MWRA monitors the water quality of Boston Harbor and Massachusetts Bay, measuring nutrients,
pathogens, metals, organics, solids, pH, oil and grease, and toxicity. See the What's New page for the latest water quality information and reports.
MWRA's NPDES discharge permit requires compliance reports on several measures of effluent quality and system maintenance. This is intended to control water pollution and ensure compliance with the federal Clean Water Act.