Ask an Expert

Our debut “Ask an Expert” feature highlights BC subject matter expert Elizabeth Wilson on new changes in the 2021 Multi-Sector General Permit.

Question: What do the new changes in the 2021 Multi-Sector General Permit mean for my facility? How and when should I prepare?

Answer: The long-awaited revisions to the Multi-Sector General Permit (MSGP) have been released and whether your facility is affected immediately or is likely to be in the next few years, now is the time to plan ahead.

If your facility is in Idaho, New Hampshire, New Mexico, Massachusetts, Washington, D.C.; or is a federal facility in Colorado, CE, Vermont, or Washington; or certain oil and gas facilities in Oklahoma or Texas, you should be reviewing lessons learned during coverage under the 2015 MSGP, developing and updating your Stormwater Pollution Prevention Plan, and preparing to file your Notice of Intent by the May 30, 2021, deadline.
For facilities in other states, your state will likely adopt similar revisions after the next permit expiration year. This means you can start preparing now, too.

While permit revisions will affect facilities in different sectors in different ways, there are several areas that you may want to explore more closely.

Benchmark values
In some cases, thresholds and/or their units of measurement (e.g., mg/L to μg/L) have been changed. Paying close attention to these changes will help more readily compare your sampling results to the MSGP benchmark concentrations.

Coal-tar sealcoat application
Indicator monitoring for polycyclic aromatic hydrocarbons (PAHs) is a requirement for operators in all industrial sectors with stormwater discharges from paved surfaces that will be initially sealed or resealed with a coal-tar sealcoat. However, the EPA indicated that simply applying coal-tar sealant does not constitute an industrial activity. This is good news for facilities that meet the No Exposure Certification criteria now but plan to sealcoat paved surfaces in the future.

Monitoring
Indicator monitoring (e.g., pH, TSS, COD) is a new requirement for certain industrial sectors under the MSGP. Monitoring in Year 4, regardless of meeting benchmark concentrations in Year 1, is also a new compliance obligation for all facilities.

Additional implementation measures
This tiered process for addressing benchmark exceedances provides an escalation model for non-compliance. Staying in baseline status at the start of permit coverage by implementing effective control measures now will provide predictable costs and effort for compliance.

Elizabeth Wilson, Principal Scientist