Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

    • Environmental Topics
    • Air
    • Bed Bugs
    • Cancer
    • Chemicals, Toxics, and Pesticide
    • Emergency Response
    • Environmental Information by Location
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Radon
    • Research
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • Our Mission and What We Do
    • Headquarters Offices
    • Regional Offices
    • Labs and Research Centers
    • Planning, Budget, and Results
    • Organization Chart
    • EPA History

Breadcrumb

  1. Home
  2. Water Quality Criteria

Metals CRADA Phase 1 Report

Related Information

Aquatic Life Criteria and Methods for Toxics

This report concludes Phase 1 of the Cooperative Research and Development Agreement (CRADA) that the U.S. Environmental Protection Agency entered with eight metals associations to develop a simplified, overarching modeling framework to predict the bioavailability of metals to support the development of updated metals Aquatic Life Ambient Water Quality Criteria (AWQC) under the Clean Water Act. This report provides a review of models that are available to predict the toxicity of metals to aquatic life considering factors that modify toxicity as a function of water chemistry (e.g., pH, hardness, dissolved organic carbon). The document focuses on the performance of Multiple Linear Regression (MLR) and Biotic Ligand Models (BLM) bioavailability modeling approaches for aluminum, copper, lead, and nickel. Given the similarities in performance between the BLM and MLR approaches for several metals, the EPA intends to use MLR models as the metal bioavailability-modeling approach in AWQC development because of the robustness, relative simplicity, transparency, decreased number of input data needed to use the model, and ease of use of the MLR approach compared to the BLM approach. The report underwent independent, external peer review and was revised considering peer review comments.

Metals CRADA Phase 1 Report and Supporting Documents:
  • Metals CRADA Phase 1 Report: Development of an Overarching Bioavailability Modeling Approach to Support US EPA’s Aquatic Life Water Quality Criteria for Metals (pdf) (1.17 MB, March 2022, EPA 822-R-22-001)
  • Metals CRADA Phase 1 Report: Supplemental Materials
  • Metals CRADA Phase 1 Report: Final External Peer Review Report (pdf) (1.37 MB, August 2021)
  • Metals CRADA Phase 1 Report: EPA’s Response to Comments of External Peer Review (pdf) (1.04 MB, March 2022, EPA 822-R-22-002)

Metals CRADA Phase 1 Report: Supplemental Materials

The report contains six appendices (labeled A-F) and one addendum:

  • Appendix A: Publications based on the SETAC Technical Workshop, Bioavailability-Based Aquatic Toxicity Models for Metals, December 2019.
  • Appendix B: Explanation of How Toxicity Modifying Factors (TMFs) Affect Individual Metals developed by CRADA Partners. Found in the CRADA Phase 1 Report.
  • Appendix C: Table 1: Bioavailability Model Comparisons, Table 2: Supporting Information, and References developed by CRADA Partners (pdf) (511.65 KB)
  • Appendix D: Report of aluminum and copper model comparisons. View the published copper portion of the analyses. View the published aluminum MLR portion of the analyses. Any subsequent publications will be listed when available.
  • Appendix E: Report of lead model comparisons. The publication for the lead analyses is in preparation and will be listed when available.
  • Appendix F: Report of nickel model comparisons. View the published MLR and BLM comparison and refinements to the nickel BLM.
  • Addendum: Summary of How Toxicity Modifying Factors (TMFs) Affect Metals Listed in Table 1. Information provided through the peer review by Christopher A. Mebane (USGS). Found in the CRADA Phase 1 Report.

Water Quality Criteria

  • Aquatic Life Criteria Table
  • Human Health Criteria Table
  • Human Health Toxics Criteria and Methods
  • Recreational Criteria and Methods
  • Aquatic Life Toxics Criteria and Methods
  • Nutrient Water Quality Criteria
  • Biological Water Quality Criteria
  • Other Aquatic Life Water Quality Resources
Contact Us about Water Quality Criteria
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on January 15, 2025
  • Assistance
  • Spanish
  • Arabic
  • Chinese (simplified)
  • Chinese (traditional)
  • French
  • Haitian Creole
  • Korean
  • Portuguese
  • Russian
  • Tagalog
  • Vietnamese
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshot
  • Grants
  • No FEAR Act Data
  • Plain Writing
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions
  • Site Feedback

Follow.