On January 15, 2021, the EPA finalized the 2021 Multi-Sector General Permit (MSGP) for discharges of industrial stormwater. This 2021 MSGP supersedes the 2015 permit. Existing and new facilities with industrial stormwater discharges need to apply for coverage under the new permit by submitting a Notice of Intent (NOI) to the EPA or a state-mandated program. In addition, all subject facilities must update their stormwater pollution prevention plan (SWPP) to conform with the 2021 MSGP requirement.

What are the new deadlines under the 2021 MSGP?

What changes under the 2021 MSGP?

Details regarding new or modified requirements to the 2021 MSGP can be found here. The most salient changes to the 2021 MSGP are noted below:

  • Public signage containing EPA contact information at publicly accessible locations proximate to the facility.
  • Quarterly “Report Only” Monitoring for pH, TSS, and COD for certain operators. These parameters do not have an action level unless other water quality standards apply.
  • “Report Only” Monitoring for Polycyclic Aromatic Hydrocarbons for certain operators twice per year during their first and fourth years of coverage. These parameters do not have an action level unless other water quality standards apply.
  • Updated benchmark thresholds for Aluminum, Copper, Selenium, and Cadmium. Facilities that exceed the revised thresholds for aluminum and copper may utilize the national recommended water quality criteria multi-variable models to demonstrate to the EPA they have not resulted in calculated exceedances of facility-specific values.
  • Suspended benchmark thresholds for Magnesium and Iron, based on a lack of acute toxicity.
  • New benchmark monitoring schedule allowing an operator that does not exceed the four-quarter annual average for one or more parameter(s) in the first four to discontinue benchmark monitoring for the subsequent eight quarters. Monitoring shall resume for all parameters for the next four quarters, allowing the operator to terminate benchmark monitoring for the remainder of MSGP coverage if there are no four-quarter annual average exceedances for a given parameter. There are similar monitoring schedule flexibility provisions for discharges to impaired waters without required total daily maximum load thresholds.
  • Consideration of heightened control measures for facilities that can be impacted by major storms to reduce pollutants during such events.  While such controls are not mandated, the 2021 MSGP requires facilities to provide documented evaluation of employing such controls.

Omni Environmental Group is here to support you!

Please contact us at info@omnieg.com if you need help with the 2021 MSGP, have questions about your facility’s compliance, or are uncertain if your facility is subject to the 2021 MSGP.  We can assist you in determining applicability, applying for stormwater coverage, preparing facility-specific SWPPP documents, and maintaining stormwater compliance.