Final Comment Period for Indiana Stormwater Permit

In September 2024, the Indiana Department of Environmental Management (IDEM) issued a draft Industrial Stormwater General Permit (ISGP), which is open for public comment until November 19, 2024.  Upon completion of the public notice period the new permit is expected to go into effect in 2025.  The new permit requirements will be more stringent in terms of sampling frequency, pollutant benchmarks, inspections, and corrective actions.  

For a new facility, within 30 days prior to the occurrence of any discharge a new permit application Notice of Intent (NOI) must be submitted.  For facilities that have existing permit coverage, within 180 days following the effective date of the new permit the facility will need to take one of the following actions:

• Submit a new NOI 

• Request to terminate permit coverage;

• Notify IDEM of eligibility for an exclusion from permit coverage;

• Submit an application for an individual permit.

All permitted facilities are required to continue to meet the conditions of the current Indiana Permit (as defined in 327 IAC 15-6) including sampling and inspection requirements until the new ISGP permit is issued sometime in 2025.  If your current permit coverage is set to expire before the new ISGP permit is issued you still need to submit a renewal NOI to maintain that permit coverage.   

We understand the new upcoming changes to the Indiana stormwater permit may feel daunting. 

If you’d like to be informed of the finalization of these regulation and tips for compliance, please drop your email below, and we will be in touch. Feel free to contact us if you’d like