The tilting on San Francisco’s Millennium Tower is inflicting a plumbing downside
A new problem may be bubbling up for residents of the lurching Millennium Tower in downtown San Francisco.
The building’s tilt — now about 22 inches to the west due to the northwest corner sinking about 18 inches — may be causing lateral sewage pipes to not drain correctly and has already resulted in “some plugging” on the third floor, according to a letter from the chief engineer to the city, obtained by NBC News.
A separate San Francisco Department of Building Inspection report filed Aug. 27, obtained by SFGATE, saw “evidence of water intrusion through the basement walls of the subterranean levels and signs of past settlement,” from the tower’s earlier sinking.
“The team identified several areas in which seals on building drains exiting the building appeared to be leaking ground water from outside the building to the inside,” the report reads. The team also observed “water seepage from the basement wall into the sewage ejector room.”
The letter states that the inspectors “did not find any observable variation” from their previous inspection in March.
Doug Elmets, spokesperson for the Millennium Tower homeowners’ association, told SFGATE that the document “clearly states that DBI found no changes in piping since their last inspection which occurred in March 2021.”
Chief engineer Ronald Hamburger added, “there are not current effects that compromise either building safety or habitability. As settlement and tilting has now returned to pre-construction levels, we do not anticipate any will occur.”
In the email from Hamburger, obtained by NBC, the engineer told the city that “sewer lines must slope (minimum of 1/8” per foot) to enable efficient flow of material,” and that at-risk drains “will experience slope decreased and may become a problem.” He added that third floor drains that have seen plugging must be “maintained with periodic chemical flushing.”
The news comes after the tower abruptly sank another inch over a period of weeks in July in the middle of the massive foundation fix on the tower, causing work to stop. A report found that the fix itself was likely causing further sinking. The moratorium came after 39 of the 52 new piles had been installed as part of the $100 million “perimeter pile upgrade.”
Supervisor Aaron Peskin has called for a new independent review of the project. “I would like there to be a pause until we know what we’re doing, and I think that construction should not resume until we can panel the best experts that this country has,” Peskin told KPIX.
The August halted on the construction fix was initially planned to last two to four weeks. It is now unclear when it might resume.