Minnesota PCA Triennial Review - 7050 and 7052

Every three years the federal Clean Water Act (CWA) requires states to obtain public comment on, and revise as needed, their water quality standards. The Minnesota Pollution Control Agency (MPCA) began the triennial review process in 2008 with proposed amendments to Minnesota Rules chapters 7050 and 7052. MPCA plans to complete the water quality standard amendments in 2011. The rule changes under consideration during this triennial review include the following:

1. Addition of eutrophication standards for river systems;
2. Modification of the existing turbidity standards;
3. Additions or revisions of numeric water quality standards for protection of aquatic life based on U. S. Environmental Protection Agency (EPA) 304(a) Ambient Water Quality Criteria for cadmium, copper, diazinon, and nonylphenol;
4. Re-evaluate the aquatic life standard for chloride;
5. MPCA-derived Class 2 water quality criteria for nitrate based on aquatic life toxicity;
6. Updates to human health-based water quality standards needed to maintain consistency with the Minnesota Department of Health’s Health Risk Limits in Minn. R. ch. 4717 (currently under revision) and EPA’s Methodology for Deriving Ambient Water Quality Criteria for the Protection of Human Health (2000);
7. Re-evaluate and update existing Class 3 (Industrial Consumption) and Class 4 (Agriculture and Wildlife) water use standards;
8. Potential water use classification changes for specific water bodies, including updating Class 2A trout waters and reviewing and adding Class 7 limited resources value waters; and
9. Minor administrative changes.

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