King County Ballard Siphon Replacement Project

OWNER King County | LOCATION Seattle, WA | PROJECT TYPE Civil, WasteWater, Utilities, CM





SCL works in conjunction with the prime, sub-contractors and the owner to provide schedules, document and record compliance verification; and validate adherence to Quality Assurance requirements.

Project Background

King County is building a new 84-inch siphon pipe under Salmon Bay between the Ballard and Interbay areas of Seattle. The new pipe will replace two 36-inch wooden stave pipes which have served the Ballard community since the 1930’s. The new siphon will be installed more than 120 feet underground and connect the Ballard Regulator Station at 5110 Shilshole Avenue Northwest in Ballard to the North Interceptor at West Commodore Way and 24th Avenue West intersection in Interbay. When the project is completed in 2013, the new pipe will accommodate growth in north Seattle and will meet north Seattle’s wastewater conveyance needs through the end of the century.




Scope of Work