Unwanted California tires end up in rivers and beaches

But efforts to use the trash as building materials in Mexico offer new hope.


In layers staggered like bricks, holding up houses assembled from old garage doors and corrugated steel; in heaps outside the second-hand shops called llanteras; in ditches, alone, abandoned — “tires and tires and tires and tires,” says Oscar Romo. He’s a professor at University of California-San Diego, and we’re driving into Tijuana. The border fence is visible behind us, and past that, California’s Tijuana River estuary. A hard rain fell the week before, which means that tires are probably being washed northward, into the estuary and the ocean that connects to it, from tributaries south of the border. “I call it Montezuma’s revenge,” Romo says with a laugh. 

Large amounts of American waste are shipped south to Mexico — our outdated electronics and appliances, our old vehicles, our used building materials, and especially our old tires. By some estimates, about a million tires flow into the Tijuana area each year. They’re not necessarily going to recycling centers or junkyards (though some end up there); they’re actually in demand. Many Tijuana residents drive cheap, used vehicles, Romo explains, and would prefer to buy inexpensive tires, even badly worn ones, rather than a new set that might cost as much or more than the car itself. “Cheap cars require cheap tires,” he says.

American tire shops take advantage of that demand and get rid of old tires that won’t sell in the United States, by selling or giving them away to llanteras, or even individual drivers, across the border. Since it would cost more to scrap or recycle them, American shops tend to see it as a good option.

The problem is that the used tires often don’t last long on the potholed highways and dirt back roads of Tijuana. But recycling or scrapping tires in Mexico costs money, just like it does in the U.S., so both car owners and the llanteras that change out the tires often dump them — in waterways and ditches, and in neighborhoods. As a result, the city and its suburbs are constantly confronted with an endless stream of scrap tires. Some are used as building materials. Others are burned, releasing noxious smoke and liquids. Still others are piled into heaps, which then collect water and provide breeding grounds for mosquitos that carry malaria and encephalitis.

Oscar Romo stands in front of a former dump site he transformed using tires and other waste.
Zach St. George

It’s a problem that can’t be solved easily or cheaply. But Romo, originally from the central Mexican state of Aguascalientes, has an idea that might help. He’s an architect and the founder of the nonprofit AlterTerra, which does coastal conservation in the Tijuana area. And he says he’s found a better way to use the waste tires for building walls and structures, a technique that will use up more of them and will be more stable. Since 2008, he's been working to educate residents of Tijuana's Los Laureles neighborhood on his new building techniques.

Most of the tires flowing to Mexico are from California, whose drivers, according to the state recycling agency, generate roughly 42 million waste tires every year. According to a 2009 study by San Diego State University, conducted for California’s Integrated Waste Management Board, the used-tire trade between California and Baja California is a roughly $180 million industry. It supports nearly 10,000 jobs, the vast majority of them retail jobs in tire shops, most of them in Mexico. But the industry is of little benefit to the residents of the colonias, where the tires often end up. They have few good options for dealing with the scrap tires (or with any other waste, for that matter).   

Discarded tires are processed as “mats” to build a retaining wall and water harvesting structure in Tijuana.
Courtesy Alter Terra

Nora Hernandez, a mother of six who lives in the Los Laureles Canyon colonia, told me that garbage truck drivers demand sizeable tips, come by only occasionally and won’t take big items. During the rainstorm the week before my visit, she saw her neighbors carrying bags of trash, old mattresses and tires down to the creek bed, where the water would carry them away.  And since Tijuana sits on higher ground than San Diego, the problem doesn’t stay south of the border. After rainstorms, mountains of trash — and hundreds of tires — are swept north by the Tijuana River and smaller tributaries. After several miles, they end up in the Tijuana estuary, polluting California wetlands, beaches and the ocean. As many as 80,000 pounds of tires are removed from the Tijuana River Estuary just north of the national border each year by state workers, volunteers and nonprofit organizations. 

Back in Romo’s truck, the two of us crest a hill and turn off the pavement onto a dirt road. Spread before us is a labyrinth of canyons and ridges, sprinkled with thousands of ramshackle houses. About 80,000 people live on the steep walls of Los Laureles Canyon, in an unplanned settlement that grew up in recent decades around the maquiladoras, or factories, many of which produce television components. Many of the colonia’s residents are migrants from other parts of Mexico and from Central and South America. The tires are everywhere, hundreds of thousands of them, and locals have embraced them as a building material. They’re Los Laureles’ retaining walls and the foundations of its homes; they serve as the pathways between its houses and mark the borders of its streets. They are the landscape’s unifying theme. The residents’ preferred building method is to fill the tires with dirt and stack them in rows like bricks. Heavy rain, though, can wash away the dirt inside and behind the tires, causing entire hillsides — and the houses that sit on those slopes — to collapse.

