Combined Sewer Overflows
Policy and Guidance Documents
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- 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.
- Combined Sewer Overflows Guidance for Financial Capability Assessment and Schedule Development (Final) (PDF)
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).
- Combined Sewer Overflows Guidance For Funding Options (PDF)
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).
- Combined Sewer Overflows Guidance For Long-Term Control Plan (PDF)
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).
- 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).
- Combined Sewer Overflows Guidance for Nine Minimum Control Measures (PDF)
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).
- 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).
- Chapter 1: Introduction (PDF)
- Chapter 2: Introduction to CSO Permitting (PDF)
- Chapter 3: Phase 1 Permitting (3.1 - 3.5) (PDF)
- Chapter 3: Phase 1 Permitting (3.5 - 3.10) (PDF)
- Chapter 4: Phase II Permitting (4.1 - 4.5) (PDF)
- Chapter 4: Phase II Permitting (4.5 - 4.7) (PDF)
- Chapter 4: Phase II Permitting (4.8 - 4.9) (PDF)
- Chapter 5: Post Phase II Permitting (PDF)
- Appendix A: Example CSO Permit Conditions (PDF)
- Appendix B: Development and Review of Monitoring and Modeling Plan (PDF)
- Appendix C (PDF)
- Appendix D (PDF)
- Glossary and References (PDF)
- 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).
- Guidance: Coordinating Combined Sewer Overflow (CSO) Long-Term Planning with Water Quality Standards Reviews (PDF)
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).
- Memorandum from Nancy Stoner and Cynthia Giles: Achieving Water Quality Through Integrated Municipal Stormwater and Wastewater Plans (PDF)
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.
- Memorandum: Implementation of the CSO Policy (PDF)
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.
- Memorandum: January 1, 1997 Deadline for Nine Minimum Controls in Combined Sewer Overflow Control Policy (PDF)
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.
- Memorandum: Water Quality-Based and Technology-Based CSO Requirements (PDF)
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.
- National Combined Sewer Overflow Control Strategy (PDF)
Combined sewer overflow strategy.
- 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.
- 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.
- Wet Weather Water Quality Act of 2000
Charges the Agency with new responsibilities under the CSO program