Capacity and service area The plant has a treatment capacity of 384 million gallons per day (mgd) or 1.45 billion liters per day, with a peak capacity (partial treatment during large storms) of over 1 billion gallons per day (3.8 billion liters/day). The plant occupies in
the southwest quadrant of Washington, D.C., and discharges to the Potomac River. It serves over 1.6 million customers in Washington, large portions of adjacent
Prince George's County and
Montgomery County in
Maryland, and portions of
Fairfax County and
Loudoun County in
Virginia. Since the mid-1980s, Blue Plains has reduced its phosphorus discharges to the limit of technology, primarily in support of
water quality goals of the Potomac River, but also for the restoration of the
Chesapeake Bay. The
1987 Chesapeake Bay Agreement was a first step in reducing nitrogen discharge to waterways that are tributaries of the Chesapeake Bay. Under the agreement, the Bay states and the District of Columbia government committed to voluntarily reduce nitrogen loads by 40 percent from their 1985 levels. Blue Plains was the first plant in the region to achieve that goal. Furthermore, in every year since the full-scale implementation of the
biological nitrogen removal (BNR) process was completed in 2000, Blue Plains has every year successfully achieved and exceeded that goal of a 40 percent reduction. In Fiscal Year 2009, the BNR process at Blue Plains reduced the nitrogen load by more than 58 percent. Installation of enhanced nutrient control systems was completed in 2014. The enhanced plant achieves nitrogen effluent levels at 4 mg/L.
Sludge treatment reactors, utilizing the Cambi process, installed in 2013 DC Water began operating its
thermal hydrolysis system, for improved treatment of
sewage sludge, in 2015. This is the largest thermal hydrolysis facility in the world as of 2016. ==History==