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Water: Wetlands

Water Quality Standards for Wetlands

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Water quality standards are the foundation of the water quality-based pollution control program mandated by the Clean Water Act (CWA). They define the goals for a water body by designating its highest attainable uses, setting criteria that reflect the current and evolving body of scientific information to protect those uses, and establishing provisions to protect water bodies from further degradation. Federal regulations (40 CFR part 230.3) implementing the CWA include wetlands as "waters of the U.S." and therefore require water quality standards. Water quality standards developed specifically for wetlands help ensure that the provisions of the Clean Water Act, which apply to all surface waters, are consistently applied to wetlands; they also provide a more relevant scientific basis for applying these provisions. Water quality standards (WQS) regulations at 40 CFR Parts 131 and 132 provide specific requirements for development of state and tribal standards including specifying appropriate water uses to be achieved and protected, providing appropriate criteria to support those uses, and applying anti-degradation policy to all waters, including wetlands. The regulation also provides states and tribes with the flexibility to adopt sub-categories of uses and associated criteria to allow for differentiation between types of wetlands, their expected uses, functions and condition.

Historically, wetlands-specific standards have been underutilized by states and tribes as a means of protecting the resource, although a number of states apply their narrative surface water quality standards to wetlands. If a state or tribe fails to adopt standards specific to wetlands, its water quality standards, which typically apply to "all waters of the State" by default, apply to wetlands as well. Often these default standards are not relevant to a wetland, e.g., a dissolved oxygen criterion that is inappropriately high for wetland environments. The most adaptive surface water standard is one that relies on narrative criteria rather than numeric criteria due to the high variability in wetlands particularly when compared with flowing waters.

Developing defensible water quality standards for wetlands is a data intensive effort and is dependent on a successful wetland monitoring and assessment program. Standards can be derived and supported using measurements of wetland function or condition. Due to the unique characteristics of wetlands relative to flowing surface waters, water quality standards for wetlands may differ from traditional standards, e.g., with potentially less emphasis on water chemistry parameters and more emphasis on diversity of vegetation or macroinvertebrate communities. Generally, a suite of measures will be required for wetland WQS to protect the full range of wetland functions and/or ecological condition. As with water quality criteria for other surface waters, criteria for wetlands can be narrative or numeric. Wetland standards may also differ from conventional standards by utilizing additional parts of State statutes and regulations that do not apply to instream water quality.

The EPA 1990 guidance on WQS for wetlands states five key steps for developing water quality standards for wetlands: 1) define wetlands as "state waters"; (2) designate uses that protect the structure and function of wetlands; (3) adopt narrative criteria and appropriate numeric criteria in the standards to protect the designated uses; (4) adopt narrative biological criteria in the standards; and (5) extend the antidegradation policy and implementation methods. Like other water quality standards, wetlands-specific WQS are submitted to EPA for approval during the triennial review process. These steps form the basis for many of the program development actions in the table below.

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Goals and Benefits

WQS for wetlands can provide a more rigorous and appropriate foundation for protecting and enhancing state or tribal wetland resources. Wetland WQS can provide the basis for actions leading to an "overall increase" in wetland function and condition, one of EPA's national wetland goals. They also provide the scientific basis for a variety of actions to protect and restore wetlands, such as:

  • Permitting – Standards provide a clear basis for making water quality based permitting decisions under CWA Sections 402 and 404 and other state and tribal programs;
  • Water quality certification – Standards are the basis for states and tribes to approve, condition, or deny certifications under CWA Section 401 programs. Wetlands-specific WQS provide a stronger basis for 401 certifications and conditions;
  • Monitoring, Assessment and Reporting – Standards provide a benchmark against which monitoring data can be used to assess and report on wetlands function and/or condition (i.e.,303(d)305(b) integrated reports;
  • Restoration and Protection – States and tribes can use standards as a basis for guiding restoration and protection efforts and gauging their effectiveness.

In addition, wetlands WQS provide the basis for decisions in other programs that affect wetlands such as the Total Maximum Daily Loads and nonpoint source pollution control programs. States and tribes can successfully adopt and apply WQS for wetlands by pursuing the following objectives:

  1. Ensure that wetlands are treated as waters within state and tribal water quality programs
  2. Develop wetland-specific water quality standards; and
  3. Incorporate wetland-specific water quality standards into agency decision-making.

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Program Building Activities Menu

The following actions and measures of progress provide more specific guidance for states and tribes interested in developing, adopting, and incorporating water quality standards into their wetlands programs.

