Experts charged with evaluating the Millennium Tower’s now sinking foundation were never directed to assess the impact of the massive Transbay transit terminal being built next door, according to a document uncovered by NBC Bay Area’s Investigative Unit.
That four-block long, $2 billion underground terminal will likely be the center of a multi-year legal battle over who is to blame for the Millennium Tower’s troubles. The 58-story structure has sunk 16 inches and is tilting to the northwest, triggering a flurry of lawsuits and recriminations.
The telltale letter dates back to early 2006. It was written by one of two experts brought in to check on the foundation of the Millennium Tower.
“We were not asked to review the effects of the Transbay Terminal project on this project,” structural engineer Hardip Pannu said in a January 2006 revision of his August 2005 peer review letter related to the Millennium foundation.
Pannu would not discuss the letter with NBC Bay Area. But in an earlier interview, stressed that his review focused on the tower’s walls, not the foundation.
“We were just looking at the seismic design and most of the time was spent on reviewing the design of the shear walls – which is the core of the building,” he said in an interview before the letter came to light.
The foundation is now the center of the dispute over what is causing the building to sink and how to fix it.
The developer, Millennium Partners, insist that the foundation was state of the art and had been reviewed by experts appointed by the city. They now blame the Transbay transit terminal project for draining out water under the tower, destabilizing the soil and exacerbating the expected sinking problem.
Transbay officials counter that the Millennium Tower's foundation should have extended its 950 foundation piles to bedrock, not Bay mud.
In any event, Pannu told us his review did not deal with geotechnical aspects of the project, and that he did not know anything about the decision to perform a peer review of the findings of the project’s soil engineers, Treadwell & Rollo.
“I don’t recall if anybody requested that or if there was one,” Pannu said.
For their part, city building inspection officials did not respond to our requests for comment about any limitations on the review process.
But they have insisted that Millennium’s project engineer flatly refused to have a geotechnical review of the project and they felt they did not have the authority to order one.
“We insisted on having a full peer review, but at that time Millennium only permitted a review of the structural aspect of the building,” Hanson Tom, San Francisco’s principal building inspection department engineer, said in a testimony during a recent public hearing on the project.
But previously undisclosed documents uncovered by NBC Bay area reveal that the scope of the review sought by the city was even more limited.
The 2006 letter shows that two peer reviewers, Pannu and UC Berkeley structural engineering professor Jack Moehle, were only charged with looking at the structural elements of the foundation.
Moehle, however, did not mention the Transbay project in his letter vouching for the foundation.
City building officials have not been able to provide several key documents we have sought related to what the two engineers were told to do while evaluating the foundation.
The only foundation review documents the city has kept are reproductions that the developer’s engineer submitted during the permit process.
While city building inspection officials promise to do more to retain key records, city Supervisor Aaron Peskin called the gaps in the records “deeply troubling.”
Peskin says the Pannu letter – which he learned about from NBC Bay Area — is proof the city building inspection department bungled the assessment of the Millennium foundation.
He said the city should have done something more when it got such a letter that vouched for the foundation “except they had not analyzed this huge hole in the ground they were going to put in next door.”
“That should have been a huge warning signal,” Peskin said. “That should have been a huge red flag wherein they should have gone back and done the analysis of what the impacts of the Transbay dig would be.”
He continued: “The fact that they didn’t” is proof that city officials “were either asleep at the wheel or complicit.”
Jerry Dodson, an outspoken advocate for his fellow owners in the building, said the letter is more proof that the city intentionally avoided a review that could scuttle the building. He said that San Francisco leaders had been alerted that such a foundation could during its review of another project at nearby 80 Natoma Street. That project was later scrapped.
On Tuesday, Dodson filed a claim against the city and Transbay officials, charging they engaged in a conspiracy to conceal the sinking problem and that the city was reckless in its review of the Millennium project.
"You don’t build next door to a gigantic construction like Transbay without analyzing its impacts on this building,” Dodson said. “And it wasn’t done. That makes no sense to me at all.”
Dodson lives on the 42nd floor of the building with his wife, Pat. He says that the fact that the city did not keep the original letter and is missing so many other documents is troubling.
“You have destruction of documents, and you also have a failure to analyze the impact of Transbay’s terminal on the construction of the Millennium tower,” he said. “Both of those to me raise serious questions to be about what people were doing at the time to protect the people who would later live in this building.”