Reference Library of Water Quality Standards Policy and Guidance Documents

Refer to Water Quality Standards Handbook for comprehensive guidance and context for the documents below.

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This page contains an index of specific EPA documents related to water quality standards, including those referenced in the Water Quality Standards Handbook. You can sort the index alphabetically, by publication date, or by topic.

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[See Water Quality Standards Handbook Appendices ]

Tier 2 Antidegradation Reviews and Significance Thresholds Memo (PDF) (4 pp, 172 K)
Antidegradation Policy Approvals and Endangered Species Act Consultations, Memorandum from Geoffrey Grubbs (PDF) (7 pp, 288 K)
Interpretation of Federal Antidegradation Regulatory Requirement, Memorandum from Tudor Davies (PDF) (6 pp, 457 K)
Antidegradation Policy, Memorandum from William Diamond (PDF) (1 pg, 58 K)
Application of Antidegradation Policy to the Niagara River, Memorandum from Martha Prothro (PDF) (2 pp, 149 K)
EPA Designation of Outstanding National Resource Waters, Memorandum from William Diamond (PDF) (7 pp, 416 K)
Antidegradation Policy, Memorandum from Martha Prothro (PDF) (5 pp, 298 K)
Antidegradation Policy, Memorandum from Patrick Tobin (PDF) (1 pg, 84 K)
Compendium of Department of the Interior Statements on Non-Degradation of Interstate Waters (PDF) (58 pp, 4 MB)
Antidegradation, Wasteloads, and Permits, Memorandum from Edwin Johnson (PDF) (1 pg, 81 K)
Answers to Questions on Nonpoint Sources and WQS (PDF) (1 pg, 70 K)
Determination of "Existing Uses" for Purposes of Water Quality Standards Implementation (PDF) (2 pp, 162 K)
Interpretation of the Term "Existing Uses" Under the Antidegradation Policy (PDF) (1 pg, 55 K)
Downgrading of Water Quality Standards (PDF) (2 pp, 97 K)
Questions and Answers on EPA's Existing Use Policy, Letter to Mr. Derek Smithee, State of Oklahoma Water Resources Board (PDF) (12 pp, 3 MB)
Initial Zones of Dilution for Bacteria in Rivers and Streams, Memorandum from Ephraim King (PDF) (3 pp, 670 K)
EPA Guidance on Application of State Mixing Zone Policies in EPA-issued NPDES Permits, Memorandum from Robert Perciasepe (PDF) (7 pp, 293 K)
Mixing Zones for Water Quality Standards, Memorandum from Richard Stoll (PDF) (2 pp, 271 K)
Decision no. 31 of the General Counsel on Matters of Law Pursuant to 40 CFR Section 125.36(m) (PDF) (5 pp, 383 K)
Mixing Zones, Memorandum from Robert Zenner (PDF) (3 pp, 353 K)
Three-Year Quality Standards Review, Memorandum from Patrick Tobin (PDF) (2 pp, 257 K)
Applicability of the Part 25 "Public Participation" Regulations to the Approval of Variances from Water Quality Standards, Memorandum from Michele Corash (PDF) (5 pp, 254 K)
Checklist For Evaluating State Submission Of Discharger-Specific Water Quality Standards Variances (PDF) (2 pp, 64 K)
Decision no. 44 of the General Counsel on Matters of Law Pursuant to 40 CFR Section 125.35(m) (PDF) (8 pp, 346 K)
Decision no. 58 of the General Counsel on Matters of Law Pursuant to 40 CFR Section 125.36(m) (PDF) (11 pp, 546 K)
Definitions of WQS Terms, Memorandum from Kenneth Mackenthun (PDF) (1 pg, 80 K)
National Assessment of State Variance Procedures: Report (PDF) (44 pp, 3 MB)
Request for Views on Allowable Duration of Water Quality Standards Variances, Memorandum from Catherine Winer (PDF) (4 pp, 456 K)
Variances in Water Quality Standards, Memorandum from Edwin Johnson (PDF) (2 pp, 13 K)
