King County to begin emergency sewer line replacement project in Ballard

To protect water quality in the Lake Washington Ship Canal, King County will begin construction this summer on a $12.9 million project to replace a 70-year-old wooden sewer pipe in the Ballard/Interbay area of Seattle. Last November, Wastewater Treatment Division staff inspected the line with sonar technology and discovered sections of the aging pipe were near collapse.

Division Director Don Theiler said there are no detectable leaks – yet. "The Ballard siphon is 50 feet under water," said Theiler. "At that depth, external water pressure has kept wastewater inside the pipe. But structurally, the pipe is in trouble. To protect the Ship Canal, we need to get this project underway now."

Built in 1935, the Ballard siphon is a 1,400-foot-long inverted wood-stave pipeline that sits on the floor of Salmon Bay near the Hiram M. Chittenden Locks. The pipe carries stormwater and wastewater south from Ballard to the Interbay area where it eventually flows to West Point Treatment Plant.

King County will work with permitting agencies, jurisdictions and affected neighbors throughout the project. Construction is scheduled to begin in early 2007 and last about 18 months.

People enjoy clean water and a healthy environment because of King County's wastewater treatment program. The county's Wastewater Treatment Division protects public health and water quality by serving 17 cities, 17 local sewer utilities and more than 1.4 million residents in King, Snohomish and Pierce counties. Formerly called Metro, the regional clean-water agency now operated by King County has been preventing water pollution for more than 40 years.