Regulatory Forecast: 2020 MSGP for Stormwater Discharges Associated with Industrial Activity

NPDES Industrial MSGP

NPDES Industrial MSGP

The 2015 Multi-Sector General Permit for Stormwater Discharges Associated with Industrial Activity (commonly referred to as the “Multi-Sector General Permit” or “MSGP”) is about halfway through its five-year permit cycle. For the 2020 renewal of the MSGP, the United States Environmental Protection Agency (USEPA) is expected to propose a revised system of benchmark monitoring and corrective action requirements to replace those in the current 2015 MSGP. These revisions may have broad implications for industrial facilities currently covered under a MSGP. Though the federal MSGP directly applies only in a few states, the District of Columbia, the United States territories, and tribal lands, other state MSGPs are required to be at least as stringent as the federal stormwater permit.

In 2016, USEPA entered into a settlement agreement with environmental groups that challenged the issuance of the 2015 MSGP (Waterkeeper Alliance v. EPA [2d Cir. 15-02091]). [1] The settlement agreement has no effect on the terms and conditions of the current 2015 MSGP, which remains in place until June 2020. However, facilities subject to benchmark monitoring should be aware of the changes that are proposed for the upcoming issuance of the 2020 MSGP. Under the current MSGP, benchmark exceedances do not specifically result in noncompliance. But presently, benchmark exceedances can trigger the need for enhanced stormwater management practices (known as Best Management Practices [BMPs]). [2]

Benchmark Monitoring: New Tiered Responses to Benchmark Exceedances

When it drafts the 2020 MSGP, USEPA has agreed to propose a three-tiered series of escalating responses or “implementation actions” that will be required whenever permit holders’ stormwater discharges exceed the benchmark monitoring levels stipulated in their MSGPs. Under the proposed 2020 MSGP, permittees would be required to implement corrective actions depending on the extent and duration of their noncompliance. Specifically, when USEPA signs a notice for the Federal Register announcing the proposed 2020 MSGP for public comment, the agency has agreed to include in the benchmark monitoring section of the proposed permit “Additional Implementation Measures” requirements. The tiered implementation measures are outlined in the 2016 settlement agreement. [1] Beveridge & Diamond, P.C. (2016), a law firm that specializes in environmental law, presents a summary of the proposed tiers in a table from an article on their website (available at [2] The table also shows a comparison to the requirements of the 2015 MSGP (available at

No More Coal Tar-Based Pavement Sealants

According to Taylor Lewellyn (2017), a Legal Editor at Business & Legal Resources, another component of the proposed 2020 MSGP is the exclusion of industrial facilities that use coal tar-based pavement sealants from coverage under the MSGP. [3] Such pavement sealants contain polycyclic aromatic hydrocarbons (PAHs), which are a class of chemicals that occur naturally in coal, crude oil, and gasoline. According to USEPA and the Centers for Disease Control and Prevention, several PAHs or specific mixtures of PAHs are known carcinogens. PAHs from coal tar-based pavement sealants are found in stormwater discharges from facilities that use them on surfaces such as driveways and parking lots. Facilities that use these pavement sealants will be required either to eliminate such discharges or to apply for an individual stormwater permit. [1]

Other Proposed Changes

USEPA has also agreed to sponsor and fund a study by the National Research Council to evaluate and recommend (1) possible improvements to the benchmark monitoring requirements of the current MSGP to more accurately evaluate the performance of BMPs; (2) the feasibility of numeric retention standards for industrial stormwater discharges; and (3) the industrial facilities or sectors that USEPA should prioritize for the consideration of additional discharge characterization and/or monitoring. In addition, USEPA will propose measures to prevent stormwater discharges that could recontaminate federal Superfund sites. [1]

Preparing for the Proposed Permit Changes

The 2016 settlement agreement forecasts potential changes to the MSGP and similar state-issued stormwater general permits. These changes could impact a broad range of industrial facilities subject to stormwater permitting under the National Pollutant Discharge Elimination System (NPDES). In particular, current MSGP permittees that continue to use coal tar-based sealants on pavement and parking lots at their facilities may be required to seek an individual stormwater permit. The application and submittal requirements for an individual stormwater permit are often resource-intensive and time-consuming procedures.

EnviroScience (ES) has NPDES permitting experts on staff, formerly with the Ohio Environmental Protection Agency, who are very familiar with NPDES MSGP regulations. Professional engineers and scientists in the Compliance Services group at ES have over 125 years of combined experience in regulatory affairs. Compliance Services can develop regulatory compliance strategies and plans for clients, including services related to stormwater permitting, stormwater pollution prevention plan development and training, design and implementation of BMPs, site assessment/inspections, and field sampling/monitoring. In anticipation of the potential changes in 2020, permittees that want to maintain MSGP eligibility should assess the costs and benefits of using available non-coal tar pavement sealants and/or the treatment costs for removing sealant pollutants from their stormwater discharges. ES can assist clients with cost-benefit analyses and help clients navigate through the continually changing and often time-consuming stormwater regulations. Call us at 800-940-4025 or read more about our services here.


[1]  Waterkeeper Alliance v. EPA (2d Cir. 15-02091, 2016). Retrieved January 31, 2018, from

[2]  Richmond, Stephen M., & Roveillo, Virginie K. (Beveridge & Diamond, P.C., 2016). Stormwater Forecast: Prepare for More Aggressive Benchmark Monitoring and Corrective Action Requirements under the Next Proposed MSGP. Beveridge & Diamond, P.C. Retrieved February 1, 2018, from

[3]  Lewellyn, Taylor. (2017). EPA’s 2020 MSGP: A Look Ahead. Retrieved January 31, 2018, from