In the 1920s, when Tijuana had a population of roughly 5,000, the city’s first sewage treatment effort – a septic tank – oozed wastewater into the Tijuana River, and then the surf.  

By 1934, Americans were so disgruntled with the cross-border contamination that the International Boundary and Water Commission, established in 1889 to apply boundary and water treaties between the United States and Mexico, convened public meetings and started studies. 

According to a timeline prepared by professor Steven Schoenherr of the South Bay Historical Society, “Tijuana attempted to correct the evil by installation of a disposal plant which put out a less objectionable effluent.”

That plant – actually a larger septic system – was designed to serve a population of 5,000 at a time when Tijuana had more than 11,000 residents.

The contamination only got worse. 

Since then, efforts to build a workable infrastructure for border sewage have literally turned into crap shoots, largely under purview of the commission. The chronology is a blackwater river of feuding, failed schemes, wasted money, treaty violations, diplomatic inertia, blue-ribbon studies, lawsuits and broken promises.  

And sickness.

Sewage water being treated at the International Wastewater Treatment Plant. Photo by Madeline Yang.

Even when infrastructure did get built, the improvements were too little, too late. 

Today, tens of millions of gallons of raw sewage flow from Tijuana into San Diego County’s southern beaches, including Coronado, because the South Bay International Wastewater Treatment plant cannot handle all the raw sewage from Tijuana when there are heavy storms.

Yet, that’s not all. 

Pesticides, slaughterhouse effluents, heavy metals, oxidizers and hospital waste also flow into the overtaxed plant in San Ysidro because there’s not a pre-treatment system across the border, said Morgan Rogers, area operations manager for the San Diego field office for IBWC.

“It’s a business that’s not going away.”

-Morgan Rogers, area operations manager for IBWC on raw sewage problem.

Rogers said the untreated waste is a serious problem, but he quipped: “It’s a business that’s not going away. I have job security here.”

Area operations manager Morgan Rogers explaining the International Treatment Plant. Photo by Madeline Yang.

The Coronado News is investigating a nearly century-long legacy of broken promises by U.S. and Mexican officials that have resulted in raw sewage flowing into the Pacific Ocean. The environmental crisis not only pollutes the water, but it affects sea life and causes health problems to residents, U.S. Border Patrol agents and Navy SEALS, The Coronado News has found. 

‘Nobody’s learning from history’

By 1965, Tijuana line breaks and overflows were so chronic that Americans agreed to build a pipeline from Mexico to the San Diego Metro Sewage System’s treatment plant at Point Loma. That same year, the commission proposed to construct a six-mile-long concrete canal through the Tijuana River estuary, prompting an environmental fight that went on for two decades.  

Next came the sewage onslaughts of 1983-84. 

According to Brian Bilbray, then mayor of Imperial Beach, an estimated 45 million gallons of Tijuana wastewater gushed into the ocean daily, contaminating Imperial Beach and Coronado shores amid summer vacation. 

Bilbray, a surfer who literally was sickened by the pollution, issued an emergency declaration and directed a copy to President Ronald Reagan, California’s former governor, while also imploring Baja California’s governor to do something. 

As the pollution and beach closures continued, Bilbray said, he and other City Council members commandeered municipal bulldozers, drove them into the estuary and – to the dismay of environmentalists – began erecting an earthen dam so the Tijuana River would back up into Mexico

The initiative, dubbed “Operation Beaver,” was three-quarters finished before authorities finally agreed to stop the spillage. 

“We are spending more and more and more.”

-Former Imperial Beach Mayor Brian Bilbray

In that instance, Bilbray said, the short-term promise was kept. And Reagan later signed an environmental collaboration agreement with Mexican President Miguel De la Madrid. 

But no funding was approved to solve the larger problem, and beach contamination escalated. 

Nearly four decades later, Bilbray noted, transborder sewage contamination “is probably worse than it has ever been… And we’re spending more and more and more. Nobody’s learning from history.”

Beaches ‘never again’ closed

In fact, money has always been a major obstacle, along with politics.

During the mid-1980s, an engineering firm proposed a “permanent solution” for Tijuana’s sewage: a new treatment plant that would process 130 million gallons of wastewater each day.

U.S. officials, stunned by the $730 million price estimate, directed the firm to find a cheaper, short-term alternative. 

They also began planning a bypass system – a huge pipe that would pump Tijuana River sewage back to Baja, where it would be carried via a canal to a place called Punta Bandera, six miles south of the city.  

In 1987, Mexico built a sewage facility at that location.

According to Schoenherr’s history, De la Madrid arrived via helicopter to preside over inauguration ceremonies for the San Antonio de los Buenos Wastewater Treatment Plant. 

