Millenium Tower deemed safe in earthquake

The developers of a controversial South of Market residential high rise that is sinking more than expected released a report Tuesday stating the building remains safe, even in an earthquake.

The report from engineering firm Simpson, Gumpertz & Heger states that the Millennium Tower at 301 Mission St. remains structurally sound despite settling much farther into the bay mud it sits on then was originally anticipated:

“We conclude that the settlements experienced by the 301 Mission tower have not compromised the building’s ability to resist strong earthquakes and have not had a significant impact on the building’s safety.”

The 58-story tower, which includes more than 400 luxury residential units, has become the subject of controversy since initial reports in August that it has sunk as much as 16 inches and is leaning around 15 inches to the northwest at its peak. Current projections suggest it could ultimately sink more than 30 inches.

Developer Millennium Partners has blamed the building’s excessive settlement on groundwater pumping from the neighboring Transbay Transit Center construction site, and today pressed that claim with the release of a report from engineer John Egan.

Egan’s report states that prior to the start of construction on the transit center in 2010, the Millennium Tower’s settlement was gradually decreasing:

“Continued dewatering of the Transbay Transit Center and other sites near 301 Mission St. is likely contributing to ongoing and future settlement of the building.”

The Transbay Joint Powers Authority responded with a lengthy statement rejecting those claims. The authority argues that the building had already settled more than expected before dewatering even started on the transit center project, and that other buildings in the area have not been similarly affected.

Instead, the authority blames the foundation used for the building, a concrete slab with piles driven into sand rather than down to bedrock, and the weight of its concrete construction.

A statement from authority spokesman Scott Boule said:

“[Millennium Partners] false allegations concerning the impact of the TJPA’s work on the Tower are designed to divert attention from [their] own liability. … Because the Tower’s foundation is grossly inadequate, the excessive settlement and tilt of the Tower would have occurred and would continue regardless of the TJPA’s activity.”

The troubled tower has become the focus of a lawsuit filed by an individual homeowner and an investigation by the City Attorney’s Office into whether Millennium Partners properly notified buyers of potential structural issues.

Supervisor Aaron Peskin also questioned Department of Building Inspection officials at a hearing on Sept. 22 to determine when they became aware of problems with the building and why they did not take action sooner.

In the midst of it all are the owners of the tower’s units, whose property values have taken a significant hit in the wake of recent media coverage. The homeowners association last week launched its own independent testing program to monitor and collect building settlement data.

The Millennium Tower Association Tuesday said in a statement it “appreciates” the engineering report’s finding that the building is safe and can withstand an earthquake:

“The association is working with other independent experts to review the … report, as well as identify an appropriate repair of all settlement-related conditions and recovery of repair costs from all responsible parties.”