Trap Rock Water Treatment Facility


Loudoun Water


Leesburg, VA

Date Completed

October 2018



The new Trap Rock Water Treatment Facility involves construction a 20million gallons per day potable water system for Loudoun County Virginia.  The new facility consists of nine new structures: Operations Building, Chemical Building, Maintenance Building, Finished Water Pump Station, Pre-Ozone Building, Thickener Building, Residual Handling, North Lower Sycolin Pump Station, and the Administration Building.  The project also includes (2) 2.75 million-gallon clearwells and a 400-foot-long tunnel with two 50-foot drop shafts.

The instrumentation for the project consisted of the following:

  • 9 Programmable Logic Controllers (PLC’s)
  • 113 local control panels/control panels
  • Over 20,000 feet of fiber optic cable
  • Over 1,000,000 feet (approx. 200 miles) of twisted shielded pair cable, #14 and #12 THHN
  • Over 500,000 instrumentation and control wire terminations

The power distribution for this project included the following: 

  • (1) 2000A 5kV Main Switchgear
  • (1) 2000kW 5KV Diesel Generator
  • (3) 2500A 5kV – 480/277V Unit Substations
  • (9) 480V Motor Control Centers
  • Over 20,000 feet of 5kV cable
  • Over 100,000 feet of 600V XHHW feeder cable

Singleton self-performed the terminations for all power distribution cabling including the 5kV cable. There was an intensive coordination and commissioning effort to make the plant operational.  Singleton Electric employees demonstrated the highest degree of quality craftsmanship and technical skills to perform an outstanding job under difficult conditions. In 2018, the craftsmen responsible for this project from Singleton Electric won two Washington Building Congress Craftsmanship Awards in the categories of Electrical Special Systems: Instrumentation and Control and Electrical Power Generation, Distribution and Switchgear.