Sewage plant phasing out its odorous method of treatment

Two million dollars over budget, 18 months behind schedule, and about 30 years later than nose-plugging neighbors would have liked, San Mateo’s sewage treatment plant is finally ridding itself of its unique reek.

The plant, which treats 13 million gallons of raw sewage a day from San Mateo, Foster City, Belmont and Hillsborough, will transition next month from its famously stinky sludge-cooking system to a new — and hopefully less offensive to the nostrils — bacterial treatment system.

The transition will be complete in October — more than 18 months behind schedule, Public Works Director Larry Patterson said. The delays, caused by a series of expensive breakdowns in the old, decaying treatment system, has cost the city more than $2 million extra to extend the contract with its construction management team, Patterson said.

The delays also come at the expense of the plant’s neighbors, which include a school and a residential neighborhood, separated by a mere fence from the facility. Residents have protested the plant’s distinctly noxious odors after its installation in 1976.

The current system, known by brand name Zimpro, is unusually foul because it pressure-cooks the sewage, explained Public Works Deputy Director Darla Reams.

In a tour of the facility recently, Reams explained that there’s nothing that can mask the smoldering-chemical-toilet smell of the plant.

“That’s Zimpro,” she said. “It’s the only one still working west of the Mississippi, that I’m aware of.”

The new treatment method, which uses anaerobic bacteria to treat the sludge, will be much less odiferous — and cheaper to run, Reams said.

The project has cost more than $30 million, and has beenpaid for with sewage fees, which were increased about fourfold last year.

The fix couldn’t come a day too soon for Zakir Ali, who moved into the neighborhood about three years ago. He said his family has considered moving because they find the odor so noxious.

“Every time you walk outside or open the window, it’s there,” he said. “When family comes over, they ask, ‘Why does it smell like that in here?’”

kworth@examiner.com

Bay Area NewsLocal

If you find our journalism valuable and relevant, please consider joining our Examiner membership program.
Find out more at www.sfexaminer.com/join/

Just Posted

A construction worker watches a load for a crane operator at the site of the future Chinatown Muni station for the Central Subway on Tuesday, March 3, 2021. (Sebastian Miño-Bucheli / Special to the S.F. Examiner)
Major construction on Central Subway to end by March 31

SFMTA board approves renegotiated contract with new deadline, more contractor payments

Neighbors and environmental advocates have found the Ferris wheel in Golden Gate Park noisy and inappropriate for its natural setting. <ins>(</ins>
Golden Gate Park wheel wins extension, but for how long?

Supervisors move to limit contract under City Charter provision requiring two-thirds approval

San Francisco school teachers and staff will be able to get vaccinations without delay with the recent distribution of priority codes. 
Shutterstock
SF distributes vaccine priority codes to city schools

San Francisco has received its first vaccine priority access codes from the… Continue reading

COVID restrictions have prompted a benefit or two, such as empty streets in The City. <ins>(Kevin N. Hume/S.F. Examiner)</ins>
Taking the scenic route through a pandemic

Streets of San Francisco are pleasantly free of traffic

Kelly Marie Tran and Awkwafina provide the voices of the title characters of “Raya and the Last Dragon.” <ins>(Courtesy Disney)</ins>
‘Raya and the Last Dragon’ boasts full-scale diversity

Though familiar in plot, Disney’s latest is buoyed by beauty, pride and power

Most Read