MWRA Quabbin–Wachusett Watershed Protection Program (USA)

The Massachusetts Water Resources Authority (MWRA) supplies drinking water to greater Boston from the Quabbin, Ware River and Wachusett reservoir system. Under the state's 1992 Watershed Protection Act, the Department of Conservation and Recreation (DCR) has kept about 75% of these watersheds as DCR-owned or otherwise protected open space, and continues to purchase roughly 1,500 additional acres of forest and farmland per year to keep development and pollutant sources away from the reservoirs.

Under the federal Surface Water Treatment Rule, a 1993 consent order gave MWRA until 1998 to either build a full filtration plant or demonstrate that source-water protection kept water quality within the criteria for filtration avoidance. MWRA built a new ozone/chloramination disinfection plant rather than a granular filtration plant, relying on upstream land protection to keep raw-water turbidity low.

After EPA opposed a waiver, the dispute went to federal court; on May 5, 2000, Judge Richard Stearns ruled that MWRA's integrated programme met all 11 federal criteria for avoiding filtration. Adding filtration would have cost an estimated $180 million more than the ozonation plant that was built instead, a saving directly attributable to decades of watershed land protection keeping raw-water turbidity low. It is one of only a handful of major U.S. utilities, alongside New York City, to have achieved a court- and regulator-validated filtration avoidance determination on the strength of upstream land conservation.