King County Wastewater Treatment Division has plans to replace the existing, nearly 100-year old Fremont siphon that runs beneath the Lake Union Ship Canal. The siphon conveys up to 220 million gallons per day of wastewater from a service area covering about 60 square miles, year round (plus an additional 54 square miles during the summer) to the West Point Treatment Plant, near Discovery Park.
King County will establish two microtunnels just west of the existing siphon to be connected to the north interceptor pipelines. The new siphon pipes will be designed to the same capacity as the existing system. The County will also retain space in the existing tunnel for future Wastewater Treatment Division uses.
This summer, the project will go into early design which will include proposals for odor control, which has been highlighted based on community feedback on problems with the current siphon.
Once 30% of the design process has been completed, environmental review will begin under the State Environmental Policy Act (SEPA), to be completed in early 2012. More outreach is planned to help the public understand the project and best participate in the SEPA process.
King County project managers also continue to work closely with Seattle’s Public Utilities, Department of Parks & Recreation, and Department of Transportation to proactively address issues related to public use of the parks, utilities, roadways and bike paths during construction.
For more information, refer to the comprehensive website for details, including contact information for any questions or concerns about this project, and the timeline. Also, read the Fremocentrist column from December 2010.
Finally, ask questions at the King County booth at the Fremont Fair, which will feature a sewer inspection truck and videos of good, bad and ugly sewers, and the famous ‘rat in sewer’ video.