What’s in the Tijuana River?
Ammonia, a byproduct of raw sewage. Phosphorous, an ingredient in soaps and cleaners that’s banned in the U.S. Metals used in the industrial plating industry. Parasitic worms. And DEHP, a chemical added to plastics.
And of course, there’s poo. Analysts discovered fecal coliform, as it’s called in the science world, at concentrations hundreds of times over the safe recommended level, especially at Dairy Mart Road, an auto bridge on the U.S. side that inadvertently acts as a bottleneck for diluted sewage and trash flowing over the border.
Some of these pollutants were found in concentrations that could be harmful to human or animal health, according to a years-long study  of the water and sediment quality in the Tijuana River by the International Boundary Water Commission, or IBWC, and Mexican counterparts. But we don’t know for sure because the study represents just a snapshot of what’s been spilling over the border from the troubled Tijuana sewage system for decades.
Nobody close to the issue is surprised.
“This isn’t anything anybody didn’t expect to find,” said Wayne Belzer, an environmental engineer who led the IBWC study, during an Oct. 27 meeting of parties on an international treaty centered on the pollution problem. “We pretty much know the challenges we’re facing in this area.”
The real problem is that no one is keeping track of the river’s contents, past or present, on a regular basis.
“It’s all right testing for a whole bunch of chemicals … but it’s sort of a shotgun approach,” said Richard Gersberg, a microbiologist at San Diego State University who specializes in water quality and risk assessment. “A better approach would be to have an ongoing monitoring system, which they’ve never had.”
The history of pollution in the Tijuana River extends back to at least the 1970s when President Jimmy Carter and Mexican President Jose Lopez Portillo agreed under treaty to prioritize border sanitation problems. The IBWC handles issues along the whole of the U.S.-Mexico border but its 2015 treaty, called Minute 320, prioritized testing in Tijuana and San Diego.
People living near the river don’t believe it was enough.
“The original draft of the treaty had tangible dollars and cents behind it,” said Chris Helmer, director of environmental and natural resources at the city of Imperial Beach, where the coast is closed a majority of the year due to pollution. “IBWC came out and said no, politically we’re not ready to move forward with that … but water quality concerns will be addressed in the very near future. We’re past that future.”
So, why hasn’t that happened yet?
Many local and state agencies believe it’s the federal government’s job to test the quality of the river and its watershed.
The IBWC says no treaty requires it to test and furthermore, it doesn’t have the money for it. When asked whether it’s ever asked Congress for money to do ongoing water quality monitoring, the agency said, “it’s not part of the mission” Congress has given it.
“Unless Congress changes the mission requirements and provides the funds for continuous monitoring, such a project would have to have other funding sources or operate only when funding is available,” IBWC spokeswoman Lori Kuczmanski wrote in an email.
Its mission is to uphold international treaties and binational agreements, which the commission itself writes but Congress has to ratify. And around and around we go.
One reason could simply be: money.
Water quality testing is expensive. It can cost hundreds to thousands of dollars per sample.
The San Diego County Water Quality Control Board – which regulates the IBWC under the Clean Water Act – estimated the watershed needs to conduct $1.4 million worth of testing about every 17 months to establish just a baseline of the pollution. A sample of the river’s sandy bed costs $6,110 a pop, according to water board documents.
The IBWC runs South Bay International Wastewater Treatment Plant and a series of waste collectors that run through the canyons between the U.S. and Mexico. The water board issues the IBWC a pollution permit every five years, regulating the waste flowing through that infrastructure. And it’s through that permitting process that the water board wants to require IBWC to take on a permanent water quality testing program.
“We should understand and be able to communicate to the public on both sides what the risks are and environmental damage of these flows,” said Dave Gibson, executive officer of the San Diego County Water Quality Control Board.
IBWC has long had static funding. The agency overseeing 2,000 miles of border operated at a flat budget of about $75 million per year since 2010. The agency’s costs increase with inflation at a rate of 3 percent per year, but its funding increased about 1.1 percent per year since then, according to a February report  by the Government Accountability Office.
It spent $456,000 from its operations budget to pay for the snapshot report.
Gibson said his agency doesn’t have the funding to take on continuous monitoring either. In the meantime, local governments pick up the slack.
For instance, San Diego County Board of Supervisors OK’d enough money in its budget to start testing nine locations six times per week, which began on Oct. 31 of this year. It used to test only two locations in that area once per week .
U.S. Customs and Border Patrol spent some of its own budget  on a private contractor to do more snapshot water quality testing a few years ago after its agents routinely complained of health problems from working among polluted waters.
It’s taken a lot of haranguing by locals to draw the eye of the federal government to the Tijuana River’s ailments. As a result, U.S. Environmental Protection Agency Director Andrew Wheeler promised to throw $300 million at the problem  from President Donald Trump’s U.S.-Mexico-Canada Agreement. That involves a new engineering study and eventually building something to handle excess pollution that’s causing beach closures on the U.S. side. But the San Diego County Water Quality Control Board, at least, says that’s a fix without accountability.
“How will we know if that’s successful unless we have a baseline of data continuously collected so we can show we’re getting results?” Gibson said.
IBWC doesn’t seem to agree that it should be the lead agency on solving the watershed’s water quality problem anyway. In a February report to Congress, IBWC said Trump’s U.S.-Mexico-Canada Agreement put EPA in charge since it has the “expertise and experience necessary” to lead and coordinate efforts on the Tijuana watershed.
California Sen. Dianne Feinstein and Rep. Juan Vargas both introduced bills this year to do just that .
EPA is already funding a number of studies on poo contamination at Imperial Beach and modeling how pollution moves through the ocean once it’s left the river mouth. But again, none of these are the kind of baseline water quality testing experts say is imperative.
So whose job is it to really keep track of what’s in the Tijuana River? Nobody’s really raising their hand.
What else is in the water?
The IBWC and Mexican officials tested for over 260 contaminants. About half of them weren’t detected at the levels their contracted lab could pick up.
The water board’s environmental analysts weren’t happy about that, either.
The IBWC study didn’t detect a highly toxic and banned insecticide commonly called DDT. (An earlier study  by U.S. Customs and Border Protection did, though.)
Keith Yaeger, an environmental scientist with the water board, said that doesn’t mean DDT isn’t in the water or the sand.
“When we’re trying to measure the impact (on human health) … we want detection limits that are as low as possible. That way, you have more confidence whether or not it’s an issue,” he said.
The same goes for Aldrin, another insecticide banned by most countries in the 1990s, and hexavalent chromium, which can cause cancer. Both were either not detected or found in “very low amounts” that were below regulation limits in both countries.
IBWC did find salmonella at all the U.S. river sample sites. And two sites on the Mexico side tested positive for cholera, a bacterial disease spread through sewage-contaminated water or food.
Gersberg, the microbiologist at SDSU, warned not to conflate sewage with toxic industrial chemicals. Sewage is bad, but it’s still organic and it doesn’t accumulate to have a toxic effect, he said.
“But (sewage) has become synonymous with toxic and industrial contamination, like Tijuana is putting out this soup of the worst stuff,” he said. “I’m not saying there isn’t bad stuff but it’s not any worse than U.S. waters as far as (industrial) chemical contamination.”
Still, no one can really say precisely what’s in the water until it’s been tested on the regular.
This story was supported by the Pulitzer Center and The Water Desk at the University of Colorado, Boulder.