Combined Sewer Overflows
Publications

• Combined Sewer Overflow (CSO) Control Policy

National policy establishes a consistent national approach for controlling discharges from CSOs to the nation's waters through the National Pollutant Discharge Elimination System (NPDES) permit program.
Document Type: Policy and Guidance Documents
Date Published: 04/19/1994
• National framework. Provides guidance to municipalities and NPDES and WQS authorities. (PDF) (1,567KB)



• Combined Sewer Overflow Management Fact Sheet: Pollution Prevention (PDF) (82KB)

(EPA 832-F-99-038)
Document Type: Factsheets and Outreach Materials
Date Published: 09/01/1999



• Combined Sewer Overflow Management Fact Sheet: Sewer Separation (PDF) (59KB)

(EPA 832-F-99-041)
Document Type: Factsheets and Outreach Materials
Date Published: 09/01/1999



• Combined Sewer Overflow Operation and Management Fact Sheet: Proper Operation and Maintenance (PDF) (87KB)

Spanish version is also available. EPA 832-F-99-039
Document Type: Factsheets and Outreach Materials
Date Published: 09/01/1999


• Spanish Version (PDF) (1,255KB)



• Combined Sewer Overflow Technology Fact Sheet: Alternative Disinfectants for Treating CSOs (PDF) (123KB)

EPA 832-F-99-033
Document Type:
Date Published: 09/01/1999



• Combined Sewer Overflow Technology Fact Sheet: Chlorine Disinfection (PDF) (10 pp, 1,875KB)

Fact sheet that discusses the use of chlorine to disinfect discharged waters from combined sewer overflows. Includes information on advantages and disadvantages of this process, as well as applicability, performance, design criteria, operation and maintenance, and costs (EPA 832-F-99-034).
Document Type:
Date Published: 09/01/1999



• Combined Sewer Overflow Technology Fact Sheet: Floatables Control (PDF) (124KB)

EPA 832-F99-008
Document Type:
Date Published: 09/01/1999



• Combined Sewer Overflow Technology Fact Sheet: Inflow Reduction (PDF) (72KB)

Describes inflow reduction, a practice designed to minimize the volume of storm water runoff that enters a combined sewer system (CSS) (EPA 832-F-99-035).
Document Type:
Date Published: 09/01/1999



• Combined Sewer Overflow Technology Fact Sheet: Maximization of In-line Storage (PDF) (100KB)

EPA 832-F-99-036
Document Type:
Date Published: 09/01/1999



• Combined Sewer Overflow Technology Fact Sheet: Netting Systems for Floatables Control (PDF) (295KB)

Describes netting systems for controlling discharges of floatable materials from combined sewer overflows (CSOs). Control of floatable material is an important component of EPA's CSO Control Policy (EPA 832-F-99-037).
Document Type:
Date Published: 09/01/1999



• Combined Sewer Overflow Technology Fact Sheet: Retention Basins (PDF) (167KB)

EPA 832-F-99-042
Document Type:
Date Published: 09/01/1999



• Combined Sewer Overflow Technology Fact Sheet: Screens (PDF) (97KB)

EPA 832-F-99-040
Document Type:
Date Published: 09/01/1999



• Combined Sewer Overflows Guidance for Financial Capability Assessment and Schedule Development (Final) (PDF) (2,385KB)

Discusses how community's financial capability and other factors identified in the CSO Policy may be used to negotiate reasonable compliance schedules for implementation of CSO controls. It presents a two-phase process for assessing financial capability, based on EPA's experience in the Construction Grants, State Revolving Fund, enforcement, and water quality standards programs. It stresses the need for flexibility and evaluation of site-specific factors in the development of implementation schedules for CSO controls (EPA 832-B-97-004).
Document Type: Policy and Guidance Documents
Date Published: 02/01/1997



• Combined Sewer Overflows Guidance For Funding Options (PDF) (2,995KB)

Plain-English description of a broad spectrum of options that may be available to fund the capital, debt service, and operational costs of CSO controls. Describes the benefits and limitations of various options (EPA 832-B-95-007).
Document Type: Policy and Guidance Documents
Date Published: 08/01/1995



• Combined Sewer Overflows Guidance For Long-Term Control Plan (PDF) (14,703KB)

