Minnesota Antidegradation Rules Revised By MPCA

The MPCA has completed rulemaking to replace the existing nondegradation rules found in Minn. R. ch. 7050 with new antidegradation rules. The new rules became effective on November 21, 2016. One of the notable revisions was MPCA changing terms from nondegradation to antidegradation to be consistent with federal regulations, EPA guidance and other states’ rules and implementation procedures.


Some of the key changes to the antidegradation rules are:

• Aligning rules with federal antidegradation regulatory policy and EPA guidance.
• Incorporating two sets of antidegradation standards addressing the differences between individual and general permits.
• Developing procedures specific to the various activities the MPCA regulates.
• Providing clarity regarding the information needed of applicants and sequence of actions taken by the MPCA in making antidegradation determinations.
• Identifing the factors the MPCA considers in conducting reviews.
• Establishing a process for determining the water quality baseline.
• Providing limited exemptions from antidegradation procedures.
• Providing for compensatory mitigation for the loss of existing uses resulting from physical alterations.

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