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For questions about the Wastewater Treatment Division Web site, please send an e-mail message or contact us at:

King Street Center
201 S. Jackson St., Suite 505
Seattle, WA 98104-3855
Phone: 206-684-1280
Fax: 206-684-1741
Telecommunication device for the deaf (TTY): 711

Get Directions to our office location in Seattle, Washington.

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Puget Sound shoreline next to the West Point Treatment Plant, Seattle

Vashon Treatment Plant

The plant (upgraded in 2006)

King County began building a new plant in 2004. Moving the marine outfall further out in the Puget Sound was completed in October 2004. Construction was completed in 2006 and an open house for the community was held in May 2007.

The new plant and improvements were needed to meet regulatory requirements and to protect human health and the environment. This project was funded in part by loans from the Public Works Trust Fund, Washington State Department of Ecology and the US Environmental Protection Agency.


Vashon Plant Entrance
Plant entrance

More plant photos
(from May 2007 Open House)