Human Health Criteria
Methylmercury Fish Tissue Criterion
Guidance for Implementing the Methylmercury Water Quality Criterion
Regulatory Review Notice
EPA is in the process of reviewing several previous agency decisions, including those covered by the White House memo on regulatory review (memo in HTML | memo in PDF (2 pp., 51 K, About PDF)). This guidance document is under review.
January 2009; EPA 823-R-09-002
In January 2001, EPA published ambient water quality criteria (AWQC) recommendations for methylmercury for the protection of people who eat fish and shellfish. This criterion, 0.3 mg methylmercury/kg fish tissue wet weight, marks EPA's first issuance of a water quality criterion expressed as a fish and shellfish tissue value rather than as an ambient water column value.
This document provides technical guidance to states and authorized tribes exercising responsibility under section CWA 303(c) on how to use the new fish tissue-based criterion recommendation as they develop their own water quality standards for methylmercury.
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– Under Review – Final Guidance Document
Complete Document (PDF) (211 pp., 1.2 MB) (EPA-823-R-09-002)
- Executive Summary and Introduction
- What is the interest in mercury?
- What are the sources of mercury in fish?
- How does methylmercury get into fish and shellfish?
- Why is EPA publishing this document?
- What is the effect of this document?
- Chapter 3: Water Quality Criteria and Standards Adoption
- What must states and authorized tribes include as they adopt the methylmercury criterion?
- What options are available to address for site-specific conditions and concerns?
- Chapter 4: Monitoring and Assessment
- What are the analytical methods for detecting and measuring methylmercury concentrations in fish and water?
- What is the recommended guidance on field sampling plans for collecting fish for determining attainment of the water quality standard?
- How should waterbody impairment be assessed for listing decisions?
- Chapter 5: Other Water Quality Standards Issues
- How does this criterion relate to the criteria published as part of the Great Lakes Initiative?
- What is the applicable flow for a water column-based criterion?
- How are mixing zones used for mercury?
- How are fish consumption advisories and water quality standards harmonized?
- What public participation is recommended for implementing the methylmercury criterion?
- Chapter 6: TMDLs
- What is a TMDL?
- How have states and tribes approached mercury TMDLs?
- Chapter 7: NPDES Implementation Procedures
- What are the general considerations in NPDES permitting?
- What is the EPA-recommended NPDES permitting approach for methylmercury?
- How does EPA recommend implementing the fish tissue criterion for NPDES permits?
- What are the procedures for developing permit limits when the criterion is adopted as a water column value or when the criterion is adopted as a fish tissue value and the permitting authority uses a water column translation of the fish tissue value?
- What are the procedures for developing permit limits when the criterion is adopted as a fish tissue value and the permitting authority does not use a water column translation of the fish tissue value?
- Chapter 8: Related Programs
- What are EPA and others doing as a whole to address mercury?
- How does pollution prevention play a role in the methylmercury criterion?
- What regulations has EPA issued pursuant to the CAA to address air emissions of mercury?
- Chapter 9: References
- Appendices
- Appendix a: Methylmercury/Mercury Ratio Exhibited in Muscle Tissue of Various Freshwater Fish Species
- Appendix B: Tables from Methylmercury Criteria Document
- Appendix C: Analytical Methods
- Appendix D. Synopsized Mercury TMDLs Developed or Approved by EPA
- Ochlockonee Watershed, Georgia
- Arivaca Lake, Arizona
- McPhee and Narraguinnep Reservoirs, Colorado
- Clear Lake, California
- Cache Creek, California
- Minnesota Statewide Mercury Total Maximum Daily Load
- Appendix E: Model Descriptions
- Appendix F: Examples of National Deposition Monitoring Networks
- Index