New Draft Tennessee Multi-Sector General Permit for Industrial Stormwater

The Tennessee Multi-Sector General Permit (TMSP) is intended to authorize industrial stormwater discharges to waters of the State of Tennessee from industrial facilities. The TMSP expires on June 30, 2025 and the Tennessee Department of Environment and Conservation (TDEC) has prepared a replacement permit and published the draft for public comment. This draft permit is subject to change prior to the final issuance.

If your Facility currently has TMSP coverage, you do not have to do anything as of right now. Information about submitting a digital Notice of Intent (NOI) form via My TDEC Forms will be sent to active permittees when the new permit is issued. If your Facility does not have coverage under the previous TMSP and operations will begin before June 30, 2025 your Facility will need to submit a completed NOI and stormwater pollution prevention plan (SWPPP). More information on TMSP coverage can be found on the TDEC website.

What’s New?

The TMSP draft 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 as well as new benchmark data, a new Sector for soil harvesting, and a new requirement for electronic submission of forms.

Benchmark Data

The TMSP requires analytical monitoring for the industry sectors or subsectors that demonstrate potential to discharge pollutants at concentrations of concern. To determine when such analytical monitoring is required, U.S. EPA established benchmark concentrations for the pollutant parameters on which monitoring results had been received. The benchmarks are the pollutant concentrations above which the U.S. EPA determined represents a level of concern, at which a stormwater discharge could potentially impair or contribute to impairing water quality or affect human health from ingestion of water or fish. TDEC will use the values to determine if a stormwater discharge from any given facility merits further monitoring to ensure that the facility has been successful in implementing a SWPPP. The benchmark concentrations are not effluent limitations as they represent a target concentration for a facility to achieve through implementation of pollution prevention measures at the facility. TDEC will assign further monitoring at their digression. TDEC collected large amounts of stormwater runoff monitoring data to provide the summary of that data, interpret information with respect to compliance benchmarks, and cross-reference information with respect to surface water quality. This analysis along with new proposed parameters are shown in the TMSP Rationale.

Sector AF: Stormwater Discharge Associate with Industrial Activity from Borrow Pits, Soil harvesting Sites and Spoil Piles

Businesses with borrow pits, soil harvestings, and spoil piles that are not associated with a single construction site and are considered industrial activities will require coverage under the replacement TMSP as proposed. Neither a construction stormwater permit nor any of the other sectors in the previous TMSP were a good fit for soil harvesting activities. Section AF is a new sector customized for this type of business. You can read more on Sector AF in the 2025 Draft TMSP.

eReporting Requirements

The replacement permit includes a requirement to submit either of the forms, the NOI and Notice of Termination (NOT), electronically in order for a person to comply with certain requirements, including, but not limited to, making reports, submitting monitoring results and applying for permit coverage. The TDEC Forms may be found here.

TDEC will hold a public hearing on the issuance of the draft TMSP on May 21, 2025. Comments will be received at least 10 days after the last hearing. Please see the Notice of Public Hearing for more information. ALL4 will follow the development of this permit and will publish an update to this article once the permit is finalized.

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