Proposed Indiana Antidegradation Standards and Implementation Procedures Rule

The Indiana Water Pollution Control Board has preliminarily adopted the new Antidegradation Standards and Implementation Procedures Rule prepared by the Indiana Department of Environmental Management (IDEM). The rules are aimed at maintaining existing water quality in all public surface waters, and especially in lakes and streams that have a higher quality of water than minimum standards require. The new rules also provide for opportunities for the public to participate in the review of new or expanding discharges.

The rule requires an evaluation of alternatives before permitting new pollutant discharges above a de minimis level. Although IDEM can not issue permits that allow violations of water quality standards, a new discharge above the de minimis level may degrade the existing water quality. In these cases, a discharger must submit an antidegradation demonstration, and has the opportunity to provide information about the social and economic benefits of the activity producing the new or increased loading, which is evaluated according to state law. In Outstanding State Resource Waters, there is an additional requirement of a water quality improvement project or fee.

Following the preliminary adoption, the proposed rule will be placed on notice in the Indiana Register. A public comment period of at least 21 days will also be held, because the proposed rule has substantially changed from the version of the rule placed on public notice in 2009. IDEM will then consider comments, and make any necessary changes before presenting the proposed rule to the board for final adoption.

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