Summary of State Biological Assessment Programs for Streams and Rivers (PDF) (168 pp, 3 MB)
Application of Clean Water Act Section 401 State Water Quality Certification to Federal Energy Regulatory Commission (FERC) Licenses, Letter to the Honorable Lois Cashell, Secretary, Federal Energy Regulatory Commission (PDF) (4 pp, 453 K)
Guidance for the Use of Conditional Approvals for State Water Quality Standards, Memorandum from Martha Prothro (PDF) (4 pp, 655 K)
Arsenic Decision, Memorandum from Robert Perciasepe (PDF) (3 pp, 342 K)
Biological Methods Manual (Biological Field and Laboratory Methods for Measuring the Quality of Surface Waters and Effluents) (PDF) (194 pp, 9 MB)
Guidance on the Use of Criteria Contained in "Quality Criteria For Water" During the Review of State Water Quality Standards Revisions (PDF) (2 pp, 128 K)
Designating Attainable Uses Symposium, 2002 (PDF) (27 pp, 286 K)
Designation of Recreation Uses (PDF) (6 pp, 515 K)
Response to Sierra Club Petition (PDF) (54 pp, 701 K)
Favorable Supreme Court Decision Concerning Interstate Water Pollution, Memorandum from Raymond Ludwiszewski (Arkansas v. Oklahoma) (PDF) (29 pp, 2 MB)
Guidance: Use of Fish and Shellfish Advisories and Classifications in 303(d) and 305(b) Listing Decisions, Letter from Geoffrey Grubbs and Robert Wayland (PDF) (9 pp, 68 K)
Water Quality Standards and Underground Waters, Memorandum from Joan Bernstein (PDF) (4 pp, 433 K)
Revision of Water Quality Standards and Implementation Plans Under [Section] 303 of the Federal Water Pollution Control Act, Memorandum from William Frick (PDF) (8 pp, 709 K)
National Stream Use Policy, Memorandum to Acting Director, Water Planning Division (PDF) (5 pp, 18 K)
Section 401 Certification of Marinas, Memorandum from Catherine Winer (PDF) (5 pp, 518 K)
Modifications to "Interim Guidance on Determination and Use of Water-Effect ratios for Metals" and EPA’s "Recalculation Procedure when Deriving Site-Specific Criteria" (PDF) (21 pp, 191 K)
Office of Water Policy and Technical Guidance on Interpretation and Implementation of Aquatic Life Metals Criteria (PDF) (49 pp, 3 MB)
Bioconfirmation, Letter to Maine Department of Environmental Protection (PDF) (4 pp, 772 K)
Response letter to the Mississippi River Petition, July 29, 2011 (PDF) (7 pp, 2 MB)
Working in Partnership with States to Address Phosphorus and Nitrogen Pollution through Use of a Framework for State Nutrient Reductions (March 2011 EPA Memo) (PDF) (6 pp, 355 K)
Letter to New England Interstate Water Pollution Control Commission, March 1, 2011 (PDF) (4 pp, 834 K)
EPA Response to the Maine Congressional Delegation’s January 21, 2011 Letter (PDF) (9 pp, 870 K)
An Urgent Call to Action: Report of the State-EPA Nutrient Innovations Task Group (August 2009) (PDF) (170 pp, 6 MB)
EPA Needs to Accelerate Adoption of Numeric Nutrient Water Quality Standards, OIG Report 09-P-0223 (PDF) (23 pp, 217 K)
Seaward Extent of State Water Quality Standards, Memorandum from Cathy Winer (PDF) (4 pp, 402 K)
Establishing Site-Specific Aquatic Life Criteria Equal to Natural Background (PDF) (3 pp, 128 K)
Water Quality Standards, Memorandum from Jack Raven (PDF) (2 pp, 108 K)
Information for States and Tribes on submittal of new and/or revised water quality standards to U.S. EPA for review under section 303(c) of the Clean Water Act and Federal regulations at 40 CFR 131 (PDF) (7 pp, 32 K)
Memorandum from LaJuana Wilcher Announcing Development of Federal Rulemaking to Promulgate State Water Quality Standards (National Toxics Rule) (PDF) (5 pp, 436 K)
