WSSI worked on DC Water’s Long Term Control Plan and the DC Clean Rivers Project. DC Water is the agency/authority responsible for the District’s water and sewer conveyance system.  As a part of the District's National Pollutant Discharge Elimination System (NPDES) permit issued by the U.S. Environmental Protection Agency (EPA), the District and DC Water were required to prepare a Long-Term Control Plan (LTCP), now known as the Clean Rivers Project (CRP).

The CRP is an ongoing initiative to reduce combined sewer overflows (CSO) in the District by installing diversion facilities and conveyance/storage tunnels at key locations throughout the sewershed to capture and convey overflows to the Blue Plains treatment facility.  The program also seeks to reduce the total volume of stormwater runoff through the implementation of low-impact development (LID) or green infrastructure (GI) practices.

WSSI was a member of Greeley and Hansen’s team, performing under a series of separate task orders to provide technical support to several DC CRPs.  Our tasks included:

  • Assessing the feasibility of several potential sewersheds in the District based on land cover, land use, demographics, and historic resources and prepared exhibits and a series of technical reports which continue to support DC Water in developing site selection criteria and concept plans for GI demonstration projects.  
  • LID retrofits for Fort Reno Reservoir and Anacostia and East Side Pumping Stations.  These retrofits included two green roofs, two pervious pavement areas, a bioswale, and a raingarden.  WSSI provided the civil and landscape design components, with other team members providing mechanical, electrical, and structural design.  WSSI staff provided full-time construction inspection/ administration services, as well as bioretention material testing.
  • Landscape design and arborist services for several tunnel portals and pump stations, as well as 20 bioretention facilities.
  • Team support for the development of DC Water’s Green Infrastructure Standards and Details that will be the CRP Team’s design basis.
  • The establishment of preliminary design and site selection criteria and developed GI conceptual designs for a series of representative city blocks and two public schools. WSSI also prepared illustrative plans and perspective rendering graphics to communicate the design intent, user experience of the proposed facilities, and construction-related site conditions for use in coordination with public agencies and stakeholder groups and to support the public outreach program.