Boston Harbor's Tributary Rivers: Patterns of River Bacteria
OF RIVER BACTERIA COMPARED TO PHASES OF CSO CONTROL
In the Charles, improvement in water quality over the past ten years has been dramatic; fecal coliform counts (geometric mean) fell by over five-fold. Although the Mystic River shows slight improvement over this period, the Mystic and Alewife Brook are still plagued with contaminated stormwater and CSOs. Implementation of MWRAs CSO Plan will control CSOs, but stormwater is a major source of bacteria. Although closing CSOs and better CSO treatment at MWRA facilities has reduced inputs of bacteria to the Neponset, stormwater sources are so much larger than were CSOs that water quality in the lower Neponset has remained about the same since monitoring began.