The San Francisco Public Utilities Commission has called in an expert to investigate the cause of a pipe break that doused a South San Francisco neighborhood and has put on hold replacements to similarly configured pipes.
The investigation could take up to three weeks, but SFPUC officials believe the Nov. 25 incident — which resulted in between 1 million and 2 million gallons of water being released — is tied to work done as part of the $4.6 billion upgrade of the Hetch Hetchy water system.
“We know for a fact that a recent replacement pipe failed — we don’t know why,” said David Briggs, a local and regional water system manager for the SFPUC. “It could be workmanship, it could be design, it could be bad material, it could be something strange like something heavy parked on the pipe — there’s all sorts of factors.”
The pipe that burst was a service pipe that connected to a section of the 19-mile main pipeline — known as Crystal Springs Pipeline No. 2 — between Hillsborough and Daly City that is being renovated.
But until the investigation determines a cause for the incident, the agency has halted all work on pipes with similar connections to service pipes.
The SFPUC is also looking into whether any other sections of pipe already installed as part of the Crystal Springs project have similar service connections that could also potentially burst.
SFPUC spokesman Tyrone Jue said the agency hired consulting firm Exponent to help with the investigation “to make sure we have an unbiased opinion to really look at what happened.”
Until then, the SFPUC is footing the bill for residents and business owners who want to file property damage claims. Jue declined to give the total value of the claims filed so far.