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Final Rule

Water Quality Standards To Protect Aquatic Life in the Delaware River

In Plain English

What is this Federal Register notice?

This is a final rule published in the Federal Register by Environmental Protection Agency. Final rules have completed the public comment process and establish legally binding requirements.

Is this rule final?

Yes. This rule has been finalized. It has completed the notice-and-comment process required under the Administrative Procedure Act.

Who does this apply to?

Consult the full text of this document for specific applicability provisions. The affected parties depend on the regulatory scope defined within.

When does it take effect?

This document has been effective since November 28, 2025.

Why it matters: This final rule amends regulations in 40 CFR Part 131.

📋 Related Rulemaking

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Regulatory History — 2 documents in this rulemaking

  1. Jan 8, 2024 C1-2023-27758 Proposed Rule
    Water Quality Standards To Protect Aquatic Life in the Delaware River
  2. Sep 29, 2025 2025-18816 Final Rule
    Water Quality Standards To Protect Aquatic Life in the Delaware River

Document Details

Document Number2025-18816
TypeFinal Rule
PublishedSep 29, 2025
Effective DateNov 28, 2025
RIN2040-AG30
Docket IDEPA-HQ-OW-2023-0222
Text FetchedYes

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Related Documents (by RIN/Docket)

Doc #TypeTitlePublished
C1-2023-27758 Proposed Rule Water Quality Standards To Protect Aquat... Jan 8, 2024

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Full Document Text (28,353 words · ~142 min read)

