Sinking Millenium Tower blamed on Transbay construction

The developers of a South of Market residential high rise Tuesday blamed the building’s excessive settlement on groundwater pumping at the neighboring Transbay Terminal construction site.

Speaking at a press conference in downtown San Francisco, Millennium Partners founding partner Christopher Jeffries said what he called “reckless behavior” on the part of the Transbay Joint Powers Authority has caused the Millennium Tower to sink more than was originally projected.

The 58-story luxury high rise at 301 Mission St., which is built on landfill, has sunk as much as 16 inches so far and is leaning around 15 inches to the northwest at its peak. Current projections suggest it could ultimately sink more than 30 inches.

Jeffries said that groundwater pumping started at the Transbay Terminal project a full year earlier than officials have previously stated and has caused groundwater in the area to drop a “staggering” 20 feet.

The authority agreed before construction started to strictly limit and monitor any effects on groundwater in the area around the Transbay Terminal site. However, when it became clear those limits had been exceeded, it refused to act and instead blamed issues on the design of the Millennium Tower and stopped responding to requests for data, Jeffries said:

“There’s been a lot of talk and speculation about what people think the problem is. … There is only one issue here. TJPA’s dewatering is the issue.”

Transbay Joint Powers Authority officials did not respond to a request for comment today, but have previously blamed the Millennium Tower’s settlement issues on the fact that it was designed with a concrete slab foundation and piles into sand rather than bedrock.

The authority has argued that the building, which was completed in 2009, had already settled more than anticipated by 2010, before construction began on the Transbay Terminal site, and that other buildings in the area have not shown similar issues.

Millennium Partners officials today argued that the building’s foundation is of the same design used by most current buildings of its size in The City, and that drilling down into bedrock is not normal practice.

While they acknowledged that the building had sunk more than projected by 2010, they said the amount was well within design limits.

The troubled tower has become the focus of litigation and city investigations, with City Attorney Dennis Herrera Tuesday issuing subpoenas to Millennium Partners in an investigation to determine whether buyers were properly notified of the structural issues.

Herrera wrote in a letter accompanying the subpoena:

“I have serious concerns that the disclosures required by state law … did not contain information about the settling of the property.”

Supervisor Aaron Peskin also plans to question city building officials at a hearing on Thursday to determine “who knew what and when they knew it.” Peskin has alleged both the developer and city officials knew about the problems by 2009 but failed to notify buyers of the building’s more than 400 units.

Homeowners also filed a lawsuit in August naming both the developer and the joint powers authority.

Millennium Partners officials today said they were currently focused on finding a fix for the building’s problems, rather than litigation, but did not rule out a lawsuit. They said they would comply with the city attorney’s subpoenas and investigation, but argued that the extent of the settlement problems only became apparent in 2014, after units in the building were all sold.