Final Tennessee Multi-Sector General Permit for Industrial Stormwater Discharge

What is the TMSP?

The Tennessee Multi-Sector General Permit (TMSP) authorizes industrial stormwater discharges to waters of the State of Tennessee from industrial applicable and covered facilities. The previous TMSP expired on June 30, 2025, and the Tennessee Department of Environment and Conservation (TDEC) issued a replacement permit that became effective July 1, 2025.

What’s New?

The TMSP replacement permit is a hybrid between the current TMSP and the United States Environmental Protection Agency’s (U.S. EPA) 2021 multi-sector permit.

The replacement permit includes:

• What is deemed to be the most effective language and permitting mechanisms from both permits in a single document,
• New benchmark concentrations for pollutants,
• Updated requirements for Sector AF (Industrial Activity from Borrow Pits, Soil Harvesting Sites, and Spoil Piles) to include water quality buffer requirements, and
• New electronic reporting requirements for Notice of Intent (NOI) and Notices of Termination (NOTs) forms.

More information on the TMSP updates can be found in our previous blog. The redline version of the differences between the draft permit and final permit after public comment can be viewed on the TDEC website.

Now What?

If your Facility currently has TMSP coverage, you should have received information about submitting a digital NOI form via MyTDEC Forms when the new permit was issued. Existing permitted facilities must submit an NOI, a map meeting the requirements of Section 2.2.1 of the TMSP, and review and update Stormwater Pollution Prevention Plan (SWPPP) (optional) no later than 91 days after the permit effective date (September 30, 2025). New facilities without TMSP coverage should submit NOI at least 30 calendar days prior to commencing discharge. More information on TMSP coverage can be found here on the TDEC website.

If you need assistance determining how the new TMSP may impact your facility operations or need help developing an NOI or updating your SWPPP, please reach out to Peyton Rodgers at prodgers@all4inc.com for assistance.