Stormwater Permit Update: Rule 6 to the ISGP

Stormwater Permit Update: IDEM Transitioning from Rule 6 to the Industrial Stormwater General Permit (ISGP)

The Indiana Department of Environmental Management (IDEM) is in the process of transitioning its Rule 6 stormwater permitting program to a new Industrial Stormwater General Permit (ISGP). During this transition period, Rule 6 requirements largely remain in effect, and facilities should continue to comply with existing stormwater regulations.

What Facilities Should Know About the Rule 6 to ISGP Transition

• Existing Rule 6 Permit Holders

  • Existing permits remain valid throughout the transition.
  • If your Rule 6 permit expires during the transition period, you must submit a Notice of Intent.

• Unpermitted Industrial Facilities

  • Continue applying for stormwater permit coverage under Rule 6 until IDEM releases the ISGP Notice of Intent.
  • Once the ISGP Notice of Intent becomes available, new applications may be submitted under the new permit.

• No Exposure Exclusion Facilities

  • No immediate action is required at this time.
  • Rule 6 remains in effect, and no exposure certifications must be renewed within 90 days of expiration.

• Preparing for the Transition

  • Review the key differences between Rule 6 and the ISGP.
  • Proactively update their Stormwater Pollution Prevention Plan (SWP3) to align with anticipated ISGP requirements.
  • Evaluate current stormwater controls, inspection procedures, and monitoring practices for potential updates.

Preparing for the Indiana Industrial Stormwater Permit Transition (Rule 6 to ISGP) now can help facilities avoid lapses in coverage and compliance issues as IDEM finalizes the new permit.

Need Help Navigating Stormwater Compliance?

Stormwater permitting transitions can be complex, especially for industrial facilities with ongoing operations. Working with an experienced environmental consultant can help ensure uninterrupted permit coverage and regulatory compliance during IDEM’s transition to the ISGP.

Patriot provides industrial stormwater permitting, SWP3 development and updates, and compliance support for facilities.

About Patriot

Call us at 317-576-8058 or email info@patrioteng.com to learn more.