Are variances to water quality standards allowed under the federal Clean Water Act?
Frequently Asked Questions
Yes, variances are allowed under the Clean Water Act. USEPA has recommended that states use variances as one tool to facilitate adoption of increasingly stringent water quality criteria for pollutants such as nutrients and ammonia. USEPA revised the water quality standards regulations in August 2015 to include additional details on the use of variances (see 40 CFR § 131.14). USEPA also has a checklist for evaluating state submissions of discharger-specific variances.