Romo wants to show me an example of his alternative method of building with tires. He parks at the top of a terraced hillside and leads the way down a flight of concrete steps to a dirt lot, roughly 300 feet long and 70 feet wide. “This was a dump site, filled with waste,” he says. “I transformed it, using waste.” One side of the lot abuts a hillside of Romo-fashioned tire terraces, and the other sides of the trash dump-turned-soccer-field and community space are lined with low tire walls. In 2010, the Environmental Protection Agency gave Romo a grant to clean up the ditch and use 3,000 tires to demonstrate techniques to build structures capable of surviving heavy rain and earthquakes. Instead of leaving the tires intact and stacking them, Romo cuts out the sidewalls, leaving an O-shaped tread. He pinches and sews or staples the waist of the O together, forming a figure-eight. By hand, he then weaves or staples these eights into a long row — 8888888. He ties the leftover sidewalls to the top of the row. He lays the row of eights horizontally, so only one end is visible. Stacked up, the rows are much more dense and stable than stacks of intact tires.

Romo employed about 150 locals, mostly women, on and off for about three months, cutting the tires, sewing them into the long mats, and filling them with dirt. He hired a bulldozer to level the lot. Some of the trash he used as fill; the rest, he incorporated into a pavilion space at the top of the hillside. All told, he used 35,000 tires for the project. When kids began playing soccer in the flat space next to the tire wall, he brought goal posts and distributed uniforms.

The transformed space is at the top of a small canyon that runs four miles north to the U.S.-Mexico border. The local government has given Romo permission to create a linear park along its length. So far, he’s completed about a mile and a half of it, paving it with a semi-permeable concrete walkway that helps keep silt out of the creek. In addition to the tire technique, he’s used the park as a space to teach locals methods of incorporating other trash, like plastic and glass bottles, into outdoor walls, terraces and new homes. 

Romo isn’t the only one trying to address the tire problem. The California Tire Recycling Act, enacted in 1990, imposed a small fee on Californians for each new tire they bought. The act directed the California Integrated Waste Management Board to use about half of that fee to develop recycling programs for scrap tires, to keep them out of landfills. California Senate Bill 167, passed in 2009, amended the act, directing the board to also develop programs in Mexico, in the border region. The amendment was an acknowledgement that the problem — and its solution — involve more than just California. So far, though, the amendment hasn’t accomplished much; CalRecycle, which manages the funds, says its constitution doesn’t allow it to spend money directly on programs in Mexico, so it can’t address the problem of dumped tires in Mexican communities. Nor is the agency able to stop the sales of used tires to Mexican dealers.        

“We don’t have authority to tell someone they can’t sell a tire, if there’s demand for it,” said Mark Oldfield, a CalRecycle spokesman.

Californians aren’t getting what they paid for, says Serge Dedina. “The state of California is charging people to recycle their tires,” he says. “It gives people the impression they’re being dealt with.” Dedina is the founder of WildCoast, an environmental nonprofit, and is also the mayor of Imperial Beach, which flanks the Mexican border. Every year, his organization pulls hundreds of tires out of the federally protected estuary, where they leach oil and heavy metals as they break down. WildCoast usually partners with San Diego County or with a private contractor, which then hauls the tires to a recycling or storage facility.

State Sen. Ben Hueso, who represents the coastal border region, says that Mexican authorities are also concerned with the tire problem in their communities, but that they lack funding to do much about it. He says that an exception should be made, so that some of California’s tire-recycle funds can be used in Mexico on both direct recycling and on more educational programs like Romo’s. Until residents of Tijuana have better options, the tires will continue to flow back north across the border into the Tijuana River Estuary during rainstorms. “You’re looking at a natural resource on this side that could only be improved by making those investments on that side,” he says. “Without those investments, we’re just going to be misspending.” 

Native plants grow in a wall constructed of tires.
Courtesy Alter Terra

Romo and I drive along the creek, back toward the national border. Occasionally, we pass an orderly wall or stairway built of tires, with tight, even rows — Romo’s signature technique. Some of the structures he physically helped build, he says. Others the residents built on their own, using his techniques.  So far, he’s trained more than 500 locals, in workshops for adults and after-school classes for the kids. It will help them to make the most of an abundant raw material, Romo says, and will hopefully make their canyon homes less susceptible to erosion and natural disaster. Every tire incorporated into a sturdy structure is one less likely to wash away and foul waterways on both sides of the border, he says: “It’s not that I’m celebrating waste, but I’m addressing it in a way that makes sense in this kind of economy. … There’s no resources to get rid of it American-style.” Tires are built to last, with nylon and steel and rubber, still sturdy even when the tire is no longer good to drive. “I hate the idea of spending money to destroy a material that has strength,” he says. “Tires don’t want to die."

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