As much as 30 million gallons of sewage-contaminated wastewater have been pouring into the Pacific Ocean each day from the Tijuana River, flowing north into U.S. waters and forcing repeated closures of some of Southern California's most popular beaches. The crisis has now reached the Pentagon: a February 2025 inspector general report documented 1,168 cases of acute gastrointestinal illness among Navy SEAL candidates exposed to the filthy water during training off Coronado.
The numbers tell the story of a border-region environmental disaster that federal, state, and local officials have failed to stop for decades. Tijuana Slough, the closest Southern California beach to the Mexican border, was closed 333 times over the last five years. Imperial Beach, which draws roughly 400,000 visitors a year, shut down 231 times. Silver Strand closed 152 times between 2020 and 2025. And Coronado, the upscale beach community just two miles from downtown San Diego, saw 73 closures due to unsafe bacteria levels in the same period, the Daily Mail reported.
The California State Lands Commission acknowledged the toll on local communities:
"This is a necessary measure to protect public health, but it is unacceptable that the community is unable to access clean and safe beaches and coastal waters."
Unacceptable barely covers it. The sewage problem dates back at least to 1933, when the Sierra Club says the earliest reports of contaminated water crossing from the Tijuana River into U.S. territory were recorded. Back then, Tijuana had a population of roughly 14,000. Today, the city is home to more than 2.2 million people, and its wastewater infrastructure has not kept pace. Outdated and overloaded treatment plants, broken pipes, and poor stormwater systems have turned the river into an open sewer.
The Pentagon's inspector general report, published in February 2025, laid bare the consequences for the military. The 1,168 gastrointestinal illness cases, marked by nausea, vomiting, and diarrhea, struck SEAL candidates who trained in contaminated waters off Coronado. Fox News reported that the inspector general found the exposure happened because Naval Special Warfare Command did not follow San Diego County's beach closure postings for contaminated water.
The report was blunt about the stakes:
"As a result of Navy SEAL candidate exposure to contaminated water during training, candidates are presented with increased health risks and NAVSPECWARCOM's training mission could be impacted."
Department of War officials noted that the declining water quality had already disrupted training for the Navy's special operations units, forcing them to cancel water exercises whenever conditions reached danger levels. San Diego County Supervisor Jim Desmond put it plainly, as Just The News reported:
"Navy SEALs are now being transported from Coronado to Oceanside for training, because too many have gotten sick from Mexico's sewage."
That a Defense Department inspector general report found 39 percent of recent special forces acute gastrointestinal illness cases were tied to exposure to contaminated water exceeding state safety standards should alarm anyone who cares about military readiness. These are some of the most elite warfighters in the world, sidelined not by enemy action but by raw sewage flowing across the southern border.
Veterans have warned that the Navy faces broader institutional challenges, and the sewage crisis adds a grim new dimension. Some have compared the long-term health risks to Camp Lejeune, the Marine Corps base where contaminated drinking water poisoned servicemembers and their families for decades before the government acknowledged the damage.
The scale of the contamination is staggering. San Diego Coastkeeper estimated that 31 billion gallons of raw sewage, polluted water, and trash traveled along the Tijuana River into the Tijuana River Valley and the Pacific Ocean from October 2023 to May of last year alone. The AP reported an even larger figure: since 2018, more than 100 billion gallons of raw sewage, industrial chemicals, and trash have poured into the Tijuana River and then into the Pacific, citing the International Boundary and Water Commission.
The U.S.-owned South Bay International Wastewater Treatment Plant was built as a backstop to catch and treat sewage spilling over from Tijuana. But the facility can handle only 25 million gallons per day, and it has been receiving about 30 million gallons per day, leaving the excess to flow straight into San Diego waters.
Mexico's track record on keeping its promises has not inspired confidence. Supervisor Desmond noted that Mexico dumped 6 million gallons of sewage into the Tijuana River after promising it would stop. That kind of follow-through makes any bilateral agreement look like a handshake written in sand.
The damage is not limited to the ocean. Earlier this year, local counties detected elevated levels of hydrogen sulfide in the air from wastewater and sewage flows out of the Tijuana River Valley. The CDC has warned that hydrogen sulfide, a toxic gas, can cause headaches, nausea, coughing, shortness of breath, skin and eye irritation, and asthma attacks. In extreme concentrations, it can be fatal.
Some residents have already left. Whitney David, a former resident of the area, described what the neighborhood became:
"It was heaven on earth and now I call it paradise lost."
David recalled seeing "all kinds of trash" floating in the ocean, food wrappers, bottles, clothing. The sewage gas and contamination have driven residents from their beach homes in surrounding communities, with hydrogen sulfide readings reportedly reaching alarming multiples of California's safety limits.
Coronado Mayor John Duncan said the community has seen its businesses affected by a growing reputation that the city is now dirty. For a town that built its identity on pristine coastline and a high quality of life, the economic consequences are real and compounding.
The United States and Mexico have agreed to speed up projects aimed at cleaning up the sewage problem, including building additional treatment plants in Mexico and expanding the South Bay International Wastewater Treatment Plant. EPA Administrator Lee Zeldin said during a February visit to San Diego that it would take about two years to resolve one of the nation's worst and longest-running environmental crises.
President Trump has called on Mexico to address its untreated wastewater issues before the contamination reaches the U.S. That demand is overdue. The federal government has known about cross-border sewage flows since at least 1933 and has spent decades managing the problem rather than solving it.
The broader context matters. At a time when the Navy is stretched across global commitments, from operations in the Strait of Hormuz to force-protection missions worldwide, having elite special operators unable to train safely in their own backyard is more than an embarrassment. It is a readiness problem with national security implications.
And the federal government's approach to environmental monitoring and wastewater surveillance has only recently begun to catch up with the scale of the contamination pouring across the border.
Forty-four billion gallons of contaminated water containing raw sewage were released along the California coast in 2023 alone, the highest recorded total since at least 2000, Fox News reported. That is not a new problem. It is a very old problem that got worse because no one with authority forced a fix.
The people who pay the price are not in Washington or Sacramento. They are the Navy SEAL candidates who got sick training in water their command should never have sent them into. They are the families in Imperial Beach and Coronado who can no longer take their kids to the shore. They are the small-business owners watching tourists go elsewhere.
For nearly a century, the Tijuana River sewage crisis has been someone else's problem. The beaches close. The SEALs get sick. The reports pile up. And the wastewater keeps flowing north.
At some point, "unacceptable" has to mean something more than a press release.
