment of water quality standards
                                     is determined through a process of
                                     evaluation and assessment, as follows:

                                     •   States adopt water quality goals
                                         or standards that, once approved
                                         by EPA, serve as the foundation
                                         of the water quality-based control
                                         program mandated by the Clean
                                         Water Act.

                                     •   States, EPA, and other federal
                                         agencies (e.g., U.S. Geological
                                         Survey) conduct water quality
                                         monitoring studies to measure
                                         water quality and assess changes
                                         over time.

                                     •   States compare measured water
                                         quality to goals or standards in
                                         a statewide assessment required
                                         under section 305(b) of the Clean
                                         Water Act  and report conditions as
                                         good, threatened, or impaired.

                                     •   Waters designated as impaired
                                         are included on a state's 303(d)
                                         list.  A total maximum daily load
                                         (TMDL) is required for each
                                         pollutant causing impairment. The
                                         TMDL establishes an allowable
                                         pollutant load that, when achieved,
                                         will result  in the attainment of the
                                         water quality standard.

                                     The discussion of environmental
                                     impacts in this chapter is focused on
                                     circumstances  in which a designated
                                     use is not being attained due entirely
or in part to CSO and SSO discharges.
The pollutants found in CSOs and
SSOs can potentially impact five
designated uses:

•  Aquatic life support, meaning the
   water provides suitable habitat for
   the protection and propagation of
   desirable fish, shellfish, and other
   aquatic organisms.

•  Drinking water supply, meaning
   the water can supply safe
   drinking water with conventional
   treatment.

•  Fish consumption, meaning the
   water supports fish free from
   contamination that could pose a
   significant human health risk.

•  Shellfish harvesting, meaning
   the water supports a population
   of shellfish free from toxics
   and pathogens that could pose
   a significant health risk to
   consumers.

•  Recreation, meaning water-
   based activities (e.g., swimming,
   boating) can be performed
   without risk of adverse human
   health effects.

As discussed in Section 4.1 of this
report, the principal pollutants
present in CSOs and SSOs are:
microbial pathogens, oxygen depleting
substances, TSS, toxics, nutrients,
and floatables. Table 5.1 summarizes
designated uses likely to be impaired
by each of these pollutants.
5-2

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                                                               Chapter 5—Environmental Impacts of CSOs and SSOs
 Oxygen-demanding substances

 Sediment (TS:

 Pathogens

 Toxics

 Nutrients

 Floatables
                                                                                                 Table 5.1
                                                                             Pollutants of Concern in
                                                                             CSOs and SSOs Likely to
                                                                             Cause or Contribute to
                                                                             Impairment
                                       The pathogens present in CSO and
                                       SSO discharges have the potential
                                       to impact several designated uses,
                                       including,drinking water supply,fish
                                       consumption,shellfish harvesting,
                                       and recreation.

5.2  What Overall Water
     Quality Impacts Have Been
     Attributed to CSO and SSO
     Discharges in National
     Assessments?
     States are required to periodically
     assess the health of their waters
     and the extent to which water
quality standards are being met.
EPA compiles these reports into the
NWQI, which offers a comprehensive
review of water quality conditions
nationwide. This section summarizes
findings from the NWQI and describes
two original analyses undertaken by
EPA to identify potential water quality
impacts from CSO and SSO discharges
at the national level.
5.2.1 NWQI 2000 Report
Since 1975, EPA has prepared a series
of biennial NWQI reports as required
under Section 305(b) of the Clean
Water Act. The NWQI 2000 Report,
the most recently published report, is
a compilation of assessment reports
on the quality of state waters (EPA
2002c). The NWQI Report  categorizes
assessed waters as follows:

Good - fully supporting all  uses
or fully supporting all uses  but
threatened for one or more uses; or

Impaired - partially or not supporting
one or more uses.
                                                                                                         5-3

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                        The national summary of the
                                        quality of assessed waters, by type, is
                                        presented in Figure  5.1. This summary
                                        shows that 19 percent of the nation's
                                        total river and stream miles; 43
                                        percent of lake, reservoir, and pond
                                        acres; 36 percent of estuarine and
                                        bay square miles; 6 percent of ocean
                                        shoreline miles; and 92 percent of
                                        Great Lakes shoreline miles were
                                        assessed.
         EPA's NWQI2000 Report also
         identified the types of pollutants or
         stressors most often found to impair
         the assessed waters as well as the
         leading sources of these pollutants.
         These results are presented in Table
         5.2 and Table 5.3, respectively. Overall,
         EPA found that the three pollutants
         most often associated with impaired
         waters were solids, pathogens, and
         nutrients. All three are present in CSO
         and SSO discharges. Therefore, at a
         minimum, CSOs and SSOs contribute
              Figure 5.1
                NWQI 2000 Report: Summary of Assessed Waters by Waterbody Type
                (EPA 2002c)
               Waterbody assessments are normally based on five broad types of monitoring data: biological
               integrity, chemical, physical, habitat,and toxicity. Monitoring data are then integrated for an overall
               assessment.
                     1
                     verall
                                            Riversand Streams(miles)
      Lakes, Reservoirs, and Ponds (acres)
                       Percent assessed

                       Assessed as good

                       Assessed as impaired
61%
                                                                        39%
                                55%
                                                                                                        45%
                                              Total miles: 3,692,830
                                                                               Total acres: 40,603,893
            Estuaries and Bays (square miles)
                                           Ocean Shoreline (miles)
                                                                             Great Lake Shoreline (miles)
                                                                                                       22%
                                                                        14%
              Total sq. miles: 87,369
                                             Total miles: 58,618
         Total miles: 5,521
5-4

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                                                                    Chapter 5—Environmental Impacts of CSOs and SSOs
Pollutant/Stressor
Habitat alterations
Metals
Nutrients
Oil and grease
Oxygen-depleting substances
Pathogens (bacteria)
Pesticides
Priority toxic organic
chemicals
Siltation (sedimentation)
Suspended solids
Total dissolved solids
Turbidity
 Rivers     Lakes,   Estuaries    Ocean      Great
  and      Ponds,   and Bays   Shoreline    Lakes
Streams     and                          Shoreline
         Reservoirs
                                                                                                        Table 5.2
                                           Pollutants and Stressors
                                           Most Often Associated
                                           with Impairment
                                           (EPA 2002c)
                                                        Overall, EPA found that the three
                                                        pollutants most often associated
                                                        with impaired waters were solids
                                                        (i.e., suspended solids,siltation,
                                                        and total dissolved solids),
                                                        pathogens,and nutrients. This
                                                        table ranks the top five pollutants
                                                        (or stressors) for each waterbody.
Pollutant Source
Agriculture
Atmospheric deposition
Contaminated sediment
Forestry
Habitat modifications
Hydrologic modifications
Industrial discharges
Land disposal
Municipal point sources
Nonpoint sources
Septic tanks
Urban runoff/storm sewers
 Rivers     Lakes,    Estuaries    Ocean      Great
  and      Ponds,    and Bays   Shoreline    Lakes
Streams     and                          Shoreline
         Reservoirs
   1
1
                                                                                                       Table 5.3
Leading Sources of
Pollutants and Stressors
Causing Water Quality
Impairment
(EPA 2002b)
Overall, EPA found that pollution
from urban and agricultural land,
transported by precipitation
and runoff, is a leading source of
impairment. This table ranks the
top five pollutant sources causing
water quality impairments.
                                                                                                                 5-5

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     to the loading of these pollutants
                                     where they occur.

                                     The NWQI2000 Report did not cite
                                     CSOs or SSOs as a leading source
                                     of impairment in any of the five
                                     waterbody types listed in Table 5.3
                                     (EPA 2002c). CSOs were identified as a
                                     source of impairment for 1,466 square
                                     miles (5 percent) of assessed estuaries
                                     and 56 miles (1 percent) of Great
                                     Lakes shoreline.

                                     The NWQI 2000 Report is based
                                     on a compilation of individual
                                     state assessments, and reporting
                                     of the source of impairment varies
                                     widely from state to state. The lack
                                     of uniformity in assessment and
                                     reporting makes it difficult to fully
                                     assess the magnitude of CSO and
                                     SSO impacts. Inconsistencies in
                                     state reporting of CSOs and SSOs as
                                     pollutant sources are described below.

                                     Unknown sources and failure to
                                     classify: Some states cite unknown
                                     pollutant sources or do not attribute
                                     impairment to a specific source.

                                     Inconsistent source listing: CSOs are
                                     tracked as a specific pollutant source
                                     in many, but not all, states where they
                                     occur. Twenty of the 32 CSO states
                                     identified "combined sewer overflow"
                                     as a source of impairment, in the
                                     NWQI at least once. Where SSOs are
                                     identified by states, they are tracked
                                     in an inconsistent manner. States
                                     use categories such as "collection
                                     system failure (SSO)," "wet weather
                                     discharges," and "spills" for tracking
                                     SSOs.

                                     Cumulative impacts from multiple
                                     pollutant sources: Impacts from CSOs
                                     and SSOs are often compounded
by impacts from other sources of
pollution, particularly during wet
weather. As such, CSOs and SSOs may
be grouped into municipal or urban
source categories.

EPA is working with the states to
develop a framework to promote
consistent listing of sources of
impairment (EPA 2002d).

5.2.2 Analysis of CSO Outfalls
      Discharging to Assessed or
      Impaired Waters
As described in Section 4.5, a key
EPA initiative undertaken as part of
this report was to  update, verify, and
digitally georeference the inventory of
CSO outfall locations documented as
part of EPA's 2001 Report to Congress-
Implementation and Enforcement of
the CSO Control Policy. Through this
effort, EPA established latitude and
longitude coordinates for over 90
percent of CSO outfalls. EPA then
linked CSO outfall locations to other
national-level data and assessments.
For example, permitted CSO outfall
locations were linked to 305(b)-
assessed waters and 303(d)-impaired
waters. These analyses are presented
in the following subsections. A similar
analysis linking permitted CSO outfall
locations with classified shellfish
growing areas is presented in Section
5.3.2. An analysis of CSO outfall
proximity to drinking water intakes
is presented in Chapter 6. More
information on each of these analyses
is provided in Appendix F.

As discussed in Chapter 4, SSOs
do not necessarily occur at fixed
locations. Therefore, a parallel effort
to georeference SSO locations and
evaluate their location with respect
5-6

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                                                                Chapter 5—Environmental Impacts of CSOs and SSOs
to other national-level data and
assessments was not possible.
       outfalls suggests some correlation
       between impairment and CSOs.
Analysis of CSO Outfalls Discharging
to EPA's 305(b) Assessed Waters
EPA was able to compare CSO outfall
locations with  assessed waters in the
NWQI2000 Report through the 305(b)
assessment database for 19 CSO
states with electronic 305(b) data.
The purpose of this analysis was to
determine the  number of CSO  outfalls
discharging to  waters classified  as good
or impaired. EPA limited the analysis
to assessed water segments located
within one mile downstream of a CSO
outfall. The results of this analysis are
summarized in Table 5.4. EPA found
that of the 59,335 assessed water
segments in CSO states with electronic
305(b) data only a small number (733
segments) were in close proximity
to CSO outfalls. Of these, 75 percent
(552 segments) were  impaired.  The
proximity of a permitted CSO outfall
to an impaired segment does not in
and of itself demonstrate that the
CSO is the cause of the impairment.
CSOs generally are located in urban
areas where waterbodies also receive
relatively high  volumes of storm water
runoff and other pollutant loads.
Nevertheless, the high percentage
of impairment associated with CSO
       Analysis of CSO Outfalls Discharging
       to EPA's 303(d) Waters
       EPA also compared CSO outfall
       locations to water segments identified
       in EPA's Section 303(d) list of impaired
       waters in states with NHD-index
       data. For the purpose of this analysis,
       EPA assumed the causes of reported
       Section 303(d)  impairment most likely
       attributed to or associated with CSOs
       were:

       •  Pathogens

       •  Organic enrichment, leading to
          low dissolved oxygen

       •  Sediment and siltation

       Again, EPA limited the analysis to
       water segments located within one
       mile downstream of a CSO outfall. The
       results of this analysis are summarized
       in Table 5.5. EPA found  that although
       less than one-tenth  of one percent
       (1,560 of more than 1,495,000) of all
       waterbody segments in CSO states
       are within one mile of a CSO outfall,
       between five and 10 percent of the
       waters assessed as impaired are within
       that one mile. EPA believes the strong
       correlation between CSO location and
       impaired waters is due in part to the
  Assessed Waters
  Assessed 305(b) segments in CSO
  states with electronic 305(b) data
  Total    Assessed as  Assessed as  Percent
Assessed     Good     Impaired   Impaired
 59,335
44,457
14,878      25%
                                                        Table 5.4
                                                                              Occurrence of 305(b)
                                                                              Assessed Waters Within
                                                                              One Mile Downstream of
                                                                              a CSO Outfall
  Assessed segments within one mile
  downstream of a CSO outfall
  733
 181
 552
75%
EPA was able to complete this
analysis only for states with
electronic 305(b) data; that is, for
19 of the 32 states with active CSO
permits.
                                    .     I
                                    "
                                                                                                           5-7

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Table 5.5
   Occurrence of 303(d)
   Listed Waters Within
   One Mile Downstream
   of a CSO Outfall
   Waters within one mile of a CSO
   outfall are much more likely to
   be assessed as impaired than a
   typical water in a CSO state.
Listed Waters
                                         Reason or Cause of Listing
Pathogens   Enrichment Leading   Sediment
             to Low Dissolved       and
                Oxygen         Siltation
Total number of listed waters in CSO
states
Number of listed waters within one
mile of a CSO outfall
3,446
191
1,892
163
3,136
149
following factors:  CSOs generally
are located in urban areas where
waterbodies also receive relatively
high volumes of storm water runoff
and other pollutant loads; and waters
within urban areas are much are more
likely to be assessed as part of the
305(b) process.

As described in the 305(b) analysis, the
existence of a permitted CSO outfall in
close proximity to an impaired water
does not in and  of itself demonstrate
that the CSO  is the cause of the
impairment. It does suggest, however,
that CSOs should be considered as
a potential source  of pollution with
respect to TMDL development.
EPA has collected anecdotal data
demonstrating that CSOs are being
considered in TMDL development
and that substantial load reductions
have been assigned to CSOs in some
communities as  a result of the  TMDL
process.

5.2.3 Modeled  Assessment of SSO
     Impacts on Receiving Water
     Quality
The unpredictable nature of most SSO
events makes it difficult to monitor
and collect the data needed to  measure
the occurrence and severity of
environmental impacts. As described
in Section 4.7 of this report, however,
EPA was able to  compile a substantial
     amount of information on the
     frequency, volume, and cause of SSO
     events. From these data, EPA found
     72 percent of these SSO events reach a
     surface water.

     Using the national SSO data, EPA
     developed a simple model for
     estimating the likely impact of SSO
     events on different size receiving
     waterbodies, based on reasonable
     assumptions about SSO event
     duration and concentrations of fecal
     coliform bacteria in SSO discharges.
     For the purpose of this report,
     modeled impacts associated with
     SSO events are evaluated in terms
     of violations of the single sample
     maximum water quality criterion for
     fecal coliform. That is, a predicted
     concentration of greater than 400
     counts of fecal coliform per 100 mL of
     surface water would be considered to
     be a water quality standards violation.

     The model was run under three
     different scenarios: one that assumed
     the entire volume of each modeled
     SSO discharge reached a surface
     water (100% delivery), a second that
     assumed half the volume of each
     modeled SSO discharge reached a
     surface water (50% delivery), and
     a third that assumed ten percent of
     the volume of each modeled SSO
     discharge reached a surface water
     (10% delivery).
5-8

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                                                               Chapter 5—Environmental Impacts of CSOs and SSOs
Flow in a particular waterbody can increase dramatically with  a  wet weather
event.  For  example,  after an extended period without rain, 2.6 inches of
rain fell  in the Washington, DC  area  over two days in late February, 2004.
This, in  turn, caused  flow in   local  waterbodies  to  increase  by varying
amounts-e.g.,  to  63 times  the  median  flow in the  Anacostia  River.  The
flows  given reflect the peak daily flow observed due  to this  rainfall  event.
Waterbody Median Flow February Storm Peak Peak Factor
(cfs) (cfs)
Potomac River
Monocacy River
Goose Creek
Seneca Creek
Anacostia River
8,490
624
250
91
47
79,300
9,130
4,480
1,630
2,950
9
15
18
18
63
Flow varies widely in receiving
waters both from year to year and
seasonally. Flow can also increase
substantially in a particular receiving
water during local wet weather
events. The potential impact  of a
specific SSO discharge depends on a
number of factors including  flow and
background pollutant concentrations
in the receiving water at the time the
discharge occurs, and the volume and
strength of the discharge that reaches
the receiving water.
The results of EPA's simple model of
  SSO-related water quality impacts are
  presented in Table 5.6 for a range of
  flow conditions, wastewater strength,
  and delivery ratios. In general, SSOs
  consisting of concentrated wastewater
  are predicted to violate water quality
  standards the majority of the time,
  particularly under low flow conditions.
  In contrast, SSOs consisting of more
  dilute wastewater are much less likely
  to cause water quality standards
  violations, particularly under high
  flow conditions.
                                          Example: Change in Flow
                                          in Washington, D.C. Area
                                          Waterbodies as a Result of Wet
                                          Weather
                                Estimated Percentage
                                Time SSOs Would Cause
                                Water Quality Standard
                                Violations

                                EPA developed a frequency
                                distribution characterizing typical
                                volumes of SSO events based on
                                available data in order to estimate the
                                likely impact of SSO events on water
                                quality.

                   Dilute Wastewater
 Flow Rate      (FC = 500,000 #/ml)
 <cfs)          10%        50%
            Delivery     Delivery     C
 100%
Delivery
                                     36%

                                     27%
            Medium Strength Wastewater
              (FC = 10,000,000 #7100 ml)
  10%       50%      100%
Delivery   Delivery    Delivery
                                     12%

                                     9%
            45%

            36%

            25%

            18%

            13%
            68%

            58%

             5%

            36%

            27%
77%

68%
                                  Concentrated Wastewater
                                  (FC = 1,000,000,000 #/ml)
           10%       50%      100%
         Delivery   Delivery   Delivery
95%

92%
99%
98%
100%

99%
45%

36%
77%

68%
92%

86%
95%

92%
                                     3%

                                     2%
             5%
            13%
             3%
             9%
18%

13%
                    77%

                    68%
                                                                                                          5-9

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    A detailed description of the
                                    methodology used to develop these
                                    estimates is presented in Appendix
                                    H. No comparable analysis of SSO
                                    discharges to lake or estuarine waters
                                    was undertaken.
                                     5.3 What Impacts on Specific
                                         Designated Uses Have Been
                                         Attributed to CSO and SSO
                                         Discharges in  National
                                         Assessments?
                                           EPA, other federal agencies,
                                           and non-governmental
                                           organizations periodically
                                     conduct national assessments of
                                     environmental impacts that are framed
                                     in terms of the loss of a specific
                                     designated use.  Examples include
                                     beach closures in waters  designated
                                     for recreation and shellfish harvesting
                                     restrictions in waters designated for
                                     shellfishing. This section summarizes
                                     findings from a number  of national
                                     assessments, with emphasis placed on
                                     environmental impacts identified as
                                     being caused, or contributed to, by
                                     CSOs or SSOs.

                                     EPA was unable to identify national
                                     assessments that specifically consider
                                     the impacts  of CSOs and SSOs on
                                     aquatic life,  although EPA found
                                     several state and local watershed
                                     assessments which do  so. These
                                     assessments are discussed in Section
                                     5.5 of this report. Also, for purposes
                                     of this report, impairment of drinking
                                     water supply as a designated use is
                                     considered to be a human health
                                     rather than an environmental impact.
                                     Consequently, drinking water supply is
                                     discussed in Chapter 6 of this report.
5.3.1   Recreation
Recreation is an important designated
use for most waters of the United
States. The results of national
assessments of recreational waters
and the causes of impairment are
described in the following subsections.

EPA BEACH Program
EPA's  Beaches Environmental
Assessment and Coastal Health
Program (BEACH Program) conducts
an annual survey of the nation's
swimming beaches, the National
Health Protection Survey of Beaches.
Nearly 2,500 agencies representing
beaches in coastal locations, the
Great Lakes, and inland waterways
participate in the survey. With respect
to designated use impairment during
the 2002 swimming season, 25
percent of the beaches inventoried
(709 of 2,823) had at least one
advisory or closing (EPA 2003a).
Elevated bacteria levels accounted
for 75 percent of recreational use
impairments, manifested as beach
advisories and closings. As shown in
Figure 5.2, a wide variety of pollutant
sources were reported as causing
beach advisories and closings. Nearly
half of the advisories and closings,
however, were reported as having an
unknown cause. CSOs were reported
to be  responsible for 1 percent of
reported advisories and closings, and 2
percent of advisories and closings that
had a known cause. SSOs (including
sewer line blockages and breaks)
were reported to be responsible for
6 percent of reported advisories and
closings, and 12 percent of advisories
and closings that had a known cause.
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                                                                Chapter 5—Environmental Impacts of CSOs and SSOs
               cso
                                                                                                  Figure 5.2
                                         Sources of Pollution
                                         that Resulted in Beach
                                         Advisories and Closings
                                         (EPA 2003a)
                                                                               EPA's BEACH Program conducts
                                                                               an annual survey of the nation's
                                                                               swimming beaches.  During the
                                                                               2002 swimming season, CSOs and
                                                                               SSOs were responsible for 1 and 6
                                                                               percent, respectively, of reported
                                                                               advisories and closings.
Floatables
Floatables are visible buoyant or semi-
buoyant solids that originate from a
variety of sources, including CSOs
and SSOs. CSOs can be a source of
floatables when debris in raw sewage
and storm water is released into the
receiving waterbody. The type of
floatables typically found in CSOs
include sewage-related items (e.g.,
condoms and tampons), street litter,
medical items (e.g., syringes), and
other material from storm drains,
ditches, or runoff (EPA 2002c).

Floatables on beaches and waterways,
also known as marine debris, create
aesthetic impacts and safety issues that
detract from the recreational value of
beaches and other public shorelines.
As defined by the EPA, marine debris
includes all objects found in the
marine environment that do not
naturally occur there. The marine
environment includes the ocean, salt
marshes, estuaries, and beaches.

The National Marine Debris
Monitoring Program (NMDMP),
coordinated by the Ocean Conservancy
(formerly the Center for Marine
Conservation) and funded by EPA,
maintains a national marine debris
database. The NMDMP has conducted
monthly beach cleanups since 1996.
Volunteers track information on
specific marine debris items that are
added to the national database.  The
most frequently collected marine
debris items from 1996 to 2002
are presented in Table 5.7  (Ocean
Conservancy 2003).

Medical and personal hygiene items
are an important component of
marine debris. Given the nature and
use of these items and their disposal in
toilets, CSOs and SSOs are considered
a possible source. The Ocean
Conservancy's 2003  International
Coastal Cleanup, a large one-day event,
found a substantial amount of medical
and personal hygiene items on U.S.
beaches (Ocean Conservancy 2004).
More than 7,500 condoms and  10,000
tampons and tampon applicators were
collected from 9,200 miles of U.S.
shoreline during this event. While this
                                                                                                        5-11

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Report to Congress on the Impacts and Control ofCSOs and SSOs
  Table 5.7
   NMDMP Marine Debris
   Survey Results from
   1996-2002 (Ocean
   Conservancy 2003)

   Funded by EPA is Office of Water,
   the NMDMP uses standardized
   data collection methods to
   determine the status of and
   trends in  marine debris pollution.
   The data are compiled in a
   national database.

                                       Marine Debris
                                       (excluding ocean-based)
Straws
Plastic beverage bottles
Other plastic bottles
Balloons
Plastic food bottles
Plastic bottles
Condoms
Syringes
Plastic bags with seam <1 meter
Cotton swabs
Metal beverage cans
Plastic bags with seam > 1 meter
Tampon applicators
Motor oil containers
Six-pack rings
                                                  Total Items
                                      information is inconclusive on its own,
                                      it does suggest that CSOs and SSOs
                                      may contribute to the occurrence of
                                      medical and personal hygiene waste
                                      found on beaches and other shorelines.

                                      5.3.2Shellfish Harvesting
                                      Commercial and recreational
                                      shellfishing in populated coastal areas
                                      has declined steadily since the early
                                      1900s, when outbreaks of typhoid
                                      were linked to untreated wastewater.
                                      Environmental impacts that restrict
                                      shellfish harvesting as a designated use
                                      are discussed in the following section.
                                      Human health impacts related to the
                                      consumption of contaminated fish and
                                      shellfish are discussed in   Chapter 6.

                                      NOAA National Shellfish Register
                                      NOAA published assessments of
                                      classified  shellfish growing waters
                                      in the contiguous states every five
                                      years between 1966 and 1995. The
                                      last report, 1995 National Shellfish
                                      Register of Classified Growing Waters,
                                      provided an assessment of 4,230
                                      different classified shellfish growing
                                      areas in 21 coastal states (NOAA
                                      1997). Areas open for harvesting are
                                      rated as "approved" or "conditionally
                                      approved;" areas where harvesting
                                      is limited are rated as "restricted" or
                                      "conditionally restricted;" and areas
                                      where harvesting  is not allowed are
                                      rated as "prohibited."

                                      Findings from the 1995  report with
                                      respect to shellfish harvesting are as
                                      follows:

                                      •   76 percent of all  classified waters
                                          were approved or conditionally
                                          approved for  harvest (14.8 million
                                          acres);
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                                                                   Chapter 5—Environmental Impacts of CSOs and SSOs
•   11 percent of all classified waters
    were restricted or conditionally
    restricted (3.9 million acres); and

•   13 percent of all classified waters
    were prohibited (2.8 million
    acres).

NOAA reported that the primary
basis for harvest restrictions was
the concentration of fecal coliform
bacteria associated with untreated
wastewater and wastes from livestock
and wildlife. CSOs are one of many
sources of fecal coliform that impact
shellfish harvesting. A summary of
all pollution sources identified in
the 1990 and 1995 National Shellfish
Registers as causing or contributing
to restrictions and prohibitions is
presented in Table 5.8.

A cooperative effort between the
Interstate Shellfish Sanitation
Conference and NOAA has resulted
in the development of a state Shellfish
Information Management System.
The system will summarize basic
information about shellfish programs
CSO controls implemented in Oswego, NY,
have helped provide suitable habitat for
desirable fish.
           Photo: P. MacNeill
         Table 5.8
         Pollution Sources Reported for Harvest Limitations on Classified Shellfish Growing
         Waters in the 1990 and 1995 National Shellfish Registers (NOAA 1997)
         Compared to the 1990 Register, the 1995 Register shows significant decreases in the acreage that is harvest-limited
         due to contributions from industry and wastewater treatment plants; the acreage impacted by CSOs remained
         relatively constant during the five-year period.
                                                          ted
Pollution Source
Urban Runoff
Precipitation-related discharges (e.g., septic leachate, animal wastes) from impervious surfaces, lawns,
and other urban land uses
Upstream Sources
Contaminants from unspecified sources upstream of shellfish growing waters
Wildlife
Precipitation-related runoff of animal wastes from high wildlife concentration areas (e.g., waterfowl)
Decentralized Wastewater Treatment Systems
Discharge of partially treated sewage from malfunctioning on-site septic systems
Wastewater Treatment Plants
Routine and accidental sewage discharge from public and private wastewater treatment plants with
varying levels of treatment
Agricultural Runoff
Precipitation- and irrigation-related runoff of animal wastes and pesticides from crop and pasture lands
Marinas
Periodic discharge of untreated or partially treated sewage from berthed vessels
Boating
Periodic discharge of untreated or partially treated sewage from vessels underway or anchored offshore
Industry
Routine and accidental discharges from production/manufacturing processes and on-site sewage
treatment
CSOs
Discharge of untreated sewage/storm water when sewage system capacity is exceeded by heavy rainfall
Total harvest-limited area, in acres
1990a
38%
46%
25%
37%
37%
11%
_
18%
17%
7%
6.4
million
1995a
40%
39%
38%
32%
24%
17%
17%
13%
9%
7%
6.7
million
 a Harvest-limited areas are impacted by multiple pollution sources. Annual values do not total 100 percent.
                                                                                                             5-13

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     in each state, replacing NOAA's
                                     national shellfish register. This system,
                                     which will provide spatial data through
                                     a web-based interface, is expected to be
                                     operational in 2004.

                                     Analysis of CSO Outfalls Discharging
                                     Near Classified Shellfish Growing Areas
                                      where shellfish harvesting is currently
                                      prohibited or restricted are in urban
                                      areas in the Northeast where CSOs
                                      are one of several factors that might
                                      account for impairment. Nevertheless,
                                      the association between prohibited and
                                      restricted conditions and the presence
                                      of CSO outfalls is strong.
     Table 5.9
     Harvest Limitations
     on Classified Shellfish
     Growing Areas Within Five
     Miles of a CSO Outfall
     Fifty-eight active CSO permits in nine
     states cover outfalls located within
     five miles of a classified shellfish
     growing area. Shellfish harvesting
     is prohibited or restricted in the
     majority of the 659 shellfish growing
     areas in proximity to CSO outfalls
     national database.
EPA associated the location of
individual CSO outfalls with classified
shellfish growing areas as reported
by NOAA in 1995, the last year for
which national data were available.
EPA limited the analysis to classified
shellfish growing areas within five
miles of a CSO outfall. The number
of classified areas was tabulated by
shellfish harvest classification. As
shown in Table 5.9, harvesting was
prohibited or restricted in most
of the classified shellfish growing
areas that are proximate to CSO
outfalls. As discussed earlier under
similar 305(b) and 303(d) analyses,
the presence of a CSO outfall alone
does not necessarily mean that the
CSO is causing or contributing to
the prohibition or restriction. Many
classified shellfish growing areas
 Shellfish Harvest Classification
 Prohibited
 Restricte'
 Approved
 Unclassified
 Total
 5.4 What Overall Water
      Quality Impacts Have Been
      Attributed to CSO and SSO
      Discharges in State and
      Local Assessments?
      State and local governments track
      environmental impacts and
      gather data for programmatic
 reasons that are not necessarily
 included in national assessments.
 Examples of environmental impacts
 included in this section were gathered
 from state and local reports and from
 watershed studies in which broad
 assessments of water quality were
 undertaken. These examples are not
 meant to be comprehensive. They are
 presented to illustrate environmental
 impacts attributed to CSO and SSO
Number of Classified Shellfish Growing Areas
      within 5 Miles of a CSO outfall
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                                                                 Chapter 5—Environmental Impacts of CSOs and SSOs
discharges, and, in some instances,
the site-specific circumstances under
which they occurred.

5.4.1 Water Quality Assessment in
     New Hampshire
In its 2000 Water Quality Report, New
Hampshire reported that bacteria is
the third leading cause of water quality
impairment in the state, causing or
contributing to 13 percent of the total
miles of impaired rivers and streams
in the state (NHDES 2000). Elevated
levels of bacteria impaired recreational
uses  as well as shellfish harvesting
uses  in New Hampshire. The overall
sources of water quality impairment to
rivers and streams in New Hampshire
are presented in Figure  5.3. As shown,
unknown  sources cause 79 percent of
the 642 miles of impairment reported.
A total of  24.1 miles were impaired
due to  CSOs; this  represents 3 percent
of all impaired waters in the state and
19 percent of impaired waters with a
known source of impairment.
5.4.2 Water Quality Assessment
     of the Mahoning River Near
     Youngstown, Ohio
Working in cooperation with
the City of Youngstown, Ohio,
USGS conducted a comprehensive
assessment of water quality and
habitat in the Mahoning River and
its tributaries (USGS 2002). The
City of Youngstown has 80 CSOs
that discharge to local receiving
waters. Water quality monitoring was
conducted during 1999 and 2000. CSO
discharges were found to contribute to
bacterial and nutrient loads observed
in the Mahoning River, but they were
not the only factor adversely affecting
water quality and habitat. USGS found
that:

    "Improvement of water quality in
    the lower reaches of the Mahoning
    River and Mill Creek (a tributary)
    to the point that each  waterbody
    meets its designated-use criteria
    will likely require an integrated
    approach that includes not only
    abatement of sewer overflow
    loadings but also identification
    and remediation of other loadings
    in Youngstown and improvement
    of water quality entering
    Youngtown."
                                    Other
                                                                                                  Figure 5.3
Agriculture
   7%
                                            Urban Runoff
                                                2%
                      CSOs
                       3%
           Municipal Point
             Sources
               2%

           Industrial Point
              Sources
               2%
                                                      Unknown
                                                        79%
                                        Sources of Water Quality
                                        Impairment in New
                                        Hampshire (NHDES 2000)
                                        In 2000, New Hampshire reported
                                        a total of 24.1 miles of rivers and
                                        streams impaired by CSOs; this
                                        represents 3 percent of all impaired
                                        waters in the state and 19 percent of
                                        impaired waters with a known sourc
                                        of impairment.
                                                                                .
                                                                                                          5-15

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     5.4.3 Water Quality in Indianapolis,
                                          Indiana
                                     The City of Indianapolis, Indiana, is
                                     working to identify and implement
                                     CSO controls. The city identified
                                     specific water quality problems in
                                     waterbodies receiving CSO discharges
                                     (City of Indianapolis 2000). The
                                     city's assessment of pollutant sources
                                     contributing to water quality problems
                                     is presented in Table 5.10. As shown,
                                     CSO discharges and wet weather
                                     bypasses at POTWs are ranked high
                                     relative to other sources of pollution.

                                     5.4.4 Water Quality Risk
                                          Assessment of CSO
                                          Discharges in King County,
                                          Washington
                                     King County, Washington, conducted
                                     a CSO water quality risk assessment
                                     for the Duwamish River and Elliot
                                     Bay, an estuary in Seattle (KCDNR
                                     1999). The water  quality assessment
                                     consisted of three main parts. First,
                                     more than 2,000 environmental
                                     samples were collected and analyzed
                                     to determine pollutant concentrations
                                     in the water, sediment, and tissues of
                                     aquatic organisms. Six CSO locations
                                     within the estuary were included in
this sampling. The samples were
analyzed for 35 chemical, physical,
and biological attributes. Next, a
computer model was developed to
describe water flow and contaminant
transport within the estuary. The
model was used to estimate current
pollution levels in estuarine water
and sediment as well as to predict
pollution levels after CSO control.
Finally, a risk assessment was
conducted to determine the impacts
of the various pollutants on aquatic
life, wildlife, and people that use
the estuary. Key study findings with
respect to risk reduction resulting
from CSO control are as follows:

•   No predicted reduction in risks
    for water-dwelling organisms;

•   Some predicted reduction in risks
    to sediment-dwelling organisms
    near the CSO discharges;

•   A possible increase in the variety
    of benthic organisms near CSOs
    as the result of a decrease in
    organic matter;

•   A possible reduction in impacts
    of localized scouring and
    sedimentation, which may be
   Table 5.10
     Relative Contributions
     of Pollutant Sources to
     Water Quality Problems in
     Indianapolis, Indiana (City
     of Indianapolis 2000)

     Indianapolis ranked the contribution
     of CSO discharges and wet weather
     bypasses at POTWs high relative
     to other sources of pollution in
     local receiving waters. Blank
     spaces represent negligible or no
     contribution in comparison to other
     sources.
Pollutant Source Dissolved Oxygen Bacteria Aesthetic
Violations Violations Problems
CSO Discharges
Upstream Sources
Storm Water
Wet Weather Bypass at POTW
Electric Utility Thermal Discharge
Sediment Oxygen Demand
Dams
Water Supply Withdrawals
Septic Tanks
High


High
Low
Low
Low
Low

High
Low
Low
High




Low
High

High






5-16

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                                                               Chapter 5—Environmental Impacts of CSOs and SSOs
    small compared to the overall
    scouring impacts of the river and
    sediment from other sources; and

•   No predicted reduction in risks
    to wildlife as other sources
    contribute the majority of the
    risk-related chemicals.

A stakeholder committee composed
of local citizens, business owners,
environmental organizations, and
tribal governments drew the following
conclusions from the study results:
not meant to be comprehensive.
They are presented to illustrate
representative environmental impacts
attributed to CSO and SSO discharges,
and, in some instances, the site-
specific circumstances under which
they occurred. CSO or SSO discharges
are clearly the cause of documented
environmental impacts in some cases,
and are a contributing factor in others.
Several examples summarize studies in
which impacts from CSOs and SSOs
were sought, but were not found.
•   Existing sediment quality and
    associated risks to people, wildlife,
    and aquatic life in the estuary are
    unacceptable;

•   Levels of human pathogens and
    fecal coliform in the estuary are
    unacceptable;

•   Controlling CSOs according to the
    King County comprehensive sewer
    plan will improve some aspects of
    environmental quality; and

•   Even if CSOs are completely
    eliminated, overall environmental
    quality of the estuary will
    continue to be unacceptable.
5.5  What Impacts on Specific
     Designated Uses Have Been
     Attributed to CSO and SSO
     Discharges in State and
     Local Assessments?
      Examples of environmental
      impacts included in this section
      were gathered from state and
local reports and watershed studies;
the examples are presented according
to the designated use impacted by
CSO and SSO discharges. They are
5.5.1 Aquatic Life Support
The designated use for aquatic
life support is achieved when the
water provides suitable habitat for
the protection and propagation
of desirable fish, shellfish, and
other aquatic organisms. Oxygen-
demanding substances are the
principal pollutants found in CSOs
and SSOs that can cause or contribute
to impaired aquatic life support.
CSO and SSO discharges can also
contribute sediment, pathogens,
nutrients, and toxics to receiving
waters, but there is  little evidence that
levels of these pollutants in CSOs
and SSOs are major causes of aquatic
life impairment. Select examples
of impacts or relevant studies are
presented below.

Fish Kills in North Carolina
Reports of impaired aquatic life (i.e.,
fish kills) have been investigated
and documented in North Carolina
since 1997 (NCDENR2003). A
summary of fish kills attributed to
sewage spills from 1997 to 2002 is
presented in Table 5.11. As shown,
SSOs are a relatively small cause of the
documented fish kills. Other causes of
                                                                                                       5-17

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Report to Congress on the Impacts and Control ofCSOs and SSOs
  Table 5.11
     Fish Kills Reported in
     North Carolina: 1997-
     2002 (NCDENR 2003)
        
     Between 1997 and 2002, NCDENR
     attributed the deaths of nearly
     10,000 fish to SSOs (sewer spills).
Year    Total Number   Number of Fish    Total Number    Number of Fish Killed
        of Fish Kills   Kills Attributed to   of Fish Killed    in Events Attributed to
                       Sewer Spills                        Sewer Spills
1997
1998
1999
2000
2001
2002
                                     fish kills include chemical spills, heavy
                                     rainfall, eutrophication, low dissolved
                                     oxygen due to unspecified causes,
                                     natural phenomena (e.g., temperature
                                     and salinity effects), and unknown
                                     causes.

                                     Individual fish kill events linked to
                                     sewage spills in North Carolina are
                                     presented in Table 5.12. Descriptive
                                     comments provided by field crews
                                     investigating the fish kills are listed in
                                     an abbreviated manner. The oxygen-
                                     depleting substances in the spilled
                                     sewage appear to reduce oxygen
                                     levels to a point at which there is
                                     insufficient oxygen to support aquatic
                                     life, particularly when spills occur in
                                     relatively small streams. No North
                                     Carolina communities are served by
                                     CSSs.

                                     Assessment of SSO Impacts on Fish
                                     and Aquatic Life at Camp Pendleton,
                                     California
                                     In September 2000, an SSO occurred
                                     at the Marine Corps  Base Camp
                                     Pendleton near Oceanside, California.
                                     The California State Water Resources
                                     Control Board investigated the spill,
                                     monitored water quality, and assessed
                                     the impact of the spill on fish and
                                     aquatic life (Vasquez 2003). The SSO
                                     occurred at a deteriorated access port
                                     in a sewer force main operated by
                                     the Marine Corps. An estimated 2.73
                                     million gallons of sewage was spilled
                                     over an eight-day period. Data showed
                                     that dissolved oxygen levels in the
                                     impacted area dropped below 1 mg/L,
                                     well below the numeric criteria of 5
                                     mg/L and levels needed to support
                                     most aquatic life, and remained low
                                     for several days. The assessment of
                                     impacted wildlife documented 320
                                     dead fish, 67 dead shrimp,  169 dead
                                     clams,  1 dead snail, and 1 dead bird.

                                     Assessment of PCBs in the Buffalo
                                     River, New York
                                     Polychlorinated biphenyls (PCBs)
                                     are a contaminant of concern for the
                                     Buffalo River in New York and the
                                     Great Lakes in general. PCB levels
                                     in the river often exceed state water
                                     quality criteria, and PCBs found in
                                     fish tissue exceed levels allowed by
                                     the Food and Drug Administration.
                                     In 1994, a study was conducted
                                     to identify sources of PCBs to the
                                     Buffalo River (Loganthan et al. 1997).
                                     Monitoring was conducted in the 700-
                                     acre Babcock Creek sewershed, one
                                     of 27 sewersheds served by combined
5-18

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                                                                    Chapter 5—Environmental Impacts of CSOs and SSOs
      Table 5.12
        Fish Kills Caused by Sewage Spills in North Carolina: 1997 - 2001
        (NCDENR2003)

        Oxygen-depleting substances in SSOs (sewer spills) can reduce in-stream dissolved oxygen to levels that
        are insufficient to support aquatic life.
 Date         Waterbody
 Investigated
 7/1/97
 7/14/97
 7/29/97
 8/13/97
 8/14/97
 8/19/97
 9/23/97
 10/7/97
 11/9/97
 1/5/98
 3/16/98
 7/6/98
 6/29/99
 4/13/00
 6/9/00
 5/3/01
 10/23/01
Tributary to Cokey Swamp
Elerbee Creek
Tributary to Elerbee Creek
Swift and Mahlers Creeks
Tributary to Northeast Creek
Coon Creek
Little Buffalo Creek
Lovills Creek
East Beaverdam Creek
Cooper's Pond
Unnamed Lake
Reedy Fork Creek
Muddy Creek
South Fork Catawba River
Town Branch
Subdivision Pond
Tributary to Hare Snipe Cree
                           Number of   Comments
                           Fish
                           Killed
300         Spill of at least 23,000 gallons of sewage
120         Sewer spill at storm drain due to sump overflow
100         30,000 gallon spill at pump station
1,000        500,000-1,000,000 gallon sewer line spill
200         20,000 gallon sewer line spill
3,500        1,200,000 gallon spill at pump station
            50,000 gallon sewage spill
            Sewage leakage at junction in sewage lines
            500,000 spill at broken manhole
            Sewage spill
            114,000 gallons spilled
            3,000 gallons spilled at pump station
            Sewer overflow reported in area
200         3,000 gallons spilled
            5,200 gallons spilled due to blockage
            Sewage overflow
            40,000 gallon sewage spill
sewers in the City of Buffalo. The
study detected the presence of PCBs
in CSO discharges from the Babcock
Creek CSO outfall and confirmed
that the city's CSS was a source of
PCBs to the river. Monitoring at other
study locations as well as watershed
modeling indicated that the PCB
loadings from unknown, non-CSO
sources were more than 10 times
greater than the loading from all of
the CSOs  in the lower Buffalo River
(Atkinson et al.  1994).
                         Whole Effluent Toxicity of CSO
                         Discharges in Toledo, Ohio
                         Whole effluent toxicity testing uses
                         Ceriodaphnia dubia (water flea)
                         and Pimephales promelas (fathead
                         minnow) to measure if a discharge
                         is toxic. The City of Toledo, Ohio,
                         conducted whole effluent toxicity
                         testing on samples collected at four
                         separate CSO outfalls during wet
                         weather conditions (Jones & Henry
                         Engineers 1997). In comparison
                         with laboratory control groups,
                         acute (short-term) toxicity was
                         observed in samples from two CSO
                                                                                                               5-19

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     outfalls, and chronic (long-term)
                                     toxicity was observed in samples from
                                     the other two CSO outfalls. Some
                                     chronic toxicity effects were also
                                     observed in river samples taken above
                                     and below the CSO discharges. Parallel
                                     modeling analysis of CSO discharges
                                     by the City of Toledo identified copper,
                                     lead, silver, and zinc as pollutants of
                                     concern.

                                     As a result of the testing, Toledo
                                     recently developed a draft Industrial
                                     Wastewater Release Minimization
                                     Plan with policies and procedures for
                                     minimizing the discharge of industrial
                                     wastewater during CSO  events (City
                                     of Toledo 2003). The plan includes
                                     a variety of measures to  reduce
                                     the volume and concentration of
                                     industrial wastewater discharged to the
                                     CSS during wet weather events. Eight
                                     industrial facilities identified as having
                                     the potential to contribute toxics to
                                     CSO discharges have implemented or
                                     scheduled changes to their operations
                                     to reduce  flow, load, or both. The
                                     city plans to contact the remaining
                                     industrial facilities participating in its
                                     Industrial Pretreatment  Program to
                                     encourage operational modifications to
                                     reduce the volume and concentration
                                     of wastewater discharged to the CSS
                                     during wet weather events.

                                     Analysis of Toxics in CSOs in
                                     Washington, D.C.
                                     The District of Columbia Water and
                                     Sewer Authority monitored its CSO
                                     outfalls for nine months during 1999
                                     and 2000  (DCWASA 2002). The
                                     purpose of the monitoring was to
                                     characterize the chemical composition
                                     of CSO discharges in order to assess
the potential for receiving water
impacts. Monitoring was carried out
for 127 priority pollutants including:

•  Total recoverable metals and
   cyanide

•  Dissolved metals

•  Pesticides and PCBs

•  Volatiles and semivolatiles

The CSO monitoring data reported
by the Water and Sewer Authority
indicated that all results for priority
pollutants were below the laboratory
method reporting limits, except for
cyanide, chloroform, and several
metals. The cyanide and chloroform
concentrations were found to be
well below the applicable water
quality criteria.  Further evaluation of
detected metals showed that all but
dissolved copper and dissolved zinc
were at acceptable levels. Additional
analysis using the EPA-approved
CORMIX and Biotic Ligand models
indicated that the effective instream
concentrations of dissolved copper and
dissolved zinc were also at acceptable
levels. Although Washington, D.C. is
not a heavily industrialized  city, 25
permitted significant industrial users
and approximately 3,000 smaller
commercial dischargers (e.g.,  medical
facilities, printing and photocopying
facilities) discharge to its sewer system.

