On March 2, 2020, the Environmental Protection Agency (EPA) proposed its new Multi-Sector General National Pollutant Discharge Elimination System Permit (MSGP), which authorizes the discharge of stormwater associated with industrial activity. 85 Feb. Reg. 12,288 (March 2, 2020). The 2015 MSGP expires on June 4, 2020. The MSGP authorizes stormwater discharges associated with a wide range of facilities and activities, including oil and gas, mining and mineral processing and manufacturing, among other operations.

The MSGP authorizes discharges in only those states where EPA is still the NPDES permitting authority (Idaho, Massachusetts, New Hampshire and New Mexico), Indian country, US Territories and other select jurisdictions. However, most states model their state-specific industrial stormwater permits on the EPA’s MSGP, which makes this permit important as the trendsetter.

The most notable development in the proposed MSGP is EPA’s incorporation of recommendations from the National Academies of Sciences, Engineering, and Medicine’s National Research Council (NRC) Study, Improving the EPA Multi-Sector General Permit for Industrial Stormwater Discharges. The NRC Study was the result of a settlement agreement between EPA and industry and environmental organizations on litigation associated with the 2015 MSGP where EPA agreed to fund a NRC Study on potential permit improvements as well as agreeing that, when drafting the proposed 2020 MSGP, it would consider the NRC Study’s recommendations.

Notable changes in the proposed MSGP based on the NRC Study include:

  • Requirement for “universal benchmark monitoring” for pH, TSS and COD for all facilities.
  • New benchmark monitoring requirements for three industrial sectors (Oil and Gas Extraction, Land Transportation and Warehousing, and Ship and Boat Building and Repair Yards).
  • New benchmark monitoring thresholds for aluminum, selenium, arsenic, cadmium, magnesium, iron and copper based on the latest toxicity information.

There are a range of other monitoring, inspection and other proposed changes based on the NRC Study. The benchmark monitoring provisions are important because they are associated with corrective action provisions that could require capital or operational improvements at facilities based on exceedances of the benchmark values.