What: On December 13, 2024, the U.S. Environmental Protection Agency (EPA) published the proposed 2026 multi-sector general permit (MSGP) for stormwater discharges from industrial activities in the Federal Register. The permit will replace the 2021 MSGP and cover 30 different industrial sectors, all of which are listed in the notice.
Why: The 2026 MSGP includes a number of changes from the 2021 permit, including:
- Revisions to data requirements for operators when designing stormwater control measures to withstand future weather conditions.
- A proposal that discharges must not contain or result in observable deposits of floating solids, scum, sheen, or substances; an observable film or sheen upon or discoloration from oil and grease; or foam or substances that produce an observable change in color.
- New monitoring requirements for Per- and Polyfluoroalkyl Substances (PFAS).
- A shift from report-only indicator monitoring to benchmark monitoring for certain sectors.
- A modified benchmark monitoring schedule requiring operators to conduct quarterly benchmark monitoring in their first three years of permit coverage or until twelve quarters of monitoring data are collected.
- Requiring operators discharging to impaired waters to complete quarterly monitoring for all pollutants for which the waterbody is impaired. If a pollutant is detected, corrective action will be required.
- Requiring facilities to conduct an inspection to identify the cause of a benchmark exceedance when a level 1 additional implementation measure (AIM) is triggered.
- A requirement for operators to provide analytical results of stormwater runoff from natural background and to get EPA approval to claim a natural background exception.
- Requiring operators to submit an AIM Triggering Event Report to the EPA in response to triggering AIM at any level.
EPA is also requesting comment on additional issues related to the 2026 MSGP, including the possible discharge of 6PPD-quinone in stormwater.
Action: Comments on the proposed 2026 MSGP are due February 11, 2025. Comments on the information collection provisions related to the permit are due January 13, 2025.
Read the Federal Register notice and submit comments.
Read additional information on the 2026 MSGP and supporting documents.
Advocacy contact: Send an email to Nick Goldstein at nick.goldstein@sba.gov.