Describes how municipalities can develop comprehensive long-term control plans that recognize the site-specific nature of CSOs and their impacts on receiving water bodies. The document describes how to develop a long-term control plan that includes technology-based and water quality-based control measures that are technically feasible, affordable, and consistent with the CSO Control Policy (EPA 832-B-95-002).
Document Type: Policy and Guidance Documents
Date Published: 09/01/1995



• Combined Sewer Overflows Guidance For Monitoring and Modeling

Provides guidelines for the use of monitoring and modeling in the development and implementation of a CSO control program. The document provides information on characterizing a combined sewer system, assessing the impact of wet weather on CSO discharges, and assessing the impact of CSOs on receiving water bodies. It focuses on the characterization process described in the CSO Policy and refers to other literature for more in-depth explanations of specific techniques (EPA 832-B-99-002).
Document Type: Policy and Guidance Documents
Date Published: 01/01/1999
• Cover (PDF) (226KB)


• Memorandum, Table of Contents, Acronyms (PDF) (54KB)


• Chapter 1: Introduction (PDF) (40KB)


• Chapter 2: Introduction to Monitoring and Modeling (PDF) (70KB)


• Chapter 3: Initial System Characterization (PDF) (132KB)


• Chapter 4: Monitoring and Modeling Plan (PDF) (326KB)


• Chapter 5: CSS Monitoring (PDF) (667KB)


• Chapter 6: Receiving Water Monitoring (PDF) (68KB)


• Chapter 7: CSS Modeling (PDF) (728KB)


• Chapter 8: Receiving Water Modeling (PDF) (164KB)


• Chapter 9: Assessing Receiving Water Impacts and Attainment of WQS (PDF) (1,311KB)


• References (PDF) (58KB)


• Appendices (PDF) (136KB)


• Entire Document (PDF) (3,960KB)



• Combined Sewer Overflows Guidance for Nine Minimum Control Measures (PDF) (4,157KB)

Provides information on nine minimum technology-based controls that communities are expected to use to address CSO problems, without extensive engineering studies or significant construction costs, before long-term measures are taken. Communities are expected to implement the nine minimum controls and submit documentation no later than January 1, 1997 (EPA 832-B-95-003).
Document Type: Policy and Guidance Documents
Date Published: 05/01/1995



• Combined Sewer Overflows Guidance For Permit Writers

Intended primarily for NPDES permitting authorities and permit writers, describes how to develop and issue NPDES permits with CSO conditions that reflect the CSO Policy. It provides example permit language and stresses the need for coordination between permittees, permit writers, water quality standards authorities, enforcement authorities, and the public (EPA 832-B-95-008).
Document Type: Policy and Guidance Documents
Date Published: 08/01/1995
• Chapter 1: Introduction (PDF) (2,122 KB)


• Chapter 2: Introduction to CSO Permitting (PDF) (2,124KB)


• Chapter 3: Phase 1 Permitting (3.1 - 3.5) (PDF) (3,582KB)


• Chapter 3: Phase 1 Permitting (3.5 - 3.10) (PDF) (3,114KB)


• Chapter 4: Phase II Permitting (4.1 - 4.5) (PDF) (3,133KB)


• Chapter 4: Phase II Permitting (4.5 - 4.7) (PDF) (2,935KB)


• Chapter 4: Phase II Permitting (4.8 - 4.9) (PDF) (2,571KB)


• Chapter 5: Post Phase II Permitting (PDF) (739KB)


• Appendix A: Example CSO Permit Conditions (PDF) (2,840KB)


• Appendix B: Development and Review of Monitoring and Modeling Plan (PDF) (1,432KB)


• Appendix C (PDF) (1,141KB)


• Appendix D (PDF) (1,363KB)


• Glossary and References (PDF) (552KB)



• Combined Sewer Overflows Screening and Ranking Guidance

An informal tool to help permitting authorities establish CSO permitting priorities. It may also help permittees rank their CSOs in order to best allocate their limited resources (EPA 832-B-95-004).
Document Type: Policy and Guidance Documents
Date Published: 08/01/1995
• Cover and Table of Contents (PDF) (196KB)


• Chapter 1: Introduction (PDF) (657KB)


• Chapter 2: The Screening Process (PDF) (253KB)


• Chapter 3 (PDF) (640KB)


