GES provided mechanical, plumbing, fire protection, and process engineering for the new $215 million Tunnel Dewatering Pump Station (TDPS) and Enhanced Clarification Facility (ECF), which was constructed at the Blue Plains advanced wastewater treatment plant in Washington, DC. The TDPS-ECF were part of the larger DC Clean Rivers Project, mandated under a federal consent decree between the United States, the District Government and DC Water, to build tunnels to temporarily store combined sewer (sanitary and storm) overflows until they could be pumped to the treatment facility.