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Water Treatment Plant General Permit

Water treatment plants produce drinking water for public consumption or "industrial water" for manufacturing or other business operations.

Treatment often involves some combinations of:

  • Filtering out sediment and disease-causing organisms
  • Chemical treatment to remove excess minerals and other contaminants
  • Further settling or filtration
  • Final disinfection and chemical adjustment to reduce scaling or corrosion within the delivery system

The Washington Department of Health is responsible for ensuring that the hundreds of local public drinking water facilities in the state provide drinking water that is safe and reliable.

Water treatment plant operations often also produce wastewater that they must dispose of safely. In accordance with the federal Water Pollution Control Act and state Water Pollution Control laws, the Department of Ecology helps to ensure that the disposal of these wastewaters causes no harm to the environment.

Ecology requires facilities that produce the majority of that wastewater to have an NPDES (National Pollutant Discharge Elimination System) permit. NPDES permits contain specific requirements and conditions for permittees to protect rivers and other water bodies that receive wastewater discharges.

Why is this a general permit?
Facilities eligible and not eligible for coverage
New! Current and previous general permits
Application for coverage



Focus Sheet - July 2014 Water Treatment Plant General Permit



Local contacts for questions about specific water treatment plants

For questions about the General Permit, contact:
Jim Maroncelli