SAN MATEO -- Crews were working Friday afternoon to repair a broken sewer main that befouled a creek in a popular park in the San Mateo hills for several days -- and possibly much longer.
At least 300 feet of Laurel Creek in Laurelwood Park were contaminated by the leak, which occurred near College of San Mateo around the headwaters of the creek. From there, the stream flows through a culvert beneath a residential neighborhood before emptying into a creek bed at the northern entrance to the park.
There was a stench in the air near the creek Friday morning. The water was discolored by green algae and a gray film cloaked most of the rocks in the streambed.
Assistant City Manager Matt Bronson said the city got its first report Wednesday about an odor coming from the creek. Public works employees tested the water, he said, and did not detect the presence of sewage.
But two regular park visitors say they noticed the leak at least a week ago. One of them, Belmont resident Peter Knopf, claims he filed an online report with the city July 24 or 25 and never got a response.
After being contacted early Friday morning by this newspaper, the city tested the water again and realized by Friday afternoon that its initial tests had been mistaken, Bronson said. Crews identified the faulty sewer line in the early afternoon and began containing the leak and posting signs to warn the public.
Gary DeJesus, the city's deputy director of environmental services, said it was unclear how long it would take to clean up the creek. Crews first had to stop the leak. Workers had begun containing the leak at the culvert Friday afternoon.
"It might be an all-night job," said DeJesus. "We'll probably have guys throughout the night manning a pump."
DeJesus said the discharge does not pose a public health risk unless people come into contact with the water, in which case they should thoroughly wash any affected body part. DeJesus recommends that the public stay away from the creek for now.
Ervin Arndt stopped by the creek around 11:30 a.m. Friday, before the city had realized its error. He and his two grandsons, 12-year-old Zachary and 10-year-old Gabriel, were making their weekly trip to catch tadpoles.
Arndt, who lives a couple blocks from the park, said he first noticed the smell two or three weeks ago. When told the city didn't think the pollution was sewage, Arndt was incredulous.
"It looks like it's sewage, it smells like it's sewage," said Arndt, 67. "It stinks -- it can't be good coming into the creek, for crying out loud."
The contamination had worsened since their last visit, Arndt said. The water at their usual tadpole-catching spot a few hundred feet from the culvert off Shasta Drive was clear last week, he said. On Friday morning, it was green and opaque.
After inspecting the water for a few minutes, Arndt and his grandsons gave up and grabbed a football to play catch, but not before Arndt had dipped the handle of his net in the stream to measure its depth. Reached later by phone, he said he washed the handle and his hands, and was not concerned about getting sick.
Contact Aaron Kinney at 650-348-4357. Follow him at Twitter.com/kinneytimes.