EPA’s next stormwater permit puts PFAS monitoring front and center

By Valerie Leone & Amanda Wade | TRC | June 26, 2026

Read the full article by Valerie Leone & Amanda Wade (TRC)

"Why Facilities Should Prepare Now  

The U.S. EPA has proposed a new Multisector General Permit (MSGP) for industrial stormwater discharges that will govern the next five-year permit cycle. While the permit is not yet final, it clearly signals where stormwater regulation is heading and why facilities should begin preparing now. The proposed changes make PFAS monitoring a priority for most sectors and will increase monitoring costs, operational oversight and public visibility of stormwater compliance results for many industrial operators. 

What’s Changing 

The proposed permit includes several notable shifts that could affect industrial facilities: 

Expanded monitoring requirements, including new PFAS indicator monitoring for many industrial sectors
Increased sampling frequency, particularly early in the permit term 
More prescriptive corrective action timelines following benchmark exceedances 
Greater scrutiny of visible indicators (sheen, foam, discoloration), which are increasingly enforced

Taken together, these changes raise both compliance effort and regulatory exposure, especially since stormwater monitoring data submitted under NPDES permits are publicly accessible. "