2026 Multi-Sector General Permit for Industrial Stormwater Discharges: National Municipal Stormwater Alliance Comments Addressing Proposed Federal Renewal

The National Municipal Stormwater Alliance (“NMSA”) submitted April 4th comments to the United States Environmental Protection Agency (“EPA”) addressing the proposed Clean Water Act National Pollutant Discharge Elimination System (“NPDES”) Multi-Sector General Permit (“MSGP”) for Stormwater Discharges Associated with Industrial Activity. See Docket No. EPA–HQ–OW–2024– 0481; FRL-11244–01– OW.

The MSGP is a general permit (as opposed to an individual permit) utilized by EPA to address stormwater discharges associated with thousands of different types of facilities in the United States.

The MSGP applies to any number of businesses and multiple industrial sectors. Examples might include cement mixing, scrap metal, trucking, food processing, printing and publishing, oil and gas extraction, asphalt paving and roofing materials, etc. A separate general permit is used for construction activities. EPA’s MSGP is utilized in states that do not have primacy for this Clean Water Act permitting program.

Note that Arkansas has been authorized to administer the NPDES stormwater permitting program for many years. As a result, the EPA 2026 MSGP will not be applicable in this state. Nevertheless, states with primacy often take into account to some extent EPA’s choices (i.e., in terms of permit conditions and limitations) in revising or reissuing their general stormwater permit.

EPA first established NPDES permit requirements for industrial stormwater discharges in 1990. The agency issued the first MSGP for these facilities in 1995. The 2026 MSGP represents the latest proposed renewal of this permit.

NMSA states that its member organization represents over 4,400 of the 7,550 total Municipal Separate Stormwater Sewer Systems (“MS4”) permittees across the United States. The member organizations are stated to be in 26 states representing all regions of the country. Further, MS4 program managers are described as the:

…stewards of urban stormwater conveyance and treatment systems that address urban runoff, which is the largest growing source of water pollution in many parts of the U.S.

NMSA’s comments focus on the proposed MSGP’s PFAS monitoring requirements. The organization states that its concerns involve:

• Nascent nature of PFAS monitoring and treatment.
• Policies associated with PFAS in the context of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) program.

Specific concerns include:

• Utility of PFAS monitoring in stormwater runoff at this time.
• Context on the purpose of PFAS monitoring in the MSGP is requested.
• Identifying PFAS as a hazardous substance changes the dynamics for MS4s.
• Concern that findings of PFAS at a location within an MS4 could makes these MS4s legally liable in third-party lawsuits as transporters of PFAS in the context of the CERCLA program.
• Despite EPA’s stated intention to not hold MS4s liable for PFAS transport, the federal agency does not have the ability to indemnify such entities from third-party lawsuits.
• Thousands of PFAS compounds can be found in stormwater runoff and the highly technical/specialized analytical techniques make such monitoring challenging because of the low concentrations in runoff.
• Request that all PFAS monitoring requirements be removed until the technological challenges have been addressed more readily and legal liabilities to public utilities/municipalities be addressed through federal statutory action.
• PFAS-related benchmark monitoring should not be applied for any identified sectors at this time because of the nature of these substances in stormwater runoff is not understood at the level needed to establish benchmarks.

A copy of the comments can be downloaded here.