Rehabilitation of the Accotink Pump Station (APS) and replacement of the existing Accotink Force Main (AFM). The APS and AFM are owned and operated by Fairfax County. The project and work are contained within Fairfax County easements located on U.S. Army Fort Belvoir property. Rehabilitation of the APS includes expansion of the existing APS structure for a new electrical and generator room, replacement of the existing pumps with new dry-pit submersible pumps, replacement of the existing screening system with a new mechanical bar screen, replacement of the existing odor control system with a new carbon adsorber scrubber system, replacement of the existing transient control system with new surge tank, replacement of the existing generator and fuel system, replacement of process mechanical piping and valves, replacement of HVAC and plumbing systems, and replacement of electrical, instrumentation and control systems. The Work includes selective demolition to accommodate the rehabilitation, installation of structure assemblies to support the rehabilitation, and installation of lining and coating systems. Additionally, miscellaneous architectural enhancements, life safety improvements and fire protection upgrades are incorporated along with stormwater improvements that include grading, drainage, and entry road modifications. Replacement of the existing AFM includes a new parallel force main and installation of a trenchless crossing to support the new parallel force main installation under Accotink Creek. The new forcemain is being constructed in a former artillery range and will require scanning for unexploded ordinance. All work is to be completed while maintaining continuous pumping operations throughout the project duration using supplemental and bypass pumping.
