Clinton Wastewater Treatment Plant NPDES Permit Update

On February 3rd, EPA issued a Draft NPDES Medium Wastewater Treatment Facilities General Permit for Massachusetts, and notified MWRA that the Clinton Wastewater Treatment Plant would be eligible for coverage under this draft permit. The period for public comment on this permit is from February 8, 2022 through April 11, 2022.

MWRA staff has identified some key areas where the new General Permit differs from the existing 2017 Clinton NDPES permit. Here are a few highlights:

  • New limits for ammonia
  • New monitoring requirements including PFAS
  • Some reduction in certain monitoring requirements
  • Reporting changes including a requirement to post the start/stop/estimated volume of any unauthorized discharges (e.g. SSOs and upsets) on the web within 24 hours, compared to the current window of five days
  • Reduction of the time to complete the local limits study from 180 days currently to 90 days in the draft general permit
  • Co-permittee language, while similar, includes some new requirements regarding alternate power sources

We should note that while the Clinton Wastewater Treatment Plant is eligible for coverage under this General Permit, the MWRA may request to be excluded from coverage.

Advisory Board staff will continue to monitor this issue and report back.