The US Plant Treating Tijuana’s Sewage Is Busted

A San Diego treatment plant at the U.S.-Mexico border is having a hard time cleaning Tijuana sewage before it contaminates the Pacific Ocean.  

That’s because parts of the plant are basically broken, which is not great news for beach communities waiting on the federal government to build a bigger, better plant with newly-promised funding from the U.S.-Mexico-Canada trade agreement. It’s clear now that a large chunk of that money will be spent fixing parts of the old plant before building anything new.  

Some of the plant’s most critical equipment hasn’t been replaced since former Vice President Al Gore helped break ground on the South Bay International Wastewater Treatment plant in 1994.  

It was built to treat 25 million gallons of Tijuana sewage per day, pollution that would otherwise spill over the border into the Tijuana River and eventually the ocean, closing beaches up and down the coast. Today, the plant is often running on overdrive. There’s widespread acknowledgement that the government initially built a plant that was too small. But Congress put $300 million on the table in 2020 to double its size. 

The plant now needs about half that amount in repairs, according to a recent assessment of plant facilities. 

“I had sticker shock,” said Héctor Aguirre, assistant director of EPA’s regional water division, when he reflected on the depth of deferred maintenance. The EPA is in charge of the plant expansion project.  

Others were less surprised.  

“The Water Board has been shouting for people to pay attention to this for years,” said David Gibson, executive officer of the San Diego Regional Water Quality Control Board. “We’ve been very clear that $300 million wasn’t half of what was needed to do the job right.” 

The plant has a two-step treatment system and the first step is what’s not working. That’s called primary treatment, where solids like human waste, trash and sand or other large matter that make its way into wastewater settle-out and separate from liquids. But the tanks are so overrun, the end product of the plant is much like watery poo.  

The plant could only remove about 34 percent of the gunk in the water, according to an April water quality report. It should be hitting 85 percent to comply with the Clean Water Act.  

Other stuff is broken, too. For instance, the U.S. can’t control the flow of sewage into the treatment plant from Mexico because a valve is stuck open. The plant has racked up 218 related Water Quality Control Board violations since 2021. 

The city of Imperial Beach, San Diego’s southernmost town where beaches are polluted by Tijuana sewage most of the time, declared a state of emergency over the pollution on Jan. 6. 

The International Boundary and Water Commission – or IBWC, the federal agency that handles binational border water issues – built, owns and operates the South Bay plant among other infrastructure along the border. Its leader, Commissioner Maria-Elena Giner, appointed by President Joe Biden in 2021, revealed recently that her agency has documented $1 billion in things it needs to fix and build and only a $50 million budget to do it.  

IBWC spent less than $5 million on major maintenance at the South Bay plant over the last 15 years, Giner said. About 37 percent of the pipes, pumps and other sewage-separating infrastructure need immediate attention. 

“It’s not going to collapse. It’s in need of serious repairs,” Giner said in an interview with Voice of San Diego. 

That’s why Giner invited California Sen. Alex Padilla to tour South Bay’s huge, concrete vats of stagnant Tijuana sewage sitting in inoperable primary treatment tanks earlier this month. These tanks have filled up with so much sand and sediment that they need to be cleaned before they can function properly.  

Giner said Padilla is the first high-ranking official to visit South Bay since Gore. As the two walked the plank between the pungent primary treatment vats, Giner explained the state of disarray she inherited at IBWC two years ago.  

“There were spreadsheets all over the place. There wasn’t a work order system,” Giner said.  

In short, IBWC administrations past didn’t have a clear understanding of what infrastructure needed fixing and when. Giner said that when she took over, she visited all eight field offices from San Diego to Mercedes, Texas to take stock of all the maintenance needs. 

“People were stunned,” Giner said.  

While South Bay needs an alarming number of upgrades, there’s also a leaking dam in Del Rio, Texas, a $276 million project. It’s up to Congress to decide how much of the U.S. State Department budget goes toward the IBWC. Padilla called South Bay’s upgrades a top priority during his June visit.  

“Over the course of decades there has been vast insufficient operations funding that leads to conditions like this which are unacceptable,” Padilla said during a June press conference at the South Bay plant.  

Ginger said she hopes to direct some money in the IBWC budget toward fixing the South Bay plant’s primary treatment system. And, she’ll be testifying before the U.S. House of Representatives in July to make the case that IBWC needs help.