Arlington Co. Water Pollution Control Plant, Phase 7A, Arlington, Va.
The $136.5-million Arlington County Water Pollution Control Plant project makes a significant contribution toward improving the environmental outlook for the delicate, imperiled Chesapeake Bay ecosystem.
In addition to expanding capacity from 30 million gallons per day to 40 MGD, the upgrade greatly reduced nitrogen discharges into a river that feeds into the ecosystem. Ten years ago, the plant was discharging 17 milligrams of nitrogen per liter of water into the Four Mile Run River. Today, it is discharging 2.5 milligrams of nitrogen.