EPA proposes PFAS indicator monitoring in proposed 2026 Multi-Sector General Permit (MSGP) for industrial stormwater

EPA released a pre-publication Federal Register notice for the proposed 2026 Multi-Sector General Permit (MSGP) for industrial stormwater that includes a new provision for PFAS “indicator monitoring” (described as quarterly, report-only analytical monitoring for PFAS for many sectors). This creates a potential new PFAS monitoring expectation for facilities operating under the MSGP in EPA-permitting areas. Compliance teams should identify affected sites/sectors, assess sampling/analytical feasibility and cost, and prepare to submit comments once the proposal is formally published (comment deadline stated as 60 days after Federal Register publication).