His environmental secretary told reporters that San Diego County beaches would never again be closed due to Tijuana sewage.

The plant promptly broke down and, a year later, it was over capacity. 

Raw wastewater continued to course into the Pacific, carried north across the border by summer currents.  

Delayed by lawsuits

In 1990, the Mexican and U.S. sides of the Boundary Commission adopted an agreement, known as Minute 283, to build yet another facility. 

The South Bay International Wastewater Treatment Plant near the border in San Ysidro would treat an average of 25 million gallons of sewage daily, instead of the 130 million gallons recommended seven years earlier.

One of the systems in the International Wastewater Treatment Plant. Photo by Madeline Yang.

Its eventual completion was a seeming success. 

But a 2003 San Diego Law Review article by environmental attorney Ross Campbell spelled out how the project was plagued by political haggling, buck-passing, litigation and delays.

Effluents from the facility were to be discharged off the coast. 

To accomplish that, the Boundary Commission and city of San Diego bore a tunnel along the seafloor and installed an enormous pipe, 11 feet in diameter. 

Its outfall point is 3.5 miles offshore and 95 feet beneath the ocean’s surface.

Work was immediately delayed by lawsuits.

Surfrider Foundation, a marine conservation group, filed a federal complaint alleging the government had not even evaluated whether ocean currents would carry the effluent to San Diego County beaches. The Sierra Club followed up with an action claiming IBWC’s plan violated the National Environmental Protection Act by ignoring an ecologically sound alternative for sewage treatment.

‘Increased threats to human health’

After a series of consent decrees, the South Bay plant was completed and began operating in 1997.

By then, however, Tijuana’s sewage volume far exceeded capacity. Some of the excess would be pumped via another pipeline south to the Punta Bandera facility, which also was overwhelmed.

This Environmental Protection Agency map explains some of the reasons associated with the Tijuana sewage crisis. The San Antonio de los Buenos Treatment Plan is located in Punta Bandera. Map courtesy of EPA.

California’s Regional Water Quality Control Board issued a cease and desist order against the U.S. plant, citing clean-water violations. More lawsuits ensued. And Tijuana continued to grow, adding toxic wastes from a booming maquiladora industry to the mostly untreated wastewater. 

Thus, for nearly a century, a border calamity has contaminated the beaches of south San Diego County, carrying pathogens and poisons that sicken swimmers and sabotage coastal tourism. Former U.S. Border Patrol Agent Chris Harris also believes the sewage has killed sealife, sharing photos with The Coronado News of dead seals on the shores following large discharges of sewage.

Writing two decades ago for the Law Review, Campbell predicted what would happen:  “It is certain that, in the near future, untreated and partially treated sewage discharged from Tijuana will continue to pose increased threats to human health, the environment, and the economy on both sides of the border. 

“As a result, there is an urgent need for a comprehensive solution to this sewage crisis… The IWTP consistently fails to meet state and federal water quality standards, and the treatment site cannot account for Tijuana’s future population growth.

At the time, Campbell was touting a unique proposal, dubbed “Bajagua,” as the savior of Tijuana’s sewage crisis. Under that plan, a Mexican company would build a $539 million plant for sewage treatment in Baja California, with reimbursement from U.S. appropriations. 

The developer, Agua Clara, vowed to cleanse nearly 60 million gallons of wastewater per day to a secondary level where it could be sold for industrial and agricultural use, easing Mexico’s reliance on a diminishing share of Colorado River water.

Top officials on both sides of the border initially endorsed Bajagua, but controversy erupted as environmental advocates and politicians fought over proposed U.S. costs and whether a government-private sewage project was appropriate. 

The combatants remain angry to this day.


Gary Sirota, a U.S. environmental attorney and first president of the Surfrider Foundation, represented the developer. Sirota said he wound up lobbying in oval offices at the White House and in Mexico, and Congress passed legislation to enable Bajagua.

Then, Sirota contends, the venture got sabotaged. 

In the United States, he said, the Boundary Commission teamed with political progressives to block it. And in Mexico, politicians were looking for payoffs.

“They way it works in Mexico, they wanted it up front.”

-Gary Sirota, a U.S. environmental attorney.

 “They all wanted their piece,” Sirota recalls. “And, the way it works in Mexico, they wanted it up front.”

Lori Saldaña offers a very different view of Bajagua’s demise. 

The former California assemblywoman got involved with Tijuana’s sewage problem while living near Ensenada in the early 1990s, and eventually became the plaintiff in a Sierra Club lawsuit against the Boundary Commission.

Saldaña said Bajagua’s scheme would have had U.S. taxpayers paying a private company to treat sewage for poor Mexicans, who then would face sewage and water fees. 

