Employers: Log In / Register
Job Seeker: Create Job Alert
By Michael Cabanatuan | San Francisco Chronicle (TNS)
On balmy Bay Area days all summer, Sheila Johnson has arrived home in Vallejo after work, thrown open the windows to air out her stuffy house — and instead gotten a blast of a strong and foul smell from outside.
"Whew!" she said. "It smells like a sewer."
She searched for how to describe the overpowering odor: "It's not quite sulfur and rotten eggs, it's just that strong gassy smell of sewer."
Johnson's house is among as many as 20,000 homes and businesses plagued for months by a foul odor in South Vallejo, a diverse neighborhood along the Mare Island Strait that includes everything from historic Victorian houses to modest tract homes.
Residents describe the stench as akin to human excrement, rotting trash or meat or fish, or the rubbery smell of an inner tube — or some combination of those unpleasant aromas.
The source of the foul smell isn't a sewer, but it's not far afield. It emanates from the Vallejo Flood and Wastewater District treatment plant on the city's south waterfront across from Mare Island, which serves an area slightly larger than the Vallejo city limits.
The district began a modernization project in March to replace aging infrastructure at the 1950s-era treatment plant on Ryder Street. The work included rehabilitating the materials that constitute a filter in one of two biotowers — which officials knew would temporarily increase odors.
They warned people living within a half-mile of the plant, sending letters that said they were "excited" about the project but that it "may result in some unpleasant odors." They expected the surge of smelliness to last a few weeks.
But the smell has gone on for four months, and officials acknowledge it's been much stronger and more widespread than anticipated, extending up to 2 miles from the plant.
And the district now says relief won't come until November, when the rehab project is completed.
The plant processes about 10 million gallons of wastewater from about 42,000 Vallejo residences and businesses a day in dry weather, said operations superintendent Orlando Cortez, but is licensed by the state to handle up to 15.5 million gallons daily. After going through multiple processes at the plant, the wastewater is released directly into the Mare Island Strait.
The smell comes from one of two biotowers at the plant, a part of the secondary treatment process that involves running wastewater from the top of a 30-foot-tall tower, with a diameter of 105 feet, through 12 layers of plastic mesh that make up a "trickling filter."
The odor, which Cortez describes as more "earthy" than feces-like, seems to blend with an existing human waste smell coming from a part of the plant handling incoming sewage.
As the 40-year-old filters were removed and destroyed, and replaced with new ones expected to extend the life of the treatment facility, the district expected "an odorous process," community outreach specialist Rachelle Canones said in a statement to the Chronicle.
But the smell continued — most likely due to having just one trickling filter tower in operation, doing the work of two. Officials also believe it was exacerbated by weather conditions that included temperatures in the 80s and still winds that prevented the smell from being dispersed as quickly.
"The persistence of odors is what we underestimated," Canones said. "We are working diligently to mitigate these odors."
So far the district has installed six small fans atop 40-gallon barrels of an odor-absorbing chemical that is sprayed into the air. Misting systems have also been installed and covers placed atop aeration basins where bubbling wastewater sends odors into the air.
"It looks like 'Willy Wonka & the Chocolate Factory,'" Cortez said of the formerly open-air aeration tanks. "But it's not chocolate."
The district is adding a system that injects chlorine into wastewater as it flows into the plant, hoping it will reduce odors throughout the process, as well as rehabilitating another filtration system.
"We're trying to address our ratepayers' concerns as much as possible and reduce the odors," Cortez said.
The Bay Area Air Quality Management District has received several complaints about the odor since April, according to spokesman Ralph Borrmann. District officials have visited the site but have not issued violation notices in the past year, he said.
Local health officials say that while the stench is a nuisance, it's not dangerous. "The odors are not toxic and do not pose any risk to the community's health; instead, they are an inconvenience," the Solano County Health Department said in a statement.
The wastewater district has received 20 formal complaints from as far as 2 miles away, most from the Heritage District, as well as the areas of Monterey Street and Curtola Parkway and Lincoln Road and Buss Avenue.
Less formally, residents and visitors have flocked to social media sites like NextDoor and Facebook to vent about the problem, and a petition has been posted on change.org urging local officials to "address persistent foul odors" that are "severely impacting our quality of life and raising serious health concerns."
It's also been a hot topic of neighborhood conversation.
"It reeks," said Cliff Chism, a paratransit driver who drops riders off at a nearby clinic. "It's almost as potent as the (wildfire) smoke we got a couple of years ago. I really try to block it out and not stay here too long."
A couple of blocks away, Ken Hawes, who manages a recycling center and spends much of his days outdoors, said the sewer plant has always emitted odors, but they usually occurred briefly a couple of times a day, making them easier to endure.
"It's become pretty bad," he said. "It kind of hits you."
Workers at the recycling center sometimes take their breaks inside with the air conditioner cranked "just to get some relief from it," he said. Customers, waiting in their cars to drop off bottles and cans, roll up their windows but still complain about the smell.
"We're ready for it to go away," he said.
So is Johnson, who sometimes sprays air freshener around the house but also finds too much of that smell annoying, too.
"I pretty much just cope with it," she said. "I'm not sure you can do anything else."
Reach Michael Cabanatuan: [email protected]; Twitter: @ctuan
___
(c)2024 the San Francisco Chronicle
Visit the San Francisco Chronicle at www.sfchronicle.com
Distributed by Tribune Content Agency, LLC.