Storms may have sent millions of gallons of wastewater into SF Bay, residents advised to 'stay out'

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Thursday, January 19, 2023
Storms may have sent millions of gallons of wastewater into SF Bay
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California's recent storms send millions of gallons of potentially untreated wastewater into San Francisco Bay, residents are advised to "stay out."

OAKLAND, Calif. (KGO) -- Whether or not you can hear it, across the Bay Area there's one, collective sigh of relief with a break in the rain.

But before you take advantage of the sunnier skies, a local environmental watchdog group has an important warning: stay out of the bay, at least for the next several days.

"I would urge people to still stay out of the water for a couple more days," said Sejal Choksi-Chugh, the executive director of San Francisco Baykeeper, told ABC7 News. "It's going to rain again tonight, and the bacteria and pathogens and viruses and chemicals haven't really had a chance to flush out of the bay yet."

"So, stay out of the water for a couple more days and hopefully the sunshine next week will be a good time to get back in the bay," she added.

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The reason, according to Choksi-Chugh, is that the influx of rain has overwhelmed water treatment plants and storm drains.

"When we have large storm events, oftentimes what happens is our wastewater treatment plants are overwhelmed and so they have to discharge a lot of untreated sewage into the bay," Choksi-Chugh said. "Sometimes those discharges happen in the streets through storm drains, and sometimes they happen through overflow plants at the wastewater treatment systems, and so when that happens you end up getting untreated wastewater in the bay and that means the water can be contaminated with pathogens and bacteria that can cause illnesses."

One of the many water treatment plants around the Bay Area is East Bay MUD's plant in Oakland.

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Spokesperson Andrea Pook said roughly 50 million gallons of wastewater are treated there daily. But, she said, during the height of the storms -- like the one on New Year's Eve -- it was a lot more.

"Our peak was something like 650 million gallons," Pook said. "That's like 13 times more than we're able to treat in one day."

Pook said the plant was able to treat 98% of that extra stormwater. But that means 2% -- or about 13 million gallons -- of potentially untreated water could also make its way into the bay.

"Not only East Bay MUD, but many dischargers around the bay, having overflows or discharges because their systems are overwhelmed with that influx of stormwater," Pook said.

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And it's for that reason that as the weather dries up, San Francisco Baykeeper is advising people to limit contact with the bay water.

"Oftentimes in our streets, we have lots of fertilizers and pesticides that we've applied to our lawns, we have metals coming from industrial facilities, all of that gets washed into the bay every time it rains," Choksi-Chugh said. "And when it rains really hard, we can look for trash and other solutions as well, and then our sewage treatment plants get overwhelmed."

SF Baykeeper said, in the short term, be cautious over the next several days if you do think about getting in the bay.

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In the long term? They're advocating for upgrades to sewage treatment plants and storm drains that can handle larger flows.

"If we had sewage treatment plants that could handle larger flows, if we had storm drains that were wider and could handle better flows, then we wouldn't see so much flooding, and we wouldn't see so much overflows," Choksi-Chugh explained. "So it's really a question of how we prioritize maintenance of our sewage treatment and our storm drain plants, and making sure we're upgrading them to deal with this new level of storms we're seeing now."

If you're on the ABC7 News app, click here to watch live