Brightwater West, Sewage Conveyance Tunnels (Shoreline, Washington)

Client: King County

The Brightwater Sewage Treatment System in King County needed new tunnels and called upon the Coluccio team to drive the completion of a four-mile, 15.5-foot tunnel that would extend from Richmond Beach to Ballinger Way. In addition to the main tunnel, the project required a micro-tunnel measuring 84 inches in diameter to connect the large tunnel to a deepwater pipeline.

Coluccio, Jay Dee Contractors and Taisei partnered to build a 21,000 foot tunnel for $102 million. Collaborating on meticulous details, the team had to construct the tunnels while protecting the Puget Sound shoreline, a mainline for Burlington Northern Santa Fe railroad, and experienced higher hydrostatic pressure to the East as the project neared completion.

Modifying the approach to fit the demands of unique circumstances, the project was completed ahead of schedule and saved taxpayers tens of millions of dollars.

"We have a lot of confidence in this contractor... the quality of work is very excellent."
- Christie True, Wastewater Treatment Director, King County (as quoted in the Seattle Times)