The heinously polluted Tijuana River, which has sickened residents and even researchers with its hydrogen sulfide fumes, is gaining attention, and now a coalition of politicians, activists, physicians and economists are pushing California Gov. Gavin Newsom to declare the fetid and toxic river valley a public health emergency.

They’ve also put together a plan to clean it up and are pleading with state lawmakers to fund it, even as the state faces a multibillion-dollar deficit.

“We’re only starting to understand the full reach of the environmental and health impacts and they’re getting worse every day,” Sarah Davidson, clean border water manager for the ocean protection group Surfrider, said at a news conference Thursday. “There’s no saying how far-reaching they are or how far-reaching they will be. So every lawmaker and resident in California should be concerned.”

In 2024, Newsom said in an interview that a state emergency declaration “would not have availed us to any real benefit except symbolism and then ultimately frustration that it didn’t mean anything.”

Four of the gubernatorial candidates — Katie Porter, Antonio Villaraigosa, Tom Steyer and Xavier Becerra — have pledged to treat the issue as a top priority.

Despite his resistance, Newsom has secured funding for the river and region, including $38 million for water quality improvements in 2019 and an additional $100 million in federal funds for the area’s infrastructure in 2025.

Among the elements in the package announced Thursday: state Senate Bill 58, which would establish air quality standards for hydrogen sulfide, a toxic pollutant emitted from the river, and Senate Bill 1046, which would set standards and guidelines for workers employed near the river.

They’re also pushing for $23 million in state transportation funds to upgrade the Saturn Boulevard crossing near San Ysidro, where the river cascades through a small channel and is considered a hot spot for spewing toxic air pollutants. Other items include $5 million for air purifiers for people in heavily affected ZIP Codes, and $2 million to update a boom on the river that collects trash moving downstream.

Support for addressing the Tijuana River crisis has been bipartisan.

Last summer, Environmental Protection Agency Administrator Lee Zeldin committed the Trump administration to “a permanent, 100% solution to the decades-old Tijuana River sewage crisis,” signing a memorandum of understanding with Mexico.

“I smelled for myself that foul smell that so many residents of Southern California have been complaining about for so long,” Zeldin said, adding that President Trump was highly motivated after hearing from Navy SEALs who must train in the polluted waters of the Pacific Ocean where the Tijuana River meets the sea.

A recent Department of Defense report showed 1,100 reported cases of illness among Navy SEALs and other service members exposed to high levels of bacteria when they trained in and around the mouth of the river near the border.

In 2024, California voters also approved Proposition 4, which allocated nearly $50 million for projects addressing water quality problems along the Mexico border and coastal areas. But most of that money has yet to be released, waiting for various agency reviews and approvals.

Trump also took an interest in the river during his first administration, committing $300 million in federal funding to the San Diego region for a new U.S. facility to capture Tijuana sewage spills before they foul shorelines.

Advocates for an emergency declaration, including those representing local communities, say an emergency declaration could help release those funds and prompt interagency action. For example, funds could be used for road and tunnel construction to improve the flow of the river, addressing several public health issues plaguing the region.

Nearly three-quarters of the Tijuana River watershed is in Mexico, with the last five miles flowing into the U.S. before emptying into the Pacific Ocean at Imperial Beach.

Pollution in the 120-mile-long river has been so egregious that recent studies have shown that even the air above the river, or the spray where it reaches the surf, is dangerous.

Using an air quality monitor nearly half a mile from the river in the community of Nestor, Calif., last year, scientists found extremely high levels of hydrogen sulfide, a gas linked to sewage that smells like rotten eggs. Their paper was published in the journal Science.

Last year, American Rivers, an environmental group, declared the Tijuana River the second-most endangered river in the nation.