Fish  Diversity in Chicago-area
Waterways
Prior to the implementation of
wastewater treatment facility upgrades
in the 1970s and CSO controls in
the 1980s, aquatic life suffered in
urban Chicago-area streams. The
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                                                                Chapter 5—Environmental Impacts of CSOs and SSOs
ability of Chicago-area waterways to
support a rich and diverse aquatic
community was severely limited
by inadequate levels of wastewater
treatment, discharges of chlorinated
effluent at treatment facilities,
and CSO discharges. In particular,
CSO discharges contributed large
amounts of oxygen-demanding
organic substances that depressed
oxygen levels in the waterways, and
the presence of chlorine in treatment
plant effluent contributed to
conditions that were toxic to aquatic
life. Improved wastewater treatment,
including facilities to  dechlorinate
treated wastewater, and CSO control
over the past 30 years have improved
the richness  and diversity of aquatic
life. As shown in Figure 5.4, the total
number of fish species found and
supported in the principal waterways
in Chicago has expanded during this
period (MWRD 1998).

5.5.2 Recreation
Primary contact and secondary
contact recreation uses are protected
when a waterbody supports swimming
and other water-based activities,
                                    such as boating, without risk of
                                    adverse human health effects from
                                    contact with the water. The principal
                                    pollutants found in CSOs and SSOs
                                    that affect recreational uses at beaches
                                    are microbial pathogens and, to a
                                    lesser extent, floatables. Select local
                                    examples of impacts to recreational
                                    uses and relevant studies are presented
                                    below. Additional information about
                                    potential human health impacts
                                    from recreational exposure to water
                                    contaminated by CSO or SSO
                                    discharges is presented in Chapter 6.

                                    Beach Closures in California
                                    SSOs were identified by the California
                                    State Water  Resources Control Board
                                    as one of several sources of beach
                                    pollution in its California Beach
                                    Closure Report 2000 (CSWRCB
                                    2001). Beach closures result from
                                    exceedences of bacterial standards. A
                                    closure provides the public with notice
                                    that the water is unsafe for contact
                                    recreation (i.e., swimming poses an
                                    unacceptable risk of illness).

                                    The majority of beach closures during
                                    2000 were attributed to unspecified
                                    creek and river sources. As shown in
3  7Ql
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     1974    1978    1982
                                1986    1990
                                  Year
                                          1994    1998   2002
                                                                              Fish Species Found in
                                                                              the Chicago and Calumet
                                                                              River System, 1974 - 2001
                                                                              (MWRD 1998; Dennisen
                                                                              2003)
The total number of fish species
found in the Chicago and Calumet
River system increased six-fold
between 1974 and 2001
                                                                                                  :ies
                                                                                                  umet

                                                                                                  d
                                                                                                        5-21

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Report to Congress on the Impacts and Control ofCSOs and SSOs
    Figure 5.5
     Sources of Contamination
     Resulting in California
     Beach Closures in 2000
     (CSWRCB2001)

     In California, problems with sewer
     lines such as line breaks; blockages
     due to grease, roots, or debris;
     and pump station failures have
     been identified as the cause of a
     to a significant number of beach
     closures.
Sources of Contamination
Resulting in Beach Closures
Percent
 \/    Unspecified river sources
 58%
       SSOs
                                     42%
       CSOs
 \/    Unknown
 Total
                                     Figure 5.5, SSOs accounted for 42
                                     percent and CSOs accounted for less
                                     than one percent of all beach closures
                                     in California during 2000. California
                                     has only two communities with CSSs:
                                     San Francisco and Sacramento.

                                     A summary of beach closures due to
                                     SSOs in California in 2000 is presented
                                     in Figure 5.6. The total number of
                                     days that at least one beach was closed
                                     is presented in the map by county.
                                     The accompanying bar graph shows
                                     closures by county in beach-mile
                                     days, a measure of beach availability
                                     for recreation that integrates miles of
                                     beach closed with days of impairment.

                                     Beach Closures in Connecticut
                                     The Connecticut Council on
                                     Environmental Quality reported
                                     on beach closures in the state in its
                                     2001 Annual Report (CTCEQ 2002).
                                     Connecticut's goal is to eliminate
                                     beach closures caused by discharges
                                     of untreated or poorly treated
                                     wastewater, which Connecticut
                                     identified as the most common cause
                                     of elevated bacteria levels. Currently,
                                     several towns close beaches following
                                     a heavy rainfall as a precaution,
                                    100%
         presuming that CSO, SSO, and
         storm water discharges will occur
         and contaminate water. The average
         number of days that beaches are closed
         depends largely on the frequency and
         amount of rainfall during the beach
         season. The long-term trend in beach
         closures reported by the Council is
         presented in Figure 5.7.

         Beach Closures in Orange County,
         California
         Orange County monitors and reports
         on bacteria levels along 112 miles of
         its ocean and bay coastline. Major
         findings documented in its Annual
         Ocean and Bay Water Quality Report
         (Orange County 2002) are:

         •  The total number of SSOs
             reported to the Orange County
             Health Care Agency has steadily
             increased over the past 15 years.

         •  The total number of ocean and
             bay beach closures due to SSOs
             has increased each year since 1999.

         •  The total number of beach mile-
             days lost as a result of sewage spills
             has remained constant since 1999.
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                                                             Chapter 5—Environmental Impacts of CSOs and SSOs
                                          Beach Mile-Days
                                                                                                Figure 5.6
                           San Diego
                             Orange
                           San Mateo
                          Los Angeles
                           Monterey
                          Mendocino
                             Ventura
                            Sonoma
                        San LuisObispo
        353.4
      133.6
• 3.9
I 2.6
I  0.7
I  0.4
I  0.1
Beach Mile-Days is the product of the number
of miles of coastline and the number of days
of impairment.
                                                                187
Beach Closures in
California During 2000
Attributed to SSOs
(CASWRCB2001)

During 2000, nine coastal counties
in California reported beach
closures as a result of SSOs. Beach
closure statistics are presented two
ways.The number shown in each
county indicates the total number
of days that are least one beach in
the county was closed in 2000. The
number of lost beach mile-days
in each county is presented in the
adjacent bar chart.
 n



1987     1989     1991     1993    1995    1997    1999    2001

                               Year
                                                                            \verage Number of
                                                                           Days per Year Coastal
                                                                           Municipalities in
                                                                           Connecticut Closed One
                                                                           or More Beaches (CTCEQ
                                                                           2002)
                                        Yearly variations in beach closures
                                        are a product of rainfall patterns
                                        and incidents such as sewer line
                                        ruptures. In 1999,a relatively
                                        dry summer led to less than two
                                        closings, on average.The sharp
                                        increase in beach  closings in 2000
                                        was the result of a rainy summer.
                                                                                                        5-23

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Report to Congress on the Impacts and Control ofCSOs and SSOs
    Summary of
    Unauthorized Wastewater
    Discharges in Orange
    County, California,
    that Resulted in Beach
    Closures (Mazur 2003)
        
    Blockages were identified as the
    cause of approximately three-
    quarters of all unauthorized
    wastewater discharges that resulted
    in beach closures in Orange County
    between 1999 and 2002.
Cause of Discharge
Line breaks
Blockages
Pump station failures
Treatment plant discharges
Miscellaneous
Total unauthorized discharges
1999
38
210
14
0
14
276
2000
55
288
8
0
25
377
2001
69
308
15
4
16
412
2002
95
409
11
2
2
522
A summary of the specific types of
unauthorized wastewater discharges
that resulted in beach closures is
presented in Table 5.13. As shown,
the total number of unauthorized
discharges resulting in beach closures
increased  steadily between 1999 and
2002. However, during this same time
period the total number of beach mile-
days lost as a result of sewage spills has
remained  constant, suggesting that the
impacts from individual spills have been
reduced. The Orange County Health
Care Agency attributes the reduced
impacts to improvements in wastewater
utility response procedures and increased
regulatory oversight.

Lake Michigan Beach Closures
The Lake Michigan Federation tracks
beach closures in Michigan, Indiana,
Illinois, and Wisconsin based on
data collected from local health
departments, parks managers, and
other municipal  agencies. EPA and
NRDC data were used to augment
these sources prior to 2000. The
Federation's tabulation  of beach
closures from 1998 to 2002 for all of
Lake Michigan is presented in Figure
5.8. The Federation believes that CSOs
are  associated with a high percentage
of the beach closures. Other sources
of pathogens that cause or contribute
to beach closures include wildlife,
storm water runoff, direct human
contamination, and re-suspension
of bacteria in sediment (Brammeier
2003).

To examine whether CSOs were
responsible for beach closures and
advisories along Lake Michigan
in Cook County, Illinois, the
Metropolitan Water Reclamation
District of Greater Chicago conducted
independent research into  river
reversals to Lake Michigan (MWRD
2003). River reversals to Lake
Michigan  occur when, due to heavy
rainfall, the gates that separate  Lake
Michigan  and the Chicago River are
opened. River water impacted by
CSOs is discharged to the lake during
river reversals. Swimming at nearby
beaches is preemptively banned for
two consecutive days by park officials
when river reversals occur.

In its report, the District noted hat
river reversals (and thus the discharge
of CSO-impacted waters) to Lake
Michigan  were infrequent and did
not explain most beach closings and
advisories (MWRD 2003). Other
sources of bacteria at Chicago beaches
include sea gulls and bacteria in sand
deposits (USGS 2001).
5-24

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                                                                Chapter 5—Environmental Impacts of CSOs and SSOs
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                  1999
2001
2002
5.5.3 Shellfish Harvesting
The designated use of shellfish
harvesting is achieved when a
waterbody supports a population
of shellfish free from toxics and
pathogens that could pose a significant
human health risk to consumers.
Accordingly, the principal pollutants
in CSO and SSO discharges found to
impact this use are pathogens, and, to
a lesser extent, toxics. An example of
shellfishing restrictions imposed as a
result of SSO discharges is presented
below.

Shellfish Harvest Limitations as a
Result of SSO to the Raritan River,
New Jersey
On March 2, 2003, a 102-inch
diameter sewer in Middlesex
County, New Jersey, ruptured and
spilled untreated wastewater into
residential areas and the Raritan River.
Approximately 570 million gallons
of wastewater were discharged over
a nine-day period while the pipeline
was being repaired. Daily monitoring
tracked the movement of elevated
bacteria levels in the river (NJDEP
2003). The spill caused high levels of
fecal coliform in nearby, downstream
waters including Raritan Bay, Sandy
Hook Bay, and the Navesink River.
                              EPA and the New Jersey Department
                              of Environmental Protection (NJDEP)
                              sampled affected waters daily and
                              determined that fecal coliform counts
                              were highest in the Raritan Bay
                              (2,400-4,500 fecal coliform counts
                              per 100 mL); counts were also high
                              in Sandy Hook Bay (up to 1,100
                              fecal coliform counts per 100 mL).
                              Once the spill was stopped, levels
                              of fecal coliform dropped to below
                              88 counts per 100 mL throughout
                              the river and bay system. By March
                              15, 2003 (two weeks after the spill
                              began), the highest level reported was
                              in the western end of Raritan Bay
                              at an acceptable level of 43 counts
                              per 100 mL. Fecal coliform was not
                              detected at nearby ocean beaches. The
                              movement of the bacteria plume and
                              its dissipation and dilution over time
                              are illustrated in Figure 5.9.

                              The spill forced NJDEP to close
                              shellfish beds totaling approximately
                              30,000 acres in  Raritan and Sandy
                              Hook Bays, as well as in the Navesink
                              and Shrewsbury Rivers. Of the total
                              acres closed, more than 6,000 acres
                              were reopened after four weeks,
                              and an additional 20,000 acres were
                              reopened after six weeks (NJDEP
                              2003).
                                                                                                   Figure 5.8
Lake Michigan Beach
Closures, 1998-2002
(Brammeier 2003)

During the 2002 swimming season,
authorities issued a total of 919
beach closures and advisories for
Lake Michigan. Of the 34 Lake
Michigan coastal counties,65
percent were monitored for beach
pollution, up from  50 percent in
2000.
                                                                                                         5-25

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Report to Congress on the Impacts and Control ofCSOs and SSOs
    Figure 5.9
     Movement of Bacteria
     Plume from SSO
     Discharge in Raritan Bay,
     New Jersey (NJDEP 2003)

     This large SSO event (570 million
     gallons over nine days, beginning
     on March 2,2003) resulted in the
     closure of more than 30,000 acres
     of shellfish beds for four to six
     weeks, until shellfish tissue was clear
     of fecal coliform, viral, and metal
     contamination. Data are not shown
     for the Navesink River and portions
     of Sandy Hook Bay.
I   1 Land
Fecal Coliform Results
(MPN/lOOOmL)
    0-88
    88-500
    500-1000
    1000-1500
    1500-2000
    2000-2500
    2500-3000
^H 3000-3500
^H 3500^)000
 • 4000-5000
Monmoutn
 County
                                               I    I Land
                                               Fecal Coliform Results
                                               [MPN/lOOOmL)
                                                   88-500
                                                   500-1000
                                                   1000-1500
                                                   1 500-2000
                                                   2000-2500
                                                   2500-3000
                                                   3000-3500
                                                   3500^1000
                                                   4000-5000
                             Monmouth
                              County
5-26

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                                                                Chapter 5—Environmental Impacts of CSOs and SSOs
5.6  What Factors Affect the
     Extent of Environmental
     Impacts Caused by CSOs
     and SSOs?

       Compiling and presenting
       information on the extent of
       environmental impacts caused
by CSOs and SSOs is complicated by
a number of factors. At the local level,
site-specific water quality impacts
vary depending on the volume and
frequency of CSO or SSO discharges,
the size and type of waterbody that
receives the overflows, other sources
of pollution, and the designated uses
for the waterbody. Depending on
the particular combination of these
factors, impacts from CSOs and SSOs
can be visible and intense or relatively
minor. Further, because CSO and SSO
discharges are intermittent and often
occur during wet weather, resulting
impacts can be transient and difficult
to monitor. This section discusses
key factors, including timescale and
receiving water characteristics, that
affect the extent of environmental
impacts caused by CSOs and SSOs.

5.6.1 Timescale Considerations
Although CSO and SSO discharges
are intermittent, the resultant impacts
may not be temporary and can persist
to varying degrees. Some impacts,
such as aesthetic impairment due to
the presence of floatable material,
occur immediately when sewers
overflow and are considered short-
term impacts. In contrast,  nutrients
discharged with CSOs and SSOs can
contribute to eutrophication on a
time scale of weeks  or months; such
impacts are classified as long-term
impacts. Similarly, chronic toxicity
impacts associated with metals,
pesticides, and synthetic organic
compounds that contaminate both
waterbodies and sediments can affect
aquatic systems over decades.

5.6.2 Receiving Water
     Characteristics
The degree to which a CSO or SSO
discharge produces an environmental
impact in a particular waterbody
depends on the rate and volume of the
discharge, the degree of mixing and
dilution, and the assimilative capacity
of the waterbody (see Section 5.2.3).
In general, the larger the waterbody
and the smaller the discharge, the
less likely it is that environmental
impacts will occur. In contrast,
small waters with little dilution and
little assimilative capacity can be
severely impacted by relatively small
discharges.

Once pollutants are discharged into
a waterbody, fate and transport
processes determine the extent and
severity of environmental impacts.
Small-scale hydraulics, such as water
movement near a discharge point,
determine the initial dilution and
mixing of the discharge. Large-scale
water movement due to river flow
and tidal action largely determine the
transport of pollutants over time and
distance. Processes identified as most
important in assessing the impacts of
CSOs and SSOs include:

•  Dilution and transport of
   pathogens and toxics in the water
   column;

•  Deposition of settleable solids;

•  Resuspension or scour of
   settleable solids; and

•  Chemical exchange or dilution
   between the water column and
   sediment pore water (Meyland et
   al. 1998).
                                                                                                        5-27

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                             Chapter  6
    Human Health  Impacts of CSOs
                        and SSOs
   In addition to causing and
   contributing to the environmental
   impacts reported in Chapter
5, CSOs and SSOs can cause or
contribute to human health impacts.
Microbial pathogens and toxics can
be present in CSOs and SSOs at levels
that pose a risk to human health.
Human health impacts occur when
people become ill  due to contact
with or ingestion of water or shellfish
that have been contaminated with
microbial pathogens or toxics.

Although it is clear that CSOs
and SSOs contain  disease-causing
pathogens and other pollutants, EPA
found limited quantitative evidence
of actual human health impacts
attributed to specific CSO and
SSO events. Factors such as under-
reporting and incomplete tracking
of waterborne illness, the presence of
pollutants from other sources, and
the use of non-pathogenic indicator
bacteria in water quality monitoring
often make it difficult to establish a
cause-and-effect relationship between
human illnesses and CSO and SSO
discharges.
This chapter documents and expands
the current understanding of human
health impacts from CSOs and
SSOs. The chapter first describes
the pollutants commonly present in
CSOs and SSOs that can cause human
health impacts. The next sections
discuss human exposure pathways;
demographic groups and populations
that face the greatest exposure and
risk of illness; and ways in which
human health impacts from CSOs and
SSOs are communicated, mitigated,
or prevented. The identification and
tracking of illnesses associated with
CSOs and SSOs are also discussed.
Several examples of human health
impacts are provided in the chapter.
6.1 What Pollutants in CSOs
    and SSOs Can Cause
    Human Health Impacts?
      The principal pollutants present
      in CSOs and SSOs that can
      cause human health impacts
are microbial pathogens and toxics.
The presence of biologically active
chemicals (e.g., antibiotics, hormones,
                                                                     In this chapter:
6.1  What Pollutants in CSOs
    and SSOs Can Cause
    Human Health Impacts?

6.2  What Exposure Pathways
    and Reported Human
    Health Impacts are
    Associated with CSOs and
    SSOs?

6.3  Which Demographic
    Groups Face the Greatest
    Risk of Exposure to CSOs
    and SSOs?

6.4  Which Populations Face
    the Greatest Risk of Illness
    from Exposure to the
    Pollutants Present in CSOs
    and SSOs?

6.5  How are Human Health
    Impacts from CSOs and
    SSOs, Communicated,
    Mitigated, or Prevented?

6.6  What Factors Contribute
    to Information Gaps in
    Identifying and Tracking
    Human Health Impacts
    from CSOs and SSOs?

6.7  What New Assessments
    and Investigative  Activities
    are Underway?
                                                                                             6-1

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     and steroids) is also a concern but is
                                     less well understood at this time.

                                     6.1.1 Microbial Pathogens
                                     Microbial pathogens include hundreds
                                     of different types of bacteria, viruses,
                                     and parasites. Microbial pathogens
                                     of human and non-human origin are
                                     present in domestic and industrial
                                     wastewater. The presence of specific
                                     microbial pathogens in wastewater
                                     depends on what is endemic or
                                     epidemic in  the local community and
                                     is often transient. Some microbial
                                     pathogens also have environmental
                                     sources. In general, microbial
                                     pathogens are easily transported
                                     by water. They can cause disease in
                                     aquatic biota and illness or even death
                                     in humans. The three major categories
                                     of microbial pathogens present in
                                     CSOs and SSOs are bacteria, viruses,
                                     and parasites. Fungi do not have a
                                     major presence in wastewater (WERF
                                     2003b), and thus in  CSOs and SSOs.

                                     Bacteria
                                     Bacteria are  microscopic, unicelluar
                                     organisms. Two broad categories
                                     of bacteria are associated with
                                     wastewater: indicator bacteria and
                                     pathogenic bacteria. Indicator bacteria
                                     are common in human waste and
                                     are relatively easy to detect in water,
                                     but they are not necessarily harmful
                                     themselves. Their presence is used
                                     to indicate the likely presence of
                                     disease-causing, fecal-borne microbial
                                     pathogens that are more difficult to
                                     detect. Enteric (intestinal) bacteria
                                     have been used for more than 100
                                     years as indicators of the presence
                                     of human feces in water and overall
                                     microbial water quality (NAS 1993).
                                     Enteric bacteria commonly used as
indicators include total coliform, fecal
coliform, E. coli, and enterococci.
Further discussion of bacterial
indicators is provided in Section 6.6.

Pathogenic bacteria are also common
in human waste and are capable
of causing disease. Human health
impacts from pathogenic bacteria
most often involve gastrointestinal
illnesses. The predominant symptoms
of pathogenic bacterial infections
include abdominal cramps, diarrhea,
fever, and vomiting. Pathogenic
bacteria can also cause diseases such
as typhoid fever, although this is
not common in the United States.
In addition to attacking the human
digestive tract, the pathogenic bacteria
present in CSOs and SSOs can
cause illnesses such as pneumonia,
bronchitis, and swimmer's ear.
Common pathogenic bacteria, typical
concentrations present in sewage
(where available), and associated
disease and effects are summarized in
Table 6.1.

Viruses
Viruses are submicroscopic infectious
agents that require a host in which
to reproduce. Once inside the host,
the virus reproduces and manifests
in illness (EPA 1999c). More than
120 enteric viruses are found in
sewage (NAS 1993). The predominant
symptoms resulting from enteric virus
infection include vomiting, diarrhea,
skin rash, fever, and respiratory
infection.  Most waterborne and
seafood-borne diseases throughout
the world are caused by viruses (NAS
2000). Many enteric viruses,  however,
cause infections that are difficult to
detect (Bitton 1999). A list of common
enteric viruses,  including typical
6-2

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                                                                    Chapter 6—Human Health Impacts of CSOs and SSOs

Bacteria Concentration
in Sewage3
(per lOOmL)
Campy/o- 3,700 -1 00,000
bacter
Pathogenic 30,000-
£ co// 1 0,000,000



Salmonella 0.2 - 1 1 ,000
S. typhi

Shigella 0.1-1,000
Vibrio
cholera
Vibrio non- 10-1 0,000
cholera

Yersinia
Diseaseb

Gastroenteritis

Gastroenteritis



Salmonellosis
Typhoid fever

Shigellosis
Cholera

Gastroenteritis


Yersinosis
Effects* Infective Dose^d ^^^^^^""^7"

Vomiting, diarrhea

Vomiting, diarrhea,
Hemolytic Uremic
syndrome (HUS),
death in susceptible
populations
Diarrhea, dehydration
High fever, diarrhea,
ulceration of the small
intestine
Bacillary dysentery
Extremely heavy
diarrhea, dehydration
Extremely heavy
diarrhea, nausea,
vomiting
Diarrhea

102-

106-



104-
103-

101-
103-

102-



106

108



107
107

102
108

106


Common Pathogenic
Bacteria Present in
Sewage
Infective dose is defined as the
number of pathogens required to
cause subclinical infection. Infective
doses are typically given as ranges,
as the actual infective dose depends
on the pathogen strain and an
individual's health condition.
^    j






106
a Details in Appendix I
bEPA1999C
c Yates and Gerba 1998
d Lue-Hing 2003
concentrations present in sewage
(where available), and associated
disease and effects are summarized
in Table 6.2. Infective doses are not
reported; enteric viruses typically are
very infectious.
          Parasites
          Parasites by definition are animals or
          plants that live in and obtain nutrients
          from a host organism of another
          species. The parasites in wastewater
          that pose a primary public health
Virus Group
Adenovirus
Astrovirus
Noravi ruses (includes
Norwalk-like viruses)
Echovirus
Enterovirus (includes
polio, encephalitis,
conjunctivitis, and
coxsackie viruses)
Reovirus
Rota virus
Concentration
in Sewage3
(per lOOmL)
10-1 0,000



0.05-100,000
0.1 -125
0.1 - 85,000
Disease1*
Respiratory disease,
gastroenteritis,
pneumonia
Gastroenteritis
Gastroenteritis
Hepatitis, respiratory
infection, aseptic meningitis
Gastroenteritis,
heart anomalies,aseptic
meningitis, polio
Gastroenteritis
Gastroenteritis
Effects b
Various effects
Vomiting, diarrhea
Vomiting, diarrhea
Various effects,
including liver
disease
Various effects
Vomiting, diarrhea
Vomiting, diarrhea
                                                                                                         Table 6.2
 a Details in Appendix I
 bEPA1999C
 c Yates and Gerba 1998
 d Lue-Hing 2003
                                                                                   Common Enteric Viruses
                                                                                   Present in Sewage

                                                                                   Enteric viruses are typically very
                                                                                   infectious: 1-10 virus particles can
                                                                                   cause infection.
                                                                                I
                                                                                                                 6-3

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                      concern are protozoa and helminths
                                      (NAS 1993). Parasitic protozoa
                                      commonly present in sewage include
                                      Giardia lamblia, Cryptosporidium
                                      parvum, and Entamoeba histolytica.
                                      These protozoa cause acute and
                                      chronic diarrhea (NAS 1993). Giardia
                                      causes giardiasis, which is one of the
                                      most prevalent waterborne diseases in
                                      the United States (EPA 2001e).

                                      Ranges of typical concentrations of
                                      protozoa in sewage and information
                                      on infective doses are summarized
                                      in Table 6.3. As shown, ingestion of
                                      a small number of parasitic protozoa
                                      is capable of initiating infection.
                                      Therefore, the presence of low levels
                                      of parasitic  protozoa in wastewater
                                      is a greater health concern than are
                                      low levels of most pathogenic bacteria
                                      (NAS 1993).

                                      Helminths,  or parasitic worms, include
                                      roundworms, hookworms, tapeworms,
                                      and whipworms. These  organisms are
                                      endemic in  areas lacking adequate
                                      hygiene. Very little documentation of
                                      waterborne transmission of helminth
                                      infection is  available (NAS 1993).
                                      Helminth infections can be difficult to
                                      diagnose and often exhibit no obvious
                                      symptoms.
                                      Indicator Bacteria and Microbial
                                      Pathogens in Sewage
                                      Microbial pathogen concentrations
                                      in sewage vary greatly depending on
                                      the amount of illness and infection in
                                      the community served by the sewer
                                      system. The time of year can also
                                      be important, as some outbreaks of
                                      viral disease are seasonal. Average
                                      concentrations of indicator bacteria
                                      (e.g., fecal coliform) and other
                                      microbial pathogens (enteric viruses
                                      and protozoan parasites) shed by
                                      an infected person are shown in
                                      Table 6.4. These high concentrations
                                      illustrate that a single person shedding
                                      pathogenic organisms can cause a
                                      large pathogen load to be discharged
                                      to a municipal sewer system.

                                      6.1.2 Toxics
                                      As described in Section 4.1 of this
                                      report, toxics are chemicals or
                                      chemical mixtures that, under certain
                                      circumstances of exposure, pose a
                                      risk to  human health. Individuals can
                                      suffer chronic health effects resulting
                                      from prolonged periods of ingestion
                                      or consumption of water, fish, and
                                      shellfish contaminated with a toxic
                                      substance. Generally, metals and
                                      synthetic organic chemicals are the
   Table 6.3
   Common Parasitic
   Protozoa Present in
   Sewage

   Parasitic protozoa have very low
   infective doses, which makes their
   presence in CSO and SSO discharges
   an important public health
   concern.
                                      Parasitic
                                      Protozoa
              Concentration  Diseaseb   Effects'1
              in Sewage3
              (per L)
Cryptosporidium  3-13,700
              Crypto-
              sporidiosis
           Diarrhea
                                              Infective Dosec
1 -150
Entamoeba
4-52
Amedbiasis  Prolonged diarrhea
(amoebic    with bleeding,abscess
dysentery)   of the liver and small
           intestine
Giardia
2-200,000      Giardiasis    Mild to severe diarrhea,
                         nausea, indigestion
                                      a Details in Appendix I
                                      bEPA1999C
                              c Yates and Gerba 1998
10-20
                                   10 - 100
6-4

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                                                                Chapter 6—Human Health Impacts of CSOs and SSOs
 Organism
 Fecal Coliform Bacteria
 Enteric Viruses
 Protozoan Parasites
toxic substances present in CSO and
SSO discharges that can cause human
health impacts. Metals and synthetic
organic chemicals are introduced into
sewer systems through a variety of
pathways (Ford  1994). These include
permitted industrial discharges,
improper or illegal connections,
improper drain  disposal of chemical
remnants, and urban runoff in areas
served by CSSs. While the occurrence
and concentration of specific toxics
in CSOs and SSOs vary considerably
from community to community and
from event to event depending on site-
specific conditions (see Tables 4.4  and
4.5), EPA found no evidence of human
health impacts due to toxics in CSO
and SSO  discharges.

Metals
The metals most commonly identified
in wastewater include cadmium,
chromium, copper, lead, mercury,
nickel, silver, and zinc (AMSA
2003a). In CSSs, storm water can also
contribute metals. EPAs Nationwide
Urban Runoff Program (NURP)
identified copper, lead, and zinc in
91 percent of urban storm water
samples collected (EPA 1983a).  That
is, all three metals were present in
91 percent of samples. Other metals
commonly detected in urban runoff
include arsenic,  cadmium, chromium,
and nickel. The NURP Program
focused on end-of-pipe samples and
         Number per Gram of Feces
         108 to 109
         103to1012
         106 to 107
therefore did not consider receiving
water impacts.

Metals are a human health concern
for two reasons. First, metals are
persistent in the environment. This
creates an increased chance of long-
term human exposure once metals are
introduced to a waterbody. Second,
metals such as arsenic, cadmium,
lead, and mercury bioaccumulate
in the human brain, liver, fat, and
kidneys, causing detrimental effects.
Other impacts that can be caused by
metals include dermatitis, hair loss,
gastrointestinal distress, bone disease,
and developmental illnesses.

Synthetic Organic Chemicals
The synthetic organic chemicals that
have been identified in CSOs  and
SSOs include chlorinated aromatic
hydrocarbons such as polychlorinated
biphenyls (PCBs), chlorinated
hydrocarbons such as pesticides, and
polycyclic aromatic hydrocarbons.
Synthetic organic chemicals can be
ingested by drinking contaminated
water or by eating contaminated
fish that have bioaccumulated the
chemical. Synthetic organic chemicals
can also be absorbed through the skin.
Their effects on humans range from
skin rash to more serious illnesses
including anemia, nervous system
and blood problems, liver and kidney
problems, reproductive difficulties,
and increased risk of cancer.
                                                                                                  Table 6.4
Concentration of
Indicator Bacteria and
Enteric Pathogens Shed
by an Infected Individual
(Schaub1995)
This table shows that a single
infected person can shed a
number of pathogenic organisms.
le
large
nisms.
                                                                                                         6-5

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     6.1.3 Biologically Active Chemicals
                                     Recent research efforts have begun to
                                     consider the presence of biologically
                                     active chemicals—antibiotics, caffeine,
                                     hormones, human and veterinary
                                     drugs, and steroids—in wastewater
                                     (Kummerer 2001). For the most part,
                                     these chemicals have not undergone
                                     extensive analysis for environmental
                                     fate and transport, human health
                                     impacts, or ecological impacts.
                                     Concerns about the presence of these
                                     biologically active chemicals focus on
                                     abnormal physiological processes and
                                     reproductive impairments, increased
                                     incidence of cancer, development
                                     of antibiotic-resistant bacteria,
                                     and potential increased toxicity of
                                     chemical mixtures. Human health
                                     effects, however, are largely unknown
                                     (Kolpin et al. 2002).
                                   Little is known about the effectiveness
                                   of conventional wastewater treatment
                                   processes in the removal of these
                                   biologically active chemicals. The
                                   relative concentrations of these
                                   chemicals in CSOs and SSOs are also
                                   unknown.
                                   6.2  What Exposure Pathways
                                        and Reported Human
                                        Health Impacts are
                                        Associated with CSOs and
                                        SSOs?
                                            Humans may be exposed
                                            to the pollutants found in
                                            CSOs and SSOs through
                                   several pathways. The most common
                                   pathways include recreating in waters
                                   receiving CSO or SSO discharges,
                                   drinking water contaminated by CSO
Sources of Synthetic Organic
Chemicals Deposition:
NY/NJ Harbor
The New York-New Jersey Harbor Estuary Program sponsored studies to estimate
pollutant loads,  including  loads of synthetic organic chemicals to New York
Harbor. As shown, the studies identified six sources of PCB inputs to the harbor.
Application of a mass balance water quality food chain model for PCBs indicated
that discharges of PCBs to  the lower estuary from municipal point sources and
CSOs are significant in  causing PCB levels in striped bass to exceed the FDA
standard for fish consumption (NYNJHEP 1996).
                                                             Atmospheric
                                                              deposition
                                                                 3%
                                                       CSOs
                                                       10%
                                                                          Landfill leachate
                                                                                      Tributaries/
                                                                                     upstream inputs
                                                                                        50%
                                                  Municipal
                                                 point sources
                                                    22%
6-6

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                                                                  Chapter 6—Human Health Impacts of CSOs and SSOs
or SSO discharges, and consuming
or handling fish or shellfish that
have been contaminated by CSO
or SSO discharges. Other pathways
include direct contact with discharges,
occupational exposure, and secondary
transmission.

During wet weather events, CSO- and
SSO-impacted waterbodies typically
receive microbial pathogens and
toxics from a variety of other sources
including municipal and industrial
wastewater discharges, urban storm
water runoff, and agricultural
nonpoint source discharges. These
"interferences" can complicate the
identification of specific cause-and-
effect relationships between individual
CSO or SSO discharges and human
health impacts.

6.2.1 Recreational Water
In the United States, millions of
people use natural waters (e.g., oceans,
lakes, rivers, and streams) each year
for a variety of recreational activities.
The National Survey on Recreation
and the Environment, conducted by
the U.S. Forest Service and NOAA,
describes nationwide participation in
50 categories of outdoor recreation
activities (Leeworthy 2001). The
survey estimates the percentage of the
population, 16 years of age or older,
  U.S. Population
  (16 and Older)
  Percent participating
  Number in millions
Boating/Floating <
      36%
                 participating in water-based recreation
                 activities. Participation in more than
                 one activity in a single water-based
                 recreation category is possible (e.g.,
                 respondents may report both sailing
                 and canoeing). Data  from the most
                 recent version of the survey (the
                 period of July 1999 to January 2001)
                 are presented in Table 6.5.

                 A number of studies have documented
                 the risks of gastroenteritis among
                 people recreating in water
                 contaminated with microbial
                 pathogens (NAS 1993; Wade et al.
                 2003). Recreational exposure generally
                 comes from contaminants suspended
                 in the water column  entering the body
                 via oral ingestion. Exposure can also
                 occur through the  eyes, ears, nose,
                 anus, genitourinary tract, or dermal
                 cuts and abrasions (Henrickson et
                 al. 2001). Contact with and ingestion
                 of ocean water near wastewater or
                 storm drain outfalls have resulted in
                 increases in reported respiratory, ear,
                 and eye symptoms by ocean swimmers
                 and surfers (Corbett et al. 1993; Haile
                 et  al. 1999).

                 As described in Chapter 5,25 percent
                 of the beaches inventoried in EPAs
                 National Health Protection Survey of
                 Beaches under the BEACH  Program
                 had at least one advisory or area
                 closing during the  2002 swimming
Fishing
 34%
Swimming'
   61%
    131
                                                         Table 6.5
                                    Participation in Water-
                                    Based Recreation in U.S.
                                    between July 1999 and
                                    January 2001
The National Survey on Recreation
and the Environment estimates
nationwide participation in various
outdoor recreation activities,
including water-based recreation.
Participation in more than one
activity is possible.
a Includes sailing, canoeing, kayaking, rowing, motor-boating, water skiing, personal watercraft use, wind
surfing,and surfing.
b Includes swimming in freshwater or saltwater, snorkeling, scuba, and visiting a beach.
                                                                                                              6-7

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Figure 6.1
    Microbial Pathogens
    Linked to Outbreaks
    in Recreational Waters,
    1985-2000

    Shigella was the most commonly
    identified cause of waterborne
    disease outbreaks linked to
    recreational waters between 1985
    and 2000. Shigella has a relatively
    low infective dose of 10-100 and
    is typically found in wastewater in
    concentrations of 0.1-1,000 per 100
    ml of sewage.
season. Elevated bacteria levels were
cited as the primary cause for 75
percent of these beach advisories or
closures. CSOs were reported to be
responsible for  1 percent of reported
closings and advisories, and 2 percent
of advisories and closures that had
a known cause.  SSOs (including
sewer line breaks) were reported to
be responsible for 6 percent of all
reported advisories and closings, and
12 percent of advisories and closing
that had a known cause (EPA 2003a).

Reported Human Health Impacts
A review of CDC Surveillance
Summaries identified 74 waterborne
disease outbreaks linked to open
recreational waters (i.e., rivers, streams,
beaches, lakes, and ponds) from 1985
to 2000. A waterborne disease outbreak
is defined by CDC as two or more
people experiencing similar illness after
exposure to a waterborne pathogen.
A total of 5,601  cases of illness were
attributed to these 74 waterborne
disease outbreaks (CDC 1988,1990,
1992, 1993, 1996a, 1998, 2000, 2002).
The source of the pathogens causing
these waterborne disease outbreaks
was not identified in CDC's reports.
These waterborne disease outbreaks,
however, were caused by the types of
microbial pathogens found in CSOs
and SSOs. Figure 6.1 shows that
Shigella, which is present in CSOs
and SSOs, caused the largest number
of recreational water-associated
outbreaks having a known cause.

Additional  information from CDC
Surveillance Summaries on outbreaks
linked to recreational exposure in
fresh or marine waters contaminated
with microbial pathogens is presented
in Appendix I.

CDC Surveillance Summaries also
identify outbreaks linked to swimming
pools or hot tubs. For swimming
pools and hot tubs, 191 recreational
waterborne disease outbreaks with
14,836 cases of illness were reported
to CDC between 1985 and 2000 (CDC
1988, 1990, 1992, 1993, 1996a, 1998,
2000, 2002). This is 265 times the
                                Other known agents
                       Norwalk-like
                         virus
                          4%
                   Giardia
                    4%

           Crypotosporidium
                                               Schistosoma spp.
                                                    7%
                                                    Pathogenic E.coli
                                                         13%
              Unknown Agent
                  23%
                                                       Shigella
                                                        21%
                                                                      Naegleria fowler!
                                                                          17%
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                                                                Chapter 6—Human Health Impacts of CSOs and SSOs
number of illnesses reported for open
recreational waters.

Estimated Illnesses at Recognized
Beaches
In developing this Report to
Congress, EPA found an absence of
direct cause-and-effect data relating
the occurrence of CSO and SSO
discharges to specific human health
impacts. Lacking comprehensive
data, EPA was able to implement an
alternate approach to estimate the
annual number of illnesses caused
by recreational exposure to CSO and
SSO discharges at a small subset of
the nation's swimming areas—that is,
those recreational beaches recognized
by state authorities ("recognized
beaches"). EPAs illness estimate was
based on existing environmental
and recreational use  databases. Data
limitations made it impossible to
develop a comprehensive estimate
of illness at all swimming areas at
this time, but EPA believes that a
significant number of additional
illnesses occur in exposed swimmers
at many inland and unrecognized
beaches.

EPAs estimation of illness at
recognized beaches was limited to
gastrointestinal illness. EPA employed
a multi-step process, including the
following:

•  Number of recognized beaches
   using specific management
   approaches;

•  Number of CSO and SSO events
   impacting recognized beaches;

•  Number of individuals exposed
   annually;
•   Average concentration of fecal
    coliform bacteria at affected
    beaches;

•   Rate of infection for exposed
    population; and

•   Total annual number of
    gastrointestinal illnesses.

The number of highly credible
gastrointestinal illnesses (HCGI)
resulting from human exposure
to SSOs and CSOs at recognized
beaches was estimated by combining
information on the number
of exposed swimmer days, the
concentration of indicator bacteria
to which swimmers are exposed, and
the Cabelli/Dufour dose-response
functions for  marine and fresh
waters. First, EPA calculated the total
number of illnesses caused by CSOs
and SSOs, and then attributed them
separately to CSO illnesses or SSO
illnesses according to the ratio of CSO
to SSO events in the BEACH Survey.
A more detailed presentation of EPAs
methodology is included in Appendix
J.

Results from the analyses are presented
in Table 6.6. The range shown reflects
differences in how compliance rates
with beach advisories were estimated.
The lower bound uses a compliance
rate of 90 percent, and the upper
bound uses a  compliance rate of 36
percent. As shown, CSOs and SSOs
are  estimated to cause between 3,448
and 5,576 illnesses annually at the
recognized beaches included in this
analysis. This  estimate captures only a
portion of the likely number of annual
illnesses attributable to CSO and SSO
contamination of recreational waters.
                                                                                                          6-9

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Table 6.6
    Estimated Illness
    Resulting from
    Recreational Exposure to
    CSOs and SSOs at Select
    Beaches

    This table shows the portion of the
    estimated number of annual illnesses
    attributable to exposure to CSO and
    SSO contaminated water at state-
    recognized beaches in the U.S. and
    its territories.
                                      Source
                                                                    Lower Bound
                                                        Upper Bound
6.2.2 Drinking Water Supplies
Public water systems regulated by EPA,
states, and tribes provide drinking
water to 90 percent of Americans (EPA
2002e). Approximately 65 percent of
the population served by these systems
receive water primarily taken from
surface water sources such as rivers,
lakes, and reservoirs. The remaining 35
percent drink water that originated as
groundwater (EPA 1999d).

Reported Human Health Impacts
People can contract waterborne
diseases through consumption of
municipal drinking water, well
water, or contaminated ice. Because
drinking water is directly ingested,
and it is generally ingested in larger
quantities than recreational water that
is accidentally ingested, drinking water
is an important pathway of exposure.
From 1985 to 2000, 251 outbreaks and
462,169 cases of waterborne illness
related to contaminated drinking
water were reported to CDC (CDC
1988, 1990, 1992, 1993, 1996a, 1998,
2000, 2002). The vast majority of
these cases of illness are from a
1993 cryptosporidiosis outbreak in
Milwaukee, Wisconsin, which affected
an estimated 403,000 people; the CDC
did not specifically identify untreated
wastewater as contributing to the
Milwaukee outbreak.

As shown in Appendix I, EPA
identified a subset of 55 of these 251
outbreaks linked to drinking source
water contaminated with human
sewage or to drinking water taken
 SSOs linked to Drinking
 Water Contamination:
 Cabool, MO
  Between December 15, 1989, and January 20, 1990, residents of and visitors to
  Cabool, Missouri, experienced 243 cases of diarrhea and four deaths (Swerdlow
  et al. 1992).The CDC conducted a household survey and concluded that persons
  drinking municipal water were  18.2 times more likely to develop diarrhea than
  persons using private well water (Geldreich et al. 1992). Observations suggested
  that Cabool's SSS was prone to excessive storm water infiltration and therefore was
  unable to convey all of the wastewater to the treatment facility. As a result, frequent
  capacity-related SSOs occurred, spilling sewage onto the ground surface in areas
  over drinking water distribution lines  and near water meter boxes. During the
  outbreak, the water distribution system was under construction,allowing untreated
  sewage to contaminate the drinking water system (Geldreich et al. 1992).
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                                                                Chapter 6—Human Health Impacts of CSOs and SSOs
                                    Other known
                            Shigella     agents
                Campylobacter
          Pathogenic Eco//'
          Cryptosporidium
              10%
                      Unknown agent
                         31%
                                        Microbial Pathogens
                                        Causing Outbreaks
                                        Linked to Drinking Water
                                        1985-2000

                                        Ciardia was responsible for 42
                                        percent of the outbreaks of
                                        waterborne disease linked to
                                        drinking water.
from rivers, streams, or lakes. Of
these, EPA identified 11 outbreaks
accounting for 7,764 cases of
waterborne illness that CDC linked
to drinking water contamination with
sewage. Only one of these outbreaks
was linked directly to CSOs or SSOs.
The outbreaks were caused, however,
by the types  of microbial pathogens
found in CSOs and SSOs. As shown in
Figure 6.2, Giardia, which is present
in significant concentrations in CSOs
and SSOs, caused the largest number
of outbreaks linked to drinking water.
A summary of these outbreaks is
provided in Appendix I.
Proximity of CSO Outfalls to Drinking
Water Intakes
As described in Chapter 5 and
documented in Appendix F, EPA geo-
referenced more than 90 percent of
all CSO outfalls. EPA compared the
locations of these CSO outfalls to
drinking water intakes. Only drinking
water systems that serve a community
on a year-round basis and that use
surface water as the primary source
of water were considered in this
analysis. Approximately 7,519 such
systems operate in the United States,
of which 6,631 (85 percent) have been
  In July 1998, a lighting strike and the subsequent power outage caused 167,000
  gallons of raw sewage to flow into Brushy Creek in Texas (TDH 1998). The sewage
  contaminated municipal drinking water wells that supplied the community of
  Brushy Creek. Although the wells are not in direct contact with surface waters (the
  wells are more than 100 feet deep and encased in cement), drought conditions at
  the time are thought to have caused water from Brushy Creek to be drawn down
  into the aquifer and into the wells through a geologic fissure. It is estimated that 60
  percent of Brushy Creek's population of 10,000 were exposed to Cryptosporidium
  and approximately 1,300 residents became ill with cryptosporidiosis. Residents of
  Brushy Creek were supplied water from the contaminated wells for approximately
  eight days (TDH 1998).
                                          Drinking Water
                                          Contaminated by Sewage:
                                          Brushy Creek, TX
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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Table 6.7
    Association of CSO
    Outfalls with Drinking
    Water Intakes

    EPA identified 59 CSO outfalls in
    seven states with outfalls located
    within one mile upstream of a
    drinking water intake.
geo-referenced to the NHD and are
included in this analysis.

