Stormwater Program Transition to Master General Permits

IDEM is in the process of transitioning from a permit by Rule to a Master General Permit for the three stormwater programs currently administered through Indiana Administrative Code (Rule).

IDEM has established a process to transition from permits by Rule to Master General Permits that includes several steps:

1. Development of a draft permit.
2. Send the draft permit to U.S. EPA for review.
3. Utilization of an advisory group to review and provide input into the draft permit.
4. Modify the draft permit.
5. Public notice and receive comments on the draft permit.
6. Consider public comments and as applicable modify the draft permit.
7. Send the draft permit to U.S. EPA for final comments and concurrence.
8. Issue the general permit

The three program areas are listed below.

Construction Stormwater:

As of 12-18-2021 this program is no longer administered through 327 IAC 15-5 and has been replaced with the new Construction Stormwater General Permit (CSGP).

Information related to the new Construction Stormwater General Permit (CSGP):

• Final CSGP Permit [PDF]
• CSGP Response to Public Comments [PDF]
• Public Information Meeting (11/16/2021):
  • Meeting Video (11/16/2021) [YouTube]
  • Presentation (11/16/2021) [PDF]
• Guidance - Buffers [PDF]

Municipal Separate Storm Sewer Systems (MS4s):

As of 12-18-2021 this program is no longer administered through 327 IAC 15-13 and has been replaced with the MS4 General Permit.

Information related to the new MS4 General Permit:

• Final MS4 Permit [PDF]
• MS4 Response to Public Comments [PDF]
• Public Information Meeting (11/30/2021):
  • Meeting Video (11/30/2021) [YouTube]
  • Presentation (11/30/2021) [PDF]
• Guidance for Implementation

Industrial Stormwater:

Currently this program is administered through 327 IAC 15-6.

IDEM is at Step Seven (7) as listed above. IDEM is currently reviewing public comments and preparing responses. IDEM is also updating our data management systems with the objective to meet the U.S. EPA Electronic Reporting Rule.

The Draft Permit that was public noticed may be viewed at:

• Draft Industrial Stormwater General Permit [PDF]

Indiana Stormwater Quality Manual – Draft Stormwater Quality Measures

In developing the new permit U.S EPA has requested Indiana to incorporate several new requirements into the permit. These requirements have resulted in the modification of several measures in the current Indiana Stormwater Quality Manual. These measures are now located at: IDEM: Storm Water Permitting: Indiana Storm Water Quality Manual.