SPU: Crews to tear up Seattle street before Bertha causes water-main break
Jul 28, 2015, 9:31 AM | Updated: Jul 29, 2015, 11:39 am
The soil in Seattle's Pioneer Square has settled more than an inch since crews began pumping water out of Bertha's repair pit in November. (WSDOT image)
(WSDOT image)
Crews are about to rip up a downtown Seattle street where ground settling near the tunnel project is putting too much pressure on an old water main.
The soil in Seattle’s Pioneer Square has settled more than an inch since crews began pumping water out of Bertha’s repair pit in November, but investigators have not officially linked dewatering to the ground’s movement.
Related: Another WSDOT official calls it quits on Seattle tunnel project
Seattle Public Utilities considers the settling to be too much for the old cast-iron pipe. The pipe, running under Western Avenue, must be replaced to prevent a rupture. Crews will tear up the street between Yesler and Spring streets in August.
“We want to replace it before the tunneling machine comes through it because in addition to the settlement that’s occurred over the last year and a half, there will be additional settlement once the tunnel goes underneath it,” explained Gavin Patterson with Seattle Public Utilities.
Patterson says the utility will install a new 24-inch steel pipe that has enough flexibility to handle any future settling and, more importantly, a major earthquake.
The repair work will last through October.
Scientists are still trying to figure out why the ground continues to settle. Also up in the air is who is going to pay for the $8 million in emergency repairs to the water system.
“Well, I think both parties want to avoid getting into lawsuits,” Patterson said. “We are still working with WSDOT following the prescribed path of dispute resolution and the memorandum agreement that we have.”
Bertha is expected to begin boring again in November with the tunnel opening scheduled for March 2018.
Related: New schedule released for Bertha, Seattle tunnel project
Meanwhile, a key employee on the project, Todd Trepanier, is stepping aside. He says his decision has nothing to do with the tunnel project.
“I have a future in Yakima as a regional administrator for the Southcentral region, but I’m not going to be gone anytime soon, so you’re going to see me a number of times still in the future at these briefings,” Trepanier said.
He said he considers the decision a great career move and a way to be closer to his family in Yakima.