All of the drinking water systems
within one mile of any CSO
outfall were selected for further
analysis. As shown in Table 6.7, EPA
identified seven states with outfalls
located within one mile upstream
of a drinking water intake. Phone
interviews were conducted with
both the  NPDES permit-holder
and drinking water authority in
the identified areas to confirm the
location of the CSO outfall, the status
of the CSOs (active/inactive), and the
location of the drinking water intake.
In many  cases, the NPDES permit-
holder reported that the CSO was
inactive, as a result of sewer separation
or other CSO controls.

EPA identified and confirmed 59
active CSO outfalls within one  mile of
a drinking water intake. One NPDES-
permit holder reported that receiving
water modeling found that the
drinking water intake (located within
one mile, but on the opposite side
of the river) was not affected by the
CSO. Interviews with drinking  water
      EPA Region
authorities found, where a primary
drinking water intake was located
within one mile of an active CSO, each
drinking water authority was aware
of the CSO. Further, in all cases, lines
of communication existed between
the drinking water authority and the
NPDES permit-holder. In many cases
the drinking water authority indicated
adjustments are made to the treatment
process during wet weather.

This assessment indicates that CSO's
generally do not pose a major risk
of contamination to most public
drinking water intakes. However, to
understand the relationship between
a discharge point and a downstream
drinking water intake the transport
and fate of the discharge between the
two points must be modeled under the
range of real world flow conditions for
that stream reach. Such modeling is
beyond the scope of this report.

6.2.3 Fish and Shellfish

Fish and shellfish are widely
consumed in the United States and
are  a valued economic and natural
resource (NYNJDEP 2002a). In 1995,
Number of CSO Outfalls within 1 mile
 upstream of a drinking water intake
                                                                          Total:
                                     Note: EPA was unable to confirm data for an additional 14 outfalls in two states ( PA and WV); these outfalls
                                     are not included in this table.
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                                                                 Chapter 6—Human Health Impacts of CSOs and SSOs
the most recent year for which data
are available, 77 million pounds of
clams, oysters, and mussels were
harvested in the coastal United States
(NOAA 1997). Shellfish grown in
contaminated waters concentrate
microbial pathogens and can have
higher concentrations than the
waters in which they are found.
Viable pathogens can be passed on
to humans by eating whole, partially
cooked, or raw contaminated shellfish.

Reported Human Health Impacts
The World Health Organization
reported that seafood is involved in 11
percent  of all disease outbreaks from
food ingestion in the United States
(WHO 2001). The most common
                                     illness associated with eating sewage-
                                     contaminated raw shellfish and fish is
                                     gastroenteritis (CERI 1999).

                                     A review of CDC Surveillance
                                     Summaries identified eight
                                     waterborne disease outbreaks linked to
                                     the consumption of contaminated fish
                                     or shellfish for the period 1985-2000.
                                     These outbreaks  resulted in 995 cases
                                     of illness (CDC 1990, 1995, 1996b,
                                     1997). More information on these
                                     outbreaks is provided in Appendix
                                     I. In most cases, the contaminated
                                     fish or shellfish were exposed to or
                                     grown in sewage-contaminated water.
                                     Waste dumped overboard by boaters
                                     and improperly treated sewage were
                                     the most commonly cited sources
                                     of fish and shellfish contamination.
The New York State Department of Health compiled data on shellfish-associated
illness (most commonly gastroenteritis) recorded in New York State from 1980 to
1999 (NYNJHEP 2002b). The incidence of reported illness has dropped markedly
since its peak in 1982. The study was able to trace most of the outbreaks in 1982 to
Rhode Island shellfish.The study noted that it is often difficult to identify the source
of the shellfish that induced the outbreak. Decreases in shellfish-associated disease
are attributed  to a number of factors including: improvements  in wastewater
treatment leading  to  reductions  in concentrations of waterborne microbial
pathogens; more restrictions on shellfish harvesting in contaminated areas; and
more public awareness of the risks associated with consuming raw shellfish. The
study also noted that although shellfish beds are carefully monitored for pathogenic
contamination, the levels of toxic contaminants in shellfish, including impacts from
marine algal toxins, need additional study.

                     Number of Reported Outbreaks of Shellfish
                        Associated Illnesses, New York State
           140
           120
         £ 100
          I  80
         5  60
         2  40
            20
             0
                                     ••
                                    Year
                                                                                Shellfish-Associated Illness:
                                                                                              New York State
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     Direct links to CSO and SSO events
                                     as a cause of contamination were not
                                     made.

                                     6.2.4 Direct Contact with Land-
                                          Based Discharges
                                     Many SSOs discharge to terrestrial
                                     environments including streets,
                                     parks, and lawns. CSSs and SSSs
                                     can also back up into buildings,
                                     including residences and commercial
                                     establishments. These land-based
                                     discharges present exposure pathways
                                     that are different than those pathways
                                     associated with typical discharges to
                                     water bodies. Exposure to land-based
                                     SSOs and building backups typically
                                     occurs through dermal contact. The
                                     resulting diseases are often similar
                                     to those associated with exposure
                                     through drinking or swimming in
                                     contaminated water, but may also
                                     include illness caused by inhaling
                                     microbial pathogens (CERI 1999).

                                     Reported Human Health Impacts
                                     In general, very few outbreaks
                                     associated with direct contact
                                     with land-based SSOs have been
                                     documented. Land-based SSOs
                                     tend to leave visible evidence of
                                     their occurrence, such as deposits of
                                     sanitary products and other wastes
                                     commonly flushed down a toilet. The
                                     presence of these items often acts as
                                     a deterrent to direct contact with the
                                     SSO. Further, municipal response
                                     to land-based SSOs often includes
                                     cleaning the impacted area by washing
                                     the sewage into a nearby manhole
                                     or storm drain and disinfecting as
                                     needed. This review identified one
                                     confirmed outbreak resulting from
                                     direct contact with a discharge of
                                     untreated sewage in Ocoee, Florida.
This event resulted in 39 cases of
hepatitis A (Vonstille 1993).

6.2.5 Occupational Exposures
Many occupational settings
occasionally expose personnel to
microbial pathogens. These include
restaurants and food processing,
agriculture, hospitals and healthcare,
emergency response, and wastewater
treatment.

Wastewater treatment plant workers
and public works department
personnel operate and maintain
wastewater treatment facilities and
respond to CSO or SSO events. In
doing so, they may be exposed to
microbial pathogens present in CSOs
and SSOs. Police, firefighters, rescue
divers, and other emergency response
personnel also face exposure to
CSOs and SSOs. Depending on the
context in which the overflow event
occurs, exposure can occur through
inhalation, ingestion, and dermal
contact. Adherence to good personal
hygiene and the appropriate use of
personal protective equipment are
important in minimizing the potential
for injury or illness.

Reported Human Health Impacts
Comprehensive epidemiologic
research on waterborne illness
associated with occupational exposure
to untreated wastewater is lacking.
Some researchers believe that
wastewater workers may experience
increased numbers of bacterial, viral,
and parasitic infections without
exhibiting signs or symptoms of
illness. These are called "sub-clinical"
infections (AFSCME 2003). One
study concluded that the lowest rates
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                                                                Chapter 6—Human Health Impacts of CSOs and SSOs
of illness are found among workers
employed in wastewater treatment
for less than five years, the highest
rates in workers with five to 10 years
of exposure, and lower rates again
in workers with 15 years or more
of exposure (Dowes et al. 2001). An
explanation for this is that workers
build immunity to many of the
microbial pathogens present in the
work environment over the course
of their employment, and those who
become very ill no longer work in the
plant. This phenomenon is also known
as the "healthy worker effect."

In general, the effect of microbial
pathogens, other than hepatitis A, on
wastewater workers has been given
little attention, and "there have been
few epidemiologic studies conducted
among sewage workers in the U.S. to
determine the actual prevalence and
types of infections" (AWR 2001).

One confirmed waterborne disease
outbreak through occupational
exposure was identified from
the review of CDC Surveillance
Summaries. In 1982, 21 cases
of gastrointestinal illness were
identified among 55 police and fire
department scuba divers training
in sewage-contaminated waters
(CDC 1983). The divers developed
gastrointestinal disease more than
four times as frequently as nondiving
firefighters, the control group in the
study. Although the causes of illness
in many divers were not identified,
gastrointestinal parasites were found
in 12 divers: Entamoeba histolytica
in five divers, and Giardia lamblia in
seven divers.
6.2.6 Secondary Transmission
An individual who contracts
an infection from exposure to a
waterborne microbial pathogen may,
in turn, infect other individuals,
regardless of whether symptoms are
apparent in the first individual. This
is commonly referred to as "secondary
transmission." The rate of secondary
transmission depends largely on
the particular microbial pathogen.
Illnesses caused by secondary
transmission are  not included in CDC
Surveillance Summaries, which list
only primary illnesses.

Reported Human Health Impacts
Secondary transmission statistics
obtained from a variety of waterborne
and non-waterborne disease outbreaks
are shown in Table 6.8 (NAS 1998). As
presented, the secondary attack ratio
represents the ratio of secondary cases
to primary cases.
6.3  Which Demographic
     Groups Face the Greatest
     Risk of Exposure to CSOs
     and SSOs?
     Several demographic groups
     face increased risk of exposure
     to the pollutants in CSOs and
SSOs because they are more likely to
spend time in locations impacted by
such discharges. These groups include
people recreating in CSO- and SSO-
impacted waters, subsistence fishers,
shellfishers, and wastewater workers.
The sections that follow describe
exposure risks for each of these groups
in greater detail. This information is
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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Table 6.8
    Examples of Secondary
    Transmission from
    Waterborne and Non-
    Waterborne Disease
    Outbreaks (MAS 1998)

    An individual who contracts an
    infection may, in turn,infect other
    individuals. This table shows for
    every two individuals infected with
    Norwalk virus, one to two individuals
    can become infected via secondary
    transmission.
Microbial Pathogen
Cryptosporidium
Shigella
Rotavirus
Giardia
Unspecified virus causing
viral gastroenteritis
Norwalk virus
Secondary Attack Ratio
0.33
0.28
0.42
1.33
0.22
0.5-1.0
Source of Outbreak
Contaminated apple cider
Child day care center
Child day care center
Child day care center
Contaminated drinking water
Contaminated recreational water
presented based on the availability of
literature documenting each group's
potential for exposure, rather than
on the relative sensitivity of each
population to the pollutants in CSO
and SSO discharges.

6.3.1  Swimmers, Bathers, and
     Waders
Swimming in marine and fresh water
has been linked directly to diseases
caused by the microbial pathogens
found in wastewater (Cabelli et
al. 1982). For example, a 1998
study comparing bathers and non-
bathers found that 34.5 percent of
gastroenteritis and 65.8 percent of ear
infections reported by participants
were linked to bathing in marine
waters contaminated with sewage.
The percentage of people who lost at
least one day of normal activity due to
contacting one of the illnesses studied
ranged from 7 to 26 percent (Fleisher
etal. 1998).

Many variables influence the exposure
of people to  pathogens in recreational
water. These factors include whether
people swim or wade, the type of
pathogens present at the time of
exposure, the route of exposure
(ingestion or skin contact), and
individual susceptibility to waterborne
disease (WSDH 2002).
6.3.2Subsistence and Recreational
     Fishers
Subsistence and recreational fishers
and their families tend to consume
more fish and shellfish than the
general population, and men tend to
consume more fish and shellfish than
women (Burger et al. 1999). Further,
in areas conducive to fishing, people
with lower education levels or lower
income levels consume more fish and
shellfish,  as it is often an inexpensive
source of protein (Burger et al. 1999).

Cultural preferences influence the
amount and frequency of fish as well
as shellfish consumption and the
methods  for preparing and serving
fish and shellfish. For example, a study
of two Native American groups in
Puget Sound in Washington found
that these groups consumed fish at
much higher rates than the general
public and at rates greater than those
recommended by EPA (Toy et al.
1996). Asians and Pacific Islanders
generally consume fish at much higher
rates than the general United States
population (Sechena et al. 1999).
In addition, cooking methods and
consumption rates of parts of the
fish that tend to concentrate toxins
(e.g., skin, head, organs, and fatty
tissue) can increase the risk of human
health impacts from consuming
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                                                                Chapter 6—Human Health Impacts of CSOs and SSOs
contaminated fish and shellfish (e.g.,
Wilson et al. 1998; WDNR 2003).

Fish and shellfish advisories target
recreational and subsistence fishers.
Despite warnings and advisories,
however, many fishers consume
their catch. May and Burger (1996)
found that a majority of urban and
suburban recreational fishers ignored
warnings issued by the New York State
Department of Health and the New
Jersey Department of Environmental
Protection.

6.3.3 Wastewater Workers
Wastewater workers are more likely
to come into contact with untreated
wastewater than the general public,
but there is insufficient data to
determine whether wastewater
workers or their families face an
increased risk of illness as a result
of this exposure. Although there is
disagreement regarding the benefits of
additional immunization above those
recommended by CDC for the adult
general population (i.e., diptheria
and tetanus), WERF (2003b) asserts
that wastewater workers should be
vaccinated for both Hepatitis A and B.
6.4  Which Populations Face
     the Greatest Risk of Illness
     from Exposure to the
     Pollutants Present in CSOs
     and SSOs?
       Certain demographic groups,
       including pregnant women,
       children, individuals with
compromised immune systems,
and the elderly, may be at greater
risk than the general population for
serious illness or a fatal outcome
resulting from exposure to the types
of pollutants present in CSOs and
SSOs. Specific characteristics of
these demographic groups that make
them particularly susceptible to these
illnesses are discussed in more detail in
the following sections. These sensitive
groups represent almost 20 percent
of the U.S. population (Gerba et al.
1996). Also, tourists and travelers may
be more prone to waterborne illnesses
than local residents (EPA 1983b). EPA
research has found that when exposed
to pathogens found in local sewage,
local residents have been shown to
develop fewer symptoms than non-
residents or visitors.

6.4.1 Pregnant Women
During pregnancy, women appear
to be at greater risk of more serious
disease outcomes from exposure to
the types of enteric viruses found
in CSOs and SSOs (Reynolds 2000).
Waterborne diseases contracted during
pregnancy may result in transfer of
the illness to the child either in utero,
during birth, or shortly after birth
(Gerba et al. 1996).

6.4.2 Children
The incidence of several waterborne
infectious diseases caused  by the
types of pollutants present in CSO
and SSO discharges is significantly
greater in infants and children than
in the general population  (Laurenson
et al. 2000). Factors contributing to
the susceptibility of children include
children's naturally immature immune
systems and child-associated behaviors
that result in abnormally high
ingestion rates during recreational
exposure to contaminated water
(Laurenson et al. 2000). For example,
                                                                                                        6-17

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    children frequently splash or swim in
                                    waters that would be considered too
                                    shallow for full-body immersion by
                                    adults (EPA 200Ib).

                                    6.4.3 Immunocompromised Groups
                                    People with compromised immune
                                    systems, such as those with AIDS,
                                    organ transplant recipients, and
                                    people undergoing chemotherapy,
                                    are more sensitive than the general
                                    public to infection and illness caused
                                    by the types of pollutants present
                                    in CSO and SSO discharges (Gerba
                                    et al.  1996). Using Wisconsin death
                                    certificate data, Hoxie et al. (1997)
                                    analyzed cryptosporidiosis-associated
                                    mortality in AIDS patients following
                                    the 1993 Milwaukee outbreak that
                                    affected an estimated 403,000 people.
                                    The researchers found that AIDS
                                    was the underlying cause of death
                                    for 85 percent of post-outbreak
                                    cryptosporidiosis-associated deaths
                                    among residents of the Milwaukee
                                    area. Further, the researchers found
                                    that AIDS mortality increased
                                    significantly in the six months
                                    immediately after the outbreak,
                                    then decreased to levels lower than
                                    expected, and then returned to
                                    expected levels. This suggests that
                                    some level of premature mortality was
                                    associated with the outbreak.

                                    6.4.4 Elderly
                                    The elderly are at increased risk for
                                    waterborne illness due to a weakening
                                    of the immune system that occurs
                                    with age (Reynolds 2000). Studies
                                    have found that people over 74 years
                                    old, followed  by those between 55
                                    and 74, and then by children under
5, respectively experience the highest
mortality from diarrhea as a result of
infection by waterborne or foodborne
illness (Gerba et al. 1996). Studies
of a giardiasis outbreak in Sweden
that occurred when untreated sewage
contaminated a drinking water supply
found people over 77 years old faced
an especially high risk of illness
(Ljungstrom and Castor 1992).
6.5  How are Human Health
     Impacts from CSOs and
     SSOs Communicated,
     Mitigated, or Prevented?
A       variety of programs are in
       place to reduce human health
       impacts associated with
exposure to microbial pathogens
and toxics. These programs generally
involve preventive measures enacted
by public health officials, including:
communication efforts to warn the
public about risk and threats; and
monitoring, reporting, and tracking
activities. This section is focused on
agencies, activities, and programs
designed to communicate, mitigate,
or prevent potential human health
impacts from exposure to CSOs and
SSOs.

6.5.1 Agencies and Organizations
     Responsible for Protecting
     Public Health
Numerous agencies and organizations
have responsibilities for monitoring,
tracking, and notifying the public of
potential human  health impacts. These
include federal and state agencies,
local public health officials, owners
and operators of municipal wastewater
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                                                                 Chapter 6—Human Health Impacts of CSOs and SSOs
collection and treatment facilities, and
non-governmental organizations.

Federal Agencies
EPA administers a national water
quality standards program that
establishes criteria to support
designated uses including recreation,
drinking water supply, and shellfish
harvesting. EPA also administers a
national safe drinking water program
with a goal that, by 2005, 60 percent of
the population served by community
drinking water systems will receive
their water from systems with active
source water protection programs
(EPA  1997b). In developing source
water protection programs, EPA
specifically encourages suppliers
to consider CSOs, sewer system
failures, and wet weather municipal
effluent point source discharges as
sources of microbial contamination.
Further, drinking water intakes and
their designated protection areas are
identified as "sensitive areas" under the
CSO Control Policy. The elimination,
control, or relocation of CSO outfalls
that discharge to sensitive areas
are to be given high priority in the
development  and implementation of
CSO LTCPs (EPA 1994a).

As discussed earlier in Section 5.5.2
of this report, EPA's BEACH program
conducts an annual survey of the
nation's swimming beaches. The
program was  created to reduce health
risks to swimmers due to contact
with contaminated water by working
to improve monitoring and public
notification procedures at beaches.

CDC's National Center for Infectious
Diseases works to prevent illness,
disability, and death caused by
infectious diseases. Waterborne
disease prevention is a priority for this
program. Working with EPA, CDC
coordinates national reporting of
waterborne illness outbreaks through
its Outbreak Surveillance System.
This system compiles state-reported
outbreaks to characterize waterborne
outbreaks epidemiologically (e.g., to
investigate the agents, reasons for the
outbreak,  and adequacy of various
treatment methods) and to strengthen
the public health community's ability
to respond. Outbreak summaries
are produced biennially. With
the cooperation of state health
departments and other national
partners, CDC's Division of Parasitic
Diseases and Division of Bacterial and
Mycotic Diseases are responsible for
the investigation, surveillance, and
control of specific groups of diseases,
including  many pathogens linked to
waterborne illness.

NOAA works to protect and
preserve U.S. living marine resources
through scientific research, fisheries
management, enforcement, and
habitat conservation. As detailed in
Section 5.3.2 of this report, NOAA
is currently working with Interstate
Shellfish Sanitation Conference
(ISSC), EPA, and FDA to  develop an
information resource on shellfish
safety. This data system will house
shellfish growing area monitoring,
survey, and classification data.

FDA administers the National Shellfish
Sanitation Program, an effort intended
to standardize the inspection and
monitoring of shellfish growing
areas and shellfish packing/shucking
facilities. Working with EPA, FDA
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     publishes guidance on the safety
                                     attributes of fish and fishery products,
                                     including acceptable levels of organic
                                     and inorganic compounds such as
                                     mercury and PCBs.

                                     USGS plays an active role in
                                     monitoring and reporting the
                                     quantity and quality of the nation's
                                     water resources. USGS helps to assess
                                     water quality problems and sources
                                     of pollution, including CSOs and
                                     SSOs, by studying how pathogens and
                                     other agents of waterborne disease
                                     interact with the environment and by
                                     monitoring and reporting the quality
                                     of the nation's water resources.

                                     State Agencies

                                     State public health agencies track
                                     communicable diseases, perform
                                     outbreak investigations, and issue
                                     warnings to the public. These agencies
                                     integrate and compile findings
                                     from local efforts, and they provide
                                     coordination with other state and
                                     federal agencies and programs. This
                                     coordination includes providing
                                     data on waterborne illness and
                                     investigations to CDC.

                                     State environmental agencies conduct
                                     water quality monitoring and
                                     assessment programs and require
                                     monitoring to be conducted by others,
                                     such as local sanitation districts,
                                     public water systems, regional
                                     planning agencies, and recreational
                                     facilities. State environmental or
                                     natural resource agencies also
                                     monitor fish and shellfish. These
                                     monitoring programs provide data
                                     for management decisions at the state
                                     level in response to environmental and
                                     public health concerns. In addition
                                     to monitoring, state agencies perform
                                     sanitary surveys to identify problems
                                     that could affect the safety of the
                                     drinking water supply. A sanitary
                                     survey is a physical inspection of the
  Coastal Beach
  Monitoring Program:
  Connecticut
  Beach Monitoring and
  Public Notification Program:
  Rhode Island
The State of Connecticut has a comprehensive monitoring program for its coastal
waters, with standards  and  guidelines  set by the state. The state collects and
analyzes samples taken  at four coastal state parks on Long Island Sound. At least
18 municipalities in the state's four coastal counties monitor their  own beaches,
following the ocean and bay beachwater-quality monitoring protocol established
by the Connecticut Departments of Public Health and Environmental Protection. In
2002, Connecticut set aside a $226,000 grant to integrate monitoring at municipal
beaches into a state-administered sampling and public notification plan for the
entire state. The beach grant funded a courier service to bring  municipal beach
samples to the Department of Public Health lab, where the state analyzes the
samples free of charge.
The Rhode Island Health Department requires every licensed beach to sample its
water and test for the presence of fecal coliform bacteria. The Rhode Island water
quality standard for recreation is 50 MPN per 100 ml  of salt water and 200 MPN
per 100 ml of fresh water. Results are posted on the department's website, along
with advisories on waterborne illness and  beach closures and openings. Public
notification of beach closures is accomplished in several ways, including the  use
of color-coded flags  at beaches, press releases, and notices on the department
website. The  website also supports on-line  reporting  by the public of suspected
beach-related illnesses.
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                                                                 Chapter 6—Human Health Impacts of CSOs and SSOs
water treatment and distribution
system and a review of operation and
maintenance practices.

States also implement notification
programs to warn citizens about
human health impacts associated with
recreation at contaminated beaches
and consumption of contaminated
water, fish, or shellfish.

Local Agencies
Local public health agencies, regional
planning authorities, and the owners
and operators of wastewater collection
and treatment facilities have distinct
responsibilities to protect public
health. Working with state oversight,
city and county health departments
often maintain separate divisions
for tracking communicable  diseases
and for environmental health. The
communicable disease divisions
of these departments generally
have responsibility for cataloging,
investigating, and reporting cases of
"reportable illness" to the appropriate
state agency. The environmental
health divisions generally have
responsibility for monitoring, analysis,
and posting of recreational waters,
where needed. Owners and operators
of municipal wastewater collection
and treatment facilities have their
own responsibilities, many of which
are stipulated as NPDES permit
requirements, including notifying
the public when SSOs occur and
reporting SSOs to state regulatory and
public health agencies. Communities
with CSSs are required to implement
public notification programs as part of
implementing the NMCs.

6.5.2 Activities to Protect Public
      Health from Impacts of CSOs
      and SSOs
The principal activities undertaken to
protect the public from the impacts
of CSOs and SSOs can be grouped
into three areas: exposure pathway
monitoring, public notification, and
research. These activities protect
public health by identifying possible
sources of pathogens, reducing public
exposure through notification and
 In California, the Orange County Health Care Agency's Ocean Water Protection
 Program has a  mission to ensure that all public recreational  waters  meet
 bacteriological water quality standards for full body contact recreation activities,
 such as swimming, surfing, and diving. Staff collect water samples at approximately
 150 locations along the shoreline of Orange County for laboratory analysis for
 indicator bacteria. Results of the analysis are reviewed by program specialists who
 determine if action needs to be taken to protect the public. Staff are available to
 respond  on  a  24-hour  basis to investigate  reports of contamination incidents,
 including SSOs, affecting Orange County's public beaches.
 The Allegheny County Health Department in Pennsylvania implemented a public
 notification  program designed to warn recreational users of health  risks  in
 CSO-impacted waters in the Pittsburgh area.  The program includes publishing
 advisories in local newspapers and producing  public service announcements on
 local television stations  to educate the public about health risks associated with
 CSO discharges.The department also installed orange warning flags that read"CSO"
 at 30 locations near CSO outfalls. The flags are raised to warn recreational users
 whenever CSO discharges cause or contribute to elevated bacteria levels.
                                          Local Public Health Activity:
                                          Orange County, CA
                                          Local Public Health Activity:
                                          Allegheny County, PA
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     use restriction, when necessary, and
                                     continuing research by public health
                                     experts to better protect public health
                                     in the future. More detail on each
                                     activity is presented below.

                                     Exposure Pathway Monitoring
                                     Exposure pathway monitoring
                                     programs focus on recreational waters,
                                     public drinking water systems, and
                                     fish and shellfish in order to reduce
                                     the risk of human health impacts from
                                     exposure to contaminated water and
                                     food.

                                     Recreational waters are typically
                                     monitored using indicator bacteria to
                                     detect the presence of or the potential
                                     for microbial pathogen contamination.
                                     If the bacteria levels in a given water
                                     sample exceed the state standard for
                                     recreational waters, advisories are
                                     posted or the waterbody is closed. For
                                     example, EPA's 2002 BEACH Program
                                     found that 91 percent of surveyed
                                     beaches had some type of water
                                     quality monitoring program. Though
                                     the frequency of monitoring varied, 63
                                     percent of the beaches were  monitored
                                     at least once per week (EPA  2003a).

                                     Public water systems are governed
                                     by National Primary Drinking Water
                                     Standards, also known as primary
                                     standards (EPA2003f). Primary
                                     standards are legally enforceable
                                     standards that protect public health
                                     by limiting the levels of specific
                                     contaminants in drinking water.
                                     To protect the health of those
                                     being served, public water systems
                                     have monitoring requirements.
                                     Contaminants monitored are as
                                     follows (EPA 2002f):
•   Microorganisms including
    indicator organisms, enteric
    viruses, and parasitic protozoa;

•   Disinfectants including chlorine,
    chlorine dioxide, and chloramine;

•   Disinfection byproducts including
    bromate, chlorite, haloacetic acids,
    and trihalomethanes;

•   Inorganic chemicals including
    metals, nitrate, and nitrite;

•   Organic chemicals including a
    broad list of agricultural and
    industrial products; and

•   Radionuclides.

If monitoring shows the drinking
water is contaminated, the owner or
operator of the public water system
is required to shut down the system
and/or direct the public to take
precautions, such as boiling water.

Fish and shellfish monitoring is
administered jointly by state agencies,
EPA, NOAA, and FDA.  Bacteriological
monitoring is used to assess the
potential presence of microbial
pathogens in shellfish harvesting areas.
States, U.S. territories, and authorized
tribes have primary responsibility for
protecting residents from the health
risks of consuming contaminated,
noncommercially caught fish. This
is accomplished by issuing of fish
consumption advisories. These
advisories inform the public when
high concentrations of  contaminants
have been found in local fish. They
also include  recommendations to
limit or avoid eating certain fish
species from specific waterbodies or
waterbody types.
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                                                               Chapter 6—Human Health Impacts of CSOs and SSOs
Public Notification
Public notification programs provide
information to communities regarding
the occurrence of CSO and SSO
events and ongoing efforts to control
discharges.

Public notification programs include
posting temporary or permanent
signs where CSOs and SSOs
occur, coordinating with civic and
environmental organizations, and
distributing fact sheets to the public
and the media. Notices in newspapers
are used to publicize CSO or SSO
discharges in some states. Radio and
television announcements may be
appropriate for CSOs and SSOs with
unusually severe impacts. Distribution
of information on websites  is rapidly
gaining wider use. Additional
information on reporting and public
notification is presented in  Chapter 8
of this Report to Congress and in the
technology descriptions included as
Appendix L.

Research
Several research activities are expected
to improve the ability of public health
programs to protect humans from
impacts associated with CSOs, SSOs,
and other sources of pollution. Two
examples are provided below.
EPA's National Epidemiological
and Environmental Assessment of
Recreational (NEEAR) Water Study
is intended to develop a better
understanding of water pollution at
beaches, recreational use of beaches,
and public health. As part of the
BEACH Program, this effort seeks to
improve beach monitoring by linking
real-time monitoring results with
meaningful risk-based guidelines.

EPA's Office of Research and
Development has completed the
first in a planned series of studies
to estimate the urban contribution
to the total Cryptosporidium and
Giardia loads to receiving waters (EPA
2003f). It is hoped that the studies will
provide a basis for designing source
water protection programs.
6.6  What Factors Contribute
     to Information Gaps in
     Identifying and Tracking
     Human Health Impacts
     from CSOs and SSOs?
     Systematic data on human
     health impacts as a result of
     exposure to CSOs and SSOs
are not readily available. The chief
factors that account for the absence
of direct cause-and-effect data
 In 1984, public drinking water for the community surrounding Braun Station,Texas,
 was drawn from an artesian well that was not filtered but was chlorinated prior
 to distribution. At the time, well water was not routinely sampled in this  region
 of Texas. Community complaints, however, convinced authorities to begin testing.
 Fecal coliform level as high as 2,600/100 ml were measured in untreated well water
 samples. Subsequent dye tests indicated that the community's SSS was leaking into
 the well water. When attempts to identify the exact site of contamination were not
 successful, an alternative water source was provided to the community (D'Antonio
 etal. 1985).
                                          Monitoring Identifies SSS
                                          as Source of Drinking Water
                                          Contamination:
                                          Braun Station, TX
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     are underreporting of waterborne
                                     disease and the reliance of water
                                     quality monitoring activities on
                                     indicator bacteria instead of microbial
                                     pathogens. Both factors are discussed
                                     below.

                                     6.6.1 Underreporting
                                     Reporting and tracking of outbreaks
                                     of waterborne disease are difficult
                                     under the best circumstances.
                                     Underreporting stems from a number
                                     of causes. CDC's waterborne disease
                                     outbreak surveillance system depends
                                     on states to report outbreaks, and
                                     this reporting is often incomplete.
                                     Existing local systems for tracking
                                     these outbreaks often lack sufficient
                                     information on the cause of the
                                     outbreak to establish whether CSOs
                                     and SSOs are suspected source.

                                     Factors that affect the likelihood that
                                     outbreaks will or will not be detected,
                                     investigated, and reported include
                                     (adapted from CDC 2000):

                                     •   Public awareness about illness
                                         symptoms, environmental
                                         conditions that might precipitate
                                         an outbreak, and where to report
                                         symptoms;

                                     •   The frequency with which people
                                         experiencing illnesses related to
                                         exposure to contaminated water
                                         seek medical care from the same
                                         provider;

                                     •   The adequacy of laboratory
                                         infrastructure to fully investigate
                                         outbreaks;

                                     •   The compatability of local
                                         reporting requirements for specific
                                         waterborne diseases with data
    tracking systems employed by the
    CDC; and

•   The integration of state and
    local reporting and investigation
    protocols for waterborne disease
    outbreaks.

Large outbreaks are more likely
to be noticed and reported than
smaller outbreaks. Nevertheless, the
source and exposure pathway of the
1993 Milwaukee cryptosporidiosis
outbreak, the largest documented in
U.S. history, remained unidentified for
more than two weeks (CDC 1996a).
This outbreak, affecting an estimated
403,000 people, was detected only
"when increased sales of antidiarrheal
medicines were observed and reported
to the local public health agency"
(Frost etal. 1995).

6.6.2 Use of Indicator Bacteria

Indicator bacteria are used to
evaluate human health risks from
contaminated water without sampling
for  every possible microbial pathogen.
As described in Section 6.1.1,
indicator bacteria are relatively easy
to detect and are used to indicate
the likely presence of fecal-borne
microbial pathogens. There is ongoing
scientific debate regarding the use of
indicators and their ability to predict
human health impacts. Some specific
criticisms of the use of indicator
bacteria are as follows:

•   A single indicator  organism
    may be insufficient to establish
    water quality standards. EPAs
    current water quality criteria
    are targeted toward protecting
    people participating in
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                                                                 Chapter 6—Human Health Impacts of CSOs and SSOs
    recreational activities from acute
    gastrointestinal illness (EPA
    2002g).

•   Current bacterial detection
    methods are subject to false
    positives and false negatives
    (Griffin et al. 2001).

•   Coliform bacteria can survive and
    replicate in waters and soils under
    certain environmental conditions.
    Their presence is not always due
    to recent fecal contamination.
    In addition, all current bacteria
    indicators are shed by animals.
    Their occurrence in the
    environment does not always
    indicate that human pathogens are
    present or that contamination was
    due to a human source (Griffin et
    al. 2001).

•   Indicator bacteria do not directly
    indicate the presence of viruses,
    which survive longer in marine
    waters and have a low infective
    dose (Seyfried et al.1984; Freeman
    2001; Schvoerer et al. 2001).

Bacteriophages have shown merit
for use as an alternative to indicator
bacteria to identify human health
risks. Specifically, Bacteroides fragilis
bacteriophages have been found to be
more resistant to chlorine than current
indicator bacteria and are thought to
be good indicators of enteric viruses.
Bacteriodes also show potential for
use as an indicator of recent fecal
contamination (Griffin et al. 2001).

Although EPA recognizes the
limitations of indicator bacteria, they
continue to be used to assess potential
human health risk because:
•   Indicator bacteria area simple and
    inexpensive to measure (Griffin et
    al. 2001).

•   Studies show that E. coll and
    enterococci exhibit a strong
    relationship to swimming-
    associated gastrointestinal illness
    (Fattal et al. 1987; Cheung et al.
    1990; EPA 2002g).

•   Indicator bacteria are present
    where fecal contamination occurs;
    they are always present in feces
    and at higher levels than most
    enteric pathogens (Griffin et al.
    2001).

EPA continues to encourage states
and authorized tribes to use E. coli
or enterococcci as the basis of their
water quality criteria for protecting
recreational  waters.
6.7  What New Assessment and
     Investigative Activities are
     Underway?
     Several local government agencies
     are implementing innovative
     programs to identify risks and
to track the types of illness associated
with the pathogens present in CSO
and SSO discharges. Select examples
are provided in this section.

6.7.1 Investigative Activities
Monitoring, modeling, and other
investigative activities are useful
tools in reducing human exposure
to pathogens, identifying waterborne
and foodborne disease outbreaks,
and assessing illness patterns. Some
innovative investigative programs
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     intended to reduce human health
                                     impacts and risk are described below.

                                     •   In Texas, the Austin-Travis Health
                                         and Human Services Department
                                         has a predictive model for
                                         recreational water quality at the
                                         Barton Springs pool. If the Barton
                                         Creek watershed receives more
                                         than one inch of rainfall, the
                                         pool is closed until monitoring
                                         determines it is safe to reopen
                                         (Staudt2002).

                                     •   New York City has an advanced
                                         rainstorm modeling system that
                                         predicts  the estimated amount of
                                         fecal matter that will contaminate
                                         beaches  after a measurable rainfall.
                                         This information is used to make
                                         decisions on beach closures and is
                                         shared with all area beaches and
                                         neighboring states (Luke 2002).

                                     •   Orange County, California,
                                         maintains a passive reporting
                                         system for illnesses from
                                         recreational waters. Between 1998
                                         and 2002, Orange County received
                                         110 ocean and bay bather illness
                                         reports and one illness report
                                         from a freshwater lake (Mazur
                                         2002).

                                     •   Boston, Massachusetts, operates
                                         a waterborne surveillance project
                                         that monitors Cryptosporidium
                                         and Giardia illnesses from
                                         drinking water. The program uses
                                         fixed populations within the city
                                         (schools, nursing homes, prisons)
                                         as control groups (Gurba 2002).
•   San Diego County, California
    Department of Environmental
    Health and a group called Surfers
    Tired of Pollution conducted a
    self-reported ocean illness survey.
    Between August 1,1997, and
    December 31, 1999, 232 illnesses
    were reported. The county plans a
    second survey (Clifton 2002).

•   The Douglas County, Nebraska
    Health Department compares
    reported illnesses with a computer
    model that provides epidemiologic
    analysis for  1- to 10-year periods.
    Reported illnesses are compared
    with projected baselines and trends
    to determine if an outbreak is
    occurring (Kurtz 2002).

•   New York City has an active
    outbreak  monitoring procedure.
    The Department of Health
    tracks reports of giardiasis and
    cryptosporidiosis by visiting labs
    in New York City on a weekly
    basis and making sure all samples
    testing positive for the pathogens
    are reported. The Department of
    Health receives weekly tallies of
    diarrheal  medicine sold in the area
    and has a clinical lab monitoring
    system to track the number of
    stool samples tested. Finally, the
    city monitors hospital emergency
    rooms for the number of people
    complaining of diarrhea and
    vomiting  (Seeley 2002).
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                           Chapter  7
       Federal  and State  Efforts to
           Control CSOs and SSOs
      The federal and state regulatory
      framework for controlling
      CSOs and SSOs affects
municipal decision-making on how
to best protect human health and the
environment from these discharges.
This chapter describes the status of
the federal framework used to address
CSOs and SSOs. The discussion on
CSO policies summarizes findings
from the 2001 Report to Congress-
Implementation and Enforcement of
the CSO Control Policy (EPA 200la)
and updates data on the status of
NPDES permit requirements for CSO
control. A brief discussion of current
SSO regulatory efforts follows. This
chapter also describes a number of
state programs to address CSOs and
SSOs, and it presents an overview of
federal compliance assistance and
enforcement efforts related to CSOs
and SSOs.
7.1  What are States and EPA
    Regions Doing to Control
    CSOs?
       On April 19, 1994, EPA
       published the CSO Control
       Policy that established
objectives for CSO  communities and
expectations for NPDES permitting
authorities (59 FR 18688). The CSO
Control Policy also presented elements
of an enforcement and compliance
program to address dry weather CSO
discharges and to enforce NPDES
permit requirements. The four key
principles of the CSO Control Policy
that ensure that CSO controls are cost-
effective and meet the objectives of the
Clean Water Act are:

1.  Provide clear levels of control
   that would be presumed to
   meet appropriate health and
   environmental objectives;
                                                                In this chapter:
7.1  What are States and
    EPA Regions Doing to
    Control CSOs?

7.2  What are States and
    EPA Regions Doing to
    Control SSOs?

7.3  What Programs Have
    Been Developed to
    Control SSOs?

7.4  What Compliance and
    Enforcement Activities
    Have Been Undertaken?
                                                                                        7-1

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    2.  Provide sufficient flexibility to
                                        municipalities, especially financially
                                        disadvantaged communities, to
                                        consider the site-specific nature
                                        ofCSOs and to determine the
                                        most cost-effective means of
                                        reducing pollutants and meeting
                                        [Clean Water Act] objectives and
                                        requirements;

                                    3.  Allow a phased approach to
                                        implementation ofCSO controls
                                        considering a community's financial
                                        capability; and

                                    4.  Provide for review and revision,
                                        as appropriate, of water quality
                                        standards and their implementation
                                        procedures when developing CSO
                                        control plans to reflect the site-
                                        specific wet weather impacts of
                                        CSOs.

                                    Objectives for CSO communities with
                                    NPDES permits are 1) to implement
                                    the NMC and submit documentation
                                    on NMC implementation; and 2) to
                                    develop an LTCP.

                                    7.1.1 Nine Minimum Controls

                                    The NMC are:

                                    1.  Proper operation and regular
                                        maintenance programs for the
                                        sewer system and the CSOs

                                    2.  Maximum use of the collection
                                        system for storage

                                    3.  Review and modification of
                                        pretreatment requirements
                                        to assure CSO impacts are
                                        minimized
5.   Prohibition of CSOs during dry
    weather

6.   Control of solids and floatable
    materials in CSOs

7.   Pollution prevention

8.   Public notification to ensure
    that the public receives adequate
    notification of CSO occurrences
    and CSO impacts

9.   Monitoring to effectively
    characterize CSO impacts and the
    efficacy of CSO controls

Municipalities were expected to
implement the NMC and to submit
appropriate documentation to NPDES
authorities as soon as reasonably
possible, but no later than January 1,
1997. Of the 828 active CSO permits
identified by EPA in July 2004, 94
percent (777 permits) required
implementation of the NMC.

7.1.2 Long-Term Control Plans

In addition to implementing the
NMC, CSO communities are expected
to develop and implement an LTCP
that includes measures to provide for
attainment of water  quality standards.
The policy identified nine elements
that an LTCP should include:

•   Characterization, monitoring, and
    modeling of the CSS

•   Public participation

•   Consideration of sensitive areas

•   Evaluation of alternatives
                                    4.  Maximizing flow to the POTW for   •   Cost/performance considerations
                                        treatment
                                                                          •   Operational plan
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                                                       Chapter 7—Federal and State Efforts to Control CSOs and SSOs
•   Maximization of treatment at the
    POTW treatment plant

•   Implementation schedule

•   Post-construction compliance
    monitoring

LTCP implementation schedules were
expected to include project milestones
and a financing plan for design and
construction of necessary controls as
soon as practicable (EPA 1994a).

In July 2004, EPA confirmed the status
of LTCPs with states and regional
NPDES authorities:

•   86 percent (708 of 828) of permits
    required development and
    implementation of an LTCP;

•   59 percent (490 of 828) of LTCPs
    have been submitted; and

•   35 percent (290 of 828) of LTCPs
    have been approved.

More information on the CSO Control
Policy is provided in EPA's 2001 Report
to Congress-Implementation and
Enforcement of the CSO Control Policy.
7.2  What are States and EPA
     Regions Doing to Control
     SSOs?
     SSOs that reach waters of the
     United States are point source
     discharges, and, like other
point source discharges from SSSs,
are prohibited unless authorized by
an NPDES permit. Moreover, SSOs,
including those that do not reach
waters of the United States, may be
indicative of improper operation  and
maintenance of the sewer system,
and thus may violate NPDES permit
conditions.

7.2.1 Application of Standard
Permit Conditions to SSOs

The NPDES regulations establish
standard permit conditions that are
incorporated into all NPDES permits.
Several existing standard permit
conditions have particular application
to SSOs. These include:

Noncompliance Reporting - When
incorporated into a permit, the
standard permit conditions for
noncompliance reporting at 40
CFR 122.41(1)(6) and (7) require
permittees to report any instance
of noncompliance to the NPDES
authority. Unpermitted discharges
from SSSs to waters of the United
States constitute noncompliance,
which the permittee would report
under these provisions.

Recordkeeping - The permit
provisions required by 40 CFR
122.4l(j)(2) require permittees to
retain copies of all reports required
by the permit for a period of at least
three years from the date of the report.
This provision  would require retention
of records of noncompliance reports
of SSOs.

Proper Operation and Maintenance
Requirements - The standard permit
conditions at 40 CFR 122.41 (d) and
(e) require proper operation and
maintenance of permitted wastewater
systems and related facilities to achieve
compliance with permit conditions
and that permittees take all reasonable
SSOs can occur at numerous locations in the
sewer system, including at manholes.
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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Table 7.1
    Summary of Electronic
    SSO Data by State
    At a minimum, states with elec-
    tronic systems for tracking SSOs
    compile information on the date,
    location, or cause of the overflow.
steps to minimize or prevent any
discharge in violation of the permit
that has a reasonable likelihood of
adversely affecting human health
or the environment. In a permit
for a wastewater treatment facility
and/or a sewer system, these two
standard conditions would require
the permittee to properly operate
and maintain its collection system
as well as take all reasonable steps to
minimize or prevent SSO discharges.
7.2.2 Electronic Tracking of SSOs
A growing number of states have
increased data collection and
tracking efforts for SSOs (excluding
building backups) in recent years.
As part of this report effort, EPA
identified 25 states that track SSO data
electronically. The states and the most
commonly tracked SSO  data elements
are listed in Table 7.1.
             CA
             CO
             CT
             FL
             GA
             HI
             IN
             KS
             MA
             MD
             ME
             Ml
             MN
             NC
             ND
             NH
             NV
             OK
             Rl
             SC
             SD
             UT
             WA
             Wl
             WY
                     Date &   Start Date   End Date     Total       SSO       SSO
                      Time     & Time    & Time/    Overflow   Location3   Cause
                    Reported              Duration     Volume
                                                     (gallons)
                                                Response   Receiving
                                                Measures     Water
                                                 Takenb     Identified
          a May not include exact SSO location point
          b May include cleanup activities, volume recovered, and corrective or preventive measures
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                                                       Chapter 7—Federal and State Efforts to Control CSOs and SSOs
SSO Data Publication via the Internet
Maryland and Michigan publish
CSO and SSO data periodically on
the Internet. In Maryland, owners or
operators of an SSS must report any
SSO that results in a discharge of raw
or diluted sewage into the waters of
the state to the Maryland Department
of the Environment (MDE). This
requirement is also applicable to
CSOs and wastewater treatment
plant bypasses. MDE coordinates
reporting requirements with local
health departments. Reports must
include the volume spilled, duration,
start and stop times, name of receiving
waters, cause, corrective action taken,
and information regarding public
notification. CSO and SSO data
reported to MDE can be found at http:
//www.mde.state.md.us/programs/
waterprograms/cso sso.asp.

