Residual Control Technology Saves Millions of Gallons of Water While Maintaining Consistent Chloramine Residual Levels Case Study

Loudoun water in Northern Virginia has a history of embracing change and seizing opportunities to create a more robust and sustainable water system. Situated in the fast-growing suburbs of Washington D.C., Loudoun Water provides chloraminated drinking water to over 65,000 households through a networkcomprisedof more than 1,200 miles of pipes and seven water storage tanks. A key element of Loudoun Water’s mission to sustainably manage water resources has been its efforts to improve the operational efficiency of its drinking water system. For a chloraminated water system, that means getting control of nitrification.

Loudoun  Water  used  to  be  a  simple  secondary  system, blending free-chlorine  drinking  water  from  the  City  of Fairfaxwithchloraminated water from neighboring Fairfax  County. Due  tothe  growthin its  service  area, Loudoun County continued to expand itscapabilitiesby building additional transmission mains and storage capacity  that  culminated  with  the  construction  of  the Dulles  South Tanks,  a  pair  of  3-MG  fluted  compositetanks serving the southern portion of its system(Figure 1).