• Appendix A (PDF) (250KB)


• References (PDF) (132KB)



• Combined Sewer Overflows: Where are we four years after adoption of the CSO Policy? (PDF) (64KB)

On May 18, 1998, Bob Perciasepe (AA-Water) released a progress report on implementation of the CSO Policy.
Document Type: Program Status Reports
Date Published: 05/18/1998



• Fact Sheet: Guidance on Coordinating Combined Sewer Overflow (CSO) Long-Term Planning with Water Quality Standards Reviews (PDF) (85KB)

Addresses impediments to implementing the water quality-based provisions in the CSO Policy, and actions that State and Interstate Water Pollution Control Directors and CSO communities should take to overcome these impediments. This guidance describes a process for integrating LTCP development and implementation with the water quality standards review. This process is the essence of EPA's commitment to facilitating the review and revision, as appropriate, of water quality standards for waters affected by CSOs.
Document Type: Factsheets and Outreach Materials
Date Published: 07/31/2001



• Guidance: Coordinating Combined Sewer Overflow (CSO) Long-Term Planning with Water Quality Standards Reviews (PDF) (498KB)

Addresses impediments to implementing the water quality-based provisions in the CSO Policy, and actions that State and Interstate Water Pollution Control Directors and CSO communities should take to overcome these impediments. This guidance describes a process for integrating LTCP development and implementation with the water quality standards review. This process is the essence of EPA's commitment to facilitating the review and revision, as appropriate, of water quality standards for waters affected by CSOs (EPA-833-R-01-002).
Document Type: Policy and Guidance Documents
Date Published: 07/31/2001



• How Do I Get Stormwater Permit Coverage for My Construction Site? A Construction Site Operator’s Guide to EPA’s Stormwater Permit Program (Revised)

This brochure provides construction companies with a brief overview of EPA's Construction General Permit (CGP) and its requirements. It was sent to construction companies to inform them of the need to obtain permit coverage for sites disturbing one acre or more. The brochure contains a summary of the major provisions of the CGP, including areas of coverage, using EPA's new electronic notice of intent system for obtaining permit coverage, developing a stormwater pollution prevention plan, and more (EPA 833-F-04-002). Also available in Spanish (EPA 833-F-04-005). Revised: September 2007. Printed copies are no longer available from EPA.
Document Type: Factsheets and Outreach Materials
Date Published: 02/01/2004
• EPA Version (PDF) (2 pp, 580KB)


• Spanish Version (PDF) (2 pp, 571KB)


• State Version (PDF) (2 pp, 562KB)


• Spanish-State Version (PDF) (2 pp, 557KB)



• Memorandum from Nancy Stoner and Cynthia Giles: Achieving Water Quality Through Integrated Municipal Stormwater and Wastewater Plans (PDF) (1.06MB)

This memo addresses how EPA will work with States and municipalities to target resources to the most cost-effective approaches while still meeting their Clean Water Act obligations.
Document Type: Policy and Guidance Documents
Date Published: 10/27/2011



• Memorandum: Implementation of the CSO Policy (PDF) (616KB)

On May 19, 1998, Bob Perciasepe (AA-Water) and Steve Herman (AA-Enforcement and Compliance Assurance) issued a joint memorandum to EPA Regional directors and state directors on implementation of the CSO Policy, and recommending stepped-up efforts in certain areas.
Document Type: Policy and Guidance Documents
Date Published: 05/19/1998



• Memorandum: January 1, 1997 Deadline for Nine Minimum Controls in Combined Sewer Overflow Control Policy (PDF) (221KB)

Memorandum to state and Regional Directors emphasizing need for CSO communities to meet deadline for implementation of the nine minimum controls identified in the 1994 CSO Control Policy.
Document Type: Policy and Guidance Documents
Date Published: 11/18/1996



• Memorandum: Water Quality-Based and Technology-Based CSO Requirements (PDF) (270KB)

This memorandum clarifies some questions that have arisen concerning the application of the water quality-based and technology-based requirements of the Clean Water Act to CSOs, particularly where enforcement cases are pending or imminent.
Document Type: Policy and Guidance Documents
Date Published: 07/07/1999



• National Combined Sewer Overflow Control Strategy (PDF) (755KB)