Objective 1: Ensure that wetlands are treated as waters within state and tribal water quality programs

Actions Menu of Activities
  1. Adopt an appropriate definition of wetlands
  • Include wetlands in state/tribal legal definition of waters
  • Ensure legal definition of waters is at least as inclusive as the CWA definition
  • Remove any regulatory language excluding defined wetlands from water quality standards
  1. Ensure the appropriate wetlands definition is included in WQS
  • Include appropriate definition of wetlands in state/ tribal policy or regulations authorizing water quality standards program (e.g., wetland size, type, ownership)

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Objective 2: Develop wetland-specific water quality standards

Actions Menu of Activities
  1. Gather and analyze monitoring data and other information that will become basis of water quality standards
  • Define wetland types/classes
  • Establish reference conditions for defined wetland types in terms of functional/condition performance and other physical measurements
  1. Establish and adopt appropriate wetland-specific designated uses to be achieved and protected
  • Establish designated uses for different wetland types (e.g., recreation, wildlife habitat,)
  • Map where designated uses apply
  1. Establish and adopt narrative criteria that qualitatively describe the condition or suite of functions that must be achieved to support a designated use
  • Establish narrative physical criteria (e.g., fill material not present; no hydrologic alterations)
  • Establish narrative biologic criteria (e.g., species composition, population dynamics, structure)
  • Develop technical documents to support the narrative criteria with numerical data. This document describes the types of narrative and numerical data that will be used in determining attainment of the standard
  1. Establish and adopt numeric criteria representing wetland specific values for chemical, physical, and biological parameters that may not be exceeded, must be exceeded, or some combination to protect or restore designated uses
  • Establish numeric criteria for biological attributes based on wetland type and location (e.g., plant or macroinvertebrate indices, algae )
  • Establish numeric criteria for chemical constituents based on wetland type and location (e.g., nutrients)
  • Establish numeric criteria for physical parameters based on wetland type and location (e.g., buffer characterizations, micro habitats)
  1. Better define state/tribal antidegradation policies for wetlands, requiring full protection of existing uses (functions and/or condition), maintenance of functions/condition in high quality wetlands, and a prohibition against lowering functions/conditions in outstanding national resource waters
  • Include wetlands in antidegradation policies
  • Include restoration potential of wetlands in antidegradation policies
  • Administer and enforce antidegradation policies for wetlands
  • Develop measures to ensure antidegradation is being applied successfully in a manner specific to wetlands

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Objective 3: Incorporate wetland-specific water quality standards into agency decision-making

Actions Menu of Activities
  1. Use water quality standards as basis for regulatory decisions
  • Base 401 certifications on wetland WQS
  • Base state/tribal permit decisions, including mitigation requirements, on WQS
  • Track wetland impacts avoided or mitigated based on WQS, via permitting actions
  1. Use water quality standards as basis for evaluating restoration/protection projects and mitigation/compensation projects
  • Use water quality standards in restoration guidelines
  • Track restoration/protection projects that are monitored for compliance with water quality standards
  • Track restoration/protection sites that meet water quality standards
  • Identify remedial measures for sites that do not meet wetland WQS
  1. Incorporate water quality standards into monitoring and assessment program
  • Update monitoring strategy and methods based on water quality standards
  • Track acres monitored for compliance with water quality standards
  • Regularly report on wetlands status and trends relative to water quality standards

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You will need Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more.

The Program Activities Menu above provides a suite of actions for developing wetland-specific water quality standards. The references below have been compiled in an effort to offer additional resources to states and tribes interested in developing or improving wetland-specific water quality standards. This list is not intended to promote any one technical approach or pathway over another but rather to serve as a source of both current and historic information that may be considered by states and tribes along with other relevant information. While some of these materials are dated, they can still offer helpful background or principles for consideration.

