“The San Diego County Board of Supervisors has declared this an emergency 22 times and sent a letter to our governor asking him to follow suit,” Aguirre said on Instagram. “Governor [Gavin Newsom] it is time. We can’t keep passing the buck to another country even if they’re the source.”

“You understand when environmental disasters rise to the level that demands urgent statewide action,” she said.

What was originally thought to be a water pollution problem has also had a major effect on air quality that far exceeded state standards. In a study published last year, researchers at the University of California San Diego Airborne Institute found that the toxic hydrogen sulfide gas in San Diego’s South Bay region had peaked at 4,500 parts per billion for at least one minute and had averaged 2,100 parts per billion over an hour — the latter being well over the state-regulated one-hour standard of 30 parts per billion. 

Kimberly Prather, lead scientist and researcher on the study, called the problem a “serious environmental justice issue” for residents living near the Tijuana River Valley since the residents who live there are almost entirely Hispanic and are living in poverty. She blamed the pollution on U.S. companies that have set up factories across the border to skirt U.S. regulations and dump toxic waste. 

“People are really sick. They have migraines, respiratory problems, heart problems, neurological problems,” Prather said. “The biggest one I hear the most about is lack of sleep, migraines, depression. I mean, it’s just crushing this community. And there’s not one fish that’s alive in the river — it’s a complete dead zone.”

In her post, Aguirre said not only has the river been causing health problems, but it’s also causing small businesses to close their doors and families to move out of the neighborhood, leaving behind properties that real estate agents can’t sell. She also expressed concern for Navy SEALs who have to train in polluted water and Border Patrol agents who work in toxic air. 

“What may once have been a wastewater infrastructure issue has become a full-blown environmental and public health crisis,” Aguirre said.

This is not the first time the area has seen pollution levels this high. Prather said the levels of pollution have ebbed and flowed since her team started measuring them in September 2024. Due to the ongoing problem, Aguirre has invited several gubernatorial candidates, including Katie Porter, Tom Steyer, Matt Mahan and Betty Yee, to visit the area — all of whom have agreed to declare a state of emergency.

“All the ones that have visited the site, by the time they were done visiting, were so appalled. It was just like, how can this be happening?” Prather said.

“If you’re going to go be president of the United States, you should be helping the people in your own backyard,” Prather said.

SFGATE reached out to Newsom’s office for comment. It did not respond to an immediate request for comment.