Combined sewer overflow strategy.
Document Type: Policy and Guidance Documents
Date Published: 08/10/1989



• Proposed Peak Wet Weather Policy

The proposed policy describes limited circumstances when certain management techniques may be used by the operator of a municipal wastewater treatment facility to address very high flows that result from storm events. The policy also indicates how the management of peak flows must be documented in National Pollutant Discharge Elimination System (NPDES) permits.
Document Type: Policy and Guidance Documents
Date Published: 12/22/2005
• Federal Register (PDF) (6 pp, 73KB)


• Prepublication (PDF) (8 pp, 126KB)


• Fact Sheet (PDF) (3 pp, 125KB)


• Transcript of Press Release Conference Call (PDF) (14 pp, 122KB)



• Report to Congress on Implementation and Enforcement of the CSO Control Policy

Identifies progress made in implementing and enforcing CSO controls prior to, and as a result of, the 1994 CSO Control Policy. All 32 states (including the District of Columbia) with combined sewer systems have developed CSO strategies, and most have adopted the key provisions of the CSO Control Policy. In spite of the progress that has been made, however, CSOs still present a potentially serious environmental and public health threat in some areas. This report outlines EPA's future plans for reducing these threats. This report was delivered to Congress on Tuesday, January 29, 2002. (EPA 833-R-01-003).
Document Type: Program Status Reports
Date Published: 12/01/2001
• Executive Summary (PDF) (625KB)


• Chapters 1 through 4 (PDF) (1,118KB)


• Chapter 5 (PDF) (893KB)


• Chapters 6 and 7 (PDF) (765KB)


• Appendix A: EPA Memoranda Relating to Implementation of the CSO Policy (PDF) (846KB)


• Appendix A: Consolidated Appropriations Act (PDF) (149KB)


• Appendix B-1: Profiles of State CSO Programs (PDF) (815KB)


• Appendix B-2: Profiles of State CSO Programs (PDF) (941KB)


• Appendix C: CSO Community Case Studies (PDF) (875KB)


• Appendices D through S (PDF) (1,096KB)



• Report to Congress: Combined Sewer Overflows to the Lake Michigan Basin (PDF) (88 pp, 1,800KB)

This EPA Report to Congress provides an assessment of the occurrences of combined sewer overflows from Publicly Owned Treatment Works (POTWs) into the Lake Michigan basin. The Report also provides information about the enforcement of existing regulations concerning discharges and the future steps the EPA plans to take to minimize such overflows.
Document Type: Program Status Reports
Date Published: 09/01/2007



• Report to Congress: Impacts and Control of CSOs and SSOs

This report was delivered to Congress on Thursday, August 26, 2004. The Report presents a comprehensive characterization of CSOs and SSOs, including the extent of environmental and human health impacts caused by CSOs and SSOs, the technologies used by municipalities to address these impacts, and the resources spent by municipalities to control CSO and SSO discharges. The Report finds that the occurrence of CSOs and SSOs is widespread, and that CSOs and SSOs cause or contribute to environmental and human health impacts. Further, the Report finds that there are many existing structural and non-structural technologies that are well-suited for CSO and SSO control (EPA 833-R-04-001).
Document Type: Program Status Reports
Date Published: 08/26/2004
• Fact Sheet (PDF) (15KB)


• Cover and Table of Contents (PDF) (551KB)


• Executive Summary (PDF) (1,700KB)


• Chapter 1: Introduction (PDF) (100KB)


• Chapter 2: Background (PDF) (1,889KB)


• Chapter 3: Methodology (PDF) (157KB)


• Chapter 4: Characterization of CSOs and SSOs (PDF) (2,963KB)


• Chapter 5: Environmental Impacts of CSOs and SSOs (PDF) (432KB)


• Chapter 6: Human Health Impacts of CSOs and SSOs (PDF) (175KB)


• Chapter 7: Federal and State Efforts to Control CSOs and SSOs (PDF) (184KB)


• Chapter 8: Technologies Used to Reduce the Impacts of CSOs and SSOs (PDF) (246KB)


• Chapter 9: Resources Spent to Address the Impacts of CSOs and SSOs (PDF) (124KB)


• Chapter 10: Conclusions and Future Challenges (PDF) (107KB)


• References (PDF) (100KB)


