What California’s Recent Atmospheric Rivers Reveal About San Francisco Bay Area’s Aging Wastewater Systems

SAN FRANCISCO (KGO) — Tens of millions of gallons of sewage and stormwater were released into San Francisco Bay from aging treatment plants and stormwater systems overwhelmed by the deluge.

Sejal Choksi-Chugh is the executive director of San Francisco Baykeeper, an environmental group that tracks pollution threats.

“So that can include pathogens, bacteria, viruses that can get into the water. And if someone comes into contact with that water, it can have a harmful effect on their health,” says Choksi-Chugh. .

VIDEO: Here’s a before and after look at the hardest hit areas in Capitola, Santa Cruz

They say the episode is an extreme example of a challenge that has been building for decades. Recent estimates place the cost of upgrading the dozens of sewage systems that surround the bay in the billions of dollars. But groups like Baykeeper say the improvements are key to protecting the bay, calling for increased federal spending during President Biden’s recent visit to the Bay Area to assess storm damage.

“And when those sewer pipes get submerged, then you just have too much water in the system in the sewer system. And you know, they’re not equipped to handle that, so much water. And that’s that’s why we really insist on upgrades at all levels,” says Choksi-Chugh.

Experts say climate-related factors also exert additional pressures, including fluctuating cycles of intense storms. Recent studies also point to rising sea levels, pushing heavier salt water below the bay’s shoreline, potentially raising the water table and further degrading underground pipes, especially during heavy storm cycles.

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Eileen White is the executive director of the San Francisco Bay Area Water Quality Monitoring Board.

“So what we saw on December 31 and then the first two weeks of January, we can expect to become the new normal with climate change,” White believes.

She echoes the need for state and federal funding, but points out that many of the major Bay Area wastewater treatment districts are already spending on upgrades.

“There’s a lot of good work going on in the Bay Area, looking at climate change and what needs to be done to prepare these sewer systems to be more resilient in the future. And for example, the San Francisco emissions worked with the regional council a year ago, and they made a deal with us that they’re going to spend over $600 million by 2028 to make improvements,” White said.

Last year’s destructive algal bloom in San Francisco Bay also shed light on potential improvements to the region’s wastewater treatment system. Indeed, nutrients in treated wastewater could be a driver of algae growth.

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