The Michigan Department of
Environmental Quality (MDEQ)
has broad statutory and regulatory
authority for SSOs under Part 31,
Water Resources Protection, and
Part 41, Sewerage Systems, of the
Natural Resources and Environmental
Protection Act, 1994 PA 451, as
amended. Facilities in Michigan are
required to notify MDEQ within
24 hours of when a CSO or SSO
discharge begins. After the discharge
ends, the facility must submit a
complete report, including the
location and volume of the discharge
as well as the start/end date and time.

MDEQ's CSO and SSO discharge
information web page provides
specific event information on CSOs
and SSOs (http://www.deq.state.mi.us/
csosso/1. In  addition to providing
final CSO and SSO reports, MDEQ's
website also displays records of recent
events for which MDEQ has not
yet received a final written report.
Recently, MDEQ produced its first
Combined Sewer Overflow (CSO) and
Sanitary Sewer Overflow (SSO) Report,
which compiled event information
during the period from July 2002
to December 2003. MDEQ expects
that subsequent reports will be made
available  on a calendar-year basis.
7.3  What Programs Have Been
     Developed to Control
     SSOs?

       Although there is no national
       regulatory program specific
       to SSOs, a number of EPA
regions and state agencies have
initiated efforts to address SSOs.
Some agencies require that permittees
assess sewer system condition or
implement specific O&M practices.
Other agencies have implemented
programs requiring sewer system
owners to obtain NPDES permit
coverage, whether or not they operate
a wastewater treatment facility.
The following descriptions are  not
intended to be comprehensive, but
represent some innovative approaches
to addressing SSO issues.

7.3.1  EPA Region 4's MOM Program

EPA Region 4's Management,
Operations, and Maintenance
(MOM) Program is implemented in
cooperation with states in the region.
The MOM program encourages
all NPDES permit-holders and
any associated satellite utilities  to
participate in a proactive approach to
managing, operating, and maintaining
their sewer system. Utilities that
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    implement good MOM Programs
                                    benefit by reducing the likelihood of
                                    Clean Water Act violations, extending
                                    the life of their infrastructure, and
                                    providing better customer service
                                    through steady rates and greater
                                    efficiency. The goal of the MOM
                                    Program is to bring 100 percent of the
                                    POTWs handling domestic wastewater
                                    in Region 4 into compliance with the
                                    "proper operation and maintenance"
                                    provision of their NPDES permits by
                                    2011.

                                    The Region 4 MOM Program
                                    addresses SSO issues in sewer systems
                                    (including satellites) by concentrating
                                    on high priority watersheds. Region
                                    4 uses a Geographic Information
                                    System (CIS) to focus on watersheds
                                    categorized as having existing water
                                    quality problems or assessed as being
                                    vulnerable to stressors (e.g., coastal
                                    and shellfish harvesting areas). Based
                                    in part on recommendations made by
                                    states in the region, Region 4 selects
                                    at least one watershed in each state
                                    for each cycle of the MOM Program.
                                    Region 4 started the second cycle of its
                                    MOM Program in September 2003.

                                    In the selected watersheds, the
                                    operators of all sewer systems are
                                    expected to provide a self-evaluation
                                    report to the region. This report
                                    identifies improvements that can be
                                    made and the schedules necessary to
                                    make those improvements. Region 4
                                    encourages participants to conduct the
                                    self-evaluation within seven months of
                                    receiving the initial requests. To assist
                                    participants with the process, Region 4
                                    provides checklists and other outreach
                                    information. Depending on the
                                    thoroughness of the self-evaluation,
                                    Region 4 may conduct follow-up
                                    inspections and initiate further
discussions regarding the evaluated
programs. Where the permittee does
not conduct an evaluation, Region
4 conducts its own site inspection.
Through voluntary participation in
the program and by self-disclosing any
needed improvements, participants
may be eligible for a reduction in civil
penalties while under a remediation
schedule.

Region 4 expects participants to
develop a plan that addresses the
MOM requirements, which the
region typically includes in a Letter
of Violation (LOV) or an AO. Region
4 recently completed the first round
of LOV inspections and found that
many MOM Program participants
have made significant positive and
productive efforts  (e.g., increased
staff, purchased maintenance
equipment, and increased cleaning
frequency) toward the development
and implementation of their MOM
Programs.

7.3.2 Oklahoma  - Collection
     System Program

The Oklahoma Department of
Environmental Quality (ODEQ)
has actively addressed SSO and
sewer system issues for many years
through its NPDES program.
Program elements include permitting,
compliance, enforcement, and
education/outreach.

Standard NPDES permit language
in Oklahoma requires proper O&M
of the sewer system and reporting
of bypasses and SSOs. A state
construction permit, which is distinct
and different from an NPDES permit,
is required for all new sewer lines
to ensure that the sewer system has
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                                                       Chapter 7—Federal and State Efforts to Control CSOs and SSOs
adequate capacity to accommodate
the growth. When a request is made
to ODEQ to expand an SSS, the
capacity of pipes, pumps, and other
system components is evaluated by
ODEQ design and engineering staff
during review of the construction
permit. These requirements encourage
municipalities to have a program in
place to address capacity, management,
operation, and maintenance issues in
their sewer system.

ODEQ evaluates system performance
through compliance evaluation
inspections, complaint and fish kill
investigations, and database record
reviews. Members of the general
public can report SSOs by calling
an ODEQ overflow hotline; ODEQ
investigates all complaints of  alleged
SSOs. Oklahoma's criterion for
significant non-compliance due to
SSOs is more than one SSO at the
same location in a 12-month  period.
As of 2003, ODEQ has 60-70  active
enforcement orders for SSOs.

ODEQ has maintained an SSO
database  and tracking system since
1987. Over the last 15 years, the
annual number of reported SSO
events has decreased by 14  percent,
and the number of enforcement
orders issued annually has decreased
by approximately 25 percent.  During
this same period, the number of
municipalities reporting at least one
SSO event has increased by 12 percent.
ODEQ attributes the increase in the
number of systems reporting SSOs
to elevated awareness of SSO  issues
by the regulated community and
the public. ODEQ's education and
outreach  efforts include operator
certification training, ODEQ-
sponsored seminars, and staff
presentations to municipal leagues,
rural water associations, regulated
communities, and other affected
groups.

7.3.3 California - Record Keeping
     and Reporting of Events

Some of California's Regional Water
Quality  Control Boards (RWQCBs)
use Waste Discharge Requirements
(WDR), a form of discharge permit,
to address SSOs. These orders
prohibit all discharges of wastewater
from a sewer system upstream of a
wastewater treatment plant. Priorities
in California are to address beach
closures linked to SSOs, such as those
occurring in Orange County, San
Diego, and Los Angeles.

The RWQCB Orders require proper
O&M, sewer system management
plans, capacity evaluations, and FOG
programs. For example, in May 1996,
the San  Diego RWQCB adopted Order
No. 96-04 prohibiting SSOs. This
order was adopted as a mechanism
to achieve a reduction in the number
and volume of SSOs and to protect
water quality, the environment,
and public health. Order No. 96-04
also brings satellite sewer systems
under a  regulatory framework. The
order regulates 48 cities and special
districts in the San Diego area
that own and operate SSSs. It also
requires a monitoring and reporting
program with specific SSO reporting
procedures.

In addition, California has a statewide
regulation requiring utilities to report
SSOs greater than or equal to 1,000
gallons and all SSOs that reach surface
waters. Reports must be made within
Advisory and closing signs are posted at
beaches throughout Orange County, CA, to
alert beachgoers of potential dangers, from
elevated bacterial levels.

    Photo: OCHA Ocean Water Protection Program.
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    24 hours of becoming aware of the
                                    spill and followed up with a written
                                    report within five days. The RWQCBs
                                    have issued several large penalty
                                    orders for SSOs (generally one dollar
                                    per gallon spilled).

                                    7.3.4 North  Carolina - Collection
                                         System Permitting

                                    In 1999, the North Carolina General
                                    Assembly ratified HB 1160 (1999
                                    NC Sessions  Laws Chapter 329),
                                    a bill that requires SSSs to obtain
                                    a comprehensive permit separate
                                    from the NPDES permit obtained
                                    by wastewater treatment facilities.
                                    The North Carolina Department
                                    of Environment and Natural
                                    Resources (NCDENR) administers
                                    this permitting program through the
                                    Non-Discharge Permitting Branch in
                                    coordination with the Enforcement
                                    Group. The focus of the NCDENR
                                    program is proactive, preventive O&M
                                    of sewer systems.

                                    NCDENR collection system permits
                                    contain five principal sections:
                                    performance standards, O&M,
                                    inspections, record keeping, and
                                    general conditions. Conditions
                                    are included  for grease control,
                                    planned reinvestment in the SSS
                                    through a capital improvement
                                    plan, alarms  for pump stations,
                                    spare parts, inspections, cleaning,
                                    mapping, observation, and preventive
                                    maintenance. The permits also include
                                    public notification and other reporting
                                    requirements. NCDENR has provided
                                    guidance for reporting SSOs that
                                    includes a standardized calculation for
                                    estimating the volume of SSOs when
                                    they occur.
NCDENR is using a phased approach
to permit all SSSs over a five-year
period (20 percent/year). This
program incorporates a number of
older satellite systems that have never
been permitted. The first round of
permits was issued in 2001. Sewer
systems that fail to meet the standard
permit conditions may be subject to
enforcement action by NCDENR. The
1999 legislation dramatically increased
the potential civil penalties that may
be assessed  against the municipality
for unauthorized discharges (G.S. 143-
215.6A).
7.4  What Compliance and
     Enforcement Activities
     Have Been Undertaken?

       The goal of EPA's water
       compliance and enforcement
       program is to ensure
compliance with the Clean Water Act.
EPA's compliance and enforcement
program has five major objectives:

•   Provide compliance assistance
    tools and information to the
    regulated community;

•   Identify instances of
    noncompliance;

•   Return violators to compliance;

•   Recover any economic advantage
    obtained by the violator's
    noncompliance; and

•   Deter other regulated facilities
    from noncompliance.

EPA established "wet weather"
(i.e., CSOs, SSOs, storm water,
and concentrated animal feeding
operations) as a national enforcement
priority for FY 2002 and FY 2003.
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                                                       Chapter 7—Federal and State Efforts to Control CSOs and SSOs
The compliance and enforcement
policies and strategies used to address
CSOs and SSOs are discussed in the
following subsections. In addition,
a summary of related enforcement
actions as of October 2003 is
presented.

7.4.1 National Municipal Policy on
     POTWs

EPA's 1984 National Municipal
Policy on Publicly-Owned Treatment
Works (NMP) provided an impetus
for control of all discharges from
municipal sewer systems, treated or
otherwise (EPA 1984b). The NMP
encouraged a collaborative effort
between EPA and states in  addressing
compliance with the Clean Water Act
at POTWs. The NMP  focused EPA's
compliance efforts on three types
of POTWs: those that had  received
federal funding and were out of
compliance, and all major POTWs,
and minor POTWs that  discharged
to impaired waters. The NMP
recommended that each EPA region
draft a strategy to bring POTWs into
compliance with the Clean Water Act.
The NMP was intended to facilitate
compliance at all POTWs by July  1,
1988. While the main focus of the
NMP was to ensure that POTWs
complied with secondary treatment
and water-quality based  NPDES
requirements, many enforcement
actions brought under the  NMP also
addressed improvements to sewer
systems.
7.4.2 Enforcement Management
     System

EPA's national enforcement guidance,
Enforcement Management System,
recommends using a scaled response
to noncompliance considering such
factors as the nature, frequency, and
severity of the violation; potential
harm to the environment and public
health; and the compliance history
of the facility. Chapter X: Setting
Priorities for Addressing Discharges
From Separate Sanitary Sewers includes
a list of priorities for dealing with
SSOs to ensure that enforcement
resources are used in ways that result
in maximum environmental  and
public health benefit (EPA 1996c). The
complete text of Chapter X is provided
in Appendix A. EPA's enforcement
response guidelines range from
informal actions such as telephone
calls or warning letters to formal
administrative or civil judicial actions.

7.4.3 Compliance and Enforcement
     Strategy (2000)

On April 27, 2000, EPA issued the
Compliance and Enforcement Strategy
Addressing Combined Sewer Overflows
and Sanitary Sewer Overflows (EPA
2000b). This strategy was designed to
ensure that CSO and SSO violations
are properly addressed by promoting
the enforcement and compliance
assistance components of the
following:

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    •   CSO Control Policy (EPA 1994a);

                                    •   Joint Office of Enforcement
                                        and Compliance Assistance/
                                        Office of Water memorandum
                                        "Enforcement Efforts Addressing
                                        Sanitary Sewer Overflows" (March
                                        7, 1995); and

                                    •   Chapter X of the Enforcement
                                        Management System (EPA 1996c).

                                    The strategy also supports the
                                    Memorandum of Agreement for
                                    EPA's regional office performance
                                    expectations, EPA's Clean Water Action
                                    Plan, and EPA's Strategic Plan.

                                    The strategy calls for each EPA
                                    region to develop compliance and
                                    enforcement plans addressing CSOs
                                    and SSOs.  The plans should include:

                                    •   A systematic approach to address
                                        wet weather violations through
                                        compliance assistance;

                                    •   The identification of compliance
                                        and enforcement targets; and

                                    •   Details on  NPDES state
                                        participation, including tracking
                                        of state CSO and SSO compliance
                                        and enforcement activities.

                                    Specifically, the SSO response plan
                                    should describe the process and
                                    criteria that the region and states
                                    use to identify  priority systems each
                                    year and include an inventory of SSO
                                    violations  (EPA 200la). As of August
                                    2003, all regions except Region 4  had
                                    developed and begun implementation
                                    of their strategies.

                                    7.4.4 Compliance Assistance

                                    EPA has developed a number of tools
                                    for tracking and sharing compliance
                                    assistance and other information for
addressing CSOs and SSOs internally
among EPA staff and externally
with states, local governments, and
others. Several of these tools have
specific references and guidance for
implementing the NMC; developing
an LTCP; and implementing capacity,
management, operations, and
maintenance (CMOM) and asset
management approaches to eliminate
or reduce SSOs. Examples include:

Local Government Environmental
Assistance Network (LGEAN) - The
EPA-sponsored compliance assistance
center for local municipal governments
provides environmental management,
planning, and wet weather regulatory
and legislative information for elected
and appointed officials, managers, and
staff (http://www.lgean.org).

National Environmental Compliance
Assistance Clearinghouse - This
clearinghouse provides compliance
assistance tools, contacts, and other
wet weather (including CSO-specific)
resources available from EPA as well as
other public and private compliance
assistance providers
(http://www.epa.gov/clearinghouse).

Statistically Valid Non-Compliance
Study - EPA's Office of Enforcement
and Compliance Assistance (OECA)
completed the Statistically Valid
Non-Compliance Study to assess
compliance with NMC requirements.
EPA has a goal of ensuring that all
CSO communities have an enforceable
mechanism requiring implementation
of the NMC, are in compliance with
those controls, and, if needed, have
developed and are implementing an
LTCP. Determination of the current
compliance rate of CSO communities
with the NMC was an EPA priority in
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                                                       Chapter 7—Federal and State Efforts to Control CSOs and SSOs
FY 2002. OECA found the national
compliance rate with the NMC was
39 percent. OECA plans to repeat the
assessment of NMC compliance in
FY 2004. The new analysis will also
assess the status of CSO communities
with respect to development and
implementation of LTCPs.

Permit Compliance System - EPA is
working to modernize PCS. When
complete, this database of NPDES
point source dischargers will track
information specifically related to
CSOs and SSOs.

CSO Implementation Guidance - EPA
has released eight guidance documents
to assist in implementation of the
CSO Control Policy. The eight
guidance documents explain technical,
financial, and permitting issues related
to implementation of the policy and
are as follows:

•  Combined Sewer Overflows
   Guidance for Funding Options
   (EPA 1995a)

•  Combined Sewer Overflows
   Guidance for Long-Term Control
   Plans (EPA 1995b)

•  Combined Sewer Overflows
   Guidance for Nine Minimum
   Control Measures (EPA 1995c)

•  Combined Sewer Overflows
   Guidance for Permit Writers (EPA
   1995d)

•  Combined Sewer Overflows
   Screening and Ranking Guidance
   (EPA 1995e)

•  Combined Sewer Overflows
   Guidance for Financial Capability
   Assessment and Schedule
   Development (EPA 1997c)
•   Combined Sewer Overflows
    Guidance for Monitoring and
    Modeling (EPA 1999&)

•   Guidance: Coordinating Combined
    Sewer Overflow (CSO) Long-Term
    Planning with Water Quality
    Standards Reviews (EPA 200Ib)

7.4.5 Summary of Enforcement
     Activities

Federal and state enforcement actions
concluded against municipalities for
CSO- and SSO-related violations
are summarized below. Individual
enforcement actions are listed in
Appendix K.

Summary of Federal Judicial Actions
Thirty-six federal judicial enforcement
actions have been concluded against
municipalities in Regions 1-5  as a
result of CSO violations. The  relevant
state served as a co-plaintiff with the
EPA region in most cases. Since 1995,
26 judicial actions have been brought
against municipalities in Regions 1 -6
and Region 9 for SSO violations. As in
the CSO judicial actions, many of the
SSO actions were initiated by  the EPA
region in cooperation with the state.

Summary of Federal Administrative
Actions
Sixty Federal AOs have been issued for
CSO violations in Regions 1, 3, and 5
since 1987. Two CSO Administrative
Penalty Orders (APOs) were issued
to municipalities in Massachusetts.
Between 1994 and 2003, 78 AOs were
issued to municipalities  in Regions
1-7 and Region 10 for SSO violations.
Twelve SSO APOs were issued during
the same period.
Guidance For Monitoring
And Modeling
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                      Summary of State Judicial Actions        state-initiated administrative actions
                                      EPA's review of available state-initiated    for CSO violations is included in
                                      CSO enforcement cases yielded 16        Appendix K. EPA's review of available
                                      CSO civil judicial actions. EPA's review    state-initiated enforcement cases
                                      of available state-initiated enforcement    found 597 administrative actions
                                      cases found six judicial actions against    against municipalities for SSO
                                      municipalities for SSO violations.        violations. In addition, EPA identified
                                                                             18 CSO administrative penalty orders
                                      c          r c.                         and 137 SSO administrative penalty
                                      Summary of State Administrative                                        ;
                                      Actions                                orders issued by states.

                                      A number of states have initiated
                                      administrative enforcement actions
                                      to address CSO violations. A list of 53
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                            Chapter  8
     Technologies Used to Reduce the
           Impacts of CSOs and SSOs
     Since the enactment of the Clean
     Water Act in 1972, federal,
     state, and local governments
have made substantial investments
in the construction, operation, and
maintenance of wastewater collection
and treatment systems. Municipalities
employ a wide variety of technologies
and operating practices to maintain
existing infrastructure, minimize the
introduction of unnecessary waste
and flow into the sewer system,
increase capture and treatment of
wet weather flows reaching the sewer
system, and minimize the impact of
any subsequent discharges on the
environment and human health.
For the purposes of this Report to
Congress, technologies used to control
CSOs and SSOs are grouped into five
broad categories:

•  Operation and maintenance
   practices

•  Collection system controls

•  Storage facilities

•  Treatment technologies

•  Low-impact development
   techniques
Most technologies and operating
practices are designed to reduce, not
eliminate, the discharge of pollutants
and attendant impacts because it is
generally not feasible to eliminate all
discharges.

This chapter provides an overview of
technologies used to control CSOs and
SSOs. In addition, the chapter also
discusses:

•  Factors that can influence the
   effectiveness of specific technology
   applications;

•  Combinations of technologies
   that have proven more effective
   than application of individual
   technologies; and

•  Emerging technologies that show
   promise in controlling CSOs and
   SSOs.

A complete set of detailed technology
descriptions is contained in Appendix
L of this report.
In this chapter:
8.1  What Technologies are
    Commonly Used to Control
    CSOs and SSOs?

8.2  How Do CSO and SSO
    Controls Differ?

8.3  What Technology
    Combinations are
    Effective?

8.4  What New Technologies
    for CSO and SSO Control
    are Emerging?
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     8.1 What Technologies are
                                          Commonly Used to Control
                                          CSOs and SSOs?

                                               Municipalities have used
                                               numerous technologies
                                               and operational practices
                                     to reduce the volume, frequency,
                                     and impacts of CSO and SSO
                                     events. The performance and cost-
                                     effectiveness of these technologies
                                     is often related to a number of site-
                                     specific factors. Technologies deemed
                                     highly effective in one location may
                                     prove inappropriate in another.
                                     Specific factors that may influence
                                     the selection of a given technology
                                     include:

                                     •   Current condition of the sewer
                                         system;

                                     •   Characteristics of wet weather
                                         flows (e.g., peak flow rate, flow
                                         volume, concentration of key
                                         pollutants, frequency and duration
                                         of wet weather events);

                                     •   Hydraulic and pollutant loading
                                         to a particular facility;

                                     •   Climate, including seasonal
                                         variations in temperature and
                                         rainfall patterns;

                                     •   Implementation requirements
                                         (e.g., land or space constraints,
                                         surrounding neighborhood, noise,
                                         disruption, etc.); and

                                     •   Maintenance requirements.

                                     This section describes 23 of the
                                     technologies and operational practices
                                     most commonly used to control CSOs
                                     and SSOs, including considerations
                                     for determining the applicability
                                     of different controls for individual
                                     locations. More  detailed information
                                     on each technology, including cost
and performance considerations,
is presented in the technology
descriptions provided in Appendix L
of this report.

8.1.1 Operation and
     Maintenance Practices
Over time, CSSs and SSSs can
deteriorate structurally or become
clogged by FOG and other
obstructions introduced into the
sewer system. Left uncorrected,
these conditions can result in dry
weather CSOs and SSOs. Further,
these conditions often  are exacerbated
during wet weather when the capacity
of sewer systems and treatment
facilities can be severely taxed.

The objective of O&M practices is
to ensure the efficient and effective
collection and treatment of wastewater
and to minimize the volume and
frequency of CSO and SSO discharges.
For purposes of this report, O&M
practices include activities designed
to ensure that sewer systems
function as designed and strategies
that rely on public education and
participation. The specific O&M
practices considered for this report are
summarized in Table 8.1 and include:

•  Inspecting and testing of the sewer
   system to track condition and
   identify potential problems;

•  Cleaning or flushing deposits of
   sludge, sediment, debris, and FOG
   from the sewer system;

•  Working with customers to reduce
   pollutant loads delivered to the
   sewer system; and
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                                                 Chapters—Technologies Used To Reduce the Impacts of CSOsand SSOs
•   Establishing procedures for
    notifying the public in the event
    of a CSO or SSO.

Sewer Inspection and Testing
Sewer inspection is used to determine
the condition of sewer lines and
identify potential problems. Common
sewer system inspection techniques
can be grouped into two categories:
manual and remote. Manual
inspection techniques, such as visual
inspection and lamping, are simple
and typically limited to the first few
feet of pipe upstream and downstream
of each accessible manhole. Remote
inspection techniques, such as closed-
circuit television and sonar, use units
that are either self-propelled or pulled
through the sewer line to capture
information on sewer condition.

In general, sewer testing techniques
are used to identify leaks that allow
unwanted infiltration into  the sewer
system and to determine the location
of direct connections of storm water
sources to the sewer system (e.g., roof
leaders, area drains, basement sump
pumps). Sewer testing techniques fall
into three categories:
•   Air testing

•   Hydrostatic testing

•   Smoke testing
Technology
 Sewer inspection and testing
 Sewer cleaning

 Pollution prevention
             Air testing and hydrostatic testing
             identify cracks and other defects in the
             sewer system that might allow storm
             water or groundwater to infiltrate.
             Smoke testing is used to identify
             connections that allow direct storm
             water inflow to the sewer system.

             Sewer Cleaning
             Sewer cleaning and flushing
             techniques remove blockages caused
             by solids, FOG, and root intrusion.
             Sewer cleaning techniques  are
             particularly important because
             blockages are the leading cause of
             SSO events (see Section 4.7). Cleaning
             techniques fall into three categories:

             •  Hydraulic

             •  Mechanical

             •  Chemical

             Hydraulic cleaning techniques employ
             the cleansing action of high velocity
             water. Cleansing velocities  are achieved
             by allowing water pressure to build
             in a sewer line or by using  a pump to
             produce water pressure. In general,
             hydraulic cleaning techniques tend
             to be simpler and more cost-effective
             in removing deposited solids when
             compared to other sewer cleaning
             techniques (CSU 2001). Alternatively,
             mechanical cleaning methods rely on
             a scraping, cutting, pulling, or pushing
             action to remove obstructions from
             sewer lines. Mechanical techniques
Type of System    Pollutants/Problems Addressed
CSS, SSS
CSS, SSS
                                                                                                    Table 8.1
                                      Summary of Operation
                                      and Maintenance
                                      Practices

                                      The objective of O&M practices
                                      is to ensure that sewer systems
                                      function as designed and convey
                                      the maximum amount of flow
                                      practicable to a treatment facility.
BOD5,TSS, nutrients, toxics, pathogens,
floatables,FOG
CSS,SSS
Water quality monitoring and   CSS, SSS
public notification
Nutrients, toxics, FOG
BOD5,TSS, nutrients, toxics, pathogens
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                      are typically used in areas where the
                                      volume, size, weight, or type of debris
                                      limits the effectiveness of hydraulic
                                      techniques. Chemicals can be used to
                                      control roots, grease, odors, concrete
                                      corrosion, rodents, and insects (CSU
                                      2001). Chemicals can be  helpful aids
                                      for cleaning and maintaining sewers,
                                      though chemical applications often are
                                      localized or coupled with a hydraulic
                                      or mechanical technique.

                                      Pollution Prevention
                                      Pollution prevention is defined as
                                      any practice that reduces the amount
                                      of pollutants, hazardous  substances,
                                      or contaminants entering the waste
                                      stream, which in turn would mean
                                      fewer pollutants in potential CSO or
                                      SSO discharges (EPA 2002b). Pollution
                                      prevention practices most often take
                                      the form of simple, individual actions
                                      that reduce the pollutants generated
                                      by a particular process. Therefore,
                                      pollution prevention programs
                                      must be implemented with broad
                                      participation to realize a  discernible
                                      reduction in pollutant loads
                                      discharged to sewer systems. Public
                                      education is a key component of
                                      most pollution prevention activities.
                                      Education programs are  most
                                     successful when tailored to a specific
                                     audience (i.e., residential, institutional,
                                     or commercial).

                                     Pollution prevention activities usually
                                     focus on best management practices
                                     for both commercial/industrial
                                     facilities and residential customers to
                                     reduce pollutant loads discharged to
                                     sewer systems. Pollutants of concern
                                     include FOG, household hazardous
                                     wastes, fertilizers, pesticides, and
                                     herbicides. In particular, the effective
                                     management of FOG has recently
                                     received attention as an important
                                     technique for controlling SSOs.

                                     As reported in Chapter 4, FOG is
                                     the leading cause of blockages in the
                                     United States, and blockages account
                                     for nearly half of all SSO discharges.
                                     The best way to prevent blockages
                                     due to FOG is to keep FOG out of the
                                     sewer system. Many municipalities
                                     have adopted regulations controlling
                                     the introduction of FOG into the
                                     sewer system. Education programs
                                     are important in making residents
                                     and owners of institutional and
                                     commercial establishments, especially
                                     restaurants, aware of their role in
                                     managing FOG. Grease trap design
                                     and maintenance is a vital part of any
Sewer Cleaning:
Sioux Falls, SD
The SSS for the City of Sioux Falls, South Dakota, consists of 578 miles of pipes
ranging in size from six to 66 inches in diameter. The sewer system is divided
into 20 drainage basins, and the maintenance program provides that the entire
system is cleaned once every three years. Maintenance records are stored  in a
database that generates work orders by date and drainage basin. Sanitary sewer
maintenance includes high pressure jetting, vacuuming to remove loosened debris,
and mechanical and chemical root control. Closed circuit television (CCTV) is used
to identify trouble spots.This results in more frequent cleaning than the scheduled
three-year interval requires in problem areas. In 2001,372 miles of sewer (64 percent
of the sewer system) were televised and cleaned. The cost for these activities was
approximately $236 per inch-diameter mile of pipe. Assuming  an average pipe
diameter of ten inches, inspection and cleaning costs about $0.45 per linear foot.
8-4

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                                                 Chapters—Technologies Used To Reduce the Impacts of CSOsand SSOs
education program for commercial
and institutional customers.

Water Quality Monitoring and Public
Notification
Water quality monitoring and public
notification practices are important in
minimizing potential human health
impacts that can result from exposure
to pathogens and other pollutants
in CSO and SSO discharges. Water
quality monitoring is used routinely
to verify the suitability of a particular
waterbody for fishing, swimming, or as
a drinking water source; and to identify
whether a specific CSO or SSO event
has impaired water quality. Public
notification programs are intended to
communicate water quality monitoring
results, general information regarding
the occurrence of CSO and SSO events,
and municipal efforts to control
discharges. Public notification program
activities include posting temporary
or permanent signs where CSOs and
SSOs occur, coordinating with  civic
and environmental organizations, and
distributing fact sheets to the public
and the media. Monitoring and public
notification programs should be a
high priority at beaches or recreational
areas, whether directly or indirectly
affected by CSOs and SSOs, due to the
increased risk of human contact with
pollutants and pathogens (EPA 2002i).

When developing a monitoring and
public notification program, the
lag time that often  occurs between
collecting water samples and providing
the public with results is important
to consider. This lag is due to the
time required (from 24 to 72 hours)
to test for the presence of bacterial
indicators of contamination. During
this time, pathogen levels, weather,
and water conditions, and related
environmental or human health risks
may change. This means that decisions
regarding beach and recreational water
postings, closings, and re-openings
using bacterial indicators often reflect
conditions as they were one to three
days earlier (EPA 2002i). Further,
contaminants may no longer be
present once test results are available,
and safe beaches may be closed
needlessly. As described in Chapter
6, some communities and beaches
have procedures to close beaches
proactively when a CSO-producing
rainfall event has occurred.

8.1.2 Collection System Controls
Collection system controls are
designed to maximize the capacity of
the sewer system to transport or store
domestic, commercial, and industrial
wastewater. This is accomplished by
adjusting hydraulic control points
to maximize available sewer system
capacity and by implementing
programs and practices to minimize
the volume of I/I that enters the sewer
system. The specific collection system
controls considered for this report are
summarized in Table 8.2, and include:

•   Maximizing flow to the treatment
    plant;

•   Installing a network of flow
    monitors to better understand and
    manage the response  of the sewer
    system to wet weather events;

•   Identifying and eliminating direct
    connections of storm water to the
    sewer system  (inflow);

•   Separating combined sewer
    systems into storm and sanitary
    systems; and
This CSO notification sign is
posted along Brandywine Creek in
Wilmington, Delaware, as part of a
public notification program. It warns
swimmers of the presence of a CSO
outfall and advises that raw sewage
and bacteria may be present after a
storm.
Photo: City ofWilmington Department of Public Works
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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Table 8.2
     Summary of Collection
     System Controls
     Collection system controls are
     designed to maximize the use
     of existing sewers to collect and
     convey wastewater to a treatment
     facility.
•   Rehabilitating sewer system
    components.

Collection system controls are
designed to maintain the structural
integrity of CSSs and SSSs, and to
maximize available capacity for
transporting wastewater to a treatment
plant. Some municipalities have found
combining various rehabilitation
techniques with inflow reduction
activities to be a cost-effective and
successful means of controlling SSOs.
Other municipalities have found
that implementing one or more of
these collection system controls in
conjunction with storage facilities or
treatment a cost-effective CSO control.

Maximizing Flow
EPA encourages plants serving CSSs
and SSSs to minimize CSOs and SSOs
during wet weather events by using
existing infrastructure to maximize
flow to the treatment plant (EPA
1994a; NYSDEC 1997). Maximizing
flow to the treatment plant often
involves simple and low-cost measures,
including:

•   Capacity evaluations of the sewer
    system and pumping stations  to
    determine the maximum amount
    of flow that can be transported
    (Sherrill et al. 1997).

•   Sewer investigations to identify
    bottlenecks or constrictions that
    limit flow in specific areas and
    prevent downstream treatment
    capacity from being fully utilized.

•   Targeted O&M activities to
    address structural deterioration,
    obstructions due to FOG and
    sediment buildup and excessive
    I/I.

The benefits of maximizing wet
weather flows to the existing treatment
plant depend on the ability of the
plant to accept and provide treatment
to increased flows. The consequences
of mismanaging extreme flows at
the  treatment plant include flooding
the  treatment plant and washing
out biological treatment processes,
which can result in reduced treatment
capacity and efficiency at the plant for
extended periods of time. Likewise,
changes in sewer system operation
without a careful analysis of transport
capacity can result in increased
building backups or street flooding.
Technology
Maximizing flow to the
treatment plant
Monitoring and real-time
control
Inflow reduction
Sewer separation
Sewer rehabilitation
Service lateral
rehabilitation
Manhole rehabilitation
Type of
System
CSS,SSS
CSS,SSS
CSS,SSS
CSS
CSS,SSS
css,sss
sss
Pollutants/Problems
Controlled
6005, TSS, nutrients, toxics, pathogens,
floa tables
Peak wet weather flow rate
I/I, peak wet weather flow rate
I/I, peak wet weather flow rate
I/I, peak wet weather flow rate
I/I, peak wet weather flow rate
I/I, peak wet weather flow rate
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                                                Chapters—Technologies Used To Reduce the Impacts of CSOsand SSOs
Monitoring and Real-Time Control
Basic flow monitoring is an important
component of O&M programs in
most systems. Effective monitoring
programs enable evaluations
of diurnal and day-to-day flow
patterns as well as I/I in a sewer
system. Moreover, monitoring is
extremely valuable in establishing
maintenance schedules, developing
hydraulic models, planning related to
capital improvements, and ensuring
regulatory compliance.

Enhanced monitoring  programs in
SSSs and real-time control systems
in CSSs use more complex flow
monitoring networks to optimize
sewer system performance. In SSSs,
enhanced monitoring information
can be used to identify blockages or
capacity-constrained areas of the
sewer system where wet weather SSOs
are likely to occur. In CSSs, integration
of real-time flow, regulator, pump, and
storage information can be used to
maximize use of storage capabilities
and to maximize flow to the treatment
plant.

Inflow Reduction
Inflow is the entry of extraneous
storm water into a sewer system from
sources other than infiltration, such
as basement drains, roof leaders,
manholes, and storm drains. Inflow
reduction refers to the identification
and elimination of these sources to
reduce the amount of storm water
that enters CSSs and SSSs. By reducing
the volume of storm water entering
the sewer system, more conveyance,
storage, and treatment capacity is
available for sanitary flows during
wet weather. This, in turn, aids in
reducing the frequency, volume, and
duration of wet weather CSO and SSO
events. Common inflow reduction
techniques include the disconnection
of roof leaders, redirection of area and
foundation drains and basement sump
pumps, and elimination of cross-
connections between separate sanitary
and storm water systems (EPA 1999f).

Inflow reduction techniques can be
an efficient way to improve sewer
system performance, especially when
the diverted storm water can be
conveniently directed either to surface
waters or to open land for infiltration
or detention (EPA 1999f). For SSSs,
inflow reduction techniques usually
target specific areas with chronic SSOs.
For CSSs, these techniques are applied
more broadly to minimize the size of
structural controls.

Sewer Separation
Sewer separation is the practice of
separating the single-pipe CSS into
separate systems for sanitary and
storm water flows. Full separation
can be applied on a system-wide basis
to eliminate the CSS. This approach
is most practical for communities
with small areas served by combined
sewers. Separation of select areas
within a CSS is widely used by large
and small CSO communities as an
element of a broader LTCP.

Sewer separation can be highly
effective in controlling the discharge
of untreated wastewater. Under ideal
circumstances, full separation can
eliminate CSO discharges. A survey
of readily available information in
NPDES files indicates that sewer
separation is the most widely used
CSO control, accounting for half of
CSO control measures found in LTCP
The Milwaukee Metropolitan Sewer District
uses real-time data to monitor the flow in its
sewer system tunnels and pipes.
    Photo: Milwaukee Metropolitan Sewer District
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Report to Congress on the Impacts and Control ofCSOs and SSOs
Monitoring and Real-
Time Control:
Seattle, WA
  The direct connection of roof leaders (shown
  above) and other inflow sources can limit
  sewer system capacity for conveying sanitary
  wastewater during wet weather.
      Photo: Milwaukee Metropolitan Sewer District
  Seattle was one of the first U.S. communities to implement and operate an advanced
  real-time control system to control CSO discharges.Seattle's system,called Computer
  Augmented Treatment and Disposal (CATAD), began operating in 1971. In the late
  1980s, treatment plant computer hardware was upgraded, remote telemetry units
  at regulators and pump stations were replaced  by programmable logic controllers,
  and graphical displays used by operators were improved. Based on the success of
  the CATAD technology, Seattle  implemented a new, predictive real-time control
  system that went on-line in early 1992. Rainfall prediction capabilities that  utilize
  rain gage data and a runoff model were added. A global optimization program
  was introduced that computed optimal flow and corresponding gate position for
  each regulator within the CSS. A distributed network allows control decisions to be
  implemented without operator intervention.The computer program uses real-time
  operation and system performance data to predict or forecast conditions through
  the system and directs control elements to utilize in-line storage during periods of
  high flow.
documentation (EPA 200la). This
suggests that many CSO communities
identify portions of their CSS in which
separation is a cost-effective CSO
control. Under these circumstances,
separation is often implemented in
conjunction with other public works
projects, including road work and
redevelopment. Sewer separation on
its own, however, does not always lead
to an overall reduction in pollution
or the attainment of water quality
standards. Storm water discharges
from the newly created separate
storm sewer system can contain
substantial pollutant loads that may
cause or contribute to water quality
problems. Implementation of storm
water controls may be necessary
following sewer separation in order to
achieve the pollutant load reductions
necessary for attainment of water
quality standards.

In practice, there are three distinct
approaches to  sewer separation:

•   Full separation wherein
    new sanitary sewer lines are
    constructed with the existing CSS
    becoming  a storm sewer system.
    This is probably the most widely
    used form of separation.

•   Full separation wherein an
    entirely new storm sewer system
    is constructed with the existing
    CSS remaining as a sanitary sewer
    system. This form of separation
    is not often used because the
    capacity of the existing CSS was
    designed to accommodate storm
    water runoff, which is more than
    what is required to accommodate
    sanitary flows.

•   Partial separation wherein a new
    storm sewer system is constructed
    for street drainage, but roof
    leaders and basement sump
    pumps remain connected to the
    existing CSS.

Sewer Rehabilitation/Replacement
The structural integrity of many sewer
system components deteriorates with
use and age. This gradual breakdown
allows more groundwater and storm
water to infiltrate into the sewer
system. This increases the hydraulic
load and, in turn, reduces the system's
ability to convey all flows to the
treatment plant. During wet weather
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                                                 Chapters—Technologies Used To Reduce the Impacts of CSOsand SSOs
events, excessive infiltration can cause
or contribute to CSOs and SSOs.
Sewer rehabilitation/replacement
restores and maintains the structural
integrity of the sewer system, in
part by reducing or mitigating the
effects  of infiltration. Common
sewer rehabilitation and replacement
techniques include:

•   Removal and replacement of
    defective lines;

•   Trenchless technologies that use
    the existing sewer to support a
    new pipe or line;

•   Shotcrete, wherein a mixture of
    cement, sand, and water is applied
    to sewer walls; and

•   Grouting and epoxy injections to
    seal leaks and cracks.

Inspecting and evaluating current
sewer condition is necessary before
a sewer rehabilitation technique
is chosen, as the condition of the
sewer may favor specific techniques.
Removing and replacing defective
lines is the most commonly used
rehabilitation technique when the
sewer line is structurally deficient
(CSU 2001). Complete replacement is
often the most effective rehabilitation
method in areas where increased
conveyance capacity is needed (WEF
1999a).

Trenchless technologies are especially
well-suited to urban areas where the
traffic disruption associated with
large-scale excavation projects can be a
significant obstacle to  a project (WEF
1999a). In addition, many sewers
are located near other underground
utilities in urban areas, which can
complicate traditional dig-and-replace
methods; trenchless technologies avoid
underground utilities by using the
existing sewer to support a new pipe
or line. Trenchless technologies include
sliplining, cured-in-place pipe (CIPP),
modified cross-section liners, and pipe
bursting.

Shotcrete, a non-invasive rehabilitation
method, is often used to rehabilitate
sewers with major structural problems.
Shotcrete, however, can be used only
in pipe with a diameter of at least 36
inches (CSU 2001).

Grouting and epoxy injections are
most appropriate when the sewer is
structurally stable but experiencing
infiltration.

Service Lateral Rehabilitation
Private building service laterals are
the pipes that convey wastewater from
individual buildings, including houses,
to the municipal sewer system. Recent
studies indicate that a significant
component of the infiltration in any
sewer system is  the result of service
lateral defects that contribute varying
quantities of I/I (WEF 1999b). During
wet weather events, excessive I/I can
cause or contribute to CSOs and SSOs.
In general, service lateral rehabilitation
techniques are similar to those used for
larger diameter sewers and include:

•   Removing and replacing defective
    service laterals;

•   Applying trenchless technologies
    that use the existing service lateral
    to support a new pipe or liner; and

•   Using grouting and epoxy
    injections to seal leaks and cracks.
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                      Assigning responsibility for the repair
                                      or replacement of service laterals is
                                      often cited as the biggest obstacle to
                                      correcting known defects. Notably,
                                      several studies highlighted significant
                                      problems in gaining access to private
                                      property until the municipality
                                      assumed full financial responsibility
                                      for the repair or replacement costs
                                      (Paulson et al. 1984; Curtis and
                                      Krustsch 1995).

                                      Manhole Rehabilitation
                                      Manholes must be maintained
                                      and kept in working condition.
                                      Structurally defective manholes can
                                      be a significant source of I/I that
                                      otherwise would not enter an SSS.
                                      Damage to  manhole covers and rims
                                      often occurs during road work, and
                                      it can allow storm water runoff from
                                      roads and sidewalks to flow directly
                                      into the sewer system. Further, cracks
                                      and openings in the sidewalk and base
                                     of the manhole can allow groundwater
                                     and storm water to infiltrate into the
                                     sewer system. Manhole rehabilitation
                                     can reduce I/I, restore the structural
                                     integrity of the manhole, and
                                     preserve SSS capacity for transporting
                                     wastewater. Common manhole
                                     rehabilitation methods include (ASCE
                                     1997):

                                     •   Sealing pick holes in the manhole
                                         cover and installing gaskets
                                         between the manhole cover and
                                         frame to eliminate storm water
                                         inflow;

                                     •   Implementing spot repairs with
                                         chemical grout or fast-drying
                                         cement to patch defects in
                                         manhole sidewalk or bases;

                                     •   Coating systems to rebuild
                                         structural integrity and protect
                                         concrete, steel, and masonry
                                         manhole structures against
                                         deterioration;
Service Lateral
Rehabilitation:
Montgomery, AL
In Alabama, the Montgomery Water Works and Sanitary Sewer Board (MWWSSB)
evaluated nearly 2.2 million linear feet of its sewer system, identifying 3,394 defects.
Eighty-five percent of these defects were in  service laterals; 97 percent of lateral
defects identified have been repaired.

Lateral repairs necessary within the city street right-of-way are made by MWWSSB
with consent and release of liability from the property owner. MWWSSB replaces
missing clean-out covers for  a  minimal cost with written permission from the
property owner.The property owners are responsible for the cost of all lateral repair
and replacement on their property.

Property owners initially received a 60-day notice of lateral repair requirements.
Another 10-day notice was sent if the property failed to respond to the initial
notice. Finally, if the property owner failed to respond to either notice, water service
to the property was shut off. Sixty-five percent of property owners responded after
receiving the initial notice.The remaining property owners corrected their defects
under threat of having their water service discontinued.

In selected areas where service lateral rehabilitation has been completed, the I/I
was reduced by an average of 42 percent. It is estimated that the annual I/I volume
in the MWWSSB service area  has  been reduced by 36 million gallons. The cost
of establishing the I/I  program was approximately $150,000. MWWSSB spends
$207,000 annually to operate the program.
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                                                  Chapters—Technologies Used To Reduce the Impacts of CSOsand SSOs
•   Reconstructing manholes in
    cases of substantial structural
    degradation; and

•   Placing inserts and liners in
    deteriorated manholes.

Inspection of the manhole components
is a necessary first step in selecting an
appropriate rehabilitation technique.
Spot repairs of manhole components
are most appropriate for addressing
minor defects, and chemical grouts
are commonly used for rehabilitating
structurally sound manholes made of
brick. Coating systems are applicable
for manholes with brick structures
that show little or no evidence of
movement or subsidence and at sites
not conducive to excavation or major
reconstruction. Structural linings
are applicable for standard manhole
dimensions (48- to 72-inch inner
diameter) where substantial structural
degradation has occurred. Structural
linings tend to be more expensive than
other rehabilitation techniques.

8.1.3   Storage Facilities
Many sewer systems experience
increased flow during wet weather. In
systems that are unable to transport or
provide full treatment for wet weather
flows, storage facilities are often used
to reduce the volume, frequency, and
duration of CSO and SSO events.
Storage facilities fill during wet
weather and are drained or pumped to
the wastewater treatment plant once
conveyance and treatment capacity
have been restored following the wet
weather event. Specific types of storage
facilities considered for this  report are
summarized in Table 8.3.

Storage facilities have seen wide
application as a CSO control because
of the large and frequent volumes of
combined sewage requiring  control;
however, a number of communities
have also found storage facilities,
especially flow equalization basins,
to be an effective wet weather SSO
control.