• Appendix A: Statutes, Policies, and Interpretive Memoranda (PDF) (4,135KB)


• Appendix B: Human Health Expert and Stakeholder Meeting Summaries (PDF) (403KB)


• Appendix C: Documentation of State and Municipal Interviews (PDF) (60KB)


• Appendix D: List of Active CSO Permits (PDF) (274KB)


• Appendix E: GPRACSO Model Documentation (PDF) (162KB)


• Appendix F: Analysis of CSO Receiving Waters Using the National Hydrography Dataset (NHD) (PDF) (6,861KB)


• Appendix G: National Estimate of SSO Frequency and Volume (PDF) (144KB)


• Appendix H: Estimation of SSO Impacts in Streams and Rivers (PDF) (62KB)


• Appendix I: Human Health Addendum (PDF) (361KB)


• Appendix J: Estimated Annual Illness from Exposure to CSOs and SSOs at BEACH Survey Beaches (PDF) (183KB)


• Appendix K: Summary of Enforcement Actions (PDF) (708KB)


• Appendix L: Technology Descriptions (PDF) (3,044KB)


• Appendix M: Financial Information (PDF) (78KB)



• Search General Permits

EPA is gathering PDF copies of NPDES general permits and fact sheets for major facilities issued after November 1, 2002. Click here to search and view general permits issued by permit category, state, permit title, or permit number.
Document Type: Example and General Permits
Date Published: 11/01/2002
• Summary of the August 14-15, 2002, Experts Workshop on Public Health Impacts of Sewer Overflows (PDF) (670KB)

In assessing the human health impact from sewer overflows in the US, 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 solicited individual opinions and provided a forum for information exchange related to this Report to Congress.
Document Type: Factsheets and Outreach Materials
Date Published: 11/01/2002



• Summary of The Listening Sessions: Observations & Recommendations for Guidance and Technical Assistance to Facilitate Water Quality And Designated Use Reviews for Waters Impacted by Combined Sewer Overflows (PDF) (66KB)

The Agency held listening sessions in Philadelphia, PA (April 21, 1999), Lowell, MA (May 5-6, 1999), and Chicago, IL (May 13-14, 1999), as well as conducted numerous conference calls to obtain perspectives from a broad range of knowledgeable individuals. The focus of the meetings and conference calls was to obtain participants' views on the impediments to implementing the water quality-based provisions of the CSO Control Policy, and actions that the Agency should take to overcome any identified impediments (EPA-823-R-99-017).
Document Type: Factsheets and Outreach Materials
Date Published: 12/01/1999



• The Long-Term Control Plan-EZ (LTCP-EZ) Template: A Planning Tool for CSO Control in Small Communities

The combined sewer overflow (CSO) Long-Term Control Plan (LTCP) Template for Small Communities (termed the "LTCP-EZ Template") is a planning tool for small communities that must develop an LTCP to address CSOs. The LTCP-EZ Template provides a framework for organization and completion of an LTCP that builds upon existing controls and leads to the elimination or control of CSOs in accordance with the federal Clean Water Act. Use of the LTCP-EZ Template and completion of the forms and schedules associated with the LTCP-EZ Template can produce a Draft LTCP. The LTCP-EZ template is not intended to replace statutory and regulatory requirements applicable to CSOs. Prior coordination with permit writers is essential. EPA is not prescribing the presumption approach over the demonstration approach. The presumption approach is used in the template because it lends itself to a simple model that may be applicable in many small communities. This document includes step-by-step instructions and a detailed template. The template includes two Excel spreadsheets that allow iterative calculations based on user input. One Excel file has embedded calculations and the other Excel file does not.
Document Type: Policy and Guidance Documents
Date Published: 05/01/2007
• LTCP-EZ Template (PDF) (1,111KB)


• Forms that allows iterative calculations based on user input with the calculations embedded (EXCEL) (216KB)


• Forms that does not include embedded calculations (EXCEL) (214KB)



• Wet Weather Water Quality Act of 2000

Charges the Agency with new responsibilities under the CSO program
Document Type: Policy and Guidance Documents
Date Published: 12/15/2000
• Part 1 (PDF) (118KB)


• Part 2 (PDF) (118KB)

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Last updated on January 04, 2012 8:23 AM
URL:http://cfpub.epa.gov/npdes/docs.cfm