Photograph Courtesy of the City of Imperial Beach

Imperial Beach Mayor Paloma Aguirre (right) showing the build-up of toxic foam in the Tijuana River to National City Mayor Ron Morrison on September 23.

The Tijuana River Valley is a large estuary complex that drains the watershed area from the east and the urban runoff of Tijuana from the south, sending both flowing out into the Pacific Ocean to the west. Thanks to cataclysmic infrastructure failures and insufficient government response and regulation south of the border, that Tijuana runoff is famously nasty, rife with raw sewage and other sick-making things. And while the dominant current along most of the San Diego County coastline runs from north to south, this portion of our coast has a predominant current that flows from south to north. As a result, the ocean delivers sewage-infused waters to the beach communities south of Point Loma. There’s an international border running between the dirty water’s source and its destination, but the water doesn’t seem to care about borders and the legal limitations they create. And given South County’s economic and political status relative to, say, La Jolla, there are those who wonder just how much the powers that be care about the water. Or, for that matter, the air.

Photograph by Bill Chizek, iStock / Getty Images Plus

On June 4, 2024, the mayors of the 18 cities in San Diego County sent a letter to California Governor Gavin Newsom. The letter made a unified and compelling plea to recognize the “urgent and escalating public health emergency” in South San Diego County, and to make a corresponding declaration of emergency in response. As the letter noted, “over one billion gallons of untreated wastewater pour into this region each month, resulting in the closing of Imperial Beach’s shoreline for more than 900 consecutive days. Additionally, Coronado beaches have been closed more than 50% of the time over the past two years. The resulting pollution is impacting the air quality of the communities of Imperial Beach, Nestor, San Ysidro, Tijuana River Valley, Egger Highlands, South Chula Vista, and Otay Mesa West. This environmental disaster is causing profound social, economic, public health, and ecological damage.”

As evidence for this claim, the letter cited a white paper published in February of 2024 by the San Diego State University School of Public Health. The paper called the situation “a public health crisis,” and noted “the unusual threats to health from pollutants arising in Mexico, including human and livestock diseases eradicated in California, pathogens carrying antibiotic-resistant genes, and industrial and municipal chemicals not permitted to be discharged into the environment in California.” It noted that Hurricane Hilary and other rainfall events “have caused further damage to aging infrastructure…exacerbating concerns.” It noted a recent study that found 175 compounds in border water that “appeared in the U.S. Environmental Protection Agencies Toxic Substance Control Act,” and that found “a substantial number of contaminants of emerging concern” for the first time.

But beyond the toxic stuff that was keeping people out of the water, the white paper noted that “community concerns about strong odors and pollution within San Ysidro from the Tijuana River have been frequently reported,” and that “a recent study…documented airborne microbes and chemicals related to the sewage and runoff over the ocean.” (That study, published in the journal Environmental Science & Technology in 2023, found that 40 tracer bacteria, used to research coastal water pollution released as sea spray aerosol by breaking waves and bursting bubbles, “comprised up to 76% of the bacteria community in IB air.” One of its lead researchers was Dr. Kimberly Prather, co-director of the recently founded Meta-Institute for Airborne Disease in a Changing Climate at UCSD, as well as founding director of the Center for Aerosol Impacts on Chemistry of the Environment.) The white paper therefore claimed that “inhalation is also a pathway of exposure, as these dangerous contaminants can also be airborne…Poorly understood pathways of exposure should be carefully and explicitly studied, such as exposures through breathing community air.” The paper concluded, “Investments by Congress and federal and state agencies are desperately needed to not only slow and prevent the ongoing and egregious contamination but also assess the health and environmental harm that has occurred as a result.”

The mayors’ letter laid out the region’s many needs, and then renewed their request for Newsom to declare a state of emergency, defined by the Emergency Services Act as “conditions of disaster or of extreme peril to the safety of persons and property within the state…which are likely to be beyond the control of…any single county, city and county, or city.” They also acknowledged that Newsom’s office had already declined to make such a declaration in an October 10, 2023 letter to the California Coastal Commission, “because it would not actually aid the ongoing response to this crisis.” That letter argued that “a state proclamation of emergency cannot accelerate federal work needed on this federal facility that is in a federally-controlled area on an international border,” highlighted what the governor had done already, and explained that “the Governor’s emergency powers extend to waiving only state statutes and regulations…No one has identified or proposed any specific relief from state statutes or regulations necessary to facilitate emergency response and recovery.”

On September 24, Mayor Aguirre sent a letter to President Biden’s Chief of Staff Jeff Zients, pleading for immediate federal emergency relief. As of this writing, she has not received a response.

Photograph Courtesy of the City of Imperial Beach

The mayors were not mollified. Their June letter argued that, beyond suspending state law, “the Governor could ‘use and employ [the State’s] property, services and resources’” to deal with the crisis, and also “’ascertain the requirements’ of our communities to avoid preventable disease and property damage stemming from this pollution…The pollution crisis in the Tijuana River violates both state and federal environmental laws, and it is incumbent upon the state to implement and enforce these laws vigorously.”

In just ten calendar days (which included a two-day weekend), a response, dated June 14, 2024, was rapidly generated by the governor’s Office of Emergency Services. The letter, signed by director Nancy Ward, outlined in three pages why a state declaration was neither appropriate nor necessary. Notably, Ward wrote that “an emergency declaration is not necessary for the deployment of state resources. For instance, [the California Department of Public Health] has actively engaged with San Diego’s County Public Health to review data and concurs with that local agency’s conclusion that there is no evidence of increased infectious diseases, including gastrointestinal illness, in connection with the pollution crisis…We will continue to monitor the situation in collaboration with San Diego County.”

