Oscar Romo confides that sustainable cities are a dream during an off-air moment to me and Corrie Slawson. We’ve come to the end of our three-week residency at TJinChina, a project space in Tijuana, Mexico where artists and writers from around the globe exchange ideas, dialogue and produce work, and Romo is interviewing us about Cleveland, its history, and our impressions of Tijuana.
We’re sharing details about Cleveland’s burning river and its vision for a more sustainable future as guests on his weekly public radio show Mar Sin Fronteras, which for ten years has explored ecology and urban issues in this shared bioregion between Mexico and the U.S.
Romo is a professor of urban planning at the University of California-San Diego and founder of Alter Terra, a non-profit organization that takes a hands-on approach to the coastal and marine ecosystem challenges in a region that is at once divided by a massively fortified border but still shares an ecosystem with the Tijuana River and the same coastal estuary that provides habitat for grey whales, bighorn sheep, and a land filled with beauty.
Trained as an architect and former diplomat for Mexico, Romo is a practitioner whose latest venture is to design systems made from upcycling solid waste to deal with stormwater pollution and hillside erosion.
Tijuana has no municipal recycling, and many here drink water from