Loudoun Water’s Quarry A (Milestone Reservoir) and Raw Water Pumping Station project (Project) is the conversion of a retired rock quarry to a 1.25 billion gallon raw water reservoir and connection of that reservoir to Loudoun Water’s existing raw water transmission main between the Potomac River and the Trap Rock Water Treatment Facility.  The Project will be delivered by a Construction Manager using Construction Management at-Risk (CMAR) project delivery.  Arcadis is the Design Engineer and Black and Veatch is the Professional Advisor.  

Project details include the following:


  • Pump Station
    • One 300-foot deep, 25-foot finished inside diameter pump shaft
    • Three 10-foot diameter intake tunnels, 200 to 400 feet in length
    • 40 MGD pump station
  • Raw Water Transmission Mains
    • Two 20+ foot diameter shafts, 70 to 90 feet in depth
    • One 14-foot diameter, 600-foot long tunnel
    • 36-inch and 42-inch transmission mains
  • Other Improvements
    • 30-foot diameter tunnel plug between quarry reservoir and an active quarry
    • Stormwater facilities
    • Rock slope stabilization
    • Water and sewer connections
    • Surface site improvements
Project Status: 
Upcoming Capital Design