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King County’s Georgetown Wet Weather Treatment Station celebrates Platinum Achievement Award for Sustainability


King County’s Georgetown Wet Weather Treatment Station earned the coveted “Platinum” rating from the Institute for Sustainable Infrastructure’s Envision rating system. This is the first Platinum-awarded Envision project in Washington and recognizes the County’s commitment to sustainable communities and the environment.


The King County Wastewater Treatment Division (WTD) models leadership in sustainable development every day. The division turns biogas from the wastewater treatment process into clean energy; cleans and recycles wastewater solids into a nutrient-rich soil builder for plants; and incorporates green building practices into construction projects.

The Georgetown Wet Weather Treatment Station project, currently under construction in Seattle’s Georgetown neighborhood, demonstrates WTD's commitment to sustainability. This Envision Platinum-awarded project consists of building a wet weather treatment station, conveyance pipelines, and outfall structure to treat combined sewer overflows prior to discharge into the Lower Duwamish Waterway. The project will reduce contamination and improve aquatic habitat and overall water quality of the Duwamish River.

The Institute for Sustainable Infrastructure’s Envision rating system assesses sustainability in five categories: quality of life, leadership, natural world, resource allocation, and climate and resilience. These contribute to positive social, economic and environmental impacts on a community during the planning, design and construction of infrastructure projects.

Key sustainable features that contributed to this project earning Envision Platinum include:

• Supporting jobs through a local hire requirement;
• Using public art and green space to enhance a key corner in Georgetown;
• Design Advisory Group that influenced the site’s look and feel;
• Diverting more than 85 percent of demolition materials from the landfill;
• Implementing a wide range of green infrastructure: permeable pavement, green roof, roadside rain gardens, and cisterns;
• Restoring shoreline along the Duwamish River;
• Reducing chemical use at the facility; and
• Planning and designing for a changing climate.

The Georgetown Wet Weather Treatment Station was the first project chosen by the Environmental Protection Agency (EPA) to receive a new type of low-interest loan, called Water Infrastructure Finance and Innovation Act. The loan will save ratepayers about $34 million. According to EPA, pursing the Envision Platinum certification played a large role in the EPA’s funding decision.

The GWWTS is one of many King County Wastewater Treatment Division’s projects that will help to clean the environment and protect public health.


King County Wastewater Treatment Division GWWTS:

Institute for Sustainable Infrastructure Envision:

Norm Mah, 206-263-0195

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About the King County Wastewater Treatment Division
King County’s Wastewater Treatment Division protects public health and enhances the environment by collecting and treating wastewater while recycling valuable resources for the Puget Sound region. The division provides wastewater treatment services to 17 cities, 17 local sewer districts and more than 1.7 million residents across a 420-square-mile area in King, Snohomish and Pierce counties.