EPA Sets Nitrogen Limits for World's Largest Advanced Wastewater Treatment Facility

On April 5, EPA announced the establishment of new limits on the amount of nitrogen that can be legally discharged by the Blue Plains wastewater treatment plant. The agency's action is designed to help improve water quality in District of Columbia waters and the Chesapeake Bay.

The nitrogen reduction from 8.5 million pounds per year to 4.7 million pounds per year is part of a modification to the facility's operating permit. To meet the new limits, the District of Columbia Water and Sewer Authority, which owns the plant, will need to upgrade the facility under a timeline outlined in a forthcoming consent agreement with EPA.

"This action is part of EPA's Chesapeake Bay initiative to reduce the amount of nitrogen, phosphorous and sediments entering the bay," said Donald S. Welsh, EPA Region 3 administrator. "Meeting these reductions will be key in our efforts to help restore the Chesapeake Bay and the waterways in and around our nation's capital."

As the world's largest advanced wastewater treatment facility, Blue Plains serves the District of Columbia, Montgomery and Prince Georges counties in Maryland and Fairfax and Loudoun counties in Virginia. The facility covers 150 acres and has a design capacity to treat 370 million gallons of effluent per day. Its collection system includes about 1,800 miles of sanitary and combined sewers. The District of Columbia sewer system is owned and operated by the District of Columbia Water and Sewer Authority.

Improvements to the Blue Plains plant will reduce the amount of nitrogen discharged to the Potomac River, which flows into the Chesapeake Bay. Excess nutrients are harmful to these waters and their fish and wildlife. They reduce the amount of oxygen, cloud the water, lead to the loss of viable underwater grasses, and decrease crucial natural habitats.

A copy of the permit and a fact sheet is available at http://www.epa.gov/reg3wapd/npdes/blueplains.htm.