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Water Quality

Award-winning performance gets national and local recognition

By July 28, 2015September 25th, 2015No Comments
West Point Plant

West Point Treatment Plant


Brightwater Treatment Plant

Commitment to environmental excellence and an outstanding record of permit compliance earned King County’s wastewater treatment plants several awards from the National Association of Clean Water Agencies, or NACWA, and the Washington State Department of Ecology.

The Carnation Treatment Plant, the Vashon Treatment Plant and the South Treatment Plant in Renton recently received the  Department of Ecology’s prestigious 2014 “Wastewater Treatment Plant Outstanding Performance” award.

The plants were recognized for perfect compliance with permit requirements under the federal Clean Water Act and the state’s Water Pollution Control Law.

The South Treatment Plant in Renton and the West Point Treatment Plant in Seattle each received NACWA’s Platinum Peak Performance Award, honoring multiple consecutive years of compliance with state and federal effluent permit limits.

To date, South Treatment Plant is recognized for 17 years of 100 percent permit compliance with its effluent limits, and West Point Treatment Plant has attained 13 years of compliance.

South Plant

South Treatment Plant in Renton

King County’s Vashon and Carnation treatment plants both received Gold awards from NACWA for 100 percent compliance for effluent limits within the past calendar year.

The Brightwater Treatment Plant, which came online in 2011, earned a silver award in 2014.

Carnation Plant

Carnation Treatment Plant

Vashon Plant

Vashon Treatment Plant

To comply with state and federal discharge permit effluent requirements, King County’s treatment plants must remove various pollutants from the wastewater in order to meet set limits for biochemical oxygen demand, total suspended solids, fecal coliform counts and total residual chlorine. The permit conditions also require each plant to conduct regular sampling and testing of both its untreated and treated wastewater.

Each day, King County treats and disinfects nearly 200 million gallons of wastewater for more than 1.6 million people in the greater Puget Sound region.

More information about the Peak Performance Awards and list of King County’s prior rankings is available online.