Brightwater update: Elizabeth to keep digging

By David Freed, Brightwater Community Relations

In February of this year, King County Executive Dow Constantine issued a declaration of emergency allowing the county to hire a new contractor to complete construction of the remaining two miles of the Central conveyance tunnel between Kenmore and Ballinger Way. Executive Constantine was concerned with construction delays and higher costs projected by the original contractor to complete this work and the resulting likelihood of impacts to public health and safety. Consequently, in early April, the county signed a contract with Jay Dee Coluccio (JDC) to complete this work.

JDC recently completed the four-mile West Tunnel between Point Wells and Ballinger Way in Shoreline. (The Elizabeth Tunnel, see photo to left). King County selected JDC to complete the Central Tunnel because of their success in mining the West Tunnel and the availability and capability of their tunneling machine to continue mining the Central Tunnel. JDC estimates they will complete the tunnel at substantially lower cost and more than a year sooner than Vinci, Parsons, Frontier-Kemper (VPFK), the current Central Tunnel contractor.

Starting this spring JDC will refurbish its tunnel machine, named Elizabeth, at the Ballinger Way site. The machine will then begin tunneling in fall 2010 and continue until fall 2011. Tunneling operations will continue to be based at Point Wells, including trucking of tunnel segments and removal of spoils by barge.

JDC’s tunneling machine will continue east for two miles from Ballinger Way to the location of a stalled tunnel machine which belongs to VPFK. This machine has been stopped since spring 2009, 300 feet below ground at 53rd Avenue NE near NE 197th Street in Lake Forest Park.

The Brightwater conveyance tunnel is being built in four sections. The East Tunnel was completed in late 2008; the West Tunnel has less than 150 feet remaining; the two Central Tunnels have been under construction since 2006 and are 70 percent and 50 percent complete. VPFK will finish the eastbound tunnel section between Kenmore and Bothell in 2010 and will also install piping inside both Central tunnels once mining is completed.

With more than ten miles of the 13-mile Brightwater conveyance system completed, the Kenmore to Ballinger Way portion is the largest section of tunnel remaining. Timely completion of Brightwater is critical to ensure the regional wastewater system has enough capacity to serve population growth and protect public health and the environment. The Brightwater treatment plant will begin operating in August 2011, with the entire system scheduled to be completed in late 2012.

Photos courtesy Brightwater