"It is in different areas of Vallejo," said Nina Garcia, who was out for a walk. "You go down Sonoma, we don't have a sewer plant down there but it smells like that."
The odor is coming from the Vallejo Wastewater Treatment Plant. The reason why it is so strong is because facility is undergoing a massive retrofitting project. Staff members are refurbishing one of their bio towers that filters the wastewater. With one tower currently out of service, that means they only have one other tower doing the work of two.
"The strength of the waste water doesn't go down whatsoever," said Orlando Cortez, the project superintendent at the facility. "But our treatment did. So we reduced it by 50% - and it is what it is."
However, Cortez says this project has been in the works for years and is necessary for the long-term sustainability of the plant.
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"There are millions upon millions of media, plastic media," he said. "Upon the media, there is a mass that actually grows and the media has not been replaced since it was brought online in 1988."
Media is a term for collection of plastic and rocks that build up in the filters. Cortez says it took a month to break down the mass that had built up before they can start the rest of the project. Cortez says they knew it would lead to a stronger odor, but they didn't anticipate how strong it would smell or how far it would travel.
"We undershot the actual radius of notifying our rate payers," Cortez said. "We went out about a half a mile. Now in hindsight, we should have gone out maybe two miles just to make sure that we covered everyone in that area."
Mix that in with it being a hot summer, and Vallejo is one stinky city. The positive news is the project is still on track to be done by November. With summer winding down, residents hope the worst of the smell is behind them.
"It is brutal on a hot day," said Ronald Smith, another resident. "When you drive by it, you will know.