The Massachusetts Water Resources Authority (MWRA) will hold a virtual public briefing on its Combined Sewer Overflow (CSO) Post-Construction Monitoring and Performance Assessment.

This briefing will be held on:

Friday, May 21, 2021
10:00 AM

The virtual meeting site link and login information are below:

Link to virtual meeting site: webex.com
Access Code:129 723 2190
Password: May21

In November 2017, MWRA commenced a multi-year study to measure the performance of its CSO Long-term Control Plan (the “LTCP”). MWRA is conducting the study in accordance with the final milestone in the 35-year-old Federal District Court Order in the Boston Harbor Case (U.S. v. M.D.C., et al, No. 85-0489 MA). The milestone requires MWRA to submit to the U.S. Environmental Protection Agency and the Massachusetts Department of Environmental Protection by December 2021 the results of CSO post-construction monitoring and performance assessments demonstrating whether the levels of CSO control including frequencies of activation and discharge volumes specified in the LTCP have been achieved. MWRA’s study includes the following key elements:

• Inspections at all CSO regulators/outfalls addressed in the LTCP to confirm closed or active status and confirm or update physical understanding of overflow structures
• Collection of extensive meter/overflow data at remaining active CSO regulators/outfalls
• Configuration updates and recalibration of MWRA’s hydraulic model of the wastewater system using recent inspection information and meter/overflow data
• Assessments of system performance for CSO control against the LTCP levels of control
• Assessments of the water quality impacts of remaining CSOs and compliance with Massachusetts Water Quality Standards, with emphasis on the CSO variance waters of Lower Charles River/Charles Basin and Alewife Brook/Upper Mystic River.

The public briefing will address the progress of the MWRA study as reported in semiannual progress reports, including the progress report issued on October 30, 2020 and the progress report MWRA will issue by April 30, 2021, copies of which can be reviewed at http://www.mwra.com/cso/pcmapa.html. The briefing will include opportunity for questions and comments.

For additional information, contact Jeremy Hall, MWRA Project Manager, at 617-759-0340 or jeremy.hall@mwra.com.

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