July 9, 2018

City wants feedback on $250M CSO tunnel

Seattle Public Utilities is asking for feedback on a major component of its $570 million Ship Canal combined sewer overflow project: the 2.7-mile storage tunnel.

A notice in the June 26 DJC says the city wants feedback from people involved in tunneling and heavy construction to improve the contract prior to advertising and bidding the tunnel, which earlier this year was estimated to cost $250 million. The notice puts the budget at $221 million.

SPU construction manager Cynthia Blazina said anyone can participate, but the city will not pay for the reviews.

This is the first time SPU is using an industry review. Blazina said SPU learned about the idea from designers who used it at Sound Transit.

Blazina said tunnel designs are 90 percent complete, but will change before the bidding. She said the current documents should not be used for estimating bids.

SPU project executive Keith Ward told the DJC in May that bids for the tunnel will be opened in May or June 2019.

The notice states tunnel construction will start by fall 2019 and finish in late 2023. Federal law requires the entire system to be operating by early 2025.

Reviews and comments are due July 30 to Blazina: email to cynthia.blazina@seattle.gov; or snail mail to Cynthia Blazina, Seattle Public Utilities, 700 Fifth Ave., P.O. Box 34018, Seattle, WA 98124-4018.

The tunnel is designed to store 29 million gallons of overflows from Ballard, Fremont, Wallingford and north Queen Anne. It will be 18 feet, 10 inches in diameter.

Costs have been rising for the overall project. In 2014, when designs were 5 percent complete, the budget was set at $423 million. SPU later increased the size of the tunnel and last fall the estimated cost went up, increasing the budget to $540 million.

The budget jumped to $570 million after a year-long analysis was finished in March by consultant Value Management Strategies.

The city also is seeking industry feedback and review for the upcoming $100 million Overlook Walk, a public path that will connect the waterfront to Pike Place Market and downtown. The DJC reported about that on Friday.