Blue Plains AWWTP Wet Weather Treatment Facility

Eliminating the potential of untreated overflows into local waterways.

Treatment Plant Facilities
Washington, DC
Delivery Method
DC Water
Year Complete

Project Overview

This $215 million design-build project added a 500-mgd tunnel dewatering pump station and 225-mgd enhanced clarification facility to the Blue Plains Advanced Wastewater Treatment Plant. The project features a ballasted flocculation clarification process, including ACTIFLO® high-rate clarification process, fine screens, grit removal and disinfection and dechlorination facilities.

Work included the conversion of a deep shaft measuring 132 feet by 159 feet as well as a secondary shaft measuring 76 feet in diameter by 130 feet deep. The facilities are designed to treat 225 million gallons of incoming combined sewer overflow (CSO) captured and stored in a network of diversion structures, drop shafts and massive underground sewage tunnels beneath Washington, DC, eliminating potential untreated overflow into the Anacostia and Potomac Rivers and Rock Creek.


Total Design-Build Construction Project Value


MGD Tunnel Dewatering Pump Station


MGD Enhanced Clarification Facility