In-line Storage
In-line or in-system storage  is the
term used to describe storage of wet
weather flows within the sewer system.
Taking advantage of storage within the
sewer system has broad application
and can often reduce the frequency
and volume of CSOs and SSOs
without large capital investments.
Maximization of storage in the
sewer system is also one of the NMC
required of all CSO communities. The
amount of storage potentially available
in the sewer system largely depends
on the size or capacity  of the pipes
that will be used for storage  and on
the suitability of sites for installing
regulating devices.
 Technology             Type of   Pollutants/Problems Addressed
                       System
 In-line storage           CSS, SSS   Peak wet weather flow rate, BOD5,TSS, nutrients, toxics,
                                pathogens, floatables
 Off-line storage          CSS, SSS   Peak wet weather flow rate, BOD5,TSS, nutrients, toxics,
                                pathogens, floatables
 On-site storage and flow   CSS,SSS   Peak wet weather flow rate, BOD5,TSS, nutrients, toxics,
 equalization basins                pathogens,floatables
Damaged manholes, such as the broken
cover shown above,can be a significant
source of storm water I/I into an SSS.
          Photo: Limno-Tech, Inc.
                                                                                                      Table 8.3
                                           Summary of Storage
                                           Facilities
                                           Storage facilities have seen wide
                                           application in attenuating peak
                                           wet weather flows in both CSS and
                                           SSS.
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                      In-line storage techniques include the
                                      use of flow regulators, in-line tanks
                                      or basins, and parallel relief sewers.
                                      Flow regulators optimize in-line
                                      storage by damming or limiting flow
                                      in specific areas of the sewer system.
                                      Storage tanks and basins constructed
                                      in-line are typically governed by flow
                                      regulators. Dry weather  flows pass
                                      directly through in-line storage tanks
                                      or basins, and flow regulators limit
                                      flow exiting the facility during wet
                                      weather periods. In-line capacity can
                                      also be created by installing relief
                                      sewers parallel to existing sewers  or
                                      by replacing older sewers with larger
                                      diameter pipes. Again, flow regulators
                                      are used to optimize storage within
                                      these facilities.

                                      Areas where the sewer slope is
                                      relatively flat typically offer the best
                                      opportunities for in-line storage. One
                                      factor that limits the applicability of
                                      in-line storage is the possibility that
                                      this approach can increase basement
                                      backups and street flooding (EPA
                                      1999g). Use of in-line storage may
                                      also slow flow, allowing sediment and
                                      other debris to settle in the sewer. If
                                      allowed to accumulate, sediment and
                                      debris can reduce available  storage
                                      and conveyance capacity. Therefore, an
                                      important design consideration for in-
                                      line storage is to ensure that minimum
                                      flow velocities are provided to flush
                                      and transport solids to the wastewater
                                      treatment plant.

                                      Off-line Storage
                                      Off-line storage is the term used
                                      to describe facilities that store wet
                                      weather flows in near-surface storage
                                      facilities, such as tanks and basins or
                                      deep tunnels located adjacent to the
                                      sewer system. Off-line storage facilities
have broad applicability and can be
adapted to many different site-specific
conditions by changing the basin size
(volume), layout, proximity to the
ground surface, inlet or outlet type,
and disinfection mechanism. For
these reasons, off-line storage facilities
are one of the most commonly
implemented CSO controls (EPA
2001a). The use of off-line storage
tends to be more expensive than in-
line storage; it is usually considered
in areas where in-line storage is
insufficient or unavailable.

A typical near-surface storage facility
is a closed concrete structure built
at or near grade alongside a major
interceptor. Deep tunnel storage
facilities are used where large
storage volumes are required and
opportunities for near-surface storage
are unavailable. As their name implies,
deep tunnels are typically located
100 to  400 feet below ground. Tunnel
diameters range from 10 to 50 feet, and
many are several miles in length.

During dry weather, untreated
wastewater is routed around, not
through, off-line storage facilities. In
contrast, during wet weather, flows
are diverted from the sewer system
to the off-line storage facilities by
gravity drainage or with pumps. The
wastewater is detained in the storage
facility and returned to the sewer
system once downstream conveyance
and treatment capacity become
available. Overflows can occur if the
capacity of off-line storage structures is
exceeded.  Some treatment is provided
through settling; however, the primary
function of such facilities is storage
and the attenuation of peak wet
weather flows.
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                                                 Chapters—Technologies Used To Reduce the Impacts of CSOsand SSOs
  As part of Philadelphia's effort to control CSOs, the City Water Department plans
  to install three inflatable dams in large diameter sewers that have available in-line
  storage. The dams will  range from 11 to  15 feet high  and  will be automatically
  controlled for both dry and wet weather conditions.The three dams will enable 16.3
  MG of flow that might otherwise discharge to local receiving waters to be stored in
  existing sewers per storm event, reducing CSO volumes by 650 MG per year.

  The first inflatable dam,  located in the city's main relief sewer, will be operational by
  the end of 2004. The associated civil  work projects including sewer rehabilitation
  have been completed for this project. When operational, the  dam will have the
  ability to store up to 4 MG of combined sewage, and it is expected to reduce the
  number of CSO discharges to the Schuylkill River from 32 per year to four per year.
  Another inflatable dam will be installed in Rock Run during the summer of 2005.The
  total cost for the installation of the dams and sewer rehabilitation is approximately
  $4.8 million, or $0.29 per gallon of storage.
                                           In-line Storage:
                                           Philadelphia, PA
On-site Storage
On-site storage, which is storage
developed at the wastewater treatment
facility, is often an effective control
for managing wet weather flows
in systems where sewer system
conveyance capacity exceeds that
of the treatment plant. On-site
storage can play an important role in
improving treatment plant operations
by providing operators with the
ability to manage and store excess
flows. The costs associated with the
development of on-site storage are,
on average, considerably lower than
the construction costs for typical near
surface off-line storage facilities built
outside the bounds of the treatment
plant. Much of the cost savings derive
from siting storage facilities on land
already owned by the utility. It should
be noted, however, that sewer system
conveyance capacity may limit the
amount of wet weather flow that
can be brought to an on-site storage
facility, and expanding conveyance
capacity can be extremely expensive.

The two most common forms of on-
site storage are flow equalization basins
 (FEBs) and converted abandoned
treatment facilities. FEBs are used to
attenuate peak wet weather flows and
to improve wet weather treatment
plant operations (Metcalf and Eddy
2003). Abandoned treatment facilities
can function in a manner similar to
FEBs in attenuating peak wet weather
flows. Abandoned facilities that have
been successfully converted for storage
include old clarifiers, treatment or
polishing lagoons, and abandoned
pretreatment facilities at industrial
sites near the treatment plant.

8.1.4  Treatment Technologies
In many systems, wet weather flows
can exceed the existing conveyance
and treatment capacity. The
development of wet weather treatment
systems presents a viable alternative
to storing excess flows. Treatment
technologies are  end-of-pipe controls,
used to provide physical, biological,
or chemical treatment to excess wet
weather flows immediately prior to
discharge from a CSS or SSS. Specific
treatment technologies can address
different pollutants, such as settleable
solids, floatables, and pathogens.
                                                                                                           8-13

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Report to Congress on the Impacts and Control ofCSOs and SSOs
 On-site Storage:
 Oakland, ME
The sewer system in Oakland, Maine, consists mainly of combined sewers.The city
has been implementing CSO controls since 1997.These efforts include separating a
portion of the CSS and targeted inflow reduction activities. As a result, Oakland has
been able to eliminate both of its CSO outfalls and transport all wet weather flows
to its wastewater treatment plant. Although the city had sufficient sewer system
capacity to transport these wet weather flows, it did not have facilities capable of
treating the peak wet weather flow. The city was able to use an  FEB installed at a
nearby textile mill  that is no longer operating. The FEB was built in 1990 by the
textile mill as part of their pretreatment program and had not been used since the
plant closed. Oakland is able to store 0.2 MG of excess wet weather flows in the
FEB, and release it back to the wastewater plant for treatment as capacity becomes
available.The FEB is mainly used to control excess wet weather flow during spring
snowmelts. Bringing the FEB back into operation  cost approximately $27,610, or
$0.14 per gallon of storage.
                                     For the purposes of this Report to
                                     Congress, treatment technologies are
                                     assumed to operate intermittently,
                                     with dry weather flows from the
                                     CSS or SSS handled by the existing
                                     wastewater treatment plant. Treatment
                                     technologies considered here include
                                     strategies for developing wet weather
                                     treatment capacity at remote locations
                                     in the sewer system and for enhancing
                                     the performance of the existing
                                     treatment facility when flows exceed
                                     the rated capacity of the plant. Specific
                                     technologies and operational practices
                                     are summarized in Table 8.4  and
                                     include:

                                     •   Constructing supplemental
                                         treatment facilities for treating
                                         excess wet weather flows;

                                     •   Modifying the POTW to better
                                         accommodate high flows;

                                     •   Disinfecting excess wet weather
                                         flows;

                                     •   Using vortex separators to provide
                                         partial treatment for excess wet
                                         weather flows; and

                                     •   Constructing facilities to remove
                                         floatables from CSO discharges.
                                     In general, treatment technologies have
                                     not been as widely applied as other
                                     CSO and SSO controls, partly due
                                     to cost and the difficulty of remote
                                     control. Also, the requirements for
                                     permitting treated discharges from off-
                                     site SSO facilities during wet weather
                                     are somewhat unclear.

                                     Supplemental Treatment
                                     As the name implies, supplemental
                                     treatment technologies are intended
                                     to supplement existing wastewater
                                     treatment capacity during periods of
                                     wet weather. Example applications
                                     include installing a small scale
                                     treatment facility in  a capacity-
                                     constrained area of the sewer system,
                                     or adding a parallel treatment process
                                     at the existing treatment plant to be
                                     operated only during wet weather.
                                     Selection of a supplemental treatment
                                     technology is determined by the
                                     level of treatment required and the
                                     characteristics of the wet weather flow.
                                     Technologies commonly considered
                                     as potential supplemental  treatment
                                     processes for excess wet weather flows
                                     include:

                                     •  Ballasted flocculation  or
                                        sedimentation using a fine-grained
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                                                 Chapters—Technologies Used To Reduce the Impacts of CSOsand SSOs
 Technology
Type of
System
 Supplemental treatment   CSS,SSS
 Plant modifications       CSS, SSS
 Disinfection             CSS, SSS
 Vortex separators         CSS
 Floatables controls        CSS
Pollutants/Problems Controlled
            Peak wet weather flow rate, 6005,TSS, pathogens
            Peak wet weather flow rate, 6005,TSS
            Pathogens
            TSS,floatables
            Floatables
    sand, or ballast, and a coagulant to
    accelerate settling of solids from
    wastewater;

•   Chemical flocculation using metal
    salts and polymers to accelerate
    settling of solids from wastewater;

•   Deep bed filtration with coarse
    sand to filter wastewater; and

•   Microscreens.

Supplemental treatment technologies
must have quick start-up times after
extended periods of no flow (or
low flow) conditions, accommodate
sudden increases in flow at unplanned
times, and provide adequate treatment
despite significant variation in
flow rates and influent pollutant
concentrations.
                Plant Modifications
                Simple modifications to existing
                wastewater treatment facilities can
                increase their ability to handle wet
                weather flows. Modifications can
                involve changes to the physical
                configuration of various treatment
                processes and the operation of
                specific plant processes during
                wet weather. Most modifications
                require the active involvement of the
                treatment plant operator to ensure
                effective implementation. Example
                modifications that maximize the
                treatment of wet weather flows
                include:

                •   Ensuring the even distribution of
                    flow among treatment units;
                                                                                                      Table 8.4
                                               Summary of Treatment
                                               Technologies

                                               Based on life-cycle cost evaluations,
                                               treatment technologies may be an
                                               effective technique for handling
                                               excess wet weather flows.
 The Central Treatment Plant (CTP) for the City of Tacoma, Washington, receives
 flow from an SSS serving a population of 208,000. The CTP has a peak biological
 treatment capacity of 78 mgd. The sewer system, however, can deliver up to  110
 mgd to the CTP.Tacoma plans to install a ballasted flocculation process at the CTP,
 in parallel with the existing processes, to handle wet weather flows in  excess of
 the peak biological treatment capacity.The ballasted flocculation process will cost
 approximately $12.4 million. All related peak wet weather flow facilities  upgrades
 are estimated at  $50.7 million. In comparison, expanding the existing  activated
 sludge  processes would cost an estimated $130 million; this estimate  does  not
 include the cost for additional primary clarification capacity. When the ballasted
 flocculation process is brought on-line for wet weather treatment, effluent from
 the process will be separately disinfected and blended with disinfected biologically
 treated effluent prior to discharge.The blended effluent is expected to meet permit
 limits.The ballasted flocculation process is expected to operate a maximum of 5.5
 days in a row,8 days in a month,and 21 days per year (Parametrix 2001).
                                                           Supplemental Treatment:
                                                           Tacoma, WA
                                                                                                            8-15

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Ultraviolet light is used to disinfect wet
   weather flows as part of the Columbus,
   Georgia, Water Works CSO Technology
   Testing Program.
           Photo: Columbus Water Works
•   Installing baffles to protect
    clarifiers from hydraulic surges
    (NYSDEC2001);

•   Using metal salts and polymers to
    increase suspended solids removal;

•   Switching the mode of delivering
    flow from the primary to the
    secondary treatment units;

•   Switching from "series" operation
    of unit processes during dry
    weather flows to "parallel"
    operation during wet weather
    flows; and

Performance evaluations are
conducted to determine whether
additional capacity can be obtained
from existing facilities. While plant
modifications are generally more
cost effective than new construction,
some modifications that improve wet
weather performance may result in
increased concentrations of pollutants
in treatment plant effluent during dry
weather. For example, if not properly
designed, a clarifier modified for wet
weather flows may have inadequate
settling characteristics during dry
weather (Metcalf and Eddy 2003).
Further, modifications that require
operator attention before and after
a wet weather event may interrupt
regular dry weather operations and
potentially compromise the quality of
treated wastewater during dry weather.

Disinfection
Disinfection of wastewater is necessary
for  public health protection when the
public may come into contact with
wastewater discharges. Wastewater
treatment plants typically include
a disinfection process  designed
specifically to inactivate bacteria,
viruses, and other pathogens in the
treated wastewater. The application
of disinfection to CSO and SSO
discharges has been limited.

Achieving adequate disinfection
of excess wet weather flows can be
difficult. High flow rates can result
in reduced exposure of wastewater
to the disinfecting agent and
possibly reduced effectiveness of
the disinfection process. Among
conventional disinfection processes,
chlorine disinfection has been used
most often to successfully disinfect wet
weather flows. Effects of this method,
however, include toxic residual
chlorine and chlorine disinfection
by-products that limit the utility of
chlorination for disinfection in some
areas. Experience with ultraviolet
(UV) light and other alternatives has
increased considerably in recent years
and may be practical for wet weather
flow receiving a minimum of primary
treatment.

Vortex Separators
Vortex separators (swirl concentrators)
are designed to  concentrate and
remove suspended solids and
floatables from wastewater or
storm water. Applications of
vortex separators, for the most
part, have been  limited to CSSs.
Vortex separators use centripetal
force, inertia, and gravity to divide
combined sewage into a smaller
volume of concentrated sewage, solids,
and floatables; and a large volume of
more dilute sewage and surface runoff.
Typically, the concentrated sewage and
debris are conveyed to the treatment
plant, and the dilute mix is discharged
to a receiving water. This discharge
may or  may not receive disinfection.
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                                                Chapters—Technologies Used To Reduce the Impacts of CSOsand SSOs
Vortex separators provide a modest
level of treatment for a modest
cost. They are useful in controlling
suspended solids and floatables and
in reducing pollutants associated
with solids such as metals bound to
sediments. Vortex separators have
limited ability to reduce dissolved
pollutant or bacteria concentrations
unless, in the latter case, disinfection
is applied in conjunction with vortex
separation (Brashear et al. 2002).
When used in combination with
other CSO controls, the placement of
vortex  separators is very important.
Because they are designed to remove
suspended solids and floatables,
vortex  separators should not be placed
downstream of other facilities that
perform the same function, such as
sedimentation basins or grit chambers.
(Moffa 1997).

Floatables Controls
Floatables controls are principally
applied in CSSs and are designed to
mitigate aesthetic impacts of CSO
discharges by minimizing the amount
of litter and other debris entrained in
the CSO. Floatables controls are widely
used to control solids and floatables
in urban storm water discharges
from separate storm sewer systems.
Improvements in water quality from
floatables controls may be secondary.
The CSO Control Policy recognized
the importance of controlling solid
and floatable material by including
it under the NMC (EPA 1994a).
Floatables controls can be grouped
into three categories:

•   Source controls that work to
    prevent solids and floatables from
    entering the CSS.
•   Collection system controls that
    keep solids and floatables in the
    sewer system, so they can be
    collected and removed at strategic
    locations or transported to the
    wastewater treatment plant.

•   End-of-pipe  controls, such as
    containment booms and skimmer
    boats, capture solids and floatables
    as they are discharged from
    the sewer system. End-of-pipe
    controls can  create temporary
    unsightly conditions near CSO
    outfalls and may be undesirable
    in areas with waterfront
    development.

Ensuring the efficient and effective
operation of all types of floatables
controls requires proper maintenance.
The optimal period between
maintenance activities ranges from a
few weeks to semi-annually, depending
on the technology employed.

8.1.5  Low-Impact Development
       Techniques
Low-impact development (LID)
techniques seek to control the timing
and volume  of storm water discharges
from impervious surfaces (e.g.,
building roofs  and parking lots) to the
sewer system as well as the  volume of
wastewater generated by residential,
commercial, and industrial customers.
Controlling the timing and volume
of storm water discharges can be an
important component of a program
to control CSOs. Reducing the volume
of wastewater generated within the
service area frees capacity within
both CSSs and SSSs for  transport of
additional flows during wet weather.
Specific LID techniques considered for
this report are  summarized in Table
8.5.
                                                                                                         8-17

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Report to Congress on the Impacts and Control ofCSOs and SSOs
    Table 8.5
   I:
Summary of Low-Impact
Development Techniques

 .ow-impact development
techniques are most useful in
attenuating peak wet weather flow
rates associated with urban and
suburban storm water runoff.
                                   Technology
Porous pavement
Green roofs
Bioretention
Water conservation
                                     While the concept of using LID to
                                     control storm water runoff is familiar,
                                     the application of LID techniques
                                     for CSO control has been limited
                                     (University of Maryland 2002). It is
                                     unlikely that LID techniques alone are
                                     sufficient to fully control CSOs, yet
                                     they have shown promise as part of
                                     larger programs in reducing the size of
                                     structural controls (e.g. storage). The
                                     use of LID as an SSS control is limited
                                     to situations in which LID might
                                     contribute to inflow control. LID
                                     has great potential as a storm water
                                     control for the separate storm sewer
                                     system that complements an SSS.

                                     Porous Pavement
                                     Porous pavement is an infiltration
                                     system in which storm water
                                     runoff enters the ground through a
                                     permeable layer of pavement or other
                                     stabilized permeable surface (EPA
                                     1999h). The use of porous pavement
                                     reduces or eliminates impervious
                                     surfaces, thus reducing the volume of
                                     storm water runoff and peak discharge
                                     volume generated by a site. Reducing
                                     the amount of stormwater that enters
                                     the CSS increases conveyance and
                                     storage capacity. This in turn leads
                                     to reductions in the volume and
                                     frequency of CSOs.

                                     Porous pavement is used as
                                     an alternative to conventional
                                     impervious pavement, under certain
                      Type of System      Pollutants/Problems Controlled
Peak wet weather flow rate
Peak wet weather flow rate
Peak wet weather flow rate
Peak wet weather flow rate
                                                                       conditions. The success of porous
                                                                       pavement applications depends
                                                                       on design criteria including site
                                                                       conditions, construction materials,
                                                                       and installation methods. Typically,
                                                                       porous pavement is most suitable for
                                                                       areas with sufficient soil permeability
                                                                       and low traffic volume. Common
                                                                       applications include parking lots,
                                                                       residential driveways, street parking
                                                                       lanes, recreational trails, golf cart and
                                                                       pedestrian paths, shoulders of airport
                                                                       runways, and emergency vehicle and
                                                                       fire access lanes. This  technology is not
                                                                       recommended for areas that generate
                                                                       highly contaminated runoff such as
                                                                       commercial nurseries, auto salvage
                                                                       yards, fueling stations, marinas,
                                                                       outdoor loading and unloading
                                                                       facilities, and vehicle washing facilities,
                                                                       as contaminants could infiltrate into
                                                                       groundwater (SMRC 2002).

                                                                       Green Roofs
                                                                       Green roofs use rooftop vegetation
                                                                       and underlying soil to intercept storm
                                                                       water, delay runoff peaks, and reduce
                                                                       runoff discharge rates and volume.
                                                                       Their use can lead to reductions in the
                                                                       volume or occurrence of CSOs. Green
                                                                       roofs are becoming an important
                                                                       tool in areas with dense development
                                                                       where the use of other space-intensive
                                                                       storm water management practices,
                                                                       such as detention ponds and large
                                                                       infiltration systems, is impractical.
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                                                 Chapters—Technologies Used To Reduce the Impacts of CSOsand SSOs
There are two basic types of green
roofs: intensive and extensive.
Intensive green roofs, also known
as conventional roof gardens, are
landscaped environments developed
for aesthetic and recreational uses that
require high levels of management.
Extensive green roofs, or eco-roofs,
make use of a continuous, thin layer
of growing medium that sustains low-
maintenance vegetation tolerant of
local climatic conditions.

Intensive and extensive green roofs
have been successfully installed in
cities across the United States, both
as part of new building design and
retrofitted to existing buildings
(e.g., Chicago, IL;  Philadelphia, PA;
Portland, OR). Green roofs can be
designed for commercial buildings,
multi-family homes, industrial
structures, and single-family homes
and garages. Factors that must be
considered before installing a green
roof include the load-bearing capacity
of the roof deck, the moisture and
root penetration resistance of the
roof membrane, roof slope and shape,
hydraulics, and wind shear.

Bioretention
Bioretention  is a soil and plant-
based storm water management
practice used to filter and infiltrate
runoff from impervious areas such
as streets, parking lots, and rooftops.
Bioretention  systems are essentially
plant-based filters  designed to mimic
the infiltrative properties of naturally
vegetated areas, reducing runoff rates
and volumes. Their use can lead to
reductions in CSO and SSO volume
and frequency. The complexity of
bioretention systems depends on the
volume of runoff to be controlled,
available land area, desired level of
treatment, and available funding.
Bioretention systems can be used as
a stand-alone practice (off-line) or
connected to a separate storm sewer
system (on-line).

Bioretention systems can be
implemented in  new development or
be retrofitted into developed areas.
Bioretention systems are easier to
incorporate in new developments,
due to fewer constraints regarding
siting and sizing. They can be
applied in heavily urbanized areas,
including commercial, residential,
and industrial developments. For
example, bioretention can be used as
a storm water management technique
in median strips, parking lots with
or without curbs, traffic islands,
sidewalks, and other impervious areas
(EPA 19991).

The effectiveness of bioretention
systems depends on infiltration
capacity and treatment capability.
Systems must be sized to match
expected runoff. Runoff volumes in
excess of the system's capacity must
be handled in such a way as to avoid
erosion and destabilization of the
site. Typical maintenance activities
for bioretention  systems include
re-mulching void areas; treating,
removing, and replacing dead or
diseased vegetation; watering plants
until they are established; inspecting
and repairing soil, as needed; and
removing litter and debris.

Water Conservation
Water conservation is the efficient
use of water in a manner that extends
water supplies, conserves energy,
and reduces water and wastewater
In-system netting can provide floatables
control at strategic locations in the sewer
system.

 Photo: New Jersey Department of Environmental Protection
                                                                                                            8-19

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Bioretention systems can reduce the
   amount of storm water runoff generated by
   impervious surfaces, such as parking lots,
   that enters a CSS during wet weather.
          Photo: Prince Georges County, MD
treatment costs. Reducing water use
can decrease the total volume of
domestic sewage conveyed by a sewer
system, which can increase conveyance
and treatment capacity during periods
of wet weather and potentially
reduce the volume and frequency of
CSOs and SSOs. Numerous indoor
and outdoor practices reduce water
consumption, including (GBS 2002):

•   High efficiency fixtures and
    appliances such as low-flow toilets,
    urinals, showerheads, and faucets,
    and water-efficient washing
    machines and dishwashers.

•   Water recycling and reuse of
    wastewater from sinks, kitchens,
    tubs, washing machines, and
    dishwashers for landscaping,
    flushing toilets, and other non-
    potable purposes.

•   Waterless technologies such as
    composting toilets and waterless
    urinals.

•   Rain harvesting, in which roof
    runoff is collected, stored, and
    used primarily for landscaping.

In most instances, money saved
from reduced water and sewer bills
offsets installation costs over time.
Among high efficiency fixtures  and
appliances, low-flow showerheads
and faucet aerators are almost always
cost-effective  to install due to their
relatively low cost and minimal
labor requirements. Low-flow toilets
also have widespread application,
particularly in commercial and
institutional settings, because the
economic offset period can be
relatively short.  The cost effectiveness
of the other water conservation
                                                                           technologies mentioned depends on
                                                                           site-specific considerations.
8.2  How Do CSO and SSO
     Controls Differ?

       Although many of the
       technologies considered
       in this report have proven
useful in controlling overflows from
both CSSs and SSSs, EPA found that
applications of certain technologies
were more common to a particular
type of system. This section highlights
technologies with particular
application in either CSSs or SSSs.

8.2.1 Common CSO Control
     Measures
Implementation of the NMC was
expected to be one of the first steps
taken by CSO communities in
response to the CSO Control Policy.
In general, the NMC are controls that
reduce CSOs and their impacts on the
environment and human health, but
do not require significant engineering
studies or major construction, and
are implemented in  a relatively
short period (e.g., within a few
years). Most activities completed
as part of implementing the NMC
are considered O&M practices or
collection system controls. The most
common NMC activities include  (EPA
2001a):

•   Sewer cleaning

•   Pollution prevention

•   Inflow reduction

In developing and implementing  a
CSO LTCP, municipalities are expected
to consider more significant structural
8-20

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                                                Chapters—Technologies Used To Reduce the Impacts of CSOsand SSOs
  Low-flow plumbing fixtures were installed in a 60-unit low income multi-family
  housing complex in Houston,Texas.The average number of occupants per unit was
  4.4. Devices installed in each unit included low-flow toilets (1.6 gallons per flush),
  low-flow aerators on faucets (2.2 gallon per minute) and new water meters. Faucet
  leaks were repaired, and tenants were educated on conservation techniques. The
  project resulted in  a reduction  in  average monthly water consumption for the
  complex from 1.3 MG pre-installation to 367,000 gallons post-installation. Average
  monthly water bills for the complex decreased from $8,644 to $1,810, resulting in
  savings of approximately $6,834 each month. Due to the success  of the project,
  Houston retrofitted four other low income housing developments with low-flow
  plumbing fixtures.
                                           Water Conservation:
                                           Houston, TX
controls. Specifically, municipalities
are asked to evaluate the applicability
of more comprehensive collection
system controls, storage facilities, and
treatment technologies.

Sewer separation is the CSO control
most widely implemented as part of
an LTCP (EPA 200la). Complete or
limited sewer separation has been
implemented or planned by the
majority of CSO communities for
which CSO controls were documented
in the NPDES authority files that EPA
reviewed as part of data collection to
support its 2001 Report to Congress-
Implementation and Enforcement of the
CSO Control Policy. Other common
CSO control measures identified in
LTCPs  include:

•   Off-line storage facilities

•   Plant modifications

•   Sewer rehabilitation

•   Disinfection facilities

8.2.2 Common SSO Control
     Measures
There is no national standard
equivalent to the LTCP for
communities with SSSs that are
working to control SSOs, so it is
difficult to determine the prevalence of
specific controls. Based on interviews
EPA conducted to support the
development of this report, it appears
that communities with recurrent dry
weather SSOs tend to rely on O&M
activities, while communities with wet
weather SSOs rely more heavily on
collection system controls (e.g., inflow
reduction, rehabilitation).
8.3  What Technology
     Combinations are
     Effective?
          Most communities evaluate
          and use a wide variety of
          technologies for their CSO
and SSO programs. Some technologies
have proven to be advantageous
when applied together. This section
describes several examples of
beneficial technology pairings;
this list should not be construed
as an exhaustive list of technology
combinations.

8.3.1 Inflow Reduction or Low-
     Impact Development Coupled
     with Structural Controls
Inflow reduction and LID techniques
reduce the quantity of storm water
runoff that enters a sewer system.
Since these controls can reduce both
the peak flow rate and volume of
storm water delivered to  a sewer
                                                                                                        8-21

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     system, the size of more capital-
                                     intensive downstream control
                                     measures, such as storage facilities
                                     or treatment technologies, can be
                                     reduced, or, in some cases, eliminated
                                     completely.

                                     8.3.2 Disinfection Coupled with
                                           Solids Removal
                                     A number of the pollutants present
                                     in wastewater can interfere with
                                     disinfection processes and reduce
                                     their efficacy. High concentrations of
                                     6005, ammonia, and iron can reduce
                                     the effectiveness of disinfection.
                                     These substances can consume or
                                     otherwise prevent the disinfectant
                                     from reaching microbial pathogens.
                                     Solids in wastewater can also interfere
                                     physically with the disinfection
                                     process. Pathogens can be "shielded"
                                     by larger solids that surround and
                                     insulate microbial pathogens from the
                                     disinfectant (Hoff and Akin  1986).
                                     Physical interference can be significant
                                     for both chlorine and UV disinfection.

                                     In general, solids removal enhances
                                     disinfection by removing interfering
                                     substances and by physically
                                     removing the pathogens themselves.
                                     The performance of disinfection
                                     facilities to treat CSO and SSO
                                     discharges can be improved through
                                     the use of technologies that provide
                                     solids control. Technologies with
                                     demonstrated abilities to remove
                                     solids include off-line storage facilities,
                                     vortex separators, and supplemental
                                     treatment facilities.
8.3.3 Sewer Rehabilitation Coupled
     with Sewer Cleaning
Sewer rehabilitation is undertaken
to restore the structural integrity
of sewers and reduce infiltration.
The presence of debris and roots
within sewer  systems can limit the
effectiveness of sewer rehabilitation
efforts, particularly where Shortcrete
or trenchless  technologies are
employed. Therefore, it is essential
that sewer cleaning techniques are
employed prior to any scheduled sewer
rehabilitation efforts.

8.3.4 Real-Time Control Coupled
     with In-line or Off-line
     Storage Facilities
Real-time control technology is
used to maximize storage within the
collection system and maximize flow
to the POTW, thereby reducing the
volume and frequency of untreated
discharges. Real-time control systems
use monitoring data, operating rules,
and customized software to operate
system components (e.g., weirs,
gates, dams, valves, and pumps)  in a
dynamic manner to optimize storage
and treatment. Real-time control is
most often applicable in CSSs, as these
systems tend  to have substantial in-
line storage in large diameter pipes
designed to transport excess wet
weather flows. CSSs may also have off-
line storage facilities (e.g., tunnels and
basins), which can be incorporated
into a real-time control strategy. The
dynamic operation possible under
real-time control tends to require less
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                                               Chapters—Technologies Used To Reduce the Impacts of CSOsand SSOs
storage than would be required for
similar performance without real-time
control.
8.4  What New Technologies for
     CSO and SSO Control are
     Emerging?

       This section describes two
       different broad types of
       measures that have potential
for widespread implementation in
controlling the impacts of CSOs or
SSOs. These controls are viewed as
"emerging" for the following reasons:
techniques are evolving and warrant
further study; and, in general,
applications to date have been limited
to larger municipalities, although the
technologies appear to have value for
use in smaller systems. Again, this
should not be construed to be an
exhaustive list.

8.4.1 Optimization of Sewer
     System Maintenance
Sewer system maintenance is critical
to providing safe and efficient service.
Optimizing sewer system maintenance
involves allocating labor, equipment,
and materials to maximize system
performance, so that the system
can efficiently collect and transport
wastewater to the treatment plant.
Determining how much maintenance
is enough is rarely straightforward,
however. Currently, there is no
standard approach for determining
the optimal frequency of various
maintenance procedures except
through experience and professional
judgement (ASCE 1999). Several
EPA regions and states, as well as
professional organizations, have
initiated efforts to develop such an
approach. These include Region 4's
MOM Program (Section 7.3.1) and
the toolkit of effective O&M practices
recently published by WERF (WERF
2003a).

8.4.2 Information Management
Effective sewer system management
largely depends on the availability
of accurate, easily accessible data.
Manual, paper-based data systems
are used to some degree in all
sewer systems (Arbour and Kerri
1998). Many utilities have been
and continue to be operated and
managed in an effective manner
without the assistance of computer-
based systems.  The use of a computer
system, however, can improve data
storage and processing. Previously,
the considerable expense of such
systems limited their applicability to
larger sewer systems. As the costs of
computers and customized software
have decreased, however, these
systems are now available to  most
utilities (CSU 2002). An information
management system can be designed
to meet multiple needs, including:

•   Simplifying maintenance planning
    and scheduling;

•   Tracking workforce productivity;

•   Developing accurate unit costs for
    specific maintenance activities;
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     •  Measuring the impact of resource
                                        allocation to various maintenance
                                        activities; and

                                     •  Developing  and tracking sewer
                                        system performance measures.

                                     A number of vendors have designed
                                     software packages specifically to
                                     assist utility staff in sewer system
                                     management. The software is typically
                                     a tailored database program that
provides a means for efficient data
organization, storage, and analysis.
Most software packages include
basic tools for sorting and filtering
maintenance data; many also offer
report generation capabilities. Other
software packages contain basic tools
as well as more advanced decision
support systems. Most packages
offer the ability to link to other
external data systems such as a CIS or
computer models.
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                            Chapter  9
    Resources Spent to Address the
         Impacts of CSOs and SSOs
      This chapter responds to
      the congressional directive
      to report on the resources
spent by municipalities to address
environmental and human health
impacts of CSOs and SSOs. The
chapter presents information on
historical investments in wastewater
infrastructure, resources spent on CSO
and SSO control to date, projected
costs to reduce CSOs and SSOs, and
financing mechanisms available to
municipalities.

Most municipalities are not required
to explicitly report costs to implement
CSO and SSO controls. Therefore,
financial information on resources
spent to address CSOs and SSOs
was drawn from alternative sources,
including: LTCPs and other facility
planning documents; municipal
interviews described in Appendix
C; information on state and
local expenditures on wastewater
infrastructure from the U.S. Census
Bureau (2002, 2003a); specific
reporting categories associated with
the CWNS (EPA 2003b) and the
CWSRF (EPA 2003J); other loan and
grant programs; and federal, state, and
industry reports, such as the AMSAs
triennial financial survey (AMSA
2003a).

All cost figures in this chapter are
presented in 2002 dollars, unless
otherwise noted. Unadjusted costs are
included in Appendix M.
9.1  What Federal Framework
    Exists for Evaluating
    Resources Spent on CSO
    and SSO Control?
      At the national level, two EPA
      programs provide information
      on the monies spent on CSO
and SSO control, as well as anticipated
needs:

•  Clean Water State Revolving Fund
   (CWSRF)
•  Clean Watersheds Needs Survey
   (CWNS)
The CWSRF is a national program
established in 1987 under the Clean
Water Act to fund water quality
projects. Through the CWSRF, all
50 states and Puerto Rico maintain
                                                                   In this chapter:
9.1  What Federal Framework
    Exists for Evaluating
    Resources Spent on CSO
    and SSO Control?

9.2  What are the Past
    Investments in Wastewater
    Infrastructure?

9.3  What Has Been Spent to
    Control CSOs?

9.4  What Has Been Spent to
    Control SSOs?

9.5  What Does it Cost to
    Maintain Sewer Systems?

9.6  What are the Projected
    Costs to Reduce CSOs?

9.7  What are the Projected
    Costs to Reduce SSOs?

9.8  What Funding Mechanisms
    are Available for CSO and
    SSO Control?
                                                                                           9-1

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     revolving loan funds to provide
                                     low-cost financing for these projects
                                     through low-interest loans. The
                                     CWSRF is primarily used to fund
                                     wastewater treatment projects, but it
                                     can also be used for nonpoint source
                                     pollution control and watershed and
                                     estuary management (EPA 2003J).
                                     The CWSRF tracks state and local
                                     expenditures on these  projects on
                                     an annual basis, and it includes a
                                     separate reporting category for CSO
                                     expenditures.

                                     The CWNS, a joint effort between
                                     states and EPA, includes a survey of
                                     needs of facilities for control of CSOs
                                     along with other wastewater and
                                     watershed needs (EPA 2003b). Survey
                                     data are maintained in a database and
                                     used to produce a CWNS Report to
                                     Congress, which provides a national
                                     estimate of needs. The CWNS and the
                                     CWSRF do not specifically track costs
                                     related to SSO control.

                                     The CSO Control Policy provides
                                     a regulatory framework for CSO
                                     control. Under the CSO Control
                                     Policy, communities are required
                                     to develop  and implement LTCPs.
                                     In developing an LTCP, the CSO
                                     Control Policy recommends that
                                     the community complete a detailed
                                     evaluation  of CSO control alternatives
                                     and develop a financing plan to
                                     fund implementation of the selected
                                     controls. This means that communities
                                     that have completed LTCPs usually
                                     report the anticipated  cost of CSO
                                     control in their plan.

                                     The costs of addressing SSO problems
                                     can vary significantly among
                                     communities. Currently, there is no
                                     national framework for SSO control
                                     that requires communities to develop
and report projected or realized costs.
Therefore, more financial information
is available for CSOs than SSOs. For
the purposes of this report, the costs
to address SSOs were estimated using
information from the CWSRF, the
CWNS, and recent EPA efforts.
9.2  What are the Past
     Investments in Wastewater
     Infrastructure?

          Municipalities, states, and
          the federal government
          have been investing in the
nation's wastewater infrastructure
since the late 19th century (EPA
2000a, 2000c). With passage of the
Clean Water Act in 1972, investment
in wastewater infrastructure increased
markedly. The Clean Water Act
dramatically increased funding for
the Construction Grants  Program,
establishing a national policy to
provide federal grants for the
construction and upgrade of POTWs.

The Construction Grants Program
provided grants for as much as 75
percent of the total capital cost for
construction of wastewater treatment
facilities from 1970 to 1995. During
this period, the Construction Grants
Program provided a total of more
than $100 billion in federal funding
for new construction and POTW
upgrades (EPA2000a). In 1981,
amendments to the Clean Water Act
cut the authorization for POTW
grants in half and reduced the
maximum federal match to 55 percent.
Legislation was amended to phase out
the Construction Grants  Program by
1991 and replace it with the CWSRF.
Federal funding for the CWSRF
totaled more than $21 billion from
9-2

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                                                    Chapter 9—Resources Spent to Address the Impacts of CSOs and SSOs
1988 to 2002, and states have made
over $47 billion available through the
CWSRF for investment in wastewater
infrastructure; both figures are in
unadjusted dollars.

As shown in Figure 9.1, federal grant
funding for capital wastewater projects
peaked in 1977 at $14.1 billion
dollars. The U.S. Census Bureau
(2002,2003a) reported that total local
and state spending on wastewater
                   infrastructure exceeded $535 billion
                   between 1970 and 2000. EPA estimates
                   that the current capital investment
                   in wastewater infrastructure from all
                   public sources—federal, state, and
                   local—is just over $13 billion annually
                   (EPA 2002a). Today, according
                   to industry organizations, local
                   governments and utilities pay as much
                   as 90 percent of capital expenditures
                   on wastewater infrastructure (AMSA
                   andWEF 1999).
                               Billions of Dollars
         0.0
3.0
6.0
9.0
12.0
15.0
• Federal
• State and local


re
0)
                                                                                                       Figure 9.1
Annual Capital
Expenditures
on Wastewater
Infrastructure, 1970-
2000

Federal funding for capital
wastewater projects peaked in
1977. At that time, federal funding
accounted for more than 60 percent
of annual capital expenditures
on wastewater projects; by 2000,
federal funding represented
about 15 percent of annual capital
expenditures. Details on annual
federal, state,and local expenditures
are shown in Appendix M (Tables
M.2,M.3).

          Sources: Construction Grants Program and CWSRF expenditures (EPA 2000a, 2000c, 2003J); and
          U. S. Census Bureau (2002).
                                                                                                               9-3

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Report to Congress on the Impacts and Control ofCSOs and SSOs
  Figure 9.2
    State and Local
    Expenditures on
    Wastewater O&M, 1970-
    2000 (EPA 2000c, U.S.
    Census Bureau 2002,
    2003b)
      As the value of the nation's wastewater
      infrastructure increased, O&M (non-
      capital) expenditures at wastewater
      facilities have increased from $1.3
      billion in 1970 to $18.0 billion in
      2000 (Figure 9.2). O&M expenditures
      now account for 60 percent of total
      spending on wastewater services
      (U.S. Census Bureau 2003a). AMSA
      (2003b) cites a "combination of aging
      infrastructure, expectations of higher
      quality service, a growing population,
    The majority of O&M expenditures
    are borne by local governments.The
    Census Bureau does not, however,
    report state and local expenditures
    separately.
!
                                                                           and increasingly expensive federal
                                                                           regulations" as contributing to
                                                                           increased O&M costs.

                                                                           Since 1970, total public investment in
                                                                           wastewater infrastructure (capital) and
                                                                           O&M exceeded $658.4 billion (EPA
                                                                           2001f). According to ASCE, water and
                                                                           wastewater systems are the second
                                                                           largest public works infrastructure
                                                                           in the country (ASCE 2003). This
                                                                           infrastructure includes:
              $0
$2
$4
Billions of Dollars
    $8     $10   $12    $14    $16   $18
                                      5 1984
                                        1985
                                        1986
                                        1987
                                        1988
                                        1989
                                        1990
                                        1991
                                        1992
                                        1993
                                        1994
                                        1995
                                        1996
                                        1997
                                        1998
                                        1999
                                        2000
9-4

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                                                 Chapter 9—Resources Spent to Address the Impacts of CSOs and SSOs
•   16,202 wastewater treatment
    facilities;

•   21,264 sewer systems (both CSS
    and SSS);

•   100,000 major pumping stations;

•   584,000 miles of sanitary sewers;

•   200,000 miles of storm sewers;
    and

•   140,000 miles of combined sewers
    (EPA2001gand2003b).
9.3  What Has Been Spent to
     Control CSOs?

      Federal funding for CSO control
      projects began in 1965.
      Although some communities
financed CSO controls through
the Construction Grants Program,
investment in wastewater
infrastructure during the 1970s and
1980s was focused on POTW upgrades
to secondary and advanced treatment
and expansion (EPA 200la). Federal
funding for CSO projects through the
Construction Grants Program totaled
$3.4 billion.

Since 1988, the CWSRF has been used
to provide loans to CSO communities.
CSO projects financed under the
CWSRF total $3 billion (EPA 2003J).
As shown in Figure 9.3, total state and
local expenditures reported under the
CWSRF program for CSO projects
have increased to $0.44 billion per
year in 2002. The exact percentage of
total annual municipal investment
in CSO control projects funded
through the CWSRF is not known.
Some communities participate in
the CWSRF for only a portion of
their CSO financing; others do not
participate in the program at all.

Statewide information on past
expenditures for CSO control
is available in some states. Two
coordinated surveys were conducted
in Michigan in 1999 to obtain
community and state information
on CSOs, SSOs, and other water
pollution control efforts (SEMCOG
 Billions of Dollars (2002)
                             $0.26
                    $0.20
                                                          $°-41  $0.41
                                                                   $0.44
                                                     $0.28
                         $0.19
                                  $0.20
 $0.00 $0.01
               $0.13

                                       $0.17      $0.16
                                           $0.14
 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001  2002
                                   Year
                                                           Figure 9.3
                                       CWSRF Annual
                                       Expenditures for CSO
                                       Projects, 1988-2002
                                       (EPA 2003b)

                                       This figure shows state and local
                                       expenditures reported under CWSRF
                                       Category V (CSO correction). Some
                                       communities participate in CWSRF
                                       for a portion of their CSO financing;
                                       other CSO communities do not
                                       participate at all.
                                                                                                         9-5

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Report to Congress on the Impacts and Control ofCSOs and SSOs
 HUD and CWSRF Funding
 Used to Fund Sewer
 Separation:
 Agawam, MA
 The Town of Agawam, Massachusetts had 132 miles of combined sewer and found
 sewer separation to be a cost-effective CSO control. The town spent a total of
 $5.85 million to implement CSO-control measures. Funding was provided through
 a Housing and Urban Development (HUD) grant in the 1970s for limited sewer
 separation. CWSRF loans provided $2 million for a pump station upgrade (1996-
 1997) and $3.5 million to complete the sewer separation (1999).
                                     2001; PSC & ECT 2002). Capital CSO
                                     control expenditures by 63 Michigan
                                     communities exceeded $1 billion
                                     between 1989 and 1999 (PSC & ECT
                                     2002). It should be noted that few of
                                     Michigan's CSO communities began
                                     implementing controls prior to 1989.

                                     No comprehensive source of
                                     individual municipal expenditures
                                     for CSO control exists. Through this
                                     report effort, however, EPA compiled
                                     expenditures to date for 48 CSO
                                     communities (Appendix M). These
                                     expenditures total $6 billion, ranging
                                     from $134,000 to $2.2 billion per
                                     community. Information on the unit
                                     costs of specific control technologies
                                     used by communities to reduce
                                     CSOs is available in the technology
                                     decriptions provided in Appendix L.
                                     9.4 What Has Been Spent to
                                         Control SSOs?

                                              Many of the expenditures
                                              associated with controlling
                                              SSOs are costs associated
                                     with renewing aging sewer system
                                     infrastructure. This makes separating
                                     costs specifically associated with SSO
                                     control from standard sewer system
                                     O&M costs difficult.

