Potomac Water Supply Program Trap Rock Water Treatment Facility

This new $133.2 million 20-mgd water treatment plant, expandable to 40 mgd, substantially increased the region’s water supply capacity.

Work included a 400-foot-long tunnel with two 50-foot drop shafts; a pre-ozone contactor facility and operations building housing flocculation basins, sediment basins, settled water ozone contactor, filters and a UV system; residuals handling facilities including backwash, equalization, clarification, sludge thickening and clearwells; a finished water pump station; 3,500 feet of 42-inch-diameter finished water transmission main; a sanitary pump station and 10,000 feet of 12-inch-diameter force main; a maintenance facility; and a LEED Gold administration building.