Antidegradation limits incremental lowering of water quality in lakes, rivers, and wetlands when applied during a permit review process. Any lowering of water quality must be found to be necessary to avoid substantial economic and social impacts. However, the surface water’s uses and values established in State law, such as swimming, boating, and fishing, must always be maintained and protected. Also included among those uses and values are the use of a surface water by fish, wildlife, and other living things, as well as the physical habitat that supports aquatic life.
The antidegradation analysis and decision only occur as part of a permitting decision for a new or increased discharge to surface waters that are high quality. The antidegradation decision is shared with the public along with the draft permit decision. Antidegradation is required by the federal Clean Water Act and Vermont State Statute.
Beginning in October 2021, the Department of Environmental Conservation refined and clarified the 2010 Interim Anti-Degradation Implementation Procedure, which was the basis of the proposed rule, working collaboratively with a small stakeholder group representing environmental advocates, municipalities, and the regulated community.