Southern California officials plead for help as cross-border sewage crisis poisons air

Southern California’s border-adjacent communities are pushing for emergency assistance from regional and state agencies as they contend with a cross-border sewage crisis that is poisoning the air they breathe.

The writers, led by Imperial Beach Mayor Paloma Aguirre, pushed for immediate action to cope with dangerous air pollution impacting area communities, in a Sunday letter sent to officials from the San Diego County Air Pollution Control District and the San Diego County Board of Supervisors.

Imperial Beach and its neighbors have for years struggled with an unrelenting, transboundary sewage situation that results from insufficient wastewater treatment on the Mexican side of the border. That fetid flow ends up in San Diego County both via ocean plumes and the Tijuana River Watershed, contaminated with a noxious mix of chemicals and pathogens.

Not only have these contaminants caused widespread water contamination and long-term beach closures, but they have also become an airborne public health threat.

Just last week, San Diego State University and University of California San Diego professors studying such impacts had to abandon their research due to “concerningly high” levels of toxic hydrogen sulfide gas, as reported by the San Diego Union-Tribune.

“Our families, children, seniors and the immunocompromised are constantly at risk, breathing in harmful toxic gases that no one should have to endure,” Aguirre said in a Sunday statement. “We are fighting not just for our health but for our right to clean air and a safe environment.”

“It is unacceptable that the agencies responsible for protecting our communities continue to drag their feet while we bear the brunt of their inaction,” she added.

The Sunday letter signatories — local politicians, citizens, health professionals, academics and environmental activists — called upon regional and state agencies to distribute KN-95 masks and air purifiers that are effective in removing both particulate matter and gases in all affected areas.

The priority, they stressed, should be on immunocompromised individuals, the elderly, families with young children and schools.

While Aguirre acknowledged in her Sunday statement that some efforts had been taken — mentioning 400 filters that had been distributed via lottery — she stressed that such action “is not enough.”

In their letter, Aguirre and her colleagues also requested calibrated particle and gas monitors to determine the safety of outdoor activities across the region, as well as the placement of advisory signs about the risk of exposure to hydrogen sulfide, sulfur dioxide and other toxic gases.

At the same time, the writers emphasized the need to stop sharing the Air Pollution Control District’s sensor data until the instruments are fully calibrated and generating accurate measurements.

Without such a step, the equipment could be leading to “potentially erroneous conclusions” and granting “a false sense of security to the community,” according to the writers. 

Likewise, they demanded the suspension of the community’s “Syndromic Surveillance Bulletin” — which highlights local health symptoms — until it includes more thorough clinical data from both the South Bay region and from Tijuana.

“The urgency of this situation can not be overstated,” they concluded. “We ask for immediate intervention and implementation of these requests by the County Office of Emergency Management, Air Pollution Control District, and Health and Human Services.”

The Hill has reached out to both Air Pollution Control District Chair Jack Shu and the Board of Supervisors Chair Nora Vargas, to whom the letter was addressed, for comment.

The Air Pollution Control District’s homepage warns that “inspectors have been documenting strong odors impacting South Bay communities,” adding that ongoing extreme heat conditions have exacerbated these issues.

“Compounds associated with these odors may cause adverse health effects,” the message cautions, advising that residents stay indoors when possible.

As for the Board of Supervisors, Vargas described current circumstances as “an emergency” in a post on X on Sunday, noting that “our communities are facing the worst environmental and social justice crisis of our time.”

“I’m continuously working with federal, state and local partners to secure immediate and long-term solutions that protect the health of our families,” she added.