Compliance with CWA Section 303(c)(2)(B), Memorandum from Martha Prothro (PDF) (3 pp, 342 K)
Guidance for State Implementation of Water Quality Standards for CWA Section 303(c)(2)(B), Memorandum from Rebecca Hanmer (PDF) (22 pp, 1 MB)
Selection of Water Quality Criteria in State Water Quality Standards, Memorandum from Edwin Johnson (PDF) (4 pp, 606 K)
Recalculation of State Toxic Criteria from October 1, 1982 (PDF) (83 pp, 8 MB)
Toxic Criteria Recommendations, Memorandum from Joseph Krivak re. November 28, 1980 (PDF) (2 pp, 292 K)
Strategy for Reviewing Tribal Eligibility Applications to Administer EPA Regulatory Programs (Strategy for Treatment in a Similar Manner to a State) (PDF) (38 pp, 546 K)
OST Expectations for Water Quality Standards for Indian Reservations for Tribes Treated as States, Memorandum from Tudor Davies (PDF) (5 pp, 458 K)
Guidance on Water Quality Standards and 401 Certification Programs Administered by Indian Tribes, Memorandum from Tudor Davies (PDF) (7 pp, 575 K)
Final WQS Regulation Amendment Concerning Indian Tribes, Memorandum from Tudor Davies (PDF) (5 pp, 301 K)
Biological Assessments: Key Terms and Concepts (PDF) (2 pp, 2 MB)
Final Policy Memo on Biological Assessments and Criteria (PDF) (19 pp, 1 MB)
Human Health Ambient Water Quality Criteria and Fish Consumption Rates Frequently Asked Questions (PDF) (5 pp, 731 K)
Letter on Marine pH Criteria: EPA to Center for Biological Diversity (PDF) (4 pp, 253 K)
Option 3 of Section 303(c)(2)(B) Guidance, Memorandum from David Sabock (PDF) (2 pp, 281 K)
A Framework for Defining and Documenting Natural Conditions for Development of Site-Specific Natural Background Aquatic Life Criteria for Temperature, Dissolved Oxygen, and PH: Interim Document (PDF) (28 pp, 875 K)
Nonpoint Source Controls and Water Quality Standards, Memorandum from Carl Myers (PDF) (9 pp, 856 K)
State Authority to Allocate Water Quantities - Section 101(g) of the Clean Water Act (PDF) (4 pp, 396 K)
Appendix E: An Approach for Evaluating Numeric Water Quality Criteria for Wetlands Protection (PDF) (51 pp, 3 MB)
Clean Water Act Authority Over Wetlands, Memorandum from Cathy Winer (PDF) (2 pp, 283 K)
What is a New or Revised Water Quality Standard Under CWA 303(c)(3)? - Frequently Asked Questions (PDF) (4 pp, 111 K)
Promoting Water, Superfund and Enforcement Collaboration on Contaminated Sediments (PDF) (3 pp, 676 K)
Water Quality Standards Handbook (PDF) (202 pp, 11 MB)
Water Quality Standards Handbook Appendices (PDF) (807 pp, 42 MB)
Nutrient Pollution and Numeric Water Quality Standards (May 2007 EPA Memo) (PDF) (8 pp, 132 K)
Establishing numeric nutrient criteria, Letter from Ben Grumbles to the Natural Resources Defense Council (PDF) (5 pp, 1 MB)
EPA, DOI, Army Corp Federal Dams memo to Oregon (PDF) (2 pp, 327 K, May 4, 2005)
Questions and Answers on Antidegradation (PDF) (16 pp, 1 MB)
A Primer on Using Biological Assessments to Support Water Quality Management (PDF) (108 pp, 6 MB, October 2011, EPA 810-R-11-01)
Summary of Biological Assessment Programs and Biocriteria Development for States, Tribes, Territories, and Interstate Commissions: Streams and Wadeable Rivers (PDF) (418 pp, 29 MB)
Stressor Identification Guidance Document (PDF) (228 pp, 2 MB, December 2000, EPA 822-B-00-025)
National Program Guidance for Surface Waters (PDF) (68 pp, 1 MB, April 1990, EPA 440/5-90-004)
Biological Assessments and Criteria: Crucial Components of Water Quality Programs (PDF) (6 pp, 956 K)
Procedures for Initiating Narrative Biological Criteria (PDF) (16 pp, 438 K, October 1992, EPA 822-B-92-002)
