EPA’s 2021 Multi-Sector General Permit for industrial stormwater expired at 11:59 p.m. Eastern on February 28, 2026. An enforcement memo dated February 27, 2026 confirms how the gap is handled.

What changed

• Facilities already covered under the 2021 MSGP are automatically granted an administrative continuance of coverage — no action needed to stay permitted.
• New facilities starting discharge during the interim must submit a Notice of Intent and comply with the 2021 MSGP terms, then file a new NOI within 90 days of the next permit taking effect.
• The proposed 2026 MSGP, whose comment period closed May 19, 2025, would add PFAS monitoring for certain sectors.

What it means in the field

Nothing in your sampling schedule pauses. Benchmark monitoring, impaired-waters monitoring, quarterly visual assessments and your SWPPP inspections all continue under the 2021 terms. If PFAS monitoring lands in the final permit, sample handling gets stricter, not just more frequent.

Gear for the wet-weather work: stormwater and NPDES, surface water monitoring, and flow and stream gauging.

Sources: EPA OECA memorandum on 2021 MSGP expiration (PDF); EPA — proposed 2026 MSGP.