“They were trying to privatize the water and sell it,” Saldaña added. “We’d have absolutely no oversight. There was no accountability.”

After five years of turmoil, Bajagua was killed.

Saldaña, who served on a Border Environmental Cooperation Commission, said infighting among environmentalists and politicians stymied progress on Tijuana sewage remedies for years.

“It turned into a huge political battle. It’s taken a generation to move beyond that,” she said.

In fact, with little new sewage infrastructure getting built and Tijuana’s population exploding, the contamination accelerated.

Closed 1,600 days

By 2021, a Pulitzer Center article succinctly summarized conditions: “If the San Diego-Tijuana region were a human body, it’d have the stomach flu: Bad stuff is coming out of both ends.”

The two border fences on the U.S. side for the U.S.-Mexico border. Photo by Madeline Yang.

The Boundary Commission had been formed more than a century ago to diplomatically resolve disputes about the international border. 

But its leaders represent sovereign nations and are subject to the laws, funding and politics of their respective countries.

Over and over, Tijuana’s sewage has been addressed with stopgap measures analogous to duct taping a leaky toilet. 

The result: South San Diego County beaches were so contaminated from 2009-18 they had to be closed to swimmers 1,600 days, according to a federal court filing.  

In summertime, according to the EPA, about 50 million gallons of untreated wastewater flows into the Pacific from the San Antonio de los Buenos plant at Punta Bandera, then north to San Diego County. 

During winter rains, an additional 109 million gallons per day of untreated sewage, industrial wastes and storm runoff gush into the ocean from the Tijuana River.

After a huge event in 2017 – condemned by Surfrider as “the largest sewage spill we’ve ever seen” – the International Boundary and Water Commission got hit with a barrage of federal lawsuits from the city of Imperial Beach, the state Attorney General, Surfrider Foundation and others.

Those complaints accused the federal agency of a gross “dereliction of duty and wanton disregard for public health” through violations of the Clean Water Act. All three cases were settled last year when U.S. and Mexican authorities adopted plans for an overhaul of infrastructure for Tijuana’s sewage at a total cost of roughly $800 million.

Congress transfers funds

In December, following months of political haggling in Washington, D.C., the initial $300 million in U.S. funding – authorized by Congress two years earlier – was finally transferred from the EPA to the IBWC. That money will pay for studies, design work and expansion of the South Bay International Wastewater Treatment Plant to handle an average of 50 million gallons of waste per day.

According to Rogers, the IBWC area operations manager for the San Diego field office, the delayed transfer of those dollars means construction work toward the plant upgrade will not even begin for at least three years.  

Meanwhile, sewage closures, advisories or warnings became common occurances last year in southern San Diego County beaches, according to the county’s Department of Environmental Quality. Imperial Beach had a combined 43, Silver Strand had 39 and Coronado had 21.

Even Maria-Elena Giner, the current U.S. leader of the Boundary Commission, concedes the agency has chronically struggled to staunch Tijuana’s transborder output of human and industrial wastes. 

In an interview with the Coronado News, Giner said she is optimistic that, in years to come, the planned projects will resolve the problem. 

In the meantime, she expressed sympathy for critics on both sides of the border who vent anger during public forums on the issue. 

“I wish I were the wastewater fairy and I could just wave my wand,” Giner said.

Coming Next: A former Border Patrol agent said he knew the risks of the job, but he didn’t think it included getting sick from raw sewage.

More News

Dennis Wagner is a veteran journalist who earned a Pulitzer Prize while working for USA Today and The Arizona Republic. His career started with a job at the former Coronado Journal 46 years ago. He can be reached by email or at 602-228-6805.

Craig Harris has 31 years of daily journalism experience and is editor and associate publisher. He most recently worked at USA TODAY as a national investigative business reporter, and he’s a two-time Polk Award winner. You can catch him at the Coronado dog beach with his beagle, Daisy, who has her own Twitter account. He can be reached by email or at 602-509-3613.

Julieta is a reporter for The Coronado News, covering education, small business and investigating the Tijuana/Coronado sewage issue. She graduated from UC Berkeley where she studied English, Spanish, and Journalism. Apart from reporting, Julieta enjoys reading, traveling, and spending quality time with family and friends.

Madeline Yang is a reporter for The Coronado News, covering the City of Coronado, the U.S Navy and investigating the Tijuana/Coronado sewage issue. She graduated from Point Loma Nazarene University with her Bachelors in Journalism with an emphasis in Visual Storytelling. She loves writing, photography and videography and one day hopes to be a filmmaker. She can be reached by phone at 916-835-5843.