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Treatment process at West Point

Learn about the process we use to clean wastewater at West Point.

West Point is a secondary treatment facility that uses an activated sludge process to clean wastewater. This process uses oxygen and microorganisms to break down pollutants and clean the wastewater. Most of the wastewater treatment process uses gravity and microorganisms. We add minimal chemicals (chlorine) to the water to meet treatment standards regulated by the Washington State Department of Ecology. Effluent (water that leaves the facility) is then pumped out into the Puget Sound and returned to nature.

NPDES permits

The Washington State Department of Ecology administers National Pollutant Discharge Elimination System (NPDES) permits under authority delegated to the department by the U.S. Environmental Protection Agency. These permits outline the conditions under which King County can discharge treated wastewater.

Learn more about West Point and other King County wastewater permits.