3-Year Extension Granted for CSO Long-Term Control Plan

On Friday, February 18th the US District Court signed off on a three-year extension to the CSO Long-Term Control Plan. The last milestone in the Boston Harbor Federal District Court case required MWRA to submit the results of a performance assessment of its Long-Term Combined Sewer Overflow Control Plan to determine whether the levels of CSO control included in the LTCP had been achieved. MWRA submitted this assessment on December 30, 2021, complying with this final milestone.

In addition to submitting this performance assessment, the MWRA also submitted an interim update on the ongoing discussions with MassDEP, EPA, and the Conservation Law Foundation (CLF) for a potential framework for this three-year extension. After reaching agreement with MassDEP, EPA, and CLF and with the permission of the MWRA Board of Directors the MWRA filed a motion with the Court to propose the following six-part framework through December 2024:

  1. Submission of the Final Assessment Report
  2. Three years of additional time for certain system improvements at six of the 16 CSO outfalls that are not meeting the LTCP goals and continued analysis of the remaining 10 outfalls
  3. Annual reporting during the three-year extension period
  4. Periodic meetings with MassDEP, EPA, CLF, Mystic River Watershed Association, and Charles River Watershed Association during the three-year extension period
  5. Submission of a supplemental report in December 2024 related to the 16 outfalls not meeting the LTCP goals
  6. Corresponding additional Schedule Seven compliance milestones for the Authority’s submission of the annual reports and a supplemental report in December 2024

The CSO Long-Term Control Program has significantly reduced both the frequency of activation and discharge volume. The LTCP goal is to reduce overall CSO discharges by 88%, and the MWRA’s current efforts have reduced them by 87% – within one percent of the target.

This far-reaching and extensive program has been a primary focus for the Advisory Board over the years, and will continue to be moving forward. Advisory Board staff will remain vigilant on this issue and report back as updates are forthcoming.