Antidegradation Two

Triggering antidegradation review

The EPA Water Quality Standards Handbook (Section 4.0) states that “[a]ny one or a combination of several activities may trigger the antidegradation policy analysis.” At the very least, an antidegradation review is required as part of each new or expanded NPDES permit and each state water quality certification. State water quality certifications are required with federal dredge and fill permits, among other federal permits and licenses.

According to the EPA, antidegradation is also triggered by other activities, such as review of water quality standards and new or revised TMDL allocations.

The EPA Water Quality Standards Handbook explicitly states that nonpoint source activities are not exempt from the provisions of the antidegradation policy. However, some states have adopted nonpoint source exemptions to the antidegradation policy in their water quality standards.

Improving state policy and procedures

The EPA is required to disapprove water quality standards that are inconsistent with the federal regulations (40CFR131.21). Yet, EPA has only recently begun to do so when antidegradation policies and procedures are inadequate, even though they are required elements of water quality standards (40CFR131.6). Once an antidegradation policy is disapproved by EPA, the state must change the policy to address EPA’s concern. If not, EPA is required to develop a new policy for the state (40CFR131.22). Regarding the implementation procedures, EPA may disapprove them and promulgate new procedures if it has been determined that all or part of the state’s process could result in circumvention of the intent and purpose of the federal antidegradation policy (Water Quality Standards Handbook, 4.3). Otherwise, it is simply up to EPA to check that something is in place to describe implementation of antidegradation.