It's one you may eventually notice on your monthly water and sewer bill. But still, engineers and environmental advocates say the investment will be worth it.
When destructive algae blooms kill fish and other wildlife in San Francisco Bay, few might realize we're contributing to the problem. At least our bathrooms are.
But that link from Bay Area homes to the Bay is about to get an upgrade.
Newly announced permitting regulations by the San Francisco Bay Water Board will affect roughly three dozen wastewater treatment plants that circle the bay. The goal, in part, is to limit the release of algae-feeding bi-products like nitrogen.
Eileen White directs the state water board for the San Francisco Bay region.
MORE: Warning issued over harmful algae blooms in Discovery Bay waterways
"The purpose of this permit is to reduce the nutrient loads at San Francisco Bay. So, as we have more harmful algae blooms in the future with climate change, they won't be able to propagate across the bay like we saw in 2022. Result: massive fish kills impact people who fish in the bay, the commercial fishermen, people who recreate in the bay. And for what's so special for the seven million people that reside in the San Francisco Bay, is San Francisco Bay," White said.
The needed upgrades will vary between treatment plants. But the overall price tag is expected to be in the neighborhood of $11 billion.
"I would say it's probably the biggest decision our board will have ever made. It's the most consequential decision, because there's so much at stake here, as probably the biggest decision since the Clean Water Act was enacted in the 1970s," White said.
Some treatment plants have already begun construction. ABC7 recently toured Palo Alto's facility, which is in the middle of an infrastructure buildout. Assistant Public Works Director Karin North said the work includes nearly $200 million in upgrades to filter out nutrients.
MORE: Improvements eyed for San Francisco Bay in wake of algae bloom
"I think for infrastructure improvements, you're probably right in the middle. In terms of nutrient reduction projects, we're closer to more on the leading edge, and that's because we looked at aging infrastructure, and it made sense to upgrade earlier for nutrient reduction," North said.
The upgrades could also include environmental innovations, like horizontal levees. which are being studied at the Oro Loma Wastewater facility in the East Bay. Environmental engineers believe they can both help purify wastewater and help protect the treatment plants from predicted sea level rise.
"So unlike in other parts of the country and even other parts of the state, where each wastewater plant might discharge to a different water body, we have a common bathtub here in the bay -- where the wastewater from 37 wastewater treatment plants from most of the urbanized area all discharge into the same common endpoint, which is the San Francisco Bay. So, we have a unique opportunity to protect it," said Jackie Zipkin, general manager of the East Bay Dischargers Authority.
MORE: Here's how horizontal levees protect shoreline projects in San Francisco Bay
There are several plans being floated for phased rate increases that could affect thousands of Bay Area customers. But agency heads say the amounts could vary significantly from district to district, based in part on the work that's already been done.
And while the overall investment is significant, backers believe the upgrades will help ensure the health of San Francisco Bay for future generations.
"So, we don't want to just look at one problem and solve that problem. We want to see 'Is it going to cause any other benefit?' Because we all we're always looking for multi-benefit projects," North said.