                                     The CWSRF does not explicitly track
                                     expenditures related to SSO control.
                                     The CWSRF, however, does track
                                     "I/I correction" and "sewer system
                                     replacement and rehabilitation"
                                     expenditures. For the purposes of this
                                     report, these CWSRF categories of
                                     expenditures are used as a surrogate
                                     for SSO capital projects, with
                                     the understanding that they may
   Figure 9.4
     CWSRF Annual
     Expenditures for I/I and
     Sewer Replacement/
     Rehabilitation (EPA 2003J)

     Although the CWSRF does not
     specifically track expenditures
     related to SSO control, spending
     related to I/I correction and
     sewer system replacement and
     rehabilitation may serve as a
     surrogate for SSO capital projects.
     These categories, however, may
     overestimate CWSRF expenditures
     on SSO control.
Billions of Dollars (2002)
D  I/I correction
•  Sewer system replacement and
   rehabilitation
                            $0.42
$0.62
         $0.53
     $0.04 $0.06
              $0.10
                   $0.13
$0.001 y   u
 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 20002001 2002
                                 Year
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                                                  Chapter 9—Resources Spent to Address the Impacts of CSOs and SSOs
overestimate CWSRF expenditures
on SSO control. As shown in Figure
9.4, total state and local spending
through the CWSRF on I/I correction
(Category III-A) and sewer system
replacement and rehabilitation
(Category III-B) was $0.53 billion in
2002. From 1988 to 2002, expenditures
totaled $4.0 billion. Spending in these
areas has increased over the last several
years and now exceeds expenditures
for CSO projects under the CWSRF
program (EPA 2003J). It should be
noted that communities may have
reported expenditures on SSO projects
under other categories, and not
all communities participate in the
CWSRF.

Some local cost information on
expenditures to control SSOs was
obtained as part of the municipal
interviews conducted for this report
(Appendix C). These  communities
had service populations ranging
from 75 to 615,000 people. Of the
45 communities with SSSs that
participated, 29 communities provided
cost information on either capital
or O&M annual expenditures on
SSO control. As shown in Table 9.1,
the total annual capital and O&M
expenditures for these 29 communities
totaled $196.8 million. The total
annual expenditures varied with
population served, from a minimum
of $20,000 in one small village
to nearly $96 million in a major
metropolitan area.

The cost of SSO control can vary
significantly, depending on the
size and condition of the SSS, the
technologies chosen to reduce
SSOs, and regulatory requirements.
Information on the unit costs of
specific control technologies used
by communities to reduce SSOs
is available in the technology
descriptions  provided in Appendix L.
9.5  What Does it Cost to
     Maintain Sewer Systems?
       As discussed in Section 9.2, the
       current capital investment by
       federal, state, and local sources
in wastewater infrastructure is $13
billion dollars per year. O&M costs
exceed $18 billion per year, more than
60 percent of total spending.

As shown  in Table 9.2, average annual
O&M costs per mile of sewer are
highly varible. Various studies have
estimated  average O&M costs between
$3,100-$12,500 per year per mile of
Type of Cost
Capital
O&M
Total
(capital + O&M)
Number of
Communities
19
26
29
Minimum
$6,000
$12,500
$20,000
Maximum
$75M
$20.9M
$95.9M
Total
$154.5M
$42.3M
$196.8M
                                                                                                  Table 9.1
                                                                             Annual Expenditures in
                                                                             Sanitary Sewer Systems
                                                                             This table shows annual capital
                                                                             and O&M expenditures for 29
                                                                             communities with SSSs, which
                                                                             service populations ranging from 75
                                                                             to 615,000.
                                                                                                          9-7

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Report to Congress on the Impacts and Control ofCSOs and SSOs
   Table 9.2
    O&M Costs for Sewers

    This table shows the average annual
    O&M costs per mile of sewer. Studies
    have found that O&M costs can vary
    widely.
                                     Source
WERF (1997)
ASCE (2000)
WERF (2003)
AMSA (2003a)
                        Annual Average O&M
                        costs per mile
               Range of O&M
               costs per mile
                   $1,033-$51,051
                    $300-$57,000
                                     sewer. A study commissioned by ASCE
                                     and EPA on optimizing maintenance
                                     of SSSs estimated that utilities should
                                     spend, on average, $8,009 per mile
                                     annually (ASCE 1999). This study
                                     found that it is often difficult to
                                     develop comparable unit costs for
                                     different O&M techniques.

                                     Communities participating in the
                                     interviews for this report also provided
                                     information on O&M expenditures.
                                     On average, these communities spent
                                     $33,000 per mile of sewer per year on
                                     capital projects. O&M expenditures
                                     averaged $7,886 per mile. These
                                      findings are consistent with the
                                      aforementioned ASCE, WERF, and
                                      AMSA findings.
                                      9.6  What are the Projected
                                           Costs to Reduce CSOs?

                                            The CWNS is the primary
                                            source of data on anticipated
                                            capital needs for CSO control
                                      at the national level.

                                      In the 2000 CWNS, EPA estimated
                                      future capital financial needs for
                                      CSO control at $50.6 billion (2000
Sewer System Operation
and Maintenance Costs:
Santa Margarita Water
District, CA
Sewer System Operation
and Maintenance Costs:
Somersworth, NH
 The Santa Margarita Water District
 in California serves 134,000 people,
 and  owns  and  operates  three
 wastewater treatment plants and
 539  miles of  SSSs; the  District
 also maintains  unknown  miles of
 private laterals. The current O&M
 budget for sewer system work is
 approximately  $5 million a  year,
 with more than one-third  covering
 labor costs.
                                                                               Lift station
                                                                              maintenance
  Pipe
replacement
   7%
 The City of Somersworth, New Hampshire, maintains 24.4 miles of sewers. Prior to
 obtaining CWSRF for SSO projects, the city typically cleaned less than one mile of
 sewer each year. CWSRF funding was used to purchase a $325,000 flushing truck.
 In 2002, the city was able to clean 15 miles of older sewer  lines for $140,000. The
 city currently anticipates spending at least $15,000 per year on O&M.The city also
 anticipates spending $100,000 to analyze the SSS and  the separate storm sewer
 system  and to enter that information into a CIS.These efforts have helped reduce
 the frequency of SSOs, which cost an average of $1,200 per event for cleanup.
9-8

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                                                Chapter 9—Resources Spent to Address the Impacts of CSOs and SSOs
dollars). This estimate is based on
LTCPs and CSO planning documents
(which indicate varying levels of
control) and a model used to estimate
missing costs. Thirty-four facilities
from 10 states documented CSO
needs using LTCPs. These needs,
totaling $3.9 billion, account for 7.7
percent of the CSO needs reported in
the CWNS. EPA also reviewed other
materials (e.g., capital improvement
program budgets) submitted by states
as part of the CWNS process which
documented municipal CSO needs. In
compiling this information EPA found
documentation of approximately
$16.7 billion in needs. The CWNS
reports that a cost curve methodology
was used to estimate the cost of CSO
control where documented needs
were not provided. The cost curve
methodology is based on communities
providing primary treatment and
disinfection, where necessary, for no
less than 85% of the CSO by volume.
Compliance with current state water
quality standards could, however,
require a higher level of control
resulting in additional needs.

Some organizations have compiled
information at the state level on
estimated capital needs for CSO
control. Recent analyses conducted
for Michigan estimated that $1.7-
$3.4 billion will be needed for CSO
communities in Michigan over the
next 12 years (PSC & ECT 2002).
Estimated costs to control CSOs
in West Virginia exceed $1 billion
(Mallory2003).

Community-specific information on
projected CSO needs is available from
several sources, including LTCPs, the
Report to Congress-Implementation
and Enforcement of the Combined
Sewer Overflow Control Policy (EPA
200la) and the 2000 CWNS (EPA
2003c). Together, these sources
provide information on the future
capital needs for CSO control in 71
communities (see Appendix M).

Information on O&M costs for CSO
control is not available at the national
level.
9.7  What are the Projected
     Costs to Reduce SSOs?

       The 2000 CWNS identified
       $3.5 billion in I/I correction
       needs (Category III-A) for
facilities reported by states as having
SSO problems (EPA 2003b). A further
$10.4 billion in needs were reported
for sewer system replacement or
rehabilitation (Category III-B). The
total needs for Category III-A and
III-B were reported at $8.2 and
$16.8 billion, respectively. Needs for
Category III-A and III-B account for
only 14 percent of the total CWNS.
As shown in Figure 9.5, needs for
Category III-A and III-B have
more than doubled since the 1996
CWNS. This increase demonstrates
that communities are planning for
the correction of problems that  are
symptomatic of SSOs (EPA 2003b).

In addition to the documented needs,
national modeled cost estimates for
reducing SSOs to one overflow every
five years for each SSS were prepared
for the 2000 CWNS (EPA 2003b).
EPA estimated that it would require
$88.5 billion in capital improvements
to reduce the frequency of SSOs
caused by wet weather and other
conditions, such as blockages, line
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Report to Congress on the Impacts and Control ofCSOs and SSOs
  Figure 9.5
    Change in Estimated
    Needs Between 1996 and
    2000 CWNS (EPA 2003b)

    Between the 1996 and 2000
    CWNS estimated needs related to
    I/I correction and sewer system
    replacement and rehabilitation have
    more than doubled, increasing by
    122% and  118%, respectively.
nave

'
                    25%
                         I Secondary
                          treatment
                                                      Advanced
                                                      treatment
                      II-A I/I correction
III-B Sewer replace-
   ment/rehab
                                                 IV-A New collector
                                                    sewers
                                                IV-B New intercepor
                                                   sewers
                                                 V CSO correction I 2%
                                                 _33<y0         I  VI Storm water
                                                                 management
                                                                 122%
                                                                118%
                                                                   1 9%
                                     breaks, or mechanical/power failures.
                                     This estimate does not include costs
                                     associated with improved system
                                     management and O&M activities
                                     necessary to actually achieve the
                                     desired level  of control. A case-by-
                                     case analysis  of each SSS is needed
                                     to determine the actual level of
                                     investment required to control SSOs.
                                     EPA notes that these modeled needs
                                     should not be added to documented
                                     needs because the documented needs
                                     may already include costs to address
                                     SSOs.

                                     SSSs, including newer systems,
                                     typically require significant, ongoing
                                     investment in O&M to reduce SSOs.
                                     O&M costs in individual communities
                                     vary significantly depending on
                                     community size, sewer system
                                     characteristics, local geology, and
                                     climate. EPA believes that needs will
                                     be greatest in communities that lack
                                              regular preventive maintenance or
                                              asset management programs. EPA
                                              estimates that the gap between
                                              projected needs and current O&M
                                              spending over the next 20 years is
                                              between $72 billion and $229 billion
                                              (with a point estimate of $148 billion),
                                              if current spending and operations
                                              practices are maintained. However, if
                                              municipalities increase spending  at the
                                              rate of expected economic growth, the
                                              gap largely disappears (EPA 2002a).
                                              9.8 What Funding Mechanisms
                                                   are Available for CSO and
                                                   SSO Control?
                                                   Significant capital and O&M
                                                   expenditures are often required
                                                   to control CSOs and SSOs.
                                              Detailed descriptions of various
                                              finance mechanisms and case studies
                                              can be found in EPAs SSO Fact Sheet
                                              Financing Capital Improvements for
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                                                   Chapter 9—Resources Spent to Address the Impacts of CSOs and SSOs
SSO Abatement (EPA 2003k) and in
CSO Guidance for Funding Options
(EPA 1995a). The following sections
provide an overview of common
financing options for capital projects,
including self-financing, CWSRF loans,
and federal and state grants. Financing
options for debt repayment and O&M
costs are more limited and often rely
solely on self-financing.


9.8.1   Self-financing
Self-financing is the most common
financing option used for CSO and
SSO control. Self-financing relies on
local revenue sources including:

•   Fees - user charges, property taxes,
    hookup fees, development charges,
    assessments, permit fees, and
    special levies.

•   Bonds - general obligation and
    revenue bonds.

•   Other local income sources -
    reserves or fund transfers, interest
    payments, sales, and other
    mechanisms.

The AMSA Financial Survey-2003
documents that local sources (i.e.,
fees, bonds, and  other sources) have
been used to fund between 90 and
95 percent of capital investment
and operating funds for wastewater
infrastructure between 1992 and 2001
(AMSA 2003a). The distribution of
revenue sources based on AMSAs most
recent financial survey is presented in
Figure 9.6.

AMSAs recent financial survey notes
that, when adjusted for inflation,
residential service rates have decreased
slightly since 1999, while rates for
industrial customers have increased
for some pollutants and decreased
for others (AMSA 2003a). Specifically
AMSA stated:

    "The overall average residential
    sewer service charge from 1999
    to 2002 rose 7.6 percent from
    $216.02 to $232.59 per year
    ($19.38 per month) for a single-
   family residence (for common 1999
    and 2002 survey respondents the
    increase was only 6.0percent).
   Adjusting for inflation, average
    residential sewer rates have actually
    decreased by 0.3 percent from 1999
    to 2002 (1.9 percent for common
    agencies). For industrial customers,
    inflation-adjusted rates for volume
    (in dollars per 1,000 gallon) and
    BOD have increased by 1 and 4
   percent, respectively, since 1999,
    while inflation-adjusted rates for
    suspended solids have decreased by
   2 percent from 1999 to 2002."
Revenue Sources
T
V
V
V
T
Total
Local fees
Other sources
Bonds
CWSRF loans
Federal & state grants

Percent
66%
16%
13%
4%
1%
100%
                                                                                                     Figure 9.6
                                                                                Revenue Sources for
                                                                                Municipal Wastewater
                                                                                Treatment (AMSA 2003a)
                                                                                Self-financing is the most common
                                                                                option used to fund capital
                                                                                investments and O&M activities
                                                                                wastewater treatment systems.
                                                                  ion

                                                                  '"
                                                                                                            9-11

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     The costs associated with the control
                                     of CSOs and SSOs can be substantial
                                     and are likely to be borne mainly at
                                     the local level. Planning is needed to
                                     spread costs over time, as appropriate,
                                     in developing comprehensive, long-
                                     term programs.

                                     9.8.2 State and Federal Funding for
                                     CSO and SSO  Control

                                     State and federal funding can offset
                                     some expenditures for capital projects
                                     needed to control CSOs and SSOs. A
                                     local match is typically required for
                                     state and federal funding, which  can
                                     create debt repayment pressures for
                                     some communities (EPA 2002d).

                                     Clean Water State Revolving Fund
                                     CWSRF programs operate much like
                                     banks that are capitalized with state
                                     and federal contributions. CWSRF
                                     monies are loaned to communities for
                                     planning, design, and construction of
                                     environmental infrastructure. Loan
                                     repayments are recycled back into the
                                     program to fund additional projects.
                                                                        The CWSRF is the federal
                                                                        government's major funding
                                                                        mechanism for financing capital
                                                                        improvements in wastewater
                                                                        infrastructure, including projects to
                                                                        address CSOs and SSOs. The CWSRF
                                                                        is used by states to provide loans at or
                                                                        below market interest rates, purchase
                                                                        existing local debt obligations, and
                                                                        guarantee local debt obligations. Loans
                                                                        are not available for O&M or other
                                                                        non-capital I/I reduction activities
                                                                        (e.g., downspout disconnection
                                                                        programs). As shown in Figure 9.7, the
                                                                        total expenditures under the CWSRF
                                                                        have increased since 1986, as has the
                                                                        amount being spent on CSO control
                                                                        (Category V) and on I/I correction
                                                                        and sewer repairs or rehabilitation
                                                                        (Category III-A and III-B, a proxy for
                                                                        SSO capital) projects.

                                                                        Total assets of the CWSRF program
                                                                        exceed $42 billion. States have
                                                                        significant control over the CWSRF
                                                                        funds. States set loan terms, including
                                                                        maximum loan amount, fees, interest
                                                                        rates (from zero percent to market
  Figure 9.7

    =
State and Local
Expenditures Under
the CWSRF Program for
CSO Correction and SSO
Capital Projects
    Total expenditures under the CWSRF
    have generally increased since
    program inception in the late 1980s.
Billions of Dollars (2002)
 D CSO correction
 d SSO capital projects (I/I correction and
   sewer rehabilitation)
 • All other CWSRF expenditures
                                                                $3.9
                                                       $2.9  $2.9
                                                               $2.5
                                                                                              $5.1
                                                                                                       $5.0
                                                                                               $4.3
                                                                        $3.4
                                                                                     $3.5  $3.5
                                                                        $2.9
                                                                                 $3.1
                                                  $1.3
                                              •  I
                                     $^102
                                     1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
                                                                    Year
9-12

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                                                  Chapter 9—Resources Spent to Address the Impacts of CSOs and SSOs
rate, sometimes on a sliding scale
based on community economics),
repayment periods (up to 20 years),
requirements on repayment dollars,
prioritization requirements, and
many other features of the program.
In some cases, legislative approval is
required for changes. Twenty-six states
are leveraging the federal funding by
issuing bonds. States can also tailor
their CWSRF programs to leverage
a number of financing mechanisms
to make funding opportunities more
attractive for communities. Options
include loans; refinancing, purchasing,
or guaranteeing local debt; and
purchasing bond insurance.

Federal Grants
As discussed in Section 9.3 of this
report, federal water pollution
control grants for CSO control were
available as early as 1965. The federal
Construction Grant Program was
used extensively during the 1970s
and 1980s to fund construction of
wastewater infrastructure, and several
communities used this program to
fund CSO projects. The program was
phased out in the late 1980s in favor of
the CWSRF.

Several other grant programs—the
Rural Utilities Service Grant
Program, the Economic Development
Administration Grant Program, and
Community Development Block
Grants—also are used for CSO and
SSO control projects, but they are only
available to small and economically
disadvantaged communities.

State Grants for CSO Control
Twenty-eight states have grant
programs specifically to help
communities implement CSO
projects (EPA 200la). These programs
vary significantly in funding level
and restrictions; many incorporate
CWSRF loan funding. Most of these
state programs are targeted at small
  The City of Lawton, Oklahoma, is using CWSRF loans along with utility rate increases
  to fund rehabilitation and replacement of the SSS. The  project is separated into
  three 7-year phases. The first phase ends in 2004. By establishing a Sanitary Sewer
  Technical Division for design in May 1998 and a Construction  Division in January
  1999, the city has been able to complete many of the tasks associated with this
  project on its own. While costs for Phase I were estimated to be $22 million, actual
  costs held to $16.8 million (see table below). This cost difference is the result of city
  efforts to use in-house designers and contractors. Actual costs for the  remaining
  phases of this project are expected to be substantially lower.

         Contract and Actual Costs for Lawton, OK SSS Rehablitation Project
Phase Contract Actual Projected SRF
Cost Cost Acutal Loan
Cost
I
II
III
$22M
$37M
$40M
$16.8M



$28M
**
$15M
$28M*

          Lawton has qualified for this loan but has not borrowed the money yet.
         * It is too early for a projected cost for Phase III.
                                               CWSRF Loans Fund SSO
                                                                Control:
                                                             Lawton, OK
                                                                                                          9-13

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Report to Congress on the Impacts and Control ofCSOs and SSOs
State Grants for CSO
Control:
Hartford and
New Haven, CT
Connecticut's state grant program for CSOs has provided $173 million to eight
communities. Without this funding, the City of Hartford would have been  unable
to proceed with CSO control, because independently the city could not issue $80
million in debt.The state grant program also allowed the City of New Haven to meet
its 12 to 15-year schedule for the LTCP, and the program kept user rates below EPA's
affordability cap (EPA 2002d).
                                     and/or economically disadvantaged
                                     communities, and often have fairly low
                                     funding levels.

                                     States with grant programs for CSO
                                     control include Connecticut, Vermont,
                                     and Maine. Connecticut established
                                     a CSO grant program in 1986 that
                                     provides grants for 50 percent of the
                                     federal eligible project costs, and a
                                     CWSRF loan at 2 percent interest for
                                     the remaining costs. Vermont has a
                                     similar program that requires a 25
                                     percent local match, provides a 25
                                     percent grant for construction costs,
                                     and allocates CWSRF loans for the
                                     remainder. Maine has a state bond
                                     issue for $2.4 million that funds grants
                                     awarded for 25 percent of the cost of
                                     development of CSO Master Plans, the
                                     functional equivalent of an LTCR
                                     State Grants for SSO Control
                                     Oklahoma and North Carolina are
                                     examples of states with targeted grant
                                     programs, primarily aimed at making
                                     funding more readily available for
                                     rural areas, that have been used for
                                     SSO control projects. Oklahoma's
                                     Water Resources Board administers
                                     the CWSRF, provides low-interest
                                     bonds, and provides competitive
                                     funding through a Rural Economic
                                     Assistance Program (REAP). REAP
                                     provides grants between $50,000 and
                                     $100,000 for towns with populations
                                     between 500 and  1,000. The state has
                                     awarded 379 REAP grants for a total
                                     of $32.7 million. North Carolina's
                                     General Assembly funded a program
                                     of grants called the High Unit Cost
                                     Program through issuance of state
                                     bonds in 1987 and again in 1993.
State Grants for CSO
Control:
Springfield and
Rutland, VT
Vermont's grant program helped the Town of Springfield make CSO projects more
acceptable to voters. The town  recently finished a $4 million project for which it
received $1 million in state grant funds and a 50-percent loan at close to zero-
percent interest. In Rutland, the Commissioner of Public Works also stated that grant
funds were beneficial and helped keep user rates down (EPA 2002d).
 State Grants for SSO
 Control:
 Nowata, OK
Nowata, Oklahoma, secured $250,000 from the Community Development Block
Grant Program and $79,000 from the Oklahoma REAP grant program to replace
7,000 feet of failing sanitary sewer line. Prior to receiving the grants, Nowata was
able to replace 3,000 feet of sewer.The city plans to replace an additional 3,000 feet
in the next five years. The grants represented a significant source of funding to the
Maintenance Department, which operates with a $190,000 annual budget.
9-14

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                          Chapter   10
                 Conclusions and
               Future Challenges
      This report has been prepared
      in response to a request by
      Congress for information
related to CSOs and SSOs. EPA
collected data and performed
technical analyses to determine the
environmental and human health
impacts of CSOs and SSOs; the
location, volume, frequency, and
constituents of such discharges; the
technologies used by municipalities
to address CSOs and SSOs; and the
resources spent by municipalities on
CSO and SSO control.

In its preparation of this report, EPA
found that:

•  The occurrence of CSOs and
   SSOs is widespread. CSOs and
   SSOs contain pollutants that
   are harmful to the environment
   and human health, and there is
   evidence that CSOs and SSOs
   may cause or contribute to
   environmental and human health
   impacts.

•  CSOs and many SSOs are caused
   by wet weather conditions and
   occur at the same time that storm
   water and other nonpoint source
   pollutant loads are delivered to
   surface waters. This often makes
   it difficult to directly attribute
   specific water quality impacts to
   CSOs and SSOs. This suggests that
   a holistic approach should be used
   to address wet weather impacts.

•  There are many existing structural
   and non-structural technologies
   that are well-suited for CSO and
   SSO control. Implementation
   of emerging technologies
   and improved information
   management hold promise
   for increased effectiveness and
   efficiency.

•  Costs associated with the
   technologies for controlling CSOs
   and SSOs are often substantial.
   Planning is needed to spread
   costs over time, as appropriate, in
   developing comprehensive, long-
   term programs.

These findings are consistent with
programmatic initiatives currently
being implemented by EPA's Office
of Water. They correspond with
emerging needs and the findings
In this chapter:
Protecting Infrastructure

Implementing the Watershed
Approach

Improving Monitoring
and Information-Based
Environmental Management

Building Strategic
Partnerships
                                                                                         10-1

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     of other recent studies such as the
                                     National Water Quality Inventory, the
                                     BEACH Program, the Gap Analysis,
                                     and the Clean Watersheds Needs
                                     Survey. Further, they support EPA's
                                     position that discharges from urban
                                     areas—particularly wet weather
                                     discharges resulting from rainfall or
                                     snowmelt—continue to be significant
                                     contributors to water quality
                                     impairments nationwide.

                                     Current challenges for clean water
                                     encompass CSO and SSO control, and
                                     include:

                                     •   Protection of existing
                                         infrastructure;

                                     •   Development, approval, and
                                         implementation of CSO LTCPs
                                         under the CSO Control Policy;

                                     •   Development and implementation
                                         of SSO controls;

                                     •   Implementation of Best
                                         Management Practices (BMPs)
                                         to reduce pollution from storm
                                         water runoff in accordance with
                                         EPA's Storm Water Phase I and II
                                         Programs;

                                     •   Integration of wet weather
                                         programs to increase the value of
                                         monitoring, reporting, tracking,
                                         and permitting to support
                                         information-based environmental
                                         management;

                                     •   Coordination of permits on a
                                         watershed basis; and

                                     •   Maintenance of valued
                                         partnerships with key stakeholder
                                         groups.
Several initiatives and actions that will
enable EPA, states, municipalities, and
citizens at large to achieve success in
meeting these future challenges are
described below.
Protecting Infrastructure

     Since 1972, EPA has worked to
     implement the Clean Water Act
     as it relates to the collection,
conveyance, and treatment of
wastewater. The national investment
in municipal wastewater infrastructure
has been substantial. This investment
has resulted in water quality and
human health improvements
throughout the United States. Today,
however, the nation's wastewater
infrastructure is aging and in need
of attention. The continued ability of
existing infrastructure to safeguard the
clean water accomplishments realized
since 1972 is at risk. Further, its ability
to serve as the platform for future
expansion of wastewater collection
and treatment  capacity is jeopardized.

Proper O&M of the nation's sewers is
integral to ensuring that wastewater
is collected, transported, and treated
at POTWs; and to reducing the
volume and frequency of CSO and
SSO  discharges. Municipal owners
and operators of sewer systems and
wastewater treatment facilities need
to manage their assets effectively
and implement new controls, where
necessary, as this infrastructure
continues to age. Innovative responses
from all levels of government and
consumers are needed to close the gap.
10-2

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                                                                      Chapter 10—Conclusions and Future Challenges
Implementing the Watershed
Approach

       CSOs and SSOs are two among
       many sources of pollution that
       can impact receiving water
quality. The watershed approach is
central to water quality assessments
and the identification of control
strategies that include all sources of
pollution that affect water quality.
The presence of sewer systems in
most developed watersheds across
the country underscores the potential
for SSOs to affect water quality on
a widespread basis. Similarly, the
presence of CSOs in 32 states places
them in many watersheds across the
country.

As described in this Report to
Congress, CSOs and wet weather
SSOs occur simultaneously with
the generation of storm water and
other forms of nonpoint source
pollution, making it difficult to
identify and assign specific cause-
and-effect relationships to observed
water quality problems. Attainment
and maintenance of water quality
standards requires that appropriate
attention is given to all sources.
Better integration of all of EPAs wet
weather programs will provide for
  Sanitation District  No. 1 of Northern Kentucky received an EPA grant to work
  with the State of Kentucky to develop a watershed permitting approach and to
  investigate the feasibility of implementing the approach. The District includes
  Campbell, Kenton, and Boone counties, and covers an area of 580 square  miles.
  Located on the southern bank of the Ohio River, directly across  from Cincinnati,
  Ohio, this three-county area contains approximately 40 incorporated cities, each
  with its own political and administrative structure.

  Prior to July 1995, the operation and maintenance of the sewer systems in  these
  counties was the responsibility of the respective municipal jurisdictions. Ownership
  for most of the sewer systems in Northern Kentucky was transferred to the District in
  1995 as a result of revisions to state legislation. With this consolidation, the District
  became responsible for managing 1,400 miles of combined and separate sanitary
  sewers, one major wastewater treatment facility, eight small wastewater treatment
  facilities, and approximately  100 CSO outfalls. Recently, with the development of a
  regional facilities plan, the District has embarked on a  program to construct two
  new regional wastewater treatment facilities at a cost of more than  $200 million
  over the next  10 years. In addition, the District is responsible for  implementing a
  CSO LTCP that includes  an  integrated watershed  approach to planning and an
  SSO Plan (requested by the  Kentucky Division of Water) to reduce the number of
  unauthorized discharges.

  At this time, the District and the Kentucky Division of Water have agreed to pursue
  additional dialog on  the development of  a draft watershed permit for Banklick
  Creek. This watershed was selected because it is impacted by urban storm  water
  runoff, CSOs, SSOs, septic systems, and rural runoff. It  should be noted that  the
  District's wastewater treatment plant does not discharge into the Banklick  Creek
  watershed. The new watershed permit will enable the District to  invest resources
  (time, labor, and money) more effectively in water quality improvement projects.
  The watershed permitting approach  will also take advantage of the extensive
  database of water quality and CIS information that the District has compiled for
  its service area. Further, it provides an opportunity  to consolidate  monitoring and
  reporting activities.         
                                                     Implementing the
                                                 Watershed Approach:
                                                               Kentucky
                                                                                                            10-3

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Report to Congress on the Impacts and Control ofCSOs and SSOs
 Improving Monitoring
 and Information-
 Based Environmental
 Management:
 Wisconsin
                                    some economies of scale in achieving
                                    this end. Similarly, concentration
                                    of resources under the watershed
                                    approach will help advance the control
                                    of CSOs and SSOs in a cost-effective
                                    manner.
                                     Improving Monitoring
                                     and Information-Based
                                     Environmental Management
                                        In developing this Report to
                                        Congress, EPA found that
                                        the data necessary to answer
                                     many of Congress' questions were
                                     limited. Improved monitoring
                                     and reporting programs would
                                     provide better data for decision-
                                     makers to assess the frequency and
                                     magnitude of CSO and SSO events,
                                     the impact these discharges have on
                                     the environment and human health,
                                     and the importance of CSO and
                                     SSO discharges  with respect to other
                                     pollution sources.

                                     Numerous federal, state, and local
                                     government agencies as well as non-
                                     governmental organizations and
                                    citizens are involved in monitoring.
                                    Monitoring and reporting efforts
                                    include collection of water quality
                                    information, tracking impacts of
                                    known activities affecting water
                                    quality, linking water quality to human
                                    health, and other activities. Effective
                                    monitoring programs provide the data
                                    and information needed to support
                                    sound decision making. Too often,
                                    however, the monitoring  data do not
                                    meet the needs of specific programs
                                    or are not readily available. Better
                                    alignment of monitoring programs to
                                    address environmental management
                                    and human health issues  is needed.
                                    Improved monitoring and reporting
                                    may foster a better understanding of
                                    cause-and-effect relationships. It may
                                    also improve state/local government
                                    and citizen access to environmental
                                    information.

                                    Along with improved monitoring and
                                    reporting, data need to be effectively
                                    managed. Modernization of EPAs
                                    PCS will help in this regard. Use
                                    of standardized reporting formats
                                    for information on the occurrence
A cooperative effort between  the  Milwaukee Metropolitan Sewerage District
(MMSD), the Wisconsin  Department of Natural Resources, USGS, and several
academic institutions resulted in the  development of a single database for
environmental data.The project team is compiling data sets from various federal,
state, and local agencies in a centralized database of hydrology, water chemistry,
macroinvertebrate, fish, habitat, and CIS information for stream corridors in the
MMSD service area. The database is  available on-line and allows the user to run
queries and retrieve data currently in the system.

The database serves as a comprehensive inventory of stream corridor conditions,
allowing for an improved understanding  of the inter-relationship between the
various types of data and establishing a baseline of existing conditions. Using these
baseline conditions, impairments can be identified and assessed,and strategies can
be developed  to address the most significant problems. MMSD plans to use the
database as a tool to prioritize future efforts to control CSO, SSO, and storm water
discharges. Future data incorporated into  the database will allow verification of
improvements and identification of necessary adjustments or additional steps.
10-4

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                                                                       Chapter 10—Conclusions and Future Challenges
and control of CSOs and SSOs will
enable EPA, states, and others to track
pollutant loads and performance
measures. Further, recent EPA efforts
such as Watershed Assessment,
Tracking, and Environmental Results
(WATERS) are working to unite
national water quality information
that was previously available only from
several independent and unconnected
databases.
Building Strategic Partnerships

       The success that the nation
       has achieved in improving
       water quality since passage
of the Clean Water Act is due to the
  The Watershed Initiative for a Safer Environment (WISE) was started by the Cities
  of Elkhart, Mishawaka, and South Bend, Indiana.These cities have 102 CSO outfalls
  that discharge to 48 miles of the St. Joseph and Elkhart Rivers. Land use within the
  two-county area is 72 percent rural. Concentrations of £ coli in the main stem and
  at the mouths of the tributaries routinely exceed water quality standards. A single
  watershed  tool was needed to educate the public and to assist in the selection of
  cost-effective strategies to reduce point and non-point pollutant sources, including
  CSOs.WISE utilized a stakeholder-driven approach to watershed planning involving
  numerous stakeholders, including:
    Indiana Department of Environmental Management
    City of Elkhart Public Works & Utilities
    City of Goshen Wastewater Utility
    City of Mishawaka Wastewater Utility
    City of South Bend Wastewater Utility
    Elkhart County Planning Division
    Jimtown Community School Corporation
    Juday Creek Task Force
    Local Farm Bureau Agency
    Michiana Area Council of Governments
    St. Joseph County Area Plan Commission
    St. Joseph County Surveyor
    St. Joseph and Elkhart County Health Departments
    St. Joseph and Elkhart County Soil and Water Conservation Districts
    Concerned citizens
  WISE secured federal funding through the Clean Water Act 205(j) grant program
  to conduct coordinated river sampling and to develop a calibrated water quality
  model of the two rivers. WISE also expects to receive a 104(b)(3) grant in January
  2004 to continue development of the model, including:

  • Isolating the sources of £ coli;
  • Identifying additional types of appropriate controls;
  • Displaying the anticipated improvements in river water quality from
    different source controls along with the cost for implementation; and
  • Evaluating whether refined water quality standards are appropriate.

  This work will provide a single model that can be used in NPDES programs to
  further refine contaminant sources and assist in the selection of cost-effective
  strategies toward meeting, and possibly refining, water quality standards.
                                             Strategic Partnerships:
                                                              Indiana
                                                                                                            10-5

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     collective efforts of federal and state
                                     agencies, municipalities, industry,
                                     non-governmental organizations, and
                                     citizens. Maintenance and enhancing
                                     existing cooperation among these
                                     groups is essential to meet the
                                     challenges to clean water that lie ahead.

                                     As described in this Report to
                                     Congress, threats to water quality
                                     and human health have numerous
                                     origins and sources; establishing direct
                                     cause-and-effect relationships  is often
                                     difficult. The information necessary to
                                     manage water quality problems also
                                     comes from many sources.
EPA recognizes the value of working
with stakeholders and has pursued
a strategy of extensive stakeholder
participation in its  policy-making
on CSO and SSO issues. This
effort should continue to improve
knowledge on the impacts of CSOs
and SSOs. Similarly, as communities
continue to implement CSO and
SSO controls, further cooperation
with municipal, industry,  and
environmental organizations
is essential to ensure successful
development and implementation of
environmental programs.
10-6

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     Appendix A
Statutes, Policies,and Interpretive
            Memoranda
        A.1 Consolidated Appropriations Act
           for Fiscal Year 2001 (P.L. 106-554)

        A.2 Combined Sewer Overflow
           (CSO) Control Policy

        A.3 Memorandum:Addition
           of Chapter X to Enforcement
           Management System

        A.4 Enforcement Management
           System-ChapterX: Setting
           Priorities for Addressing
           Discharges from Separate
           Sanitary Sewers

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                                                                                                                                                         Appendix A
A.1 Consolidated Appropriations Act for Fiscal Year 2001  (P.L. 106-554)
               December 15, 2000
CONGRESSIONAL RECORD —HOUSE
                                H12273
                 SFC. m Wer WtATHfK  WATER QUALITY,  (a)
                COMeiNto SEWER OVERFLOWS    Section 402 of
                the  Federal  Water  Pollution Control Act  (33
                U.$.C 1342)  is amended lay adding at the end
                the following:
                  "M COMBINED SeWfR OVFRFl_OWS,~
                  "(1) RfQUIKEMENT FOR PERMITS. ORDERS, AND
                DECREES.—Each permit, order, or decree issued
                pursuant to this Act after the date of enactment
                of this subsection for a discharge from a munic-
                ipal combined  storm and sanitary  sewer shall
                conform  to the Combined Sewer Overflow Con-
                trol Policy signed by the Administrator on April
                11, 1994  (in  this subsection referred  to as the
                'CSO control policy').
                 "(2) WATER QUALITY AND otsicnATED USE RE-
                VIEW GUIDANCE.—Not later than July 31.  2O01,
                and after providing  notice  and opportunity for
                public comment,  the Administrator shall issue
                guidance to facilitate the conduct of water qual-
                ity and  designated  use reviews for  municipal
                combined sewer overflew receiving waters.
                  "(3) REPORT.—Not later  than September  1,
                2001,  the Administrator shall transmit to Con-
                gress a report on the progress made by the Envi-
                ronmental Protection Agency, States, and mu-
                nicipalities in  implementing and enforcing the
                CSO control policy.".
                 (b) WET WEATHER PILOT PKIKHAM.—Title I of
                the  Federal  Water  Pollution Control Act  (33
                U.S.C. 1?S1 et seq.) Is amended by adding at the
                end the following:
                "SEC.  111. WET W&ATHRR  WATERSHED PILOT
                          PROJECTS.
                  "(a) IN GENERAL.—The Administrator, in co-
                ordination with the Stales, may provide tech-
                nical assistance and grants for treatment works
                to carry out pilot projects relating to the fol-
                lowing areas of wet weather discharge control:
                  "(1) WATERSHED MANAGEMENT  a^ WLI  WEATH-
                LN DISCHARGES.—The management of  municipal
                combined sewer overflows, sanitary sewer over-
                flows, and stormwater discharges, on an inte-
                grated watershed or iubwatershed basis for the
                purpose of demonstrating the effectiveness of a
                unified wet weather approach.
       "(2) STORMWATF.R REST  MANAGiMtNT  PRAC-
      TICES.—The control of pollutants  from munic-
      ipal separate storm sewer systems for the pur-
      pox of demonstrating and determining controls
      that are cost-effective and that use innovative
      technologies in reducing such  pollutants from
      stormwater discharges.
       "(b) ADMINISTRATION.—The Administrator, in
      coordination with the States, shall provide mu-
      nicipalities participating in a pilot project under
      this section  the ability to engage in innovative
      practices, including the ability to unify separate
      wet weather control efforts under a single per-
      mit.
       "(c) FUNDING.—
       "ft) IN GENERAL.—There is authorized  to ba
      appropriated to carry out this section f 10,000.000
      for fiscal year 2002, t15.000.QOO for fiscal year
      2003,  and 00,000,000 for fiscal  year 2004.  Such
      funds shall remain available until expended.
       "(!) STORMWATER.—The Administrator  shall
      make  available  not less  than 20 percent of
      amounts appropriated for a fiscal year pursuant
      to this subsection to carry out  the purposes of
      subsection (a)(2).
       "(3) ADMINISTRATIVE EXPENSES.—The Admin-
      istrator may retain not to exceed 4 percent of
      any amounts appropriated for a fiscal year pur-
      suant fo this subsection for the reasonable and
      necessary costs of administering this section.
       "(d) REPORT TO CONGRESS.—Not later than 5
      years after the date of enactment of this section,
      the Administrator shall transmit to Congress a
      report on the results of the pilot projects con-
      ducted under this section and their possible ap-
      plication nationwide.".
       (c) SEWER OVERFLOW CONTKOL GRANTS.—Title
      II of the Federal Water Pollution  Control Act
      (33 U.$.C. 1341 et seq.) is amended by adding at
      the end the following:
      -S«C. 1S1. SBWSH  OVERFLOW CONTROL GRANTS.
       "(a) IN GENERAL.—In any fiscal year in which
      the Administrator has available  for obligation at
      least S13SO.OOO.OOO for the purposes of section
      sot—
       "(1) the Administrator may  make grants to
      States for the purpose of providing grants to a
      municipality or municipal  entity for planning.
      design,  and construction of treatment works to
      intercept, transport, control, or treat municipal
      combined sewer overflows  and sanitary sewer
      overflows: and
       "(i) subject to subsection (g), the Adminis-
      trator may  make a direct grant to a munici-
      pality or municipal entity  for the purposes de-
      scribed in paragraph (1).
       "(b)   pRiORiTiZATiON.—ln   selecting   from
      among municipalities applying for grants under
      subsection (a), a State  or the Administrator
      shall give priority to an applicant that—
       "(1) is a municipality that is a financially dis-
      tressed community under subsection (c):
       1 '(2) has implemented or is complying with an
      implementation schedule for the 9 minimum con-
      trols specified in the CSO control policy referred
      to  In  section 402(q)(1) and  has begun  imple-
      menting a long-term municipal comoined sewer
      overflow  control  plan or  a separate sanitary
      sewer overflow control plan,- or
       "(3) is requesting a grant for  a project that is
      on  a State's intended use plan pursuant to sec-
      tion 606fc): or
       ' '(4) is an Alaska Native Village.
       "(c) FINANCIALLY DISTRESSED COMMUNITY.—
       "(I) DEFINITION.—In subsection (b), the term
      'financially distressed community' means a com-
      munity that meets sffordability criteria  estab-
      lished by the  State In which the community is
      located, if such criteria are developed after pub-
      lic review and comment.
       ' '(2) CONSIDER* TION OF IMPACT ON WA TER AND
      SfWtR KAILS.—In determining if a community is
      a distressed community for the  purposes of sub-
      section (b),   the  State  shall  consider,  among
      other factors,  the extent to which the rate of
      growth of a community's tax basf has been his-
      torically stow such ttiat implementing a plan de-
scribed in subsection (of (2} would result in a sig-
nificant  increase in any water car sewer rote
charged  by the  community's publicly owned
wastewater treatment facility.
  "(3) INFORMATION TO ASSIST STATES.—The Ad-
ministrator may  publish infonnalion to assist
States   in  establishing  afforttabtlity  criteria
under paragraph  (1).
  "(d) COST SHARING.—The Federal share of the
cost of activities carried out using amounts from
a grant made under subsection (a) shall be not
less than SS percent of the cost.  The non-Fed-
eral share of  the  cost  may include,  in  any
amount,  public and private funds and In kind
services,  and may include, notwithstanding sec-
tion 603(h),   financial  assistance,  including
loans, from a State water pollution control re-
volving fund.
  "(e)  AOMINISTKATIVE  REPORTING  REQUIRE-
MENTS—If a project receives grant  assistance
under subsection  (a) and loan assistance from a
State water pollution control revolving fund and
the loan assistance is for 1$ percent or more of
the cost  of the project, the project may be ad-
ministered in accordance with State water pol-
lution control revolving fund administrative re-
porting requirements for the purposes of stream-
lining such requirements.
  "(f)  AUTHORIZATION OF  APPROPRIATIONS.—
There is  authorized to oe appropriated to carry
out this  section S750,000,ooo  for each of fiscal
years 200! and 2003. Such  sums shall remain
available until expanded.
  ' '(g) ALLOCATION OF FUNDS.—
  "(i) FISCAL  VF.M aw—Subject to  subsection
(h). the Administrator shall use the amounts ap-
propriated  to  carry out  this section for fiscal
year 2002 for  making grants to municipalities.
and municipal  entities under subsection  (a)(2),
in accordance with  the criteria set forth in sub-
section (b).
  "(2) FISCAL  y«ff 2003.—Subject to subsection
(h), the Administrator shall use the amounts ap-
propriated  to  early out  this section for fiscal
year 2003 as follows:
  "(A) Not  to  exceed (250,000,000 for making
grants to municipalities and municipal entitles
under subsaction  (a)(2), in accordance  with the
criteria set forth in subsection (b).
  1YSJ All remaining amounts for making grants
to States under subsection (a)(1), in accordance
with a formula  to oe established by the Adminis-
trator,  after providing notice  and an oppor-
tunity for public comment,  that allocates to
each State a proportional share of such amounts
based on the total needs of the State for munic-
ipal combined sewer overflow controls and sani-
tary sewer overflow controls identified in the
most recent survey  conducted pursuant to sec-
tion SiefblO).
  "(h)    ADMINISTRATIVE  EXPENSES.—or  the
amounts appropriated to carry out this section
for  each  fiscal year—
  "(1) the Administrator may retain an amount
not to exceed  1 percent for the reasonable and
necessary costs of administering this section;
and
  "(!) the Administrator,  or a State, may retain
an  amount not to exceed 4 percent of any grant
made to a municipality or municipal  entity
under subsection (a),  for the reasonable  and
necessary costs of administering the grant.
  "(i) REPORTS,—Not later  than December 31.
2003, ana periodically thereafter, thm Adminis-
trator shall transmit to Congress a report con-
taining recommended funding levels  for grants
under  this section.  The  recommended funding
levels shall be sufficient to ensure the continued
expeditious  Implementation  of municipal com-
bined sewer overflow and sanitary sewer over-
flow controls nationwide.",
  (d) INFORMATION ON CSOS AND 5SO5.—
  (i) REPORT  TO CONGRESS.— Nat later then 3
years after the date of enactment of this  Act,
the Administrator of the  Environmental Protec-
tion Agency shall transmit to Congress a report
summariifng—
                                                                                                                                                                    A-1

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                H12274                          CONGRESSIONAL RECORD CHOUSE              December 15,2000
                  (A) the extent of the human health and envi-
                ronmental  impacts caused  by  municipal com-
                bined wivsr overflow* and sanitary sewer over-
                flows, including the location of discharges caus-
                ing such impacts,  the volume of pollutants dis-
                charged, and the constituents discharged;
                  (B)  the resources spent by municipalities to
                address these impacts; and
                  (C) an avafuation of the technologies used by
                municipalities to address these impacts.
                  (2)    TeCHNQL QGY    CL EARiNGHOUSt:.—After
                transmitting a report  under paragraph (J), the
                Administrator shall maintain a clearinghouse of
                cost-effective and efficient technologies for ad-
                dressing human health find environmental im-
                pacts  due  to municipal  combined sewer over-
                flows and sanitary sewer overflows.
 A-2

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A.2 Combined Sewer Overflow (CSO) Control Policy
                                                                                                                                  Appendix A
            18688   Federal Register / Vol. 59, No.  75 / Tuesday.  April 19,  1994 / Notices
            ENVIRONMENTAL PROTECTION
            AGENCY
            [FRL-473Z-7]

            Combined Sewer Overflow (CSO)
            Control Policy

            AGENCY: Environmental Protection
            Agency (EPA).
            ACTKm: Final policy.

