Water Quality Standards Regulations: Indiana
Presented are water quality standards in effect for Clean Water Act (CWA) purposes for this state.
The EPA is posting these standards as a convenience to users and has made a reasonable effort to assure their accuracy. For each document listed under "State Standards in Effect for CWA Purposes", the EPA has made a reasonable effort to identify parts of the standards that are disapproved or are otherwise not in effect for CWA purposes. Additionally, please note the documents may also contain provisions that the EPA does not have the authority and duty to act on under the Clean Water Act because the provisions are not water quality standards.
On this page:
State Standards in Effect for CWA Purposes
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Article 2. Water Quality Standards (pdf)
(Effective October 18, 2023) This document contains water quality standards for all State waters. Please note that not all provisions are effective for Clean Water Act purposes (refer to cover page for more information). -
Article 5 Excerpts: 327 IAC 5-3-4.1 (Determination on variances from water quality standards and effluent limitations) and 327 IAC 5-3.5. (Streamlined Mercury Variance Requirements and Application Process) (pdf)
(Effective September 28, 2021) Section 327 IAC 5-3-4-1 contains requirements for variance applications. Section 327 IAC 5-3.5 was added to establish a process and application requirements for obtaining a variance from the existing water quality criterion used to establish a water quality-based effluent limitation for mercury in wastewater discharges permitted under the National Pollutant Discharge Elimination System (NPDES) program. Please note that not all provisions are effective for Clean Water Act purposes (refer to cover page for more information).