Yellowish tap water reported by several Mission District and SoMa residents is safe, and all streets affected by the sinkhole on Division Street will be open for the morning commute tomorrow, according to Michael Carlin, assistant general manager of the San Francisco Public Utilities Commission.
Residents should run the tap until sediment caused by a break in a water pipe clears their faucets.
At around 8:30 p.m. on Saturday a 16-inch, century-old pipe broke, creating a water spill that lasted until 10:45 p.m. and dumped out “millions” of gallons of water.
The spill lasted so long because even after they shut off water to the pipe, lingering pressure kept dumping out water, Tyrone Jue, a spokesman for the public utilities commission said.
The pipe broke due to a combination of cold weather and the age of the pipe Carlin said.
“What we have here is an old pipe, about 100 years old that gave out in a very spectacular way,” Carlin said.
The city has some 1,200 miles of pipes that vary in age, he said. Every year the city goes out and replaces eight to ten miles of the oldest pipes.
Currently there is a crew of around 20 people working in an open trench repairing the pipe. They expect to have it patched up by tonight, Carlin said.
Brannan Street, the only street currently closed, will not allow westbound traffic between 9th and 10th streets while the city paves the street tomorrow morning.
All water service has resumed and the “yellowish water” some residents have reported is sediment, according to Jue.
Jue said this is normal and advises residents to let the water run until the water is clean.
“Anytime you have vibration it shakes up the pipes and causes sediment to get stirred up,“ he said. “Sometimes when there is heavy construction going on we get reports of yellowish water – but the water is safe.”
Two employees from the Boston Market restaurant on 16th and Potrero Street said their water had a “yellowish” color, similar to what Mission District residents have reported.
Susan To, an employee at the Boston Market said the yellowish water began running sometime around 10:00 p.m. while she was closing down the restaurant. The water returned to normal in the morning, she said.
Gonzalo Veradra, also an employee, said the yellowish water was also running at his home on 6th and Mission until midnight.