EPA Resources

  1. Wetland-specific Water Quality Standards Information
    • Water Quality Standards for Wetlands: National Guidance (July 1990 and Appendix D of the Water Quality Standards Handbook: Second Edition, August 1994)
      This document provides program guidance to States on how to apply water quality standards (WQS) to wetlands. This guidance reflects the level of achievement EPA expected States to accomplish by the end of FY 1993. Phase 1 activities presented in this guidance include the development of WQS elements for wetlands based upon existing information and science. Phase 2 involves the further refinement of these basic elements using new science and program developments.
    • Nutrient Criteria Technical Guidance Manual: Wetlands (June 2008)
      This document describes elements of wetland nutrient criteria development including: classification of wetlands, monitoring program sampling design, and three methods for developing nutrient criteria. These methods are: using reference systems, refining classification systems using models and/or examining system biological attributes, and using or modifying published nutrient and vegetation, algal, and soil relationships as criteria. It focuses on developing numeric criteria for wetland systems in an ecoregion.
    • An Approach for Evaluating Numeric Water Quality Criteria for Wetlands Protection (PDF) (51 pp, 2.8MB) (July 1991 and Appendix E of the Water Quality Standards Handbook: Second Edition, August 1994)
      This report provides an overview of the need for standards and criteria for wetlands and a description of the national numeric aquatic life criteria. It provides a possible approach for detecting wetland types that might not be protected by direct application of national numeric criteria and for making modifications based on site-specific guidelines.
    • Questions and Answers on Antidegradation (PDF) (17 pp, 1.3MB) (August 1985 and Appendix G of the Water Quality Standards Handbook: Second Edition, August 1994)
      This document provides guidance on the antidegradation policy component of water quality standards and its application. The document begins with the text of the policy as stated in the water quality standards regulation, 40 CFR 131.12 (40 FR 51400, November 8, 1983), the portion of the Preamble discussing the antidegradation policy, and the response to comments generated during the public comment period on the regulation. The document then uses a question-and-answer format to present information about the origin of the policy, the meaning of various terms, and its application in both general terms and in specific examples. Question #13 addresses the application of antidegradation policy in the case of wetland fill permits under Clean Water Action Section 404.
  2. General Water Quality Standards Information
    • Water Quality Standards Handbook: Second Edition (August 1994)
      Provides guidance issued in support of the Water Quality Standards Regulation (40 CFR 131, as amended).
    • Water Quality Standards Academy
      To support water quality standards development, EPA offers the Water Quality Standards Academy which presents classroom-based and online courses, along with occasional satellite broadcasts. Online training models and information on classroom courses can be accessed at this website.
  3. Linkage with Clean Water Act Section 401
  4. Linkage with Monitoring and Assessment
    • Impacts on Quality of Inland Wetlands of the United States: A Survey of Indicators, Techniques, and Applications of Community Level Biomonitoring Data (Excerpts from Report #EPA/600/3-90/073, now out of print)
      This report describes how (a) existing resource data might be applied in the designation of "uses" for wetlands, (b) ambient biological criteria for wetlands might be developed or modified, and (c) wetlands might be periodically sampled (and data interpreted) to estimate their relative ecological condition, compliance with biological criteria, or need for restoration. Because of the lack of appropriate comparative studies of wetlands, the report does not provide biocriteria for wetlands, evaluate or prioritize potential indicators of wetland condition, nor endorse specific techniques for wetland biomonitoring and data analysis. Its intended use is mainly as a technical source document for future design, testing, and reporting of indicators.
    • EPA's Wetlands Monitoring and Assessment Homepage
      A necessary foundation for development of wetland-specific water quality standards is an understanding of existing wetland types and characterization of desired quality/condition. This is usually achieved through wetlands monitoring and assessment.
    • Methods for Evaluating Wetland Condition (March 2002 – December 2008)
      These modules are a starting point to help states and tribes establish biological and nutrient water quality criteria specifically refined for wetlands. They provide information that will help states and tribes develop biological assessment methods to evaluate both the overall ecological condition of wetlands and nutrient enrichment.

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Non-EPA Resources

This page provides links to non-EPA websites that provide additional information about water quality standards. You will leave the EPA.gov domain and enter another page with more information. EPA cannot attest to the accuracy of information on that non-EPA page. Providing links to a non-EPA website is not an endorsement of the other site or the information it contains by EPA or any of its employees. Also, be aware that the privacy protection provided on the EPA.gov domain (see Privacy and Security Notice) may not be available at the external link. Exit EPA Disclaimer

  1. Information Supporting Development of Water Quality Standards for Wetlands by States and Tribes
    • Association of State Wetland Managers
      • Wetland Water Quality Standards for States (PDF) (100 pp, 2.2MB) (2012)
        This report was prepared by the Association of State Wetland Managers as part of a broader project to help states adopt water quality standards for wetland ecosystems. It addresses selected issues with regard to the formulation and adoption of such standards. It provides the states with some examples of draft narrative standards in Appendices A and B.
      • Water Quality Standards for Wetlands webpage
        The Association of State Wetland Managers maintains this webpage to provide information related to wetlands and water quality as well as to provide resources for states and tribes that are preparing for adoption of water quality standards for wetlands.
  2. Information on Existing State Wetland-specific Water Quality Standards

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