            SUMMARY: EPA has issued a national
            policy statement entitled "Combined
            Sewer Overflow (CSO) Control Policy."
            This policy establishes a consistent
            national approach for controlling
            discharge* from CSOs to the Nation's
            waters through the National Pollutant
            Discharge Elimination System (NPDES)
            permit program.
            Few FURTHER INFORMATION CONTACT:
            Jeffrey Lape. Office of Wastewater
            Enforcement and Compliance, MC—
            4201, U.S. Environmental Protection
            Agency. 401 M Street SW., Washington,
            DC 20460. (202) 260-7361.
            SUPPLEMENTARY INFORMATION: The main
            purposes of the CSO Control Policy are
            to elaborate on the Environmental
            Protection Agency's (EPA's) National
            CSO Control Strategy published on
            September 8.1989. at 54 PR 37370. and
            to expedite compliance with the
            requirements of the Clean Water Ad
            (CWA). While implementation of the
            1389 Strategy has resulted in progress
            toward controlling CSOs, significant
            public health and water quality risks
            remain.
              This Policy provides guidance to
            permittees with CSOs, NPDES
            authorities and State water quality
            standards authorities on coordinating
            the planning, selection, and
            implementation of CSO controls that
            meet the requirements of the CWA and
            allow for public involvement during the
            decision-mating process.
              Contained in the Policy are provisions
            for developing appropriate, site-specific
            NPDES permit requirements  for all
            combined sewer systems (CSS) that
            overflow as a result of wet weather
            events. For example, the Policy lays out
            two alternative approaches—the
             "demonstration" and the
             "presumption" approaches—that
             provide communities with targets for
             CSO controls that achieve compliance
             with the Act, particularly protection of
             water quality and designated uses. The
             Policy also includes enforcement
             initiatives to require the immediate
             elimination of overflows that occur
             during dry weather and to ensure that
             the remaining CWA requirements are
             complied with as soon as practicable.
               The permitting provisions of the
             Policy were developed as a result of
extensive input received from key
stakeholders during a negotiated policy
dialogue. The CSO stakeholders
included representatives from States.
environmental groups, municipal
organizations and others. The negotiated
dialogue was conducted during the
Summer of 1992 by the Office of Water
and the Office of Water's Management
Advisory Group. The enforcement
initiatives, Including one which is
underway to address CSOs during dry
weather, were developed by EPA's
Office of Water and Office of
Enforcement.
  EPA Issued a Notice of Availability on
the draft CSO Control Policy on January
19,1993. (58 FR 4994) and requested
comments on the draft Policy by March
22,1993. Approximately forty-one sets
of written comments were submitted by
a variety of interest groups including
cities and municipal groups.
environmental groups, States,
professional organizations and others.
All comments were considered as EPA
prepared the Final Policy. The public
comments were largely supportive of
the draft Policy. EPA received broad
endorsement of and  support for the key
principles and provisions from most
commentary. Thus, this final Policy
does not include significant changes to
the major provisions of the draft Policy,
but rather, it includes clarification and
better explanation of the elements of the
Policy to address several of the
questions that were  raised in the
comments. Persons wishing to obtain
copies of the public comments or EPA's
summary analysis of the comments may
write or call the EPA contact person.
   The CSO Policy represents a
comprehensive national strategy to
ensure that municipalities, permitting
authorities, water quality standards
authorities and the public engage in a
comprehensive and coordinated
 planning effort to achieve cost effective
CSO controls that ultimately meet
 appropriate health and environmental
 objectives. The Policy recognizes the
 site-specific nature of CSOs and  their
 impacts and provides the necessary
 flexibility to tailor controls to local
 situations. Major elements of the Policy
 ensure that CSO controls are cost
 effective and meet the objectives and
 requirements of the CWA.
   The major provisions of the Policy are
 as follows.
   CSO permittees should immediately
 undertake a process to accurately
 characterize their CSS and CSO
 discharges, demonstrate implementation
 of minimum technology-based controls
 identified in the Policy, and develop
 long-term CSO control plans which
 evaluate alternatives for attaining
compliance with the CWA, including
compliance with water quality
standards and protection of designated
uses. Once the long-term CSO control
plans are completed, permittees will be
responsible to implement the plans'
recommendations as soon as
practicable.
  State water quality standards
authorities will be involved in the long-
term CSO control planning effort as
well. The water quality standards
authorities will help ensure that
development of the CSO permittees'
long-term CSO control plans are
coordinated with the review and
possible revision of water quality
standards on CSO-impacted waters.
  NPDES authorities will issue/reissue
or modify permits, as appropriate, to
require compliance with the technology-
based and water quality-based
requirements of the CWA. After
completion of the long-term CSO
control  plan, NPDES permits will be
reissued or modified to incorporate the
additional requirements specified in the
Policy, such BS performance standards
for the selected controls based on
average design conditions, a post-
construction water quality assessment
program, monitoring for compliance
with water quality standards, and a
reopener clause authorizing the NPDES
authority to reopen and modify the
permit if it is determined that the CSO
controls fail to meet water quality
standards or protect designated uses.
NPDES authorities should commence
enforcement actions against permittees
that have CWA violations due to CSO
discharges during dry weather. In
addition, NPDES authorities should
ensure  the  implementation of the
minimum technology-based controls
and incorporate a schedule into an
appropriate enforceable mechanism,
 with appropriate milestone dates, to.
 implement the required long-term CSO
 control plan. Schedules for
 implementation of the long-term CSO
 control plan may be phased based on
 the relative importance of adverse
 impacts upon water quality standards
 and designated uses, and on a
 permittee's financial capability.
   EPA  is developing extensive guidance
 to support the Policy and will announce
 the availability of the guidances and
 other outreach efforts through various
 means, as they become available. For
 example, EPA is preparing guidance on
 the nine minimum controls,
 characterization and monitoring of
 CSOs, development of long-term CSO
 control plans, and financial capability.
   Permittees will be expected to comply
 with any existing CSO-related
 requirements in NPDES permits.
                                                                                                                                            A-3

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                      Federal Register / Vol. 59, No.  75 / Tuesday. April  19.  1994 / Notices
                                                                    18689
                   consent decrees or court orders unless
                   revised to be consistent with this Policy.
                     The policy is organized as follows;
                   I. Introduction
                     A Purpose and Principles
                     B. Application of Policy
                     C Effect on Cumnl CSO Control Efforts
                     D. Small System Consideration*
                     E. Implementation Responsibilities
                     P. Policy Development
                   IL EPA Objective* for Permittees
                     A. Overview
                     B. Implementation of IhtNine Minimum
                      Controls
                     C Long-Term CSO Control Plan
                     1. Charactorizalion, Monitoring, and
                      Modeling of the Combined Sewer
                      Systems
                     2. Public Participation
                     3. Cons ideratlon of Sens itivo Arms
                     4. Evaluation of Alternative*
                     S. Cod/Performance Conilderalion
                     8. Operational Plan
                     7. Maximizing Treatment at the Existing
                       POTWTre«tmenl Plant
                     8. Implementation Schedule
                     9. Post-Construction Compliance
                       Monitoring Program
                   III. Coordination With State Water Quality
                       Standards
                     A. Overview
                     B. Water Quality Standards Reviews
                   IV. Expectations for Permitting Authorities
                     A. Overview
                     B. NPDES Permit Requirement!
                     1. Phase 1 Permlla — Requirement* for
                       Demonstration of the Nine Minimum
                       Controls and Development of the Long-
                       Term CSO Control Plan
                     2. Phase II Permits— Requirements for
                       Implementation of a Long-Tenn CSO
                       Control  Plan
                     3. Phtsing Considerations
                    V. Enforcement and Compliance
                     A. Overview
                     B. Enforcement of CSO Dry Weather
                       Discharge Prohibition
                     C. Enforcement of Wet Weather CSO
                       Requirements
                     1. Enforcement for Compliance With Phase
                       I Permits
                     2. Enforcement for Compliance With Phase
                       II Permit!
                     D. Penalties

                    List of Subjects in  40 CFR Put 122

                      Witer pollution control.
                     Authorityt Clean Water Act. 33 U.S.C. 1251
                      Deled: April 8. 1994.
                    Carol M. Browner,
                    Administrator.
                    Combined Sower Overflow (CSO)
                    Control Policy

                    /. Introduction

                    A. Purpose and  Principles
                      The main purposes of this Policy are
                    to elaborate on EPA's National
                    Combined Sewer Overflow (CSO)
                    Control Strategy published on
                    September B. 1989 at 54 FR 37370 (1989
Strategy) and to expedite compliance
with the requirements of the Clean
Water Act (CWA). While
Implementation of the 1989 Strategy has
resulted in progress toward controlling
CSOs, significant water quality risks
remain.
  A combined sewer system (CSS) is a
wastewater collection system owned by
a State or municipality (as defined by
section 502(4)  of the CWA) which
conveys sanitary wastewaters (domestic,
commercial and industrial wastewaters)
and storm water through a single-pipe
system to a Publicly Owned Treatment
Works (POTW) Treatment Plant (as
defined In 40 CFR 403.3(p)). A CSO is
the discharge from a CSS at a point prior
to the POTW Treatment Plant. CSOs are
point sources subject to NPDES permit
requirements Including both
technology-based and water quality-
based requirements of the CWA. CSOs
are not subject to secondary treatment
requirements; applicable to POTWs.
   CSOs consist of mixtures of domestic
sewage, industrial and commercial
wastewaters, and storm water runoff.
CSOs often contain high levels of
suspended solids, pathogenic
microorganisms, toxic pollutants,
floatable*, nutrients, oxygen-demanding
organic compounds, oil and grease, and
other pollutants. CSOs  can cause
exceedances of water quality standards
 (WQS). Such exceedajices may pose
 risks to human health, threaten aquatic
 life and its habitat, and impair the use
and enjoyment of (he Nation's
 waterways.
   This Policy is Intended to provide
 guidance to permittees with CSOs.
 National Pollutant Discharge
 Elimination System (NPDES)  permitting
 authorities. State water quality
 standards authorities and enforcement
 authorities. The purpose of the Policy is
 to coordinate  the planning, selection.
 design and implementation of CSO
 management practices and controls to
 meet the requirements of the CWA and
 to involve the public fully during the
 decision making process.
   This Policy reiterates the objectives of
 the  1989 Strategy:
 1. To ensure that If CSOs occur, they are
   only as a result of wet weather.
 Z. To bring all wet weather CSO
   discharge points into compliance with
   the technology-based and water
   quality-based requirements of the
   CWA; and
 3. To minimize water quality, aquatic
   biota, and human health impacts from
   CSOs.
   This CSO Control Policy represents a
 comprehensive national strategy to
 ensure that municipalities, permitting
authorities, water quality standards
authorities and the public engage in a
comprehensive and coordinated
planning effort to achieve cost-effective
CSO controls that ultimately meet
appropriate health and environmental
objectives and require merits. The Policy
recognizes the site-specific nature of
CSOs and their impacts and provides
the necessary flexibility to tailor
controls to local situations. Pour key
principles of the Policy ensure that CSO
controls are cost-effective and meet the
objectives of the  CWA. The key
principles are:
1. Providing clear levels of control that
  would be presumed to meet
  appropriate health and environmental
  objectives;
2. Providing sufficient flexibility to
  municipalities, especially financially
  disadvantaged communities, to
  consider the site-specific nature of
  CSOs and to determine the most cost-
  effective means of reducing pollutants
  and meeting CWA objectives and
  requirements:
3. Allowing a phased approach to
  implementation of CSO controls
  considering a community's financial
  capability; and
4. Review and revision, as appropriate,
  of water quality standards and their
  implementation procedures when
  developing CSO control plans to
  reflect the site-specific wet weather
  impacts of CSOs.
  This Policy is being Issued  in support
 of EPA's regulations and policy
 initiatives. This Policy is Agency
 guidance only and does not establish or
 affect legal rights or obligations. It does
 not establish a binding norm and It not
 finally determinative of the issues
 addressed. Agency decisions In any
 particular case will be made by applying
 the law and regulations on the basis of
 specific facts when permits are issued.
 The Administration has recommended
 that the 1994 amendments to the CWA
 endorse this final Policy.

 B.  Application of Policy
   The permitting provisions of this
 Policy apply to all CSS* that overflow
 as a result of storm water flow,
 including snow melt runoff (40 CFR
 122.26(b)(13)). Discharges from CSSs
 during dry weather are prohibited by
 the CWA. Accordingly, the permitting
 provisions of this Policy do not apply to
 CSOs during dry weather. Dry weather
 flow is the flow in a combined sewer
 that results from domestic sewage,
 groundwater infiltration, commercial
 and industrial wastewaters, and any
 other non-precipitation related flows
 (e.g.. Udal infiltration). In addition to
 A-4

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                                                                                                                   Appendix A
18690
Federal  Register / Vol. 59, No. 75  / Tuesday,  April 19. 1994 / Notices
the permitting provisions, the
Enforeainont and Compliance section of
this Policy describes an enforcement
initiative being developed for overflows
that occur during dry weather.
  Consistent with the 1989 Strategy. 30
States that submitted CSO permitting
strategies have received EPA approval
or, in the case of one State, conditional
approval of its strategy. Stales and EPA
Regional Offices should review these
strategies and negotiate appropriate
revisions to them to implement this
Policy. Permitting authorities are
encouraged to evaluate water pollution
control needs on a watershed
management basis and coordinate CSO
control efforts with other point and
nonpoint source control activities.

C. Effect on Current CSO Control Efforts
  EPA recognizes that extensive work
has been done by  many Regions, Stales,
and municipalities to abate CSOs. As
such, portions of this Policy may
already have  been addressed by
permittees' previous efforts to control
CSOs. Therefore, portions of this Policy
may not apply, as determined by the
permitting authority on a case-by-case
basis, under the following
circumstances:
   1. Any permittee that, on the date of
publication of this final Policy, has
completed or substantially completed
construction  of CSO control facilities
that are designed to meet WQS and
protect designated uses, and where it
has been determined that WQS are
being or will  be attained, is not covered
by the initial planning and construction
provisions in this Policy; however,  the
operational plan and post-construction
monitoring provisions continue to
apply. If, after monitoring, it is
determined that WQS are not being
attained, the  permittee should be
required to submit a  revised CSO
control plan that, once Implemented,
will attain WQS.
   2. Any permittee that, on the date of
publication of this final Policy, has
substantially developed or is
implementing a CSO control program
pursuant to an existing permit or
enforcement  order, and such program is
considered by the NPDES permitting
authority to be adequate to meet WQS
and protect designated uses and is
reasonably equivalent to the treatment
objectives of this Policy, should
complete those facilities without further
planning activities otherwise expected
by this Policy. Such programs, however,
should be reviewed and modified to be
consistent with the sensitive area,
financial capability, and post-
construction monitoring provisions of
this Policy.
                     3. Any permittee that has previously
                   constructed CSO control facilities in an
                   effort to comply with WQS but has
                   failed to meet such applicable standards
                   or to protect designated uses due to
                   remaining CSOs may receive
                   consideration for such efforts in future
                   permits or enforceable orders for long-
                   term CSO control planning, design and
                   implementation.
                     In the case of any ongoing or
                   substantially completed CSO control
                   effort, the NPDES permit or other
                   enforceable mechanism, as appropriate.
                   should be revised to include all
                   appropriate permit requirements
                   consistent with Section IV.B, of this
                   Policy.

                   D. Smalt System Considerations
                     The scope of the long-term CSO
                   control plan, including the
                   characterization, monitoring and
                   modeling, and evaluation  of alternatives
                   portions of this Policy may be difficult
                   for some small CSSs. At the discretion
                   of the NPDES Authority, jurisdictions
                   with populations under 75,000 may not
                   need to complete each of the  formal
                   steps outlined in Section II.C. of this
                   Policy, but should be required through
                   their permits or other enforceable
                   mechanisms to comply with the nine
                   minimum controls (H.B). public
                   participation  (It.C.2). and  sensitive areas
                   (II,C 3) portions of this Policy. In
                   addition, the permittee may propose to
                   implement any of the criteria contained
                   in this Policy for evaluation of
                   alternatives described in II.C.4.
                   Following approval of the proposed
                   plan, such jurisdictions should
                   construct the control projects and
                   propose a monitoring program sufficient
                   to determine whether WQS are attained
                   and designated uses are protected.
                      In developing long-term CSO control
                   plans based on the small system
                   considerations discussed  in the
                   preceding paragraph, permittees are
                   encouraged to discuss the scope of their
                   long-term CSO control plan with the
                   WQS authority and the NPDES
                   authority. These discussions will ensure
                   that the plan includes sufficient
                   information to enable the permitting
                   authority to identify the appropriate
                   CSO control-!.

                   E. Implementation Responsibilities
                      NPDES authorities (authorized States
                   or EPA Regional Offices, as appropriate)
                   are responsible for implementing this
                   Policy, It is their responsibility to assure
                   that CSO permittees develop long-term
                   CSO control plans and that NPDES
                   permits meet the requirements of the
                   CWA. Further, they are responsible for
                   coordinating the review of the long-term
CSO control plan and the development
of the permit with the WQS authority to
determine if revisions to the WQS are
appropriate. In addition, they should
determine the appropriate vehicle (i.e.,
permit reissuance, information request
under CWA section 308 or State
equivalent or enforcement action) to
ensure that compliance with the CWA is
achieved as soon as practicable.
  Permittees are responsible for
documenting the implementation of the
nine minimum controls and developing
and implementing a long-term CSO
control plan, as described in this Policy.
EPA recognizes that financial
considerations are a major factor
affecting the implementation of CSO
controls. For that reason, this Policy
allows consideration of a permittee's
financial capability in connection with
the long-term CSO control planning
effort, WQS review, and negotiation of
enforceable schedules. However, each
permittee is ultimately responsible for
aggressively pursuing financial
arrangements for the implementation of
its long-term CSO control plan. As part
of this effort, communities should apply
to their State Revolving Fund program.
or other assistance programs as
appropriate, for financial assistance.
  EPA and the States will undertake
action to assure that all permittees with
CSSs are subject to a consistent review
in the permit development process.
have permit requirements that achieve
compliance with the CWA, and are
subject to enforceable schedules that
require the earliest practicable
compliance date considering physical
and financial feasibility.
F. Policy Development
  This Policy devotes a separate section
to each step involved in developing and
implementing CSO controls. This is not
to Imply that each function occurs
separately. Rather, the entire process
surrounding CSO controls, community
planning. WQS and permit
development/revision, enforcement/
compliance actions and public
participation must be coordinated to
control CSOs effectively. Permittees and
permitting authorities are encouraged to
consider innovative and alternative
approaches and technologies that
achieve the objectives of this Policy and
the CWA.
  In developing this Policy. EPA has
included information on what
responsible parties are expected to
accomplish. Subsequent documents will
provide additional guidance on how the
objectives of this Policy should be met.
These documents will provide further
guidance on: CSO permit writing, the
nine minimum controls, long-term CSO
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     rt fn Tnngrpcc nn thp ImnnrK nnri Cnntrnl nfTSfk nnrt SSfk
                                                                                                                   Chapter 1—Introduction
                                    Federal Regtrtar / Vol. 59. No. 75 / Tuesday, April 19. 1994 / Notices
                                                                   18691
                 control plans, financial capability,
                 sewer system characterization and
                 receiving water monitoring and
                 modeling, and application of WQS to
                 CSO-impacted waters. For most CSO
                 control efforts however, sufficient detail
                 has been included In this Policy to
                 begin immediate implementation of its
                 provisions,

                 U. EPA Objectives for Permittees
                 A. Overview
                   Permittees with CSSs that have CSGs
                 should immediately undertake a process
                 to accurately characterize their sewer
                 systems, to demonstrate implementation
                 of the nine minimum controls, and to
                 develop a long-term CSO control plan.
                 B. Implementation of the Nine
                 Minimum Controls
                   Permittees with CSOs should submit
                 appropriate documentation
                 demonstrating implementation of the
                 nine minimum controls, including any
                 proposed schedules for completing
                 minor construction activities. The nine
                 minimum controls are:
                 1. Proper operation and regular
                   maintenance programs for the sewer
                   system and the CSOs;
                 2. Maximum use of the collection
                   system for storage;
                 3. Review and modification of
                   pretreatment requirements to assure
                   CSO impacts are minimized;
                 4. Maximization of flow to the POTW
                   for treatment;
                 S. Prohibition of CSOs during dry
                   weather,
                 6. Control of solid and floatable
                   materials in CSOs;
                 7. Pollution prevention:
                 8. Public notification to ensure that the
                   public receives adequate notification
                   of CSO occurrences and CSO impacts;
                   and
                 9. Monitoring to effectively characterize
                   CSO impacts and the efficacy of CSO
                   controls.
                   Selection and implementation of
                 actual control measures should be based
                 on site-specific considerations including
                 the specific CSS's characteristics
                 discussed under the sewer system
                 characterization and monitoring
                 portions of this Policy. Documentation
                 of the nine minimum controls may
                 include operation and maintenance
                 plans, revised sewer use ordinances for
                 industrial users, sewer system
                 inspection reports, infiltration/inflow
                 studies, pollution prevention programs,
                 public notification plans, and facility
                  plans for maximizing the capacities of
                 the existing collection, storage and
                 treatment systems, as well as contracts
                 and schedules for minor construction
programs for Improving the existing
system's operation. The permittee
should also submit any information or
data on the degree to which the nine
minimum controls achieve compliance
with water quality standards. These data
and Information should include results
made available through monitoring and
modeling activities done in conjunction
with the development of the long-term
CSO control plan described in this
Policy.
  This documentation should be
submitted as soon as practicable, but no
later than two years after the
requirement la submit such
documentation is included in an NPDES
permit or other enforceable mechanism.
Implementation of the nine minimum
controls with appropriate
documentation should be completed as
soon as practicable but no later than
January 1.1997. These dates should be
included in an appropriate enforceable
mechanism.
  Because the CWA requires immediate
compliance with technology-based
controls (section 301 (bl), which on a
Best Professional Judgment basis should
include the nine minimum controls, a
compliance schedule for implementing
the nine minimum controls, If
necessary, should be included in an
appropriate enforceable mechanism.
C. Long-Term CSO Control Plan
  Permittees with CSOs are responsible
for developing and implementing long-
term CSO control plans that will
ultimately result in compliance with the
requirements of the CWA. The long-
term plans should consider the site-
specific nature of CSOs and evaluate the
cost effectiveness of a range of control
options/strategies. The development  of
the long-term CSO control plan and its
subsequent implementation should also
be coordinated with the NPDES
authority and the State authority
responsible for reviewing and revising
the State's WQS. The selected controls
should be designed to allow cost
effective expansion or cost effective
retrofitting if additional controls are
subsequently determined to be
necessary to meet WQS, including
existing and designated uses.
  This policy identifies EPA's major
objectives for the long-term CSO control
plan. Permittees should develop and
submit this long-term CSO control plan
as soon as practicable, but generally
within two years after the date of the
NPDES permit provision. Section 308
information request, or enforcement
action requiring the permittee to
develop the plan. NPDES authorities
may establish a longer timetable for
completion of the long-term CSO
control plan on a case-by-case basis to
account for site-specific factors which
may influence the complexity of the
planning process. Once agreed upon,
these dates should be included in on
appropriate enforceable mechanism.
  EPA expects each long-term CSO
control plan to utilize appropriate
information to address the following
minimum elements. The Plan should
also include both fixed-date project
implementation schedules (which may
be phased) and a financing plan to
design and construct the project as soon
as practicable. The minimum elements
of the long-term CSO control plan are
described below.

1. Characterization, Monitoring, and
Modeling of the Combined Sewer
System

  In order to design a CSO control plan
adequate to meet the requirements of
the CWA, a permittee should have a
thorough understanding of its sewer
system, the response of the system to
various precipitation events, the
characteristics of the overflows, and the
water quality Impacts that result from
CSOs. The permittee should adequately
characterize through monitoring,
modeling, and other means as
appropriate, for a range of storm events,
the response of its sewer system to wet
weather events including the number,
location and frequency of CSOs,
volume, concentration and mass of
pollutants discharged and the impacts
of the CSOs on the receiving waters and
their designated uses. The permittee
may need to consider information on
the contribution and importance of
other pollution sources in order to
develop a final plan designed to meet
water quality standards. The purpose of
the system characterization, monitoring
and modeling program initially is to
assist the permittee in developing
appropriate measures to implement the
nine minimum controls and, if
necessary, to support development of
the long-term CSO control plan. The
monitoring and modeling data also will
be used to evaluate the expected
effectiveness of both the nine minimum
controls and. if necessary, the long-term
CSO controls, to meet WQS.
   The major elements of a sewer system
characterization are described below.
   a. Rainfall Records—The permittee
should examine the complete rainfall
record for the geographic ana of its
existing CSS using sound statistical
procedures and best available data. The
 permittee should evaluate flow
 variations in the receiving water body to
correlate between CSOs and receiving
water conditions.
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                                                                                                                  Appendix A
18692
Federal Register /  Vol.  59, No. 75  /  Tuesday, April 19. 1994  /  Notices
  b. Combined Sewer System
Characterization—The permittee should
evaluate the nature and extent of it*
sewer system through evaluation of
available sewer system records. Geld
inspections and other activities
necessary to understand the number.
location and frequency of overflows and
their location relative to sensitive areas
and to pollution sources in the
collection system, such as indirect
significant industrial users.
  c, CSO Monitoring—The permittee
should develop a comprehensive,
representative monitoring program that
measures the frequency, duration, flow
rate, volume and pollutant
concentration of CSO discharges and
assesses the impact of the CSOs on the
receiving waters. The monitoring
program  should include necessary CSO
effluent and ambient in-stream
monitoring and. where appropriate.
other monitoring protocols such as
biological assessment, toxicity testing
and sediment sampling. Monitoring
parameters should include, for example.
oxygen demanding pollutants, nutrients.
toxic pollutants, sediment
contaminants, pathogens.
bacteriological  indicators (e.g.,
Enlerococcus, E. Coli), and toxicity. A
representative sample of overflow
points can be selected that is sufficient
to allow  characterization  of CSO
discharges and their water quality
Impacts and to facilitate evaluation of
control plan alternatives.
   d. Modeling—Modeling of a sewer
system is recognized as a valuable tool
for predicting sewer system response to
various wet weather events and
assessing water quality impacts when
evaluating different control strategies
and alternatives. EPA supports the
proper and effective use of models,
where appropriate, in the evaluation of
the nine minimum controls and the
development of the long-term CSO
control plan. It is also recognized that
there are many models which may be
used to do this. These models range
from simple to complex. Having
decided  to use a model, the permittee
should base its choice of a model on the
characteristics of its sewer system, the
 number  and location of overflow points,
 and the sensitivity of the receiving
water body to the CSO discharges. Use
of models should include appropriate
 calibration and verification with Geld
 measurements. The sophistication of the
 model should relate to the complexity of
 the system to be modeled and to the
 information needs associated with
 evaluation of CSO control options and
 water quality impacts. EPA believes that
 continuous simulation models, using
 historical rainfall data, may be the best
                   way to model sewer systems, CSOs. and
                   their impact!. Because of the iterative
                   nature of modeling sewer systems,
                   CSOs. and their impacts, monitoring
                   and modeling efforts are complementary
                   and should be coordinated.

                   2. Public Participation

                     In developing its long-term CSO
                   control plan, the permittee will employ
                   a public participation process that
                   actively involves the affected public in
                   the decision-making to select the long-
                   term CSO controls. The affected public
                   includes rate payers, industrial users of
                   the sewer system, persons who reside
                   downstream from the CSOs, persons
                   who use and enjoy these downstream
                   waters, and any other interested
                   persons.

                   3. Consideration of Sensitive Areas

                     EPA expects a permittee's long-term
                   CSO control plan to give the highest
                   priority to controlling overflows to
                   sensitive areas. Sensitive areas, as
                   determined by the NPDES authority in
                   coordination with State and Federal
                   agencies, as appropriate, include
                   designated Outstanding National
                   Resource Waters, National Marine
                   Sanctuaries, waters with threatened or
                   endangered species and their habitat.
                   waters with primary contact recreation.
                   public drinking water intakes or their
                   designated protection areas, and
                   shellfish beds. For such areas, the long-
                   term CSO control plan should:
                     a. Prohibit new or significantly
                   increased  overflows;
                     b.  i. Eliminate or relocate overflows
                   that discharge to sensitive areas
                   wherever physically possible and
                   economically achievable, except where
                   elimination or relocation would provide
                   less environmental protection than
                   additional treatment; or
                     ii. Where elimination or relocation is
                   not physically possible and
                   economically achievable, or would
                   provide less environmental protection
                   than additional treatment, provide the
                   level of treatment for remaining
                   overflows deemed necessary to meet
                   WQS for full protection of existing and
                   designated uses, hi any event, the level
                   of control should not be less than those
                   described in Evaluation of Alternatives
                   below; and
                     C Where elimination or relocation has
                   been proven not to be physically
                   possible and economically achievable,
                   permitting authorities should  require,
                   for each subsequent permit term, a
                   reassessment based on new or improved
                   techniques to eliminate or relocate, or
                   on changed circumstances that
                   influence economic achievability.
4. Evaluation of Alternatives
  EPA expects the long-term CSO
control plan to consider a reasonable
range of alternatives. The plan should.
for example, evaluate controls that
would be necessary to achieve zero
overflow events per year, an average of
one to three, four to seven, and eight to
twelve overflow events per year.
Alternatively, the long-term plan could
evaluate controls that achieve 100%
capture, 90% capture. 85% capture,
80% capture, and 75% capture for
treatment The long-term control plan
should also consider expansion of
POTW secondary and primary capacity
in the CSO abatement alternative
analysis. The analysis of alternatives
should be sufficient to make a
reasonable assessment of cost and
performance as described in Section
n.CS. Because the  final long-term CSO
control plan will become the basis for
NPDES permit limits and requirements,
the selected controls should be
sufficient to meet CVVA requirements.
   In addition to considering sensitive
areas, the long-term CSO control plan
should adopt one of the  following
approaches:
a. "Presumption" Approach
   A program that meets  any of the
criteria  listed below would be presumed
to provide an adequate level of control
to meet the water quality-based
requirements of the CVVA. provided the
permitting authority determines that
such presumption  Is reasonable in light
of the data and analysis  conducted in
the characterization, monitoring, and
modeling of the system and the
consideration of sensitive areas
described above. These criteria are
provided because data and modeling of
wet weather events often do not give a
clear picture of the level of CSO controls
necessary to protect WQS.
   i. No more than an average of four
overflow events per year, provided that
the permitting authority may allow up
to two additional overflow events per
year. For the purpose of this criterion,
an overflow event  is one or more
overflows from a CSS as the result of a
precipitation event that  does Dot receive
the minimum  treatment specified
below; or
   ii. The elimination or the capture for
treatment of no less than 85% by
volume of the combined sewage
collected in the CSS during
precipitation events on a system-wide
annual average basis; or
   iU. The elimination or removal of no
 less than the mass of the pollutants,
 identified as causing water quality
 impairment through the sewer system
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                     Federal Register / Vol. 59, No.  75 / Tuesday, April 19, 1994  /  Notices            18693
                  characterization, monitoring, and
                  modeling effort, for the volumes that
                  would be eliminated or captured for
                  treatment under paragraph ii. above.
                  Combined sewer flows remaining after
                  implementation of the nine minimum
                  controls and within the criteria
                  specified at II.C.4.a.i or ii. should
                  receive a minimum of:
                    • Primary clarification (Removal of
                  floatables and settleable solids may be
                  achieved by any combination of
                  treatment technologies or methods that
                  are shown to be equivalent to primary
                  clarification.):
                    • Solids and floatables disposal;  and
                    • Disinfection of effluent, if
                  necessary, to meet WQS. protect
                  designated uses and  protect human
                  health, including removal of harmful
                  disinfection chemical residuals, where
                  necessary.

                  b. "Demonstration" Approach
                    A permittee may demonstrate that a
                  selected control program, though not
                  meeting the criteria specified in II.C.4.a.
                  above is adequate to meet the water
                  quality-based requirements of the CWA.
                  To be a successful demonstration, the
                  permittee should demonstrate each of
                  the following;
                    i. The planned control program is
                  adequate to meet WQS and protect
                  designated uses, unless WQS or uses
                  cannot be met as a result of natural
                  background conditions or pollution
                  sources other than CSOs;
                    ii. The CSO discharges remaining
                  after implementation of the planned
                  control program will not preclude the
                  attainment of WQS or the receiving
                  waters' designated uses or contribute to
                  their impairment. Where WQS and
                  designated uses are not met in part
                  because of natural background
                  conditions or pollution sources other
                  than CSOs, a total maximum daily  load,
                  including a wasleload allocation and a
                  load allocation, or other means should
                  be used to apportion pollutant loads:
                     ill. The planned control program will
                  provide the maximum pollution
                  reduction benefits reasonably attainable;
                  and
                     iv. The planned control program is
                  designed to allow cost effective
                  expansion or cost effective retrofitting if
                  additional controls are subsequently
                  determined to be necessary to meet
                  WQS or designated  uses.

                  S. Cost/Performance Considerations
                     The permittee should develop
                  appropriate cost/performance curves to
                  demonstrate the relationships among a
                  comprehensive set of reasonable control
                  alternatives that correspond to the
                  different ranges specified in Section
n.C.4. This should include an analysis
to determine where the increment of
pollution reduction achieved in the
receiving water diminishes compared to
the increased costs. This analysis, often
known as knee of the curve, should be
among the considerations used to help
guide selection of controls.
6. Operational Plan
  After agreement between the
permittee and NPDES authority on the
necessary CSO controls to be
implemented under the long-term CSO
control plan, the permittee should
revise the operation and maintenance
program developed as part of the nine
minimum controls to include the
agreed-upon long-term CSO controls.
The revised operation and maintenance
program should maximize the removal
of pollutants during and after each
precipitation event using all available
facilities within the collection and
treatment system. For any flows in
excess of the criteria specified at
Il.C 4.a,i.. ii. or iii and not receiving the
treatment specified in Il.C.4.H. the
operational plan should ensure that
such  flows receive treatment to the
greatest extent practicable.
7. Maximizing Treatment at  the Existing
POTW Treatment Plant
  In some communities. POTW
treatment plants incy have primary
treatment capacity in excess of their
secondary treatment capacity. One
effective strategy to abate pollution
resulting from CSOs is to maximize the
delivery of flows during wet weather to
the POTW treatment plant for treatment.
Delivering these flows can have two
significant water quality benefits: First,
increased flows during wet weather to
the POTW treatment plant may enable
the permittee to  eliminate or minimize
overflows to sensitive areas: second, this
would maximize the use of available
POTW facilities  for wet weather flows
and would ensure that combined sewer
 flows receive at  least primary treatment
prior to discharge.
   Under EPA regulations, the
 intentional diversion of waste streams
 from  any portion of a treatment facility.
 including secondary treatment, is a
bypass. EPA bypass regulations at 40
 CFR  122.41(m) allow for a facility to
 bypass some or all the flow from its
 treatment process under specified
 limited circumstances. Under the
 regulation, the permittee must show that
 the bypass was unavoidable to  prevent
 loss of life, personal injury or severe
 property damage, that there was no
 feasible alternative to the bypass and
 that the permittee submitted the
 required notices. In addition, the
regulation provides that a bypass may
be approved only after consideration of
adverse effects.
  Normally, it is the responsibility of
the permittee to document, on a case-by-
base basis, compliance with 40 CFR
122.41 (m) in order to bypass flows
legally. For some CSO-related permits.
the Study of feasible alternatives in the
control plan may provide sufficient
support for the permit record and for
approval  of a  CSO-related bypass in the
permit itself, and to define the specific
parameters under which a bypass can
legally occur. For approval of a CSO-
related bypass, the long-term CSO
control plan,  at a minimum, should
provide justification for the cut-off point
at which  the flow will be diverted from
the secondary treatment portion of the
treatment plant, and provide a benefit-
cost analysis demonstrating that
conveyance of wet weather flow to the
POTW for primary treatment is more
beneficial than other CSO abatement
alternatives such as storage and pump
back for secondary treatment, sewer
separation, or satellite treatment. Such a
permit must define under what specific
wet weather conditions a CSO-related
bypass is allowed end also specify what
treatment or what monitoring, and
effluent limitations and requirements
apply to  the bypass flow. The permit
should also provide that approval for
the CSO-related bypass will be reviewed
and may be modified or terminated if
there is a substantial increase in the
volume or character of pollutants being
 introduced to the POTW. The CSO-
 related bypass provision in the  permit
 should also make it clear that all wet
 weather  flows passing the headworks of
 the POTW treatment plant will receive
 at least primary clarification and solids
 and floatables removal and disposal,
 and disinfection, where necessary, and
 any other treatment that can reasonably
 be provided.
   Under this approach, EPA would
 allow a permit to authorize a CSO-
 related bypass of the secondary
 treatment portion of the POTW
 treatment plant for combined sewer
 flows in  certain identified
 circumstances. This provision would
 apply only to those situations where the
 POTW would ordinarily meet the
 requirements of 40 CFR 12Z.41(m) as
 evaluated on a case-by-case basis.
 Therefore, there must be sufficient data
 in the administrative record (reflected in
 the permit fact sheet or statement of
 basis] supporting all the requirements in
 40 CFR 122.41(m)(4) for approval of an
 anticipated bypass.
   For the purposes of applying this
 regulation to CSO permittees, "severe
 property damage" could include
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                                                                                                                Appendix A
18694
Federal  Register  /  Vol.  59,  No. 75  /  Tuesday. April 19.  199*  /  Notices
situations where flows above a certain
level wash out the POTW's secondary
treatment system. EPA further believes
that the feasible alternatives
requirement of the regulation can be met
if the record shows that the secondary
treatment system is properly operated
and maintained, that the system has
been designed to meet secondary limits
for flows greater than the peak dry
weather flow, plus an appropriate
quantity of wet weather flow, and thai
it is either technically or financially
infoasible to provide secondary
treatment at the existing facilities for
greater amounts of wet weather flow.
The feasible alternative analysis should
include, for example, consideration of
enhanced primary treatment (e.g.,
chemical addition] and non-biological
secondary treatment.  Other bases
supporting a finding of no feasible
alternative may also be available on a
case-by-case basis. As part of its
consideration of possible adverse effects
resulting from the bypass, the
permitting authority should also ensure
that the bypass will not cause
exceedances of WQS.
  This Policy does not address the
appropriateness at approving
anticipated bypasses through NPDES
permits in advance outside the CSO
context.

8. Implementation Schedule
  The permittee should include all
pertinent information in the long term
control plan necessary to develop the
construction and financing schedule for
implementation of CSO controls.
Schedules for implementation of the
CSO controls may be phased based on
the relative importance of adverse
impact* upon WQS and designated
uses, priority projects identified in the
long-term plan, and on a permittee's
financial capability.
   Construction phasing should
consider
   a. Eliminating overflows that
discharge to sensitive areas as the
highest priority;
   b. Use impairment;
   c. The permittee's financial capability
 including consideration of such factors
as:
   i. Median household income;
   ii. Total annual waste water and  CSO
 control costs per household as a percent
 of median household income;
   iii. Overall net debt as a percent of
 full market property value:
   iv. Property tax revenues as a percent
 of full market property value;
   v. Property tax collection rate;
   vi. Unemployment; and
   vii. Bond rating:
   d. Grant and loan availability,
                     e. Previous and current residential,
                   commercial and industrial sewer user
                   fees and rate structures; and
                     f. Other viable funding mechanisms
                   and sources of financing.

                   9. Post-Construction Compliance
                   Monitoring Program
                     The selected CSO controls should
                   include a post-construction water
                   quality monitoring program adequate to
                   verify compliance with water quality
                   standard* and protection of designated
                   uses as well as to ascertain the
                   effectiveness of CSO controls. This
                   water quality compliance monitoring
                   program should include a plan to be
                   approved by the NPDES authority that
                   details the monitoring protocols to be
                   followed, including the necessary
                   effluent and ambient monitoring and,
                   where appropriate, other monitoring
                   protocols such as biological
                   assessments, whole effluent toxicity
                   testing, and sediment sampling.
                   /W. Coordination With State Water
                   Quality Standards
                   A. Overview
                     WQS are State adopted, or Federally
                   promulgated rules which serve as the
                   goals for the water body and the legal
                   basis for the water quality-based NPDES
                   permit requirements under the CWA,
                   WQS consist of uses which States
                   designate for their water bodies, criteria
                   to protect the uses, an anti-degradation
                   policy to protect the water quality
                   improvements gained and other policies
                   affecting the implementation of the
                   standards. A primary objective of the
                   long-term CSO control plan is to meet
                   WQS, including the designated uses
                   through reducing risks to human health
                   and the environment by eliminating,
                   relocating or controlling CSOs to the
                   affected waters.
                      State WQS authorities, NPDES
                   authorities, EPA regional offices,
                   permittees, and the public should meet
                   early and frequently throughout the
                   long-term CSO control planning
                   process. Development of the long-term
                   plan should be coordinated with the
                   review and appropriate revision of WQS
                   and implementation procedures on
                   CSO-impacted waters to ensure that the
                   long-term controls will be sufficient to
                   meet weter quality standards. As part of
                   these meetings, participants should
                   agree on the data, information and
                   analyses needed to support the
                   development of the long-term CSO
                   control plan and the review of
                   applicable WQS, and implementation
                    procedures, if appropriate. Agreements
                   should be reached on the monitoring
                    protocols and models that will be used
to evaluate the water quality impacts of
the overflow), to analyze the
alt ui nubility of the WQS and to
determine the water quality-based
requirements far the permit. Many
opportunities exist for permittees and
Stales to share information as control
programs are developed and as WQS are
reviewed. Such information should
assist States in determining the need for
revisions to WQS and implementation
procedures to better reflect the site-
specific wet weather impacts of CSOs.
Coordinating the development of the
long-term CSO control plan and the
review of the WQS and implementation
procedures provides greater assurance
that the long-term control plan selected
and the limits and requirements
included in the NPDES permit will be
sufficient to meet WQS and to comply
with sections 30l(b)(l)(C) and 40Z(a)(Z)
of the CWA.
  EPA encourages States and permittees
jointly to sponsor workshops for the
affected public in the development of
the long-term CSO control plan and
during the development of appropriate
revisions to WQS for CSO-impacted
waters. Workshops provide a forum for
including the public in discussions of
the implications of the proposed long-
term CSO control plan on the  water
quality and uses for the receiving water.

