The MWRA submitted a third supplement to its 2021 Final CSO Assessment Report to the EPA and MassDEP at the end of December. The purpose of the report “is to document the progress made toward meeting the Long-Term Control Plan (LTCP) at each of the 16 locations” that did not meeting LTCP goals at the end of 2021.
Significant progress toward compliance was achieved for 10 of the 16 outfalls, with construction of improvements completed at 8 locations and construction of recommended improvements underway at 2 locations.
This leaves, as the court describes, the “Incorrigible Six.” In 2021, these outfalls presented significant challenges toward finding reasonable and effective measures to meet LTCP goals. Due to reductions in CSO volumes, two of these outfalls along the Charles River are now considered to be effectively meeting their LTCP goals, though differences between meter data and model predictions led to a recalibration of the model in the area of CAM401A, bringing this outfall along Alewife Brook out of compliance.