The project to build a new wastewater tunnel along the Ship Canal has hit a milestone in Ballard, having removed about 22,000 tons of contaminated soil from the Ballard worksite.
The tunnel project, known as the Ship Canal Water Quality Project, will build a 2.7-mile, 18-foot-wide tunnel between Wallingford and Ballard that will capture and temporarily hold more than 29 million gallons of stormwater mixed with some sewage during heavy rains. After storms, the flow will be sent to the West Point Wastewater Treatment Plant in Magnolia.
At the Ballard worksite (5300 24th Ave NW), the removal of contaminated soil will help protect water quality in the canal as crews begin to construct a 100-foot-deep, 90-foot-wide shaft for the tunnel boring machine’s entry point. The site will eventually be the permanent home of the Ballard Pump Station, which will house the equipment needed to send wastewater to West Point.
The tunnel shaft digging is expected to start in 2020.
To keep tabs on the project, you can follow along on the project website.
Photo: SPU
Wow! I had no idea it was such a huge tunnel!
Seems like if they can do a 2.7-mile 18ft wide tunnel for some stormwater detention they could build some 1.5 mile 21ft wide lightrail tunnels across Salmon Bay…