B. Water Quality Standards Reviews
  The CWA requires States to
periodically, but at least once every
three years, hold public hearings for the
purpose of reviewing applicable water
quality standards and, as appropriate,
modifying and adopting standards.
States must provide the public an
opportunity to comment on any
 proposed revision to water quality
 standards and all revisions must be
submitted to EPA for review and
 approval.
   EPA  regulations and guidance provide
 States with the flexibility to adapt their
 WQS, and implementation procedures
 to reflect site-specific conditions
 Including those related to CSOs. For
 example, a State may adopt site-specific
 criteria for a particular pollutant if the
 Slate determines that the site-specific
 criteria fully protects the designated use
 (40 CFR 131.11). In addition, the
 regulations at 40 CFR 131  10(g), (h). and
 (j) specify when and how a designated
 use may be modified. A State may
 remove a designated use from its water
 quality standards only if the designated
 use is not an existing use. An existing
 use is a use actually attained in the
 water body on or after November 28,
 197S. Furthermore, a State may not
 remove a designated use that  will be
 attained by implementing the
                                                                                                                          A-9

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    Federal  Register /  Vol. 59, No. 75  /  Tuesday,  April 19.  1994 /  Notices
                                                                    18695
                 technology-baaed effluent limits
                 required under sections 301(b) and 306
                 of the CWA and by implementing co*l-
                 effective and reasonable best
                 management practices for nonpoint
                 source controls. Thus, if a State has a
                 reasonable basis to determine that the
                 current designated use could be attained
                 after implementation of the technology-
                 based controls of the CWA, then the use
                 could not be removed.
                   In determining whether a use is
                 attainable and prior to removing a
                 designated use. States must conduct and
                 submit to EPA a use attainability
                 analysis. A use attainability analysis is
                 a structured scientific assessment of the
                 factors affecting the use, including the
                 physical, chemical, biological, and
                 economic factors described in 40 CFR
                 131.10(g). As part  of the analysis. States
                 should evaluate whether the designated
                 use could be attained if CSO controls
                 were implemented. For example, States
                 should examine if sediment loadings
                 from CSOs could be  reduced so as not
                 to bury spawning  beds, or if
                 biochemical oxygen  demanding material
                 In the effluent or the toxicity  of the
                 effluent could be corrected so as to
                 reduce the acute or chronic
                 physiological stress on or
                 bioaccumulation potential of aquatic
                 organisms.
                   In reviewing the attainability of their
                 WQS and the applicability of their
                 implementation procedures to CSO-
                 impacted waters, States are encouraged
                 to define more explicitly their
                 recreational and aquatic life uses and
                 then, if appropriate, modify the criteria
                 accordingly to protect the designated
                 uses.
                   Another option is  for States to adopt
                 partial uses by defining when primary
                 contact recreation such as swimming
                 does not exist, such  as during certain
                 seasons of the year in northern climates
                 or during a particular type of storm
                 event, hi making such adjustments to
                 their uses. States must ensure that
                 downstream uses  are protected, and that
                 during other seasons or after the storm
                 event has passed,  the use is fully
                 protected.
                   In addition to defining recreational
                 uses with greater specificity. States are
                 also encouraged to define the aquatic
                 uses more precisely. Rather than
                 "aquatic life use protection," States
                 should consider defining the type of
                 fishery to be protected such as a cold
                 water fishery (e.g., trout or salmon) or a
                 warm weather fishery (e.g., bluegill or
                 large mouth bass). Explicitly defining
                 the type of fishery to be protected may
                 assist the permittee in enlisting the
                 support of citizens for a CSO control
                 plan.
  A water quality standard variance
may be appropriate, in limited
circumstances on CSO-impacled waters,
where the State is uncertain as to
whether a standard can be attained and
time is needed for the State to conduct
additional analyses on the attainability
of the standard. Variances are short-term
modifications in  water quality
standards. Subject to EPA approval.
States, with their own statutory
authority, may grant a variance to a
specific discharger for a specific
pollutant. The justification fora
variance is similar to that required for
a permanent change in the standard,
although the showings needed are less
rigorous. Variances are also subject to
public participation requirements of the
water quality standards and permits
programs and are reviewable  generally
every three years. A variance  allows the
CSO permit (o be written lo meet the
"modified" water quality standard as
analyses are conducted and as progress
is made to Improve water quality.
  Justifications for variances  are the
same as those identified In 40 CFR
131 .lUfg) for modifications in uses.
States must provide an opportunity for
public review and comment on all
variances. If States use the permit as the
vehicle to grant the variance, notice of
the permit must  clearly slate  that the
variance modifies the State's  water
quality standards. If the variance is
approved, the State appends  the
variance to the Slate's standards and
reviews the variance every three years.
IV. Expectations for Permitting
Authorities
A. Overview
  CSOs are point sources subject to
NPDES permit requirements  including
both technology-based and water
quality-based requirements of the CWA.
CSOs are not subject to secondary
treatment regulations applicable to
publicly owned treatment works
(Montgomery Environmental Coalition
vs. Costle. 646 F.2d 56fl (D.C. Cir.
1980)).
  All permits for CSOs should require
the nine minimum controls as a
minimum best available technology
economically achievable and best
conventional technology (BAT/BCT)
established on a best professional
judgment (BPT) basis by the permitting
authority (40 CFR 125.3). Water quality-
based requirements are to be established
based on applicable water quality
standards.
  This policy establishes B uniform,
nationally consistent approach to
developing and issuing NPDES permits
to permittees with CSOs. Permits for
CSOs should be developed and issued
expeditiously A single, system-wide
permit generally should be issued for all
discharges, including CSOs, from a CSS
operated by a single authority. When
different parts of a single CSS are
operated by more than one authority,
permits issued to each authority should
generally require joint preparation and
implementation of the elements of this
Policy and should specifically define
the responsibilities and duties of each
authority. Permittees should be required
to coordinate system-wide
implementation of the nine minimum
controls and the development and
implementation of the long-term CSO
control plan.
  The individual authorities are
responsible for their own discharges and
should cooperate with the permittee for
the POTW receiving the flows from the
CSS. When a CSO is permitted
separately from the POTW. both  permits
should be cross-referenced for
informational purposes.
  EPA Regions and Slates should
review the CSO permitting priorities
established in the State CSO Permitting
Strategies developed in response to the
1989 Strategy. Regions and Slates may
elect to revise these previous priorities.
In setting permitting priorities, Regions
and States should not just focus on
those permittees that have initiated
monitoring programs. When setting
priorities, Regions and States should
consider, for example, the known or
potential impact of CSOs on sensitive
areas, and the extent of upstream
industrial user discharges to the CSS.
  During the permittee's development
of the long-term CSO control plan, the
permit writer should promote
coordination between the permittee and
State WQS authority in connection with
possible WQS revisions. Once the
permittee has completed development
of the long-term CSO control plan and
has coordinated with the permitting
authority the selection of the controls
necessary to meet the requirements of
the CWA. the permitting authority
should  include in an appropriate
enforceable mechanism, requirements
for implementation of the long-term
CSO control plan, including conditions
for water quality monitoring and
operation and maintenance.

B. NPDES Permit Requirements

  Following are the major elements of
NPDES permits to implement this
Policy and ensure protection of water
quality.
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                                                                                                                  Appendix A
18896
Federal  Register  / Vol.  59. No. 75 / Tuesday. April 19. 1994 / Notices
1. Phase I Permits—Requirements for
Demonstration of Implementation of the
Nine Minimum Controls and
Development of the Long-Term CSO
Control Plan
  In the Phase I permit Issued/modified
to reflect this Policy, the NPDES
authority should at least require
permittees to:
  a. Immediately implement BAT/BCT.
which at a minimum includes the nine
minimum controls, as determined on a
HP) basis by the permitting authority:
  b. Develop and submit a report
documenting the implementation of the
nine minimum controls within two
years of permit issuance/modification;
  c. Compiy with applicable WQS. no
later than the date allowed under the
State's WQS, expressed in the form of a
narrative limitation; and
  d. develop and submit, consistent
with this Policy and based on a
schedule in an appropriate enforceable
mechanism, a long-term CSO control
plan as soon as practicable, but
generally within two years after the
effective date of the permit issuance/
modification. However, permitting
authorities may establish a longer
timetable for completion of the long-
term CSO control plan on a case-by-case
basis to account for site-specific factors
that may influence the complexity of the
planning process.
  The NPDES authority should include
compliance dates on the fastest
practicable schedule for each of the nine
minimum controls in an appropriate
enforceable mechanism issued in
conjunction with the Phase I permit.
The use of enforceable orders is
necessary unless Congress amends the
CWA. All orders should require
compliance with the nine minimum
controls no later than January 1,1997.

Z. Phase II Permits—Requirements for
Implementation of a Long-Term CSO
Control Plan
  Once the permittee has completed
development of the long-term CSO
control plan and the selection of the
controls necessary to meet CWA
 requirements has been coordinated with
 the permitting and WQS authorities, the
 permitting authority should include, in
an appropriate enforceable mechanism,
 requirements for implementation of the
 long-term CSO control  plan as soon as
 practicable. Where the  permittee has
 selected controls based on the
 "presumption" approach described in
 Section I1.C.4. the permitting authority
 must have determined  that the
 presumption that such level of
 treatment will achieve water quality
 standards is reasonable in light of the
                   data and analysis conducted under this
                   Policy. The Phase II permit should
                   contain:
                     a. Requirements to implement the
                   technology-based controls including the
                   nine minimum controls determined on
                   a BPJ basis:
                     b. Narrative requirements which
                   insure that the selected CSO controls are
                   implemented, operated and maintained
                   as described in the long-term CSO
                   control plan;
                     c. Water quality-based effluent limits
                   under 40 CFR 122.44(d)(l) and
                   122.44(k), requiring, at a minimum.
                   compliance with, no later than the date
                   allowed under the State's WQS, the
                   numeric performance standards for the
                   selected CSO controls, based on average
                   design conditions specifying at least one
                   of the following:
                     i. A maximum number of overflow
                   events per year for specified design
                   conditions consistent with II.C.4.a.i: or
                     ii. A minimum percentage capture of
                   combined sewage by volume for
                   treatment under specified design
                   conditions consistent with Il.C.l.a.ii; or
                     iii. A minimum removal of the mass
                   of pollutants discharged for specified
                   design conditions consistent with
                   ll.C.4.a.iii; or
                     iv. performance standards and
                   requirements that are consistent with
                   H.C.4.b. of the Policy.
                     d. A requirement to implement, with
                   an established schedule, the approved
                   post-construction water quality
                   assessment program including
                   requirements to monitor and collect
                   sufficient information to demonstrate
                   compliance with WQS and protection of
                   designated uses as well as to determine
                   the effectiveness of CSO controls.
                     e. A requirement to reassess overflows
                   to sensitive areas in those cases where
                   elimination or relocation of the
                   overflows is not physically possible and
                   economically achievable. The
                   reassessment should be based on
                   consideration of new or improved
                   techniques to eliminate or relocate
                   overflows or changed circumstances
                   that influence economic achievability:
                      f. Conditions establishing
                   requirements for maximizing the
                   treatment of wet weather flows at the
                   POTVV treatment plant, as appropriate,
                   consistent with Section D.C.7. of this
                   Policy;
                      g. A reopener clause authorizing the
                    NPDES authority to reopen and modify
                    the permit upon determination that the
                   CSO controls fail to meet WQS or
                    protect designated uses. Upon such
                    determination, the NPDES authority
                    should promptly notify the permittee
                    and proceed to modify or reissue the
                    permit. The permittee should be
required to develop, submit and
implement, as soon as practicable, a
revised CSO control plan which
contains additional controls to meet
WQS and designated uses. If the Initial
CSO control plan was approved under
the demonstration provision of Section
Il.C.4.b., the revised plan, at a
minimum, should provide for controls
that satisfy one of the criteria in Section
1I.C.4.B. unless the permittee
demonstrates that the revised plan is
clearly adequate to meet WQS at a lower
cost and it is shown that the additional
controls resulting from the criteria in
Section II.C.4.8. will not result in a
greater overall improvement in water
quality.
  Unless the permittee can comply with
all of the requirements of the Phase II
permit, the NPDES authority should
include, in an enforceable mechanism,
compliance dates on the fastest
practicable schedule for those activities
directly related to meeting the
requirements of the CWA. For major
permittees, the compliance schedule
should be placed in a judicial order.
Proper compliance with the schedule
for implementing the controls
recommended in the long-term CSO
control plan constitutes compliance
with the elements of this Policy
concerning planning and
implementation of a long term CSO
remedy.
3. Phasing Considerations
  implementation of CSO controls may
be phased based  on the relative
importance of and adverse impacts
upon WQS and designated uses, as well
as the permittee's financial capability
and its previous efforts to control CSOs.
The NPDES authority should evaluate
the proposed implementation schedule
and construction phasing discussed in
Section U.C.8. of this Policy. The permit
should require compliance with the
controls proposed in the long-term CSO
control plan no later than the applicable
deadline(s) under the CWA or State law.
If compliance with the Phase II permit
is not possible, an enforceable schedule.
consistent with the Enforcement and
Compliance Section of this Policy,
should be issued in conjunction with
the Phase II permit which specifies the
schedule and milestones for
implementation  of the long-term CSO
control plan.

 V. Enforcement and Compliance
 A. Overview
   It is important that permittees act
 immediately to take the necessary steps
 to comply with the CWA. The CSO
 enforcement effort will commence with
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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                   Fedora) Register / Vol. 59, No.  75 / Tuesday, April 19, 1994  /  Notices
                                                                   18697
                an Initiative to address CSOs that
                discharge during dry weather, followed
                by an enforcement effort in conjunction
                with permitting CSOs discussed earlier
                In this Policy. Success of the
                enforcement effort will depend in large
                part upon expeditious action by NPDES
                authorities in issu ing enforceable
                permits that include requirements both
                for the nine minimum controls and for
                compliance with all other requirements
                of the CWA. Priority for enforcement
                actions should be set based on
                environmental impacts or sensitive
                areas affected by CSOs.
                  As a further inducement for
                permittees to cooperate with this
                process, EPA is prepared to exercise its
                enforcement discretion in determining
                whether or not to seek civil penalties for
                past CSO violations if permittees meet
                the objectives and schedules of this
                Policy and do not have CSOs during dry
                weather.
                B. Enforcement of CSO Dry Weather
                Discharge Prohibition
                  EPA intends to commence
                immediately an enforcement Initiative
                against CSO permittees which have
                CWA violations due to CSOs during dry
                weather. Discharges during dry weather
                have always been prohibited by the
                NPDES program. Such discharges can
                create serious public health and water
                quality problems. EPA will use its CWA
                Section  308 monitoring, reporting, and
                inspection authorities, together with
                NPDES State authorities, to locate these
                violations, and to determine their
                causes. Appropriate remedies and
                penalties will be sought for CSOs during
                dry weather. EPA will provide NPDES
                authorities more  specific guidance on
                this enforcement initiative separately.
                C Enforcement of Wet Weather CSO
                Requirements
                  Under the CWA, EPA can use several
                enforcement options to address
                permittees with CSOs. Those options
                directly applicable to this Policy are
                section  308 Information Requests,
                section  309(a) Administrative Orders,
                section  309(g)  Administrative Penalty
                Orders, section 309 {b) and (d) Civil
                Judicial Actions, and section 504
                Emergency Powers. NPDES States
                should use comparable means.
                   NPDES authorities should set
                priorities for enforcement based on
                environmental impacts or sensitive
                areas affected by CSOs. Permittees that
                have voluntarily initiated monitoring
                and are progressing expeditiously
                toward appropriate CSO controls should
                be given due consideration far their
                efforts.
1. Enforcement for Compliance With
Phase I Permits
  Enforcement for compliance with
Phase 1 permits will focus on
requirements to implement at least the
nine minimum controls, and develop
the long-term CSO control plan leading
to compliance with the requirements of
the CWA. Where immediate compliance
with the Phase I permit is infeasible, the
NPDES authority should issue an
enforceable schedule, in concert  with
the Phase I permit, requiring
compliance with the CWA and
imposing compliance schedules with
dates for each of the nine minimum
controls as soon as practicable. All
enforcement authorities should require
compliance with the nine minimum
controls no later than January 1,1997.
Where the NPDES authority is issuing
an order with a compliance schedule for
the nine minimum controls, this order
should also include a schedule for
development of the long-term CSO
control plan.
  If a CSO permittee fails to meet the
final compliance date of the schedule,
the NPDES authority should initiate
appropriate judicial action.
2. Enforcement for Compliance With
Phase II Permits
  The main focus for enforcing
compliance with Phase II permits will
be to incorporate the long-term CSO
control plan through a civil judicial
 action, an administrative order, or other
enforceable mechanism requiring
compliance with the CWA and
 imposing a compliance schedule with
 appropriate milestone dates necessary to
 implement the plan.
   In general, a judicial order is the
 appropriate mechanism for
 incorporating the above provisions for
 Phase II. Administrative orders.
 however, may be appropriate for
 permittees whose long-term control
 plans will take less tban Pvc years to
 complete, and for minors that have
 complied with the final date of the
 enforceable order for compliance with
 their Phase 1 permit. If necessary, any of
 the nine minimum controls that have
 not been implemented by this time
 should be included in the terms of the
 judicial order.
 D. Penalties
   EPA is prepared not to seek civil
 penalties for past CSO violations, if
 permittees have no discharges during
 dry weather and meet the objectives and
 schedules of this Policy.
 Notwithstanding this, where a permittee
 has other significant CWA  violations for
 which EPA or the State is taking judicial
action, penalties may be considered as
part of that action for the following:
  1. CSOs during dry weather;
  2. Violations of CSO-related
requirements in NPDES permits;
consent decrees or court orders which
predate this policy: or
  3. Other CWA violations.
  EPA will not seek penalties for past
CSO violations from permittees that
fully comply with the Phase I permit or
enforceable order requiring compliance
with the Phase ! permit. For permittees
that fail to comply, EPA will exercise its
enforcement discretion in determining
whether to seek penalties for the time
period for which the compliance
schedule was violated. If the milestone
dates of the enforceable schedule are  not
achieved and penalties are sought.
penalties should be calculated from the
last milestone date that was met.
   At the time of the judicial settlement
imposing a compliance schedule
implementing the Phase [I permit
requirements, EPA will not seek
penalties  for past CSO violations from
permittees that fully comply with the
enforceable  order requiring compliance
with the Phase I  permit and if the terms
of the judicial order are expediliously
agreed to  on consent. However,
stipulated penalties for violation of the
judicial order generally should be
included  in the order, consistent with
existing Agency  policies. Additional
guidance on stipulated penalties
concerning  long-term CSO controls and
attainment of WQS will be issued.

 Paperwork  Reduclion Act

   The information collection
 requirements in  this policy have been
 approved by the Office of Management
 and Budget (OMB) under the Paperwork
 Reduction Act. 44 U.S.C. 3501  et seq
 and have been assigned OMB control
 number 2040-0170.
   This collection of information has an
 estimated reporting burden averaging
 578 hours per response and an
 estimated annual recordkeeping burden
 averaging 25 hours per recordkeeper.
 These estimates include time for
 reviewing instructions, searching
 existing data sources, gathering and
 maintaining the data needed, and
 completing and  reviewing the  collection
 of information.
   Send comments regarding the burden
 estimate  or any other aspect of this
 collection of information, including
 suggestions for reducing this burden to
 Chief, Information Policy Branch: EPA:
 401 M Street SW. (Mail Code 2136):
 Washington. DC 20460: and to the
 Office of Information and Regulatory
 Affairs, Office of Management and
 A-12

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                                                                                                         Appendix A
18698   Federal Register / Vol.  59. No. 75  / Tuesday.  April 19. 1994 / Notices

Budget. Washington. DC 20503. marked
"Attention: Desk Officer for EPA."
|FR Doc. 94-9295 Filed 4-1S-94; 8:45 am)
BMJJtQ COOC «i«0 II f
                                                                                                                 A-13

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Report to Congress on the Impacts and Control of CSOs and SSOs
A-14

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                                                                     Appendix A

A.3 Memorandum: Addition of Chapter X to Enforcement Management System


                                       March 7,  1996
   MEMORANDUM

   SUBJECT:  Addition of Chapter X to Enforcement  Management
               System (EMS):   Setting Priorities for Addressing
               Discharges from Separate Sanitary Sewers

   FROM:      Steven A.  Herman   [SIGNED]
               Assistant  Administrator

   TO:        Water  Management  Division  Directors,  Regions I-X
               NPDES  State Enforcement Directors
               Regional Counsels,  Regions I-X

         I am pleased to transmit  to  you a new chapter in  final  form
   for  the  Enforcement Management System  (EMS) Guide.  This  new chapter
   provides  a  method of  setting priorities for addressing  discharges
   of untreated sewage  from separate sanitary sewer collection  systems
   prior  to  the headworks of a sewage treatment plant.   Included with
   this chapter is an Enforcement Response Guide,  specifically  tailored
   to these  types of discharges.

         I want to express my appreciation to those Regional,
   Headquarters,  State personnel,  and the members  of  the  Federal
   Advisory  Sub-Committee for Sanitary Sewer Overflows  (SSO)  who helped
   develop  this document.  The Advisory Sub-Committee reviewed  it at
   two  public  meetings  in August and October, 1995.   The  cooperation
   and  hard  work of all  interested parties has produced  this final
   document  which I believe will help protect public  health  and the
   environment from these serious sources of water pollution.

         This guidance supplements the current  EMS  by establishing
   a series  of guiding principles and priorities for  use  by  EPA
   Regions  and NPDES States in responding to separate sanitary  sewer
   discharge violations.  The guidance allows sufficient  flexibility
   to alter  these priorities based on the degree of public health
   or environmental  risk presented by specific discharge  conditions.
   Implementation of this guidance by EPA and the  States  will promote
   national  consistency  in addressing discharges from separate  sanitary
   sewers.   Implementation will also ensure  that
                                                                         A-15

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                                    - 2  -

    enforcement resources are used in ways that maximize  public health
    and environmental benefits.

         The Regions  should ensure that all  approved States are aware
    of this additional EMS  guidance,  and the Regions  and  NPDES States
    should begin the process  of  modifying their written EMS documents
    to include it.  Both  Regions and States  should  have  these documents
    revised and implemented no  later  that November  15, 1996.

         If you have  questions about this  document, please feel free  to
    contact Brian J. Maas,  Director,  Water Enforcement Division (202/
    564-2240),  or Kevin Bell  of  his staff  (202/564-4027).
    cc:   Mike Cook, OWM
A-16

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                                                                            Appendix A
A.4 Enforcement Management System - Chapter X

                          THE ENFORCEMENT MANAGEMENT SYSTEM

                  NATIONAL POLLUTANT  DISCHARGE ELIMINATION SYSTEM

                                   (CLEAN WATER ACT)
              CHAPTER X:   Setting Priorities for Addressing Discharges
                           from Separate Sanitary Sewers
                        U.S.  ENVIRONMENTAL  PROTECTION AGENCY

                          OFFICE OF REGULATORY ENFORCEMENT

                                          1996
         ENFORCEMENT MANAGEMENT SYSTEM - CHAPTER X
                                                                                 A-17

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Report to Congress on the Impacts and Control ofCSOs and SSOs
                Setting Priorities  for Addressing Discharges from
                             Separate Sanitary Sewers

             Discharges of raw or diluted sewage from separate sanitary
        sewers before treatment can cause significant public health and
        environmental problems.   The exposure of the public to these
        discharges and the potential health and environmental impacts are
        the primary reasons EPA is developing this  additional guidance on
        these discharges.   This document provides a method of setting
        priorities for regulatory response,  and serves as a supplement to
        the Enforcement Management System guidance  (EMS,  revised February
        27,  1986).   As such,  this document addresses only those
        discharges which are in violation of the Clean Water Act.   As a
        general rule, the discharges covered by this guidance constitute
        a subset of all discharges from separate sanitary sewer systems.

        Legal Status

             In the  context of this document, a  "discharge from a
        separate sanitary sewer system" (or "discharge")  is defined as
        any wastewater (including that combined with rainfall induced
        infiltration/inflow)  which is discharged from a separate sanitary
        sewer that reaches waters of the United States prior to treatment
        at a wastewater treatment plant.  Some permits have specific
        requirements for these discharges,  others have specific
        prohibitions under most circumstances,  and  still other permits
        are silent on the status of these discharges.

             The legal status of any of these discharges is specifically
        related to the permit language and the circumstances under which
        the discharge occurs.   Many permits authorize these discharges
        when there are no feasible alternatives,  such as when there are
        circumstances beyond the control of the municipality (similar to
        the concepts in the bypass regulation at 40 CFR Part 122.41 (m)).
        Other permits allow these discharges when specific requirements
        are met,  such as effluent limitations and monitoring/reporting.
             Most permits require that any non-compliance including
        overflows be reported at the end of each month with the discharge
        monitoring report (DMR)  submittal.   As a minimum, permits
        generally require that overflow summaries include the date, time,
        duration,  location,  estimated volume, cause,  as well as any
        observed environmental impacts, and what actions were taken or
        are being taken to address the overflow.  Most permits also
        require that any non-compliance including overflows which may
        endanger health or the environment be reported within 24 hours,
        and in writing within five days.  Examples  of overflows which may
        endanger health or the environment include  major line breaks,
        overflow events which result in fish kills  or other significant
        harm,  and overflow events which occur in environmentally
        sensitive areas.
A-18

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                                                                  Appendix A
    For a person to be in violation of the Clean Water Act:
1) a person must own, operate, or have substantial control over
the conveyance from which the discharge of pollutants occurs,
2) the discharge must be prohibited by a permit, be a violation
of the permit language, or not be authorized by a permit, and 3)
the discharge must reach waters of the United States.  In
addition, discharges that do not reach waters of the United
States may nevertheless be in violation of Clean Water Act permit
requirements, such as those requiring proper operation and
maintenance  (O&M) ,  or may be in violation of state law.

Statement  of Principles

     The following six principles should be considered as EPA
Regions and States set priorities for addressing violating
discharges from separate sanitary sewers:

1.  All discharges (wet weather or dry weather) which cause or
contribute significantly to water quality or public health
problems (such as a discharge to a public drinking water supply)
should be addressed as soon as physically and financially
possible.  Other discharges may, if appropriate, be addressed in
the context of watershed/basin plans (in conjunction with state
or federal NPDES authorities).

2.  Discharges which occur in high public use or public access
areas and thus expose the public to discharges of raw sewage
(i.e., discharges which occur in residential or business areas,
near or within parks or recreation areas, etc.) should be
addressed as soon as physically and financially possible.

3.  Dry weather discharges should be addressed as soon as
physically and financially possible.

4.  Discharges due to inadequate operation and routine
maintenance should be addressed as soon as possible. (Physical
and financial considerations should be taken into account only in
cases where overflow remedies are capital intensive.)

5.  Discharges which could be addressed through a comprehensive
preventive maintenance program or with minor capital investment
should be addressed as soon as physically and financially
possible.

6.  With respect to principles 1 through 5 above, schedules of
compliance which require significant capital investments should
take into account the financial capabilities of the specific
                                                                       A-19

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Report to Congress on the Impacts and Control ofCSOs and SSOs
        municipality, as well as any procedures required by state and
        local law for publicly owned facilities in planning, design, bid,
        award, and construction.   (See later sections on Schedules).
        Causes  of Sanitary Sewer Discharges

              Discharges  from  separate sanitary sewers can be caused by a
        variety of factors including, but not  limited to:

        1.    Inadequate  O&M of the collection system.  For example,
        failure to routinely clean  out pipes,  failure to properly  seal  or
        maintain manholes, failure  to have regular maintenance of
        deteriorating sewer lines,  failure to  remedy  poor  construction,
        failure to design and  implement a long term replacement or
        rehabilitation program for  an aging system, failure  to deal
        expeditiously with line blockages, or  failure to maintain  pump
        stations  (including back-up power).

        2.    Inadequate  capacity of the  sewer system  so that systems
        which experience increases  in flow during storm events are unable
        to convey the sewage to the wastewater treatment plant.  For
        example, allowing new  development without modeling to determine
        the impact on downstream pipe capacity, insufficient allowance
        for extraneous flows in initial pipe design (e.g.  unapproved
        connection of area drains,  roof leaders, foundation  drains), or
        overly optimistic Infiltration/Inflow  reduction calculations.

        3.    Insufficient capacity at the wastewater  treatment plant so
        that discharges  from the collection system must occur on a
        regular basis to limit flows  to the treatment plant.  For
        example, basic plant designs which do  not allow sufficient design
        capacity for storm flows.

        4.   Vandalism and/or  facility or pipeline failures  which  occur
        independent of adequate O&M practices.

        Applicable Guidance

             For many years, EPA and  the States have  been  working  with
        municipalities to prevent discharges from separate sanitary  sewer
        systems.  The preferred method has been to use the general policy
        on responding to all violations of the Clean  Water Act which is
        contained in the EMS guidance.  Factors which are  considered are
        the frequency, magnitude, and duration of the violations,  the
        environmental/public health impacts, and the  culpability of  the
        violator.  This guidance sets up a series of  guiding principles
        for responding to separate  sanitary sewer discharge  violations,
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                                                                  Appendix A
and it supplements the current EMS.

     Every EPA Region and State uses some form of this general
enforcement response guidance as appropriate to the individual
state processes and authorities.  Under the guidance, various EPA
Regions and States have taken a large number of formal
enforcement actions over the past several years to address
sanitary sewer discharge problems across the country.  Responses
have included administrative orders and/or civil judicial actions
against larger municipalities to address sanitary sewer discharge
problems, resulting in substantial injunctive relief in some
cases.

     As a result of EPA Region and State enforcement efforts, a
number of municipalities have invested substantial resources in
diagnostic evaluations and designing, staffing, and implementing
O&M plans.  Other municipalities have undertaken major
rehabilitation efforts and/or new construction to prevent
sanitary sewer discharges.

Priorities  for Response

     There are approximately 18,500 municipal separate sanitary
sewage collection systems (serving a population of 135 million),
all of which can, under certain circumstances, experience
discharges.   Given this fact, the Agency has developed a list of
priorities in dealing with the broad spectrum of separate
sanitary sewer discharges to ensure that the finite enforcement
resources of EPA and the States are used in ways that result in
maximum environmental and public health benefit.  However, these
priorities should be altered in a specific situation by the
degree of health or environmental risks presented by the
condition(s).

     In the absence of site-specific information,  all separate
sanitary sewer discharges should be considered high risk because
such discharges of raw sewage may present a serious public health
and/or environmental threat.  Accordingly, first priority should
be given within categories  (such as dry weather discharges and
wet weather discharges) to those discharges which can be most
quickly addressed.  The priority scheme listed below takes this
into account by first ensuring that municipalities are taking all
necessary steps to properly operate and maintain their sewerage
systems.  Corrective action for basic O&M is typically
accomplished in a short time, and can yield significant public
health and environmental results.

     Risk again becomes a determinant factor when conditions
                                                                       A-21

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Report to Congress on the Impacts and Control ofCSOs and SSOs
       warrant long term corrective action.  The goal here  should be  to
       ensure that capital intensive, lengthy compliance projects are
       prioritized to derive maximum health and environmental  gains.

            The priorities for correcting separate  sanitary sewer
       discharges are typically as follows:

       1)  Dry weather, O&M related:  examples include  lift stations  or
       pumps that are not coordinated, a treatment  plant
       that is not adjusted according to the influent flow,  poor
       communication between field crews and management,
       infiltration/inflow, and/or pretreatment problems.

       2)  Dry weather, preventive maintenance related: examples  include
       pumps that fail due to poor maintenance, improperly  calibrated
       flow meters and remote monitoring equipment,  insufficient
       maintenance staff, deteriorated pipes, and/or sewers that  are  not
       cleaned regularly.

       3)  Dry weather, capacity related:  examples include an
       insufficient number or undersized pumps or lift  stations,
       undersized pipes, and/or insufficient plant  capacity.

       4)  Wet weather, O&M related:  examples include  excessive  inflow
       and/or infiltration  (such as from improperly sealed  manhole
       covers), inadequate pretreatment program  (i.e. excessive
       industrial connections without regard to line capacity),
       uncoordinated pump operations, treatment plant operation that  is
       not adjusted according to the influent flow,  poor coordination
       between field crews and management, illegal  connections, and/or
       no coordination between weather forecast authorities and sewer
       system management.

       5)  Wet weather, preventive maintenance related:  examples
       include poor pump maintenance leading to failure, improperly
       calibrated flow meters and remote monitoring equipment,
       insufficient maintenance staff, and/or sewers that are  not
       cleaned regularly.

       6)  Wet weather, O&M minor capital improvement related:  examples
       include the upgrading of monitoring equipment, pumps, or computer
       programs, and/or repair or replacement of broken manholes  or
       collapsed pipes.

       7)  Wet weather capacity, quick solution related:  examples
       include a known collection system segment that is a  "bottleneck",
       pumps beyond repair in need of replacement,  and/or need for
       additional crews or technical staff.
A-22

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                                                                  Appendix A
                                  7

8)  Wet weather, capacity, health impact related requiring long
term corrective action:  examples include frequent discharges to
public recreational areas, shellfish beds, and/or poor
pretreatment where the total flow is large.

9)  Wet weather, capacity, sensitive area related requiring long
term corrective action:  examples include discharges to
ecologically and environmentally sensitive areas, as defined by
State or Federal government.

Selecting  A Response

     The appropriate regulatory response and permittee response
for separate sanitary sewer discharges will depend on the
specifics of each case.  The regulatory response can be informal,
formal, or some combination thereof.  Typical regulatory
responses include a phone call, Letter of Violation (LOV),
Section 308 Information Request, Administrative Order (AO),
Administrative Penalty Order (APO),  and/or judicial action.   The
permittee response can range from providing any required
information to low cost,  non-capital or low capital improvements
to more capital intensive discharge control plans.

     The attached chart lists some categories of separate
sanitary sewer noncompliance along with the range of response for
each instance.  The chart is intended as a guide.  The responses
listed on the chart are not to be considered mandatory responses
in any given situation.  EPA and the States should use the full
range of regulatory response options (informal, formal,  or some
combination thereof)  to ensure that the appropriate response or
remedy is undertaken by the permittee or municipality.  All
regulatory responses should be in accordance with the concept of
the EMS regarding orderly escalation of enforcement action.

Developing Compliance Schedules

     A compliance schedule should allow adequate time for all
phases of a sanitary sewer discharge control program,  including
development of an O&M plan, diagnostic evaluation of the
collector system, construction, and enhanced O&M.
Municipalities should be given a reasonable length of time to
develop schedules so they can realistically assess their
compliance needs, examine their financing alternatives,  and work
out reasonable schedules for achieving compliance.  Nevertheless,
timelines for schedules should be as short as physically and
financially possible.

Short  Term Schedules
                                                                       A-23

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Report to Congress on the Impacts and Control ofCSOs and SSOs
            In general,  short term schedules would be appropriate for
       sanitary sewer discharges involving O&M problems,  or where only
       minor capital expenses are needed to correct the problem.   The
       schedule should have interim dates and a final compliance date
       incorporated in the administrative order or enforcement
       mechanism.

       Comprehensive Discharge Control  Schedules

            Comprehensive discharge control schedules should be used
       where specific measures must be taken to correct the discharges,
       and the measures are complicated,  costly,  or require a
       significant period of time to implement.  If appropriate,  these
       schedules should include the use of temporary measures to address
       high impact problems,  especially where a long term project is
       required to correct the sanitary sewer discharge violation.

            When working with municipalities to develop comprehensive
       schedules,  EPA Regions and States should be sensitive to their
       special problems and needs,  including consideration of a
       municipality's financial picture.   Factors that should be
       considered are the municipality's current bond rating, the amount
       of outstanding indebtedness,  population and income information,
       grant eligibility and past grant experience, the presence or
       absence of user charges,  and whether increased user charges would
       be an effective fund-raising mechanism,  and a comparison of user
       charges with other municipalities of similar size and population.

            Physical capability should be considered when schedules are
       developed.   Schedules should include interim milestones and
       intermediate relief based on sound construction techniques and
       scheduling such as critical path method.  Compliance schedules
       should be based on current sewer system physical inspection data
       adequate to design sanitary sewer discharge control facilities.
       Schedules should not normally require extraordinary measures such
       as overtime,  short bidding times,  or other accelerated building
       techniques.  Where possible,  schedule development should be
       completed according to normal municipal government contracting
       requirements.

            Financial capability should also be considered in schedule
       development,  including fiscally sound municipal financing
       techniques such as issuing revenue bonds,  staging bond issuance,
       sequencing project starts,  sensitivity to rate increase
       percentages over time.
A-24

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                                                                Appendix A
Note: The intent of this guidance is to aid the Regions and
States in setting priorities for enforcement actions based on
limited resources and the need to provide a consistent level of
response to violations.  This does not represent final Agency
action, but is intended solely as guidance.  This guidance is not
intended for use in pleading, or at hearing or trial.  It does
not create any rights, duties, obligations, or defenses, implied
or otherwise, in any third parties.  This guidance supplements
the Agency's Enforcement Management System Guide (revised
February 27, 1986).
                                                                     A-25

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 Report to Congress on the Impacts and Control ofCSOs and SSOs
                                            ENFORCEMENT RESPONSE GUIDE
                                   DISCHARGES FROM SEPARATE SANITARY SEWERS
              NONCOMPLIANCE

              Discharge without a
              permit or in violation
              of general prohibition

              Discharge without a permit
              or in violation of general
              prohibition

              Discharge without a permit
              or in violation of general
              prohibition

              Discharge without a permit
              or in violation of general
              prohibition

              Discharge without a permit
              or in violation of general
              prohibition

              Discharge without a permit
              or in violation of general
              prohibition

              Discharge without a permit
              or in violation of general
              prohibition

              Discharge without a permit
              or in violation of general
              prohibition
             Discharge without a permit
             or in violation of general
             prohibition
             Discharge without a permit
             or in violation of general
             prohibition
  CIRCUMSTANCES

Isolated & infrequent,
dry weather O&M
 related

Isolated & infrequent,
dry weather capacity
related

Isolated & infrequent,
wet weather O&M
related

Isolated & infrequent,
wet weather, quick and
easy solution

Isolated & infrequent, wet
weather capacity related,
health and/or sensitive areas

Isolated & infrequent, wet
weather capacity related,
non-health, non-sensitive areas

Cause unknown
Permittee does not respond
to letters, does not follow
through on verbal or written
agreement

Frequent, does not signifi-
cantly affect water quality,
no potential public health
impact

Frequent, cause or contribute
significantly to WQ problems,
or occur in high public use and
public access areas, or other-
wise affect  public health
  RANGE OF RESPONSE

Phone call, LOV,
308 request
308 request, AO,
APO, Judicial action
Phone call, LOV,
308 request
LOV, 308 request
LOV, 308 request, AO,
APO
Phone call, LOV, 308
request
Phone call, LOV, 308
request
AO, APO, judicial
action
LOV, 308 request,
AO, APO
AO, APO, judicial
action
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                                                                                             Appendix A
                                             - 2 -
                             ENFORCEMENT RESPONSE GUIDE
                    DISCHARGES FROM SEPARATE SANITARY SEWERS
NONCOMPLIANCE
 CIRCUMSTANCES
 RANGE OF RESPONSE
Missed interim date in CDCP
Will not cause late final date
or other interim dates
LOV
Missed interim date in CDCP
Missed final date in CDCP
Missed final date in CDCP
Failure to report overflows
(as specified in permit)

Failure to report overflows
(as specified in permit)

Failure to report overflows
(as specified in permit)
Failure to report permit
requirements
Will result in other missed
dates, no good and valid cause

Violation due to force
majeure
Failure or refusal to comply
without good and valid
cause

Isolated and infrequent,
health related

Isolated and infrequent, water
quality and environment related

Permittee does not respond to
letters, does not follow through
on verbal or written agreement,
or frequent violation

Any  instance
LOV, AO, APO,
judicial action

Contact permittee and
require documentation of
good or valid cause

AO, APO or judicial
action
Phone call, LOV, AO, APO
Phone call, LOV, AO, APO
AO, APO, judicial action,
request for criminal
investigation
Phone, LOV, AO, APO
CDCP=Comprehensive Discharge Control Plan
                                                                                                    A-27

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       Appendix  B
Human Health Expert and Stakeholder
         Meeting Summaries
       B.1 Summary of the August 14-15,2002,
          Experts Workshop on Public
          Health Impacts of Sewer Overflows
          (Abstract and Background)

       B.2 Stakeholder Meeting Summary,
          Washington, D.C.

       B.3 Stakeholder Meeting Summary,
          Huntington Beach,CA

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                                                                           Appendix B
B.1 Summary of the August 14-15, 2002, Experts Workshop on Public Health Impacts of Sewer Overflows (Abstract
  and Background)
                     United States            Off ice of Wastewater Management      EPA 833-R-02-002
                     Environmental Protection       Washington, D.C. 20460           November 2002
                     Agency               www.epa.gov/npdes
                     Summary of the August 14- 15, 2002,
                     Experts Workshop on Public Health
                     Impacts of Sewer Overflows
                                                                                B-1

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Report to Congress on the Impacts and Control ofCSOs and SSOs
      Summary of the August 14 - 15, 2002, Experts Workshop on Public
                        Health Impacts of Sewer Overflows
                                     Table of Contents
     Abstract   1
     Background 1
     Rationale for the Workshop 1
     Opening Remarks    3
     Review of Goals and Agenda 3
     Overview of the 2001 and 2003 Reports to Congress  5
     The Public Health Chapter of the 2003 CSO/SSO Report to Congress:
     Questions and Proposed Methods 8
     Discussion Session 1: Characterizing Pathogens and Pollutants  13
     Discussion Session 2: Pathways of Exposure 22
     Discussion Session 3: Open Discussion Session  25
     Welcome and Structure of Day Two   26
     Breakout Session A:  Significance of the CSO and SSO Problem   26
     Breakout Session B: Options for the Current Study  28
     General Discussion 30
     Final Comments and Next Steps  31

     Appendices
           Appendix A: Attendee List
           Appendix B: Agenda
           Appendix C: Clarifying Questions from Observers
           Appendix D: The Public Involvement Process for the 2001 and 2003 Reports to Congress
B-2

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                                                                                         Appendix B
Abstract

In embarking upon the task of assessing the human health impact portion of Congress' request for
a report on the impacts and control of sewer overflows in the United States, initial research
revealed that relatively little data were available that linked waterborne illness or other exposures
to combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs). In response to these
challenges, EPA held a Public Health Impacts Experts Workshop on August 14 and 15, 2002. A
group of nine external and EPA experts in public health, epidemiology, and wastewater treatment
attended the workshop. Observers included representatives of stakeholder groups and EPA
personnel. This workshop did not constitute an advisory committee under the Federal Advisory
Committees Act (FACA), but rather solicited individual opinions and provided a forum for
information exchange related to this Report to Congress.
Background

In the Consolidated Appropriations Act for fiscal year 2001, also known as the "Wet Weather
Water Quality Act of 2000"or "2000 Amendments to the Clean Water Act" (CWA), Congress
made several changes to the CWA regarding combined sewer overflows (CSOs) (P.L. 106-554).
Among these changes was a requirement for the U.S. Environmental Protection Agency (EPA) to
provide two Reports to Congress. The first report, Implementation and Enforcement of the
Combined Sewer Overflow Control Policy (EPA 833-R-01-003), was delivered on January 29,
2002. The second report, which is due to Congress on December 15, 2003, is to investigate:

       •      The extent of the human health and environmental impacts caused by municipal
             CSOs and sanitary sewer overflows (SSOs), including the location of discharges
             causing such impacts, the volume of pollutants discharged, and the constituents
             discharged;
             The resources spent by municipalities to address these impacts; and
       •      An evaluation of the technologies used by municipalities to address these impacts.
Rationale for the Public Health Experts Workshop

In embarking upon the task of assessing the human health impact portion of Congress' request,
initial research revealed that relatively little data were available that linked waterborne illness or
other exposures to CSOs and SSOs. Factors complicating collection of information and data in
this arena include public perception of reporting overflows in recreational areas; difficulty in
contributing CSO/SSO loadings of pathogens in our nation's waters from other background
sources; multiple possible pathways for fecal-related illness; underreporting of certain types of
waterborne illnesses; and a lack of comprehensive local or national tracking for such illnesses.
                                                                                               B-3

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Report to Congress on the Impacts and Control ofCSOs and SSOs
       In response to these challenges, EPA held a Public Health Impacts Experts Workshop on August
       14 and 15, 2002. The purpose of this workshop was to enlist technical and subject matter experts
       from federal agencies, local health departments, and academia to ensure that EPA frames the
       study questions correctly, benefits from all pertinent data, and develops a methodology that bears
       out actual experiences. A group of recognized experts in the field of public health and interested
       observers met with the goals and objectives of:

             •      Fully elucidating the issues and the magnitude of those issues associated with
                    health impacts of CSOs and SSOs;
             •      Reviewing and supplementing data and information sources identified to date; and
                    Critiquing the proposed methodology for gathering and analyzing the public health
                    information and data for the 2003 report.

       The experts were asked to give individual opinions relating to the study questions. No consensus
       opinions or policy recommendations were solicited.

       This Public Health Experts workshop is part of a larger public involvement process for the 2001
       and 2003 CSO/SSO Reports to  Congress.  It occurs between two broader stakeholders' meetings
       (June 2001 and summer 2003, anticipated),  at  which a broad range of stakeholders discuss and
       provide input on draft report findings and recommendations, experiences in CSO control, and
       future policy and program directions. For a more detailed discussion of the overall stakeholder
       approach, please refer to Appendix D of this summary.
B-4

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                                                                                              Appendix B
B.2 Stakeholder Meeting Summary, Washington, D.C.

           2003 Report to Congress on the Impacts and Control of Combined Sewer
                             Overflows and Sanitary Sewer Overflows

                                     Stakeholder Meeting Summary
                                           Washington, D.C.

       On June 23 and 24, 2003, the U.S. Environmental Protection Agency held a meeting in Washington,
       D.C., to discuss the upcoming Report to Congress on the impacts and control of CSOs and SSOs. The
       meeting held at the Renaissance Hotel, 999 9th St. NW, provided an opportunity for EPA to present the
       results of the data collection, request verification of information and data sources, and solicit feedback on
       preliminary findings and interpretation.

       The main goals of the meeting were to:

             •   Discuss the data, report methodology, and analysis of the 2003 Report to Congress;
             •   Discuss implications of the major analyses in the report; and
             •   Discuss participants' experiences in controlling impacts from CSOs and SSOs.

       The summary below describes the presentations given to outline the contents of the report and recounts
       the resulting discussions. The summary is organized into the following major sections, which correspond
       to the meeting agenda:

                 Opening Remarks
                 Background on the Report
                 Characterization of CSOs and SSOs
                 Environmental Impacts of CSOs and SSOs
                 Closing Remarks, Day One
                 Recap of Day One and Agenda Review for Day Two
                 Welcome and Opening Remarks, Day Two
                 Human Health Impacts of CSOs and SSOs
                 Technologies for CSO and SSO Control
                 Resources Spent Addressing CSOs and SSOs
                 Common Themes Heard During the Meeting
                 Closing Remarks, Day Two


       Opening Remarks
       James A. Hanlon - Director, Office of Wastewater Management, EPA

       Mr. Hanlon opened the meeting by welcoming the participants to Washington, D.C., and providing
       an overview of the 2000 Wet Weather Water  Quality Act, the 2001 CSO Report to Congress, and its
       associated stakeholder meeting. Mr. Hanlon reminded the participants that this Report was not intended
       to set policy, instead it was intended to present data and cite additional data sources that Congress
       could look to when entering into policy discussions. He mentioned that responding to the charge from
       Congress had proven difficult, specifically in identifying loadings and in correlating discharges with
       environmental and human health impacts.
                                                                                                     B-5

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Report to Congress on the Impacts and Control ofCSOs and SSOs
       Background on the 2003 Report to Congress
       Kevin DeBell - Office of Wastewater Management, EPA

       Mr. DeBell presented the background to the 2003 Report to Congress. He started by mentioning
       the near-term EPA policies that directly led to the request for the 2003 Report to Congress.  First, he
       described the 1994 National CSO Control Policy which formalized EPA's management expectations for
       CSS communities. Next, a summary of the 2001 Report to Congress - Implementation and Enforcement of
       the Combined Sewer Overflow Control Policy was presented. This report acted as a program evaluation in
       which success of CSO Control Policy implementation was assessed; one useful product of the 2001 Report
       is the CSO database, which includes information on all CSO permits.  Mr. DeBell then mentioned the
       draft SSO Notice of Proposed Rulemaking, and the 2000 Wet Weather Water Quality Act, which required
       the 2003 Report. The statutory requirements for the 2003 Report are stated below:

              The Administrator of the Environmental Protection Agency shall transmit to Congress a report
              summarizing:
                   a.  the extent of human health and  environmental impacts caused by municipal combined
                      sewer overflows and sanitary sewer overflows, including the location of discharges causing
                      such impacts, the volume of pollutants discharged, and the constituents discharged;
                   b.  resources spent by municipalities to address these impacts; and
                   c.   an evaluation of the technologies used by municipalities to address these impacts.

       Mr. DeBell next explained that EPA is not required to have a public review of Reports to