Pretreatment Program

Pretreatment is the reduction, the elimination, or the alteration of pollutants in wastewater to a less harmful state prior to discharging the wastewater to the sanitary sewer system. DC Water's federally mandated Industrial Pretreatment Program was established in 1986, as required by the Clean Water Act, to regulate non-domestic (e.g., industrial) discharges that introduce pollutants to the sanitary sewer system.

DC Water's Industrial Pretreatment Program has the following objectives:

  • Prevent the introduction of pollutants that will interfere with the operation of DC Water's wastewater treatment plant
  • Prevent the pass-through of pollutants to protect the Potomac River water quality and maintain compliance with DC Water's National Pollutant Discharge Elimination System permit
  • Improve opportunities to recycle and reclaim municipal and industrial wastewaters and sludges
  • Protect the health and safety of the general public and DC Water workers

Our approved Industrial Pretreatment Program is under the direct supervision of the U.S. Environmental Protection Agency (EPA), Region III office. We issue wastewater permits under this program to regulate non-domestic wastewater discharged into the District of Columbia's sanitary and combined sewer system. The Program meets its objectives by establishing discharge standards for pollutants of concern and through permitting Significant Industrial Users (SIUs), testing SIU discharges for compliance with permit limits, and routinely conducting comprehensive facility inspections.

While neighboring jurisdictions discharge wastewater into DC Water's collection system, industrial users from Prince Georges, Montgomery, Fairfax, and Loudoun counties must follow the rules and regulations of their jurisdictional pretreatment programs, in addition to meeting the discharge standards for DC Water.

For more information, you can download a copy of DC Water's Pretreatment Annual Report (PDF 3.8 mb) .

What can you find in this section?

  • Regulations
    Learn more about pretreatment regulations and discharge standards.
  • Permits
    Find out more about DC Water’s criteria and process for pretreatment permits, including industrial wastewater discharge permits, temporary discharge authorization permits, and waste hauler permits.
  • Inspections
    DC Water conducts scheduled and unscheduled inspections and monitoring of industrial discharges.
  • Enforcement
    All violations of federal, state and local discharge limitations and requirements are met with enforcement action in accordance with an EPA-approved Enforcement Response Plan.
  • FAQ
    Learn more about DC Water’s pretreatment program by reviewing questions and answers.
  • Pollution Prevention
    DC Water promotes the reduction of pollutants in wastewater through source reduction and product substitution, recycling, reuse, alternative disposal methods, and other best management practices.
  • Related Links
    Access local and federal information on pretreatment programs and related topics.
  • Documents and Forms
    Download important documents and forms for DC Water’s pretreatment program.
  • Contacts
    All the contact information you need for DC Water’s pretreatment program.

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