Stormwater Discharges from Industrial Activities-EPA's 2021 MSGP

Stormwater Discharges from Industrial Activities Topics

Overview

EPA’s 1990 stormwater regulations established NPDES permit requirements for industrial stormwater discharges, and the Agency issued the first Multi-Sector General Permit (MSGP) for those facilities in 1995. The 2021 MSGP became effective on March 1, 2021. Subsequently, EPA finalized a minor modification to the 2021 MSGP that became effective on September 29, 2021.

A note for current MSGP permittees: Eligible discharges available for coverage under the 2021 MSGP are not altered in this modification and coverage remains available to operators of eligible facilities. Any industrial facility operator that has permit coverage under the 2021 MSGP prior to the final issuance of the modification will automatically remain covered under the permit. 

EPA’s 2021 MSGP applies in areas of the country where EPA is the NPDES permitting authority and has made the permit available for coverage. These areas include:

  • Four states:  Massachusetts, New Hampshire, New Mexico, and Idaho
    • On July 1, 2021, NPDES permitting authority for industrial stormwater was transferred to Idaho; for more information about Idaho’s NPDES authorization visit Idaho NPDES Program Authorization
  • The District of Columbia
  • Puerto Rico
  • All U.S. territories except for the Virgin Islands
  • Federally operated facilities in Colorado, Delaware, Vermont, and Washington
  • Most Indian country lands, and
  • Other designated activities in specific states (e.g., oil and gas activities in Texas and Oklahoma)

2021 MSGP

On January 15, 2021, EPA issued the 2021 MSGP.

EPA hosted two public informational webinars on the new 2021 MSGP on February 19, 2021 and March 4, 2021. The webinars covered industrial stormwater program basics, discussed the structure and requirements of the new permit, including how to renew coverage or get coverage for the first time, and highlighted new provisions and changes from the 2015 MSGP.

View the recorded webinar held February 18, 2021:

Permit, Associated Documents, and Federal Register Notice

Below are the permit, associated documents, and the Federal Register Notice.

2021 MSGP – Permit

2021 MSGP – Appendices

2021 MSGP – Fact Sheet

2021 MSGP – Federal Register Notice

Background on 2021 Multi-Sector General Permit Minor Modification

Following the issuance of the 2021 MSGP, EPA identified several typographical and similar errors in the permit. On July 16, 2021, EPA issued Errata for the 2021 Multi-Sector General Permit for Industrial Stormwater to clarify the identified errors.

Through the memorandum below, EPA expressed its intent to issue, pursuant to 40 CFR 122.63, a minor modification to the 2021 MSGP for stormwater discharges associated with industrial activity. The modification was finalized in September 2021 to incorporate the corrections listed in the memorandum and outlined in the July 16, 2021 errata. The modification does not create any new or additional obligations for you or your facility/facilities. These minor clarifications improve the readability of the permit and fact sheet for permittees.

National Pollutant Discharge Elimination System (NPDES)

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Last updated on March 29, 2025