Some 750,000 gallons of diluted raw sewage flowed out of Peninsula sewer pipes and into the Bay during the blustery winter storm that ravaged the Bay Area in early January, according to the state water control authority.
More than half of the raw sewage from two trouble spots in San Mateo, where residents described manhole covers exploding off the street and untreated sewage spewing upward like a geyser. Another 270,000 gallons came from sewers in residential Hillsborough, according to the California Water Resources Control Board.
Sewage overflows — though particularly severe during January’s storm — are not a new problem, said <a title="Martha DeBry" href="/Subject-Martha_DeBry.html" target="_blank" onClick="var s=s_gi('examinercom'); s.tl(this,'o','Inline Entity Link'); " >Hillsborough Public Works Director Martha DeBry. As infrastructure ages, sewage lines crack or break. In heavy rains, storm water flows into the pipes through the breaks in the line and completely overload the system.
“Then the sewage has no place to go but up,” she said.
The watered-down sewage then “pops” manhole covers and floods into the street, and then flows into creeks that lead to the Bay. This not only creates a public health risk, but also an environmental one, DeBry said.
The problems won’t be cheap to fix, said Darla Reams, deputy director for San Mateo’s Department of Public Works. San Mateo’s two biggest problem areas — Delaware Street south of Highway 92, and Norfolk Street in the Los Prados area — are likely to cost at least $25 million to replace. Sewage rates have been raised since 2004 to start funding repairs, but they’re likely to go even higher, Reams said. The city may even need to float a bond for the repairs, she said.
The San Mateo City Council recently approved a $269,000 contract with an engineer to design a fix to the Los Prados sewage system — but it will likely take years before it’s replaced, Reams said.
On Delaware Street — near the San Mateo Police Department — employees of F ’n’ F Supply, a plumbing supply store, said the entire parking lot was flooded with sewage water during the latest storm — and ironically the store toilet wasn’t working.
“Believe me, now, when it’s a sunny day, it’s easy to laugh about it, but at the time, we were very worried about the water coming in,” said employee Miguel Mazariego.
Down the street, Delaware Street resident Chet Nahine said the street has been periodically flooded with sewer water since he moved in 15 years ago.
“You can smell it, that’s for sure,” he said.
He was glad to hear a fix might eventually arrive.
“It’s long overdue,” he said, shaking his head.