Brightwater Wastewater Treatment System

In response to increased growth in a rapidly developing region of the Seattle metropolitan area, King County began exploring sites to construct a new regional wastewater treatment plant.

Why does this project matter?

This major wastewater system includes a 36- to 50-million-gallon treatment facility, conveyance system, and marine outfall.

What is ESA doing to help?

ESA directed the high-profile and award-winning four-year siting and environmental evaluation process for the new Brightwater wastewater treatment system. Our team eased the usually contentious process by developing clear siting criteria and working with agencies and the public to identify sites that were feasible. Key issues analyzed in the siting process included community impact and acceptance, technical considerations for conveyance-system tunneling, connection to the existing system, support for future water reuse programs, endangered species impacts, and the new marine outfall impact on Puget Sound.

ESA conducted environmental screenings of more than 75 potential sites that was ultimately narrowed to two. We then led a team of 50 scientists, engineers, and planners in the preparation of the state environmental impact statement (EIS) on the two "finalist" sites and associated conveyance routes and outfall locations. We responded to more than 5,000 comments on the 16-volume draft EIS, preparing a final EIS in a very compressed timeframe. We led the preparation of federal, state, and local permit applications.

ESA completed the siting and EIS process within King County's anticipated budget and schedule, resulting in construction initiation on schedule. Following completion of the EIS process, ESA has supported ongoing permitting efforts, mitigation design and implementation, and monitoring.

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