Bowman partnered with English Construction for this Design-Build project. The project is for a central wastewater collection, treatment and disposal system to serve the service districts of Catlett and Calverton located along State Route 28 in Fauquier County. The project includes a new collection system consisting of individual Septic Tank Effluent Pump (STEP) systems that transfer wastewater to a central wastewater treatment plant. The wastewater treatment plant will treat wastewater utilizing an Integrated Fixed Film Activated Sludge (FAS) technology. Effluent will be disposed of through the use of subsurface drip irrigation drain fields. The design of the wastewater collection and treatment system is based on the Virginia Sewage Collection and Treatment (SCAT) Regulations. The design of the subsurface disposal system is based on the Virginia Regulations for Alternative onsite Sewage Systems.
The STEP collection system will be installed for the collection and conveyance of the wastewater to the treatment plant. Each property will be provided with an individual compartmented septic tank and effluent pump that will transfer wastewater into common force mains. The force mains will range in size from 2″ through 4″, depending on the number of connections that are to be served. The STEP pump system will consist of a septic tank, effluent pumps installed within a filtered pump chamber within a septic tank, and a control/alarm panel. Depending on the number of houses to be served by the septic tank, the pump will be capable of either 11 gpm or 19 gpm.