WSDOT comes under fire for report warning of ‘catastrophic failure’ with Bertha repair pit

The Washington State Department of Transportation says a report warning of a risk of “catastrophic failure” with the Bertha rescue pit was taken out of context and a mis-characterization of the safety of project.

Several WSDOT leaders came under fire Monday at a Seattle City Council briefing on the status of the Seattle tunnel project.

The Seattle Department of Transportation and Seattle Public Utilities sent a letter to WSDOT last week, calling on the state to explain why project contractor Brierley and Associates wrote in a draft report posted December 18, 2014, by WSDOT:

“If we continue the current ‘repair as we go’ method of excavation, we significantly increase the risk of a catastrophic failure. Therefore excavation shall not proceed.”

Read the letter from the city of Seattle to WSDOT here.

But the letter, first released by The Stranger, says the language changed in a version of the report dated seven days later, and demands to know why.

The amended language reads:

“In summary, we believe that the untreated soil zones…will have a significant impact on the structural, geotechnical and hydraulic adequacy of the shaft structure.”

The letter, signed by SPU director Ray Hoffman and SDOT director Scott Kubly, raises questions about the actual risk to surrounding property and infrastructure, and demands to know why WSDOT failed to bring the matters promptly to the city’s attention.

“The extent of any such failure or concern about adequacy is not described; however it is clear that alarm bells were going off,” the letter reads.

But Todd Trepanier, WSDOT Viaduct Replacement Project Manager, told council members the sentence was taken out of context and insisted work on the 120-foot pit to access Bertha the drilling machine is structurally sound.

“So there never has been and there currently is not any risk of failure. That is a gross mis-characterization of that word ‘catastrophic’ in the report,” Trepanier said.

According to Trepanier, the statement was merely a directive to Seattle Tunnel Partners to take certain steps before resuming work on the repair access pit. That work was stalled for several weeks as crews investigated ground settling and building cracking around Pioneer Square and the Alaskan Way Viaduct believed to be tied to pumping of groundwater from around the repair pit.

Councilmember Kshama Sawant was among several who questioned WSDOT’s assessment of the situation, calling the discounting of the report “disingenuous” and “incomprehensible.”

“I used to be an engineer. Engineers are not given to hyperbole, so when an engineer says ‘catastrophic failure,’ it has to mean something of importance to the public,” Sawant said.

Sawant also criticized WSDOT for failing to provide the full report to the council prior to Monday’s meeting, yet criticizing the city’s interpretation of it.

In a testy exchange, WSDOT also came under fire from several councilmembers for threatening to limit access to a project database following the latest controversy.

“I would just say we will fulfill our obligations by agreement to give the timely information that is required by our two agencies,” Trepanier responded.

Excavation on the repair pit to access Bertha continued Monday. Officials say the project has now reached a depth of 90 feet, and that no additional settling has occurred in more than six weeks. And WSDOT told the council it has come up with an alternative plan if Bertha cannot break through the wall of the repair pit once it is complete.

The city has now hired its own engineering consultants to take an independent look at the Alaskan Way Viaduct and determine whether the Bertha repair work poses a danger, SDOT director Scott Kubly told the council Monday.

Seattle Tunnel Partners now estimates the tunnel will be completed in September 2017. But WSDOT says it cannot stand behind the estimates until the repair work on Bertha is completed.