The Toxic Crisis at the Tijuana River: A Community’s Fight for Clean Air

Living with the Unbearable Stench of Cross-Border Sewage

For Steve Egger and his wife, every night brings a familiar nightmare: the overwhelming smell of rotten eggs seeping into their Southern California home. At 72 years old, Egger has spent his entire life in this area where three generations of his family once operated a thriving dairy farm. But today, instead of pastoral memories, he and his wife wake up with pounding headaches, congested sinuses, and phlegm-filled lungs. Despite installing a hospital-grade air filtration system that cycles fresh air every 15 minutes, the toxic fumes still invade their home. The source of their misery is the nearby Tijuana River, which has become a flowing nightmare of raw sewage and industrial waste from Mexico, foaming up with contamination before it reaches the Pacific Ocean. The sight is so dramatic that the river’s foam can now be seen from space. For Egger and tens of thousands of neighbors, this isn’t just an environmental problem—it’s a daily assault on their health and quality of life. “Most nights we breathe in a horrible stench,” Egger said simply. “It’s awful.”

The Staggering Scale of Contamination

The numbers tell a story of environmental catastrophe that has been unfolding for years. Since 2018, more than 100 billion gallons of raw sewage—laden with industrial chemicals and trash—have poured into the Tijuana River, according to the International Boundary and Water Commission. To put this in perspective, just since January of this year, the river has carried 10 billion gallons of mostly raw sewage and industrial waste across the U.S. border. This stands in stark contrast to other sewage incidents that have received immediate federal attention: when a massive pipe rupture sent 244 million gallons of untreated sewage into the Potomac River near affluent, largely white communities, federal intervention came within weeks. The Tijuana River crisis, affecting a largely poor, Latino population, has festered for years without comparable urgency. The 120-mile-long river begins in the Mexican city of Tijuana, crosses into California, and empties into the ocean, forcing the closure of San Diego County beaches for years at a time. Even Navy SEALs who train in these waters have fallen ill from the contamination. What was once a seasonal waterway that flowed only during rainy periods has transformed into a year-round toxic stream of sewage and industrial waste.

Understanding the Hidden Health Dangers

The problem extends far beyond an unpleasant smell. Raw sewage emits hydrogen sulfide, a toxic gas that poses serious health risks that scientists are only beginning to fully understand. According to the Centers for Disease Control and Prevention, exposure to hydrogen sulfide can erode neurons in the nose, trigger asthma attacks, and cause headaches, nausea, delirium, tremors, cough, shortness of breath, and skin and eye irritation. In extreme cases, it can even cause death. The long-term health consequences are only starting to be documented and understood by researchers. What’s particularly alarming is that there is no federal safety standard for hydrogen sulfide exposure except for workers at sites with extreme risk, such as wastewater treatment plants or manure pits. A few states established standards decades ago, but these are now considered outdated. California is proposing to update its 56-year-old standard to reflect modern scientific understanding of the gas’s health risks, while Texas lawmakers are considering similar updates. However, even if California’s bill passes, the new standard likely won’t be developed until 2030—meaning communities like Egger’s will continue suffering without adequate protection for years to come.

Scientific Evidence Validates Community Concerns

In September 2024, researchers led by Kimberly Prather, a chemistry professor at the University of California, San Diego, installed air monitors in Egger’s neighborhood. What they discovered was shocking: hydrogen sulfide concentrations reached levels 4,500 times higher than typical urban environments and 150 times higher than California’s air quality standards when river flows peaked at night. For many residents like Egger, these findings brought a sense of validation after years of having their concerns minimized. “They’d been being more or less gaslit and told, ‘There’s gas. It’s a nuisance. It smells, but it’s not bad,'” Prather explained. Even more disturbing, her research team has since detected thousands of other gases emanating from the river—many of which don’t produce noticeable odors but are actually more toxic than hydrogen sulfide. A 2024 sampling conducted by San Diego County and the CDC of roughly 40,000 households near the Tijuana River found that 71% could smell sewage inside their homes, and 69% had at least one family member become sick from exposure. Ryan Sinclair, an associate professor of environmental microbiology at Loma Linda University School of Public Health, described the experience of even low-level exposure: “You’re going to feel like it’s in your sinuses. You can’t get rid of the smell. It’s going to be a constant irritation.”

The Human Cost: Stories from the Frontlines

The health impacts are not abstract statistics but real suffering experienced by real people every day. Dr. Matthew Dickson and Dr. Kimberly Dickson run a medical clinic about a mile from what scientists call “the Saturn hot spot,” where the river shoots out of pipes after being forced underground near Saturn Boulevard. The stench at this location is so overwhelming that it permeates passing cars even with the windows closed, and the smell lingers inside vehicles for days. At their clinic, the doctors treat patients suffering from migraines, nausea, wheezing, eye infections, and brain fog. Patients with asthma report needing their inhalers more frequently when the air reeks of sewage. “They’d say, ‘You know, I feel better when it doesn’t smell outside,'” Dr. Kimberly Dickson recalled. The doctors’ electronic health records provide hard data confirming what they observed firsthand: when river flows increase, the number of patients they treat for respiratory problems jumps by 130%. The crisis reached a critical point in August 2023 when a tropical storm caused the river to overflow onto streets. Within days, the doctors’ caseloads tripled. “Every day that this isn’t fixed,” Dr. Matthew Dickson said, “more people are getting sick.” For Steve Egger, doctors have recommended that he move away from the area, though they haven’t provided written documentation of his suffering from hydrogen sulfide exposure. But leaving isn’t a simple decision—his wife grew up in Tijuana, his brother and late brother’s family live in neighboring houses on what was once Egger Dairy, and nearby stand the remnants of their family heritage: a dilapidated milk barn and rusting farm equipment. “This is where I’ve lived all my life, with my family, my parents, my grandparents,” Egger said. “This is home.”

The Path Forward and the Fight for Justice

The United States and Mexico signed an agreement last year aimed at cleaning up this longstanding problem by upgrading wastewater treatment plants to keep pace with Tijuana’s population growth and the industrial waste from factories—many of which are owned by U.S. companies. During a February visit to San Diego, Environmental Protection Agency Administrator Lee Zeldin acknowledged the severity of one of the nation’s worst and longest-running environmental crises, stating it will take about two years to resolve. In the meantime, the EPA says it is working with local and state officials to find ways to mitigate the smell, and San Diego County distributed over 10,000 air filters to homes this year. But residents know these band-aid solutions don’t address the root problem—the air remains a threat to their health and wellbeing. Egger believes the river should be restored to its historical route, which ran closer to the border and farther from most residences and schools, preventing the ponding that creates hot spots of hydrogen sulfide gas. A “Stop the Stink” sign on Egger’s fence represents his participation in a campaign launched by Citizens for Coastal Conservancy demanding that officials finally clean up the cross-border sewage crisis. The situation highlights a disturbing pattern of environmental injustice, where largely poor, Latino communities are forced to endure conditions that would never be tolerated in wealthier, whiter neighborhoods. As researchers continue to uncover the full extent of health impacts and thousands of families suffer daily, the question remains: how many more people must get sick before meaningful action is taken to protect this community’s fundamental right to clean air and water?