Wastewater Treatment

DC Water receives and treats wastewater collected from the District of Columbia sewer system and from the Maryland and Virginia suburbs. On an average day, more than 330 million gallons of raw sewage flow into the Blue Plains Advanced Wastewater Treatment Plant from area jurisdictions. And based on 2005 projections by the Metropolitan Washington Council of Governments, this is expected to rise to the plant's capacity of 370 million gallons a day by 2030.

The Blue Plains Advanced Wastewater Treatment Plant discharges flows to the Potomac estuary, and DC Water is required to meet some of the most stringent National Pollutant Discharge Elimination System standards (NPDES) in the United States. Historically, the Blue Plains plant's effluent parameter levels have remained well below established limitations.

We are continually improving and enhancing our wastewater treatment facility and processes to better serve the community, protect the environment, and ensure the safety and reliability of our water. DC Water uses both contracted and on-site laboratories to provide sample analyses to meet federal, state, and local permit and regulatory requirements. In-house, we conduct more than 100,000 analyses a year.

Our wastewater treatment goals include the following:

  • Protect the water quality of the Potomac River
  • Provide treatment capacity for current and future needs
  • Replace aging facilities and continually improve system reliability
  • Reduce biosolids odors onsite and offsite
  • Improve biosolids so they are easier and cheaper to manage and recycle
  • Continue to achieve the goals of the Chesapeake Bay Agreement

For more information about DC Water's wastewater treatment program, please download our brochure, Blue Plains Advanced Wastewater Treatment Plant.


For more information about nitrogen removal and our NPDES permit, please visit Nitrogen Reduction Program.

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