Streamlined Water-Effect Ratio Procedure for Discharges of Copper (PDF) (41 pp, 119 K)
Ambient Aquatic Life Water Quality Criteria for Dissolved Oxygen (Saltwater): Cape Cod to Cape Hatteras (PDF) (140 pp, 6 MB)
Estimated per capita fish consumption in the United States (PDF) (262 pp, 2 MB)
Water Quality Guidance for the Great Lakes System: Supplementary Information Document (SID) (PDF) (515 pp, 41 MB)
Interim Guidance on Determination and Use of Water-Effect Ratios for Metals, Memorandum from Tudor Davies (PDF) (186 pp, 13 MB)
Compilation of EPA Mixing Zone Documents (PDF) (39 pp, 487 K)
Allocated Impact Zones for Areas of Non-Compliance (PDF) (72 pp, 2 MB)
State Water Monitoring and Waste Load Allocation (PDF) (51 pp, 3 MB)
Guidance Specifying Management Measures For Sources Of Nonpoint Pollution In Coastal Waters (PDF) (822 pp, 22 MB)
EPA's Contaminated Sediment Management Strategy (PDF) (128 pp, 9 MB)
Procedures for the Derivation of Equilibrium Partitioning Sediment Benchmarks (ESBs) for the Protection of Benthic Organisms: PAH Mixtures (PDF) (176 pp, 2 MB)
Guidelines for Deriving Numerical Aquatic Site-Specific Water Quality Criteria by Modifying National Criteria (PDF) (2 pp, 98 K)
Strategy for Water Quality Standards and Criteria (PDF) (48 pp, 1 MB)
Fact Sheet: Strategy for Water Quality Standards and Criteria: Setting Priorities to Strengthen the Foundation for Protecting and Restoring the Nation's Waters (PDF) (4 pp, 36 K)
Water Quality Criteria and Standards Plan: Priorities for the Future (PDF) (60 pp, 542 K)
Water Quality Standards for the 21st Century: Proceedings of the Fourth National Conference (PDF) (561 pp, 32 MB)
Water Quality Standards for the 21st Century: Proceedings of the Third National Conference (PDF) (400 pp, 23 MB)
Guidance for State Implementation of Water Quality Standards for CWA Section 303(C)(2)(B) (PDF) (26 pp, 1 MB)
Reference Guide to Water Quality Standards for Indian Tribes (PDF) (44 pp, 3 MB)
UAAs and Other Tools for Managing Designated Uses (PDF) (466 pp, 10 MB)
Wetlands and 401 Certification: Opportunities for States and Eligible Indian Tribes (PDF) (72 pp, 4 MB)
Guidance for Water Quality-based Decisions: The TMDL Process (PDF) (62 pp, 5 MB)
An Approach for Evaluating Numeric Water Quality Criteria for Wetlands Protection (PDF) (48 pp, 2 MB)
Watershed Monitoring and Reporting Requirements for Section 319 National Monitoring Program Projects (PDF) (219 pp, 8 MB)
Plan for Supporting States and Tribes on Designated Use Issues, 2004 (PDF) (9 pp, 45 K, August 9, 2004)
Modernizing Public Hearings for Water Quality Standard Decisions Consistent with 40 CFR 25.5 (PDF) (31 pp, 686 K, June 2019, EPA 823-F-19-005)
Memo from Geoff Grubbs: Questions and Answers on EPA’s “Alaska Rule” (PDF) (6 pp, 188 K, 9/15/2000)
Guidance: Coordinating CSO Long-Term Planning with Water Quality Standards Review (PDF) (79 pp, 497 K, July 31, 2001, EPA-R-01-002)
Technical Support Manual: Waterbody Surveys and Assessments for Conducting Use Attainability Analyses (PDF) (621 pp, 21 MB, November 1983)
Water Quality Standards: Examples of Alternatives to Changing Long-term Designated Uses to Achieve Water Quality Goals (PDF) (14 pp, 844 K, March 2005)
Improving the Effectiveness of the Use Attainability Analysis Process, Memorandum from Ephraim King (PDF) (2 pp, 392 K, March 13, 2006)
Water Quality Standards for Coastal Recreation Waters: Considerations for States as They Select Appropriate Risk Levels (PDF) (3 pp, 31 K, August 2006, EPA-823-F-06-012)