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<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 131</CFR> <DEPDOC>[EPA-HQ-OW-2023-0222; FRL 10760-02-OW]</DEPDOC> <RIN>RIN 2040-AG30</RIN> <SUBJECT>Water Quality Standards To Protect Aquatic Life in the Delaware River</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The U.S. Environmental Protection Agency (EPA) is finalizing revised water quality standards (WQS) largely as proposed for certain water quality management zones of the mainstem Delaware River under the Clean Water Act (CWA). Specifically, the EPA is promulgating a designated use of protection and propagation of resident and migratory aquatic life and corresponding dissolved oxygen water quality criteria for the mainstem Delaware River in Zone 3, Zone 4, and the upper portion of Zone 5 (in total, river miles 108.4 to 70.0). </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This final rule is effective on November 28, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> The EPA has established a docket for this action under Docket ID No. EPA-HQ-OW-2023-0222. All documents in the docket are listed on the <E T="03">https://www.regulations.gov</E> website. Although listed in the index, some information is not publicly available, <E T="03">e.g.,</E> Confidential Business Information or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and will be publicly available only in hard copy form. Publicly available docket materials are available electronically through <E T="03">https://www.regulations.gov</E> . <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Hannah Lesch, Office of Water, Standards and Health Protection Division (4305T), Environmental Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460; telephone number: (202) 566-1224; email address: <E T="03">Lesch.Hannah@epa.gov</E> . </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION: </HD> The information in this preamble is organized as follows: <EXTRACT> <FP SOURCE="FP-2">I. General Information</FP> <FP SOURCE="FP1-2">A. Does this action apply to me?</FP> <FP SOURCE="FP1-2">B. How did the EPA develop this final rule?</FP> <FP SOURCE="FP-2">II. Background</FP> <FP SOURCE="FP1-2">A. Statutory and Regulatory Authority</FP> <FP SOURCE="FP1-2">B. Relevant Ecological History of the Delaware River</FP> <FP SOURCE="FP1-2">C. Administration of Water Quality Standards in the Delaware River</FP> <FP SOURCE="FP1-2">D. Relevant Aquatic Life Designated Uses and Dissolved Oxygen Criteria Prior to Promulgation of This Final Rule</FP> <FP SOURCE="FP1-2">E. Summary of the EPA Administrator's Determination</FP> <FP SOURCE="FP-2">III. Final Water Quality Standards</FP> <FP SOURCE="FP1-2">A. Scope of the EPA's Rule</FP> <FP SOURCE="FP1-2">B. Aquatic Life Designated Use</FP> <FP SOURCE="FP1-2">C. Dissolved Oxygen Criteria To Protect Aquatic Life Propagation</FP> <FP SOURCE="FP-2">IV. Endangered Species Act Consultation</FP> <FP SOURCE="FP-2">V. Applicability</FP> <FP SOURCE="FP-2">VI. Conditions Under Which Federal Water Quality Standards Would Be Withdrawn</FP> <FP SOURCE="FP-2">VII. Alternative Regulatory Approaches and Implementation Mechanisms</FP> <FP SOURCE="FP1-2">A. Water Quality Standards Variances and NPDES Permit Compliance Schedules</FP> <FP SOURCE="FP1-2">B. Clean Water Act Section 303(d)/305(b) Water Quality Assessments</FP> <FP SOURCE="FP-2">VIII. Economic Analysis</FP> <FP SOURCE="FP1-2">A. Baseline for the Analysis</FP> <FP SOURCE="FP1-2">B. Development of the Policy Scenario</FP> <FP SOURCE="FP1-2">C. Potential Costs</FP> <FP SOURCE="FP1-2">D. Potential Benefits</FP> <FP SOURCE="FP1-2">E. Conclusion</FP> <FP SOURCE="FP-2">IX. Statutory and Executive Order Reviews</FP> <FP SOURCE="FP1-2">A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review</FP> <FP SOURCE="FP1-2">B. Executive Order 14192: Unleashing Prosperity Through Deregulation</FP> <FP SOURCE="FP1-2">C. Paperwork Reduction Act (PRA)</FP> <FP SOURCE="FP1-2">D. Regulatory Flexibility Act (RFA)</FP> <FP SOURCE="FP1-2">E. Unfunded Mandates Reform Act (UMRA)</FP> <FP SOURCE="FP1-2">F. Executive Order 13132: Federalism</FP> <FP SOURCE="FP1-2">G. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments</FP> <FP SOURCE="FP1-2">H. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks</FP> <FP SOURCE="FP1-2">I. Executive Order 13211: Actions That Significantly Affect Energy Supply, Distribution, or Use</FP> <FP SOURCE="FP1-2">J. National Technology Transfer and Advancement Act (NTTAA)</FP> <FP SOURCE="FP1-2">K. Congressional Review Act (CRA) </FP> </EXTRACT> <HD SOURCE="HD1">I. General Information</HD> <HD SOURCE="HD2">A. Does this action apply to me?</HD> Table 1 of this preamble identifies a range of individuals and entities that could be indirectly affected by this final rule. For example, entities that discharge pollutants to certain waters under the jurisdiction of the States of Delaware, New Jersey, and Pennsylvania—such as industrial facilities and municipalities that manage stormwater, separate sanitary, or combined sewer systems—could be indirectly affected by this rule because the Federal WQS promulgated by the EPA in this rule are applicable WQS for these waters for CWA purposes. Specifically, these Federal WQS are the applicable standards that must be used in CWA regulatory programs, such as permitting under the National Pollutant Discharge Elimination System (NPDES) under CWA section 402  <SU>1</SU> <FTREF/> and identifying impaired waters under CWA section 303(d). In addition, individuals and entities who rely on or benefit from aquatic life in these waters may be indirectly affected. <FTNT> <SU>1</SU>  Before any water quality-based effluent limit could be included in an NPDES permit, the permitting authority (here, the states of Delaware, New Jersey, and Pennsylvania), must first determine whether a discharge “will cause or has the reasonable potential to cause, or contribute to an excursion above any WQS.” 40 CFR 122.44(d)(1)(i) and (ii). </FTNT> <GPOTABLE COLS="2" OPTS="L2,nj,i1" CDEF="s100,r200"> <TTITLE>Table 1—Entities Potentially Indirectly Affected by This Rule</TTITLE> <CHED H="1">Category</CHED> <CHED H="1">Examples of potentially indirectly affected entities</CHED> <ROW> <ENT I="01">Industry</ENT> <ENT>Industrial point sources discharging to certain waters in Delaware, New Jersey, and Pennsylvania. Commercial fishing operations that harvest fish.</ENT> </ROW> <ROW> <ENT I="01">Municipalities, including those with stormwater or combined sewer system outfalls</ENT> <ENT>Publicly owned treatment works or similar facilities responsible for managing stormwater, separate sanitary, or combined sewer systems that discharge to certain waters in Delaware, New Jersey, and Pennsylvania.</ENT> </ROW> <ROW> <ENT I="01">Recreation and Tourism</ENT> <ENT>Anglers and tourists seeking recreational opportunities related to aquatic life in certain waters in Delaware, New Jersey, and Pennsylvania.</ENT> </ROW> </GPOTABLE> This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities that could be indirectly affected by this action. If you have questions regarding the applicability of this action to a particular entity, consult the person listed in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section above. <HD SOURCE="HD2">B. How did the EPA develop this final rule?</HD> In developing this final rule, the EPA carefully considered the public comments and input received from interested parties. The EPA provided a 60-day public comment period after publishing the proposed rulemaking in the <E T="04">Federal Register</E> on December 21, 2023. <SU>2</SU> <FTREF/> In addition, the EPA held two online public hearings on February 6 and 7, 2024, to discuss the contents of the proposed rulemaking and accept verbal public comments. <FTNT> <SU>2</SU>  United States Environmental Protection Agency. Proposed Rule: Water Quality Standards to Protect Aquatic Life in the Delaware River. 88 FR 88315, December 21, 2023. </FTNT> The EPA received approximately 4,800 total comments on a range of issues. Most commenters were supportive of the EPA's proposal to revise WQS in the Delaware River. Some commenters expressed concerns regarding potential implementation costs and the potential cost to water utility ratepayers. Other commenters focused on aspects of the methods the EPA used to derive the dissolved oxygen criteria and the stringency of the proposed criteria. In this preamble, the EPA explains how it responded to certain comments received on aspects of the proposal. A complete record of the comments received and the EPA's responses is available in the associated response to comments document in the official public docket. <SU>3</SU> <FTREF/> <FTNT> <SU>3</SU>  A complete record of the comments received and the EPA's responses is available in the associated Response to Comments document in the official public docket ( <E T="03">regulations.gov,</E> docket ID EPA-HQ-OW-2023-0222). </FTNT> <HD SOURCE="HD1">II. Background</HD> <HD SOURCE="HD2">A. Statutory and Regulatory Authority</HD> CWA section 101(a)(2) establishes a national goal of “water quality which provides for the protection and propagation of fish, shellfish, and wildlife and provides for recreation in and on the water” (hereafter, collectively referred to as “101(a)(2) uses” or “101(a)(2) goals”), wherever attainable. <SU>4</SU> <FTREF/> CWA section 303(c)(2)(A) provides that WQS must pr ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 206k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
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