That was June. By September, Imperial Beach’s beach closure broke 1000 consecutive days. Soon after, they were re-opened. Soon after that, they were re-closed. Some 40-60 million gallons of untreated sewage continued their daily invasion of coastal waters. On September 9, researchers from SDSDU and UCSD (including Dr. Prather) claimed that hydrogen sulfide and hydrogen cyanide were spreading from the Tijuana River through the air. Hydrogen cyanide is toxic; schools were closed in response. But the county argued that the researchers had it wrong about the concentration of those chemicals and the danger they represented. And it seems the county may have been at last partly right: later claims by the researchers stopped mentioning hydrogen cyanide and focused on hydrogen sulfide.

Hydrogen sulfide smells terrible. But it’s worse than that. On September 8, the San Diego County Air Pollution Control District posted on X that “inspectors have been documenting strong odors impacting South Bay communities. The current extreme heat is exacerbating ongoing odor issues in the Tijuana River Valley and surrounding communities. Compounds associated with these odors may cause adverse health effects. Residents near the affected areas who notice strong odors are advised to limit outdoor physical activity. Whenever possible, remain indoors, especially if you have respiratory or heart conditions, are elderly, or have young children in your household. We continue to assess the situation and we’ll continue to keep the public informed.”

There it was: “Compounds associated with these odors may cause adverse health effects.” But then there was that caveat: “may cause.” Under what circumstances? Part of the problem is that noxious hydrogen sulfide can be smelled long before it is considered dangerous. The California Air Resources Board has a standard of .03 parts per million per hour, which is the level at which the gas becomes detectable by people; that standard gives air regulators the go-ahead to start investigations. But according to a recent Voice of San Diego story, regulators set the safety level for exposure at 20 parts per million per hour. The readings for the South Bay? Just three parts per million at their peak, and a more sustained level of .958 parts per million per hour. Well below the threshold — for an hour, at least.

By September, Imperial Beach’s beach closure broke 1000 consecutive days. Soon after, they were re-opened. Soon after that, they were re-closed.

Photograph by budgetstockphoto/iStock/Getty Images Plus

The issue in South County is prolonged exposure. The Occupational Safety and Health Administration says that 2-5 parts per million, over time, “may cause nausea, tearing of the eyes, headaches or loss of sleep.” Plus “airway problems (bronchial constriction) in some asthma patients.” It sets a 10 parts per million limit on people working just eight-hour shifts. When you have coastal winds blowing hydrogen sulfide in from the ocean during the afternoon, and then air flowing out to sea during the wee hours, you get a day-and-night, back-and-forth wash of bad air over your South County neighborhood. And if people can’t sleep, their health is compromised in other ways as well. While collecting data in the region, some members of Prather’s team found they couldn’t sleep; it seemed a clear confirmation of the problem.

And yet: no emergency. When Covid was floating in the air, that was an emergency. When forest fires choke the sky with smoke and ash, that’s an emergency. Storms, yes. Droughts, yes. Even tree mortality. But not sewer gas.

“Emergency,” according to Public Resources Code Section 30624, means “a sudden, unexpected occurrence demanding immediate action to prevent or mitigate loss or damage to life, health, property, or essential public services.” It’s true that by this point, the flow of sewage can be seen as neither sudden nor unexpected. But then, is California’s annual fire season sudden or unexpected? We get fires every fall like clockwork, and yet the emergency de-clarations keep coming. The same could be said for winter storms and the resultant floods.

On September 3, Governor Newsom declared a state of emergency for the accelerated impacts of coastal landslides in Rancho Palos Verdes. There have been landslides in that area for decades: I know, because I grew up near there. I remember going to Marineland (now Terranea Resort) and experiencing the roller-coaster feel of the undulating roadway, which was always undergoing repair and maintenance. It’s true that recent winter storms have proved a catalyst for an acceleration of landslide movement — one that affects the mostly affluent coastal enclave of Portuguese Bend on the Palos Verdes Peninsula. But as the SDSU white paper noted, it’s also true that Hurricane Hilary exacerbated the problem in the waters off Imperial Beach. And something relatively sudden and unexpected has resulted. It didn’t used to smell this way.

On September 24, Imperial Beach Mayor Paloma Aguirre sent a letter to President Biden’s chief of staff Jeff Zients, pleading for immediate federal emergency relief. As of this writing, she has not received a response. But that’s not to suggest that no one is paying attention. Whether or not all politics is local, local politicians have taken note — and not just those 18 mayors. The county board of supervisors has been renewing its proclamation of a local emergency regarding cross-border sewage every 60 days since it first issued it in June of 2023. In addition, it allocated $100,000 to provide air purifiers to homes impacted by the odors. In October of 2023, the Air Pollution Control District set up an air sensor in South County to investigate odors. It added four more in August of this year. The district also set up a website and hot-line to investigate odor complaints. Research continues: The Tijuana River Project at SDSU now has a website documenting its efforts and offering an ongoing community health survey at tjriver.sdsu.edu. And last week, the CDC conducted 210 interviews over a 30-block region in an effort to understand better the public’s experience of the sewage crisis.

And happily, there is positive precedent for a situation like this. In late September of 2021, a warehouse caught fire in the city of Carson, and the resultant release of chemicals in to the Dominquez Channel brought about the release of a massive cloud of hydrogen sulfide. Residents of Carson, Gardena, Long Beach, and other cities were sickened and eventually evacuated. The Los Angeles County Department of Public Works paid for hotel rooms for more than 3000 people, and distributed 27,000 air purifiers to homes. Grassroots residential activism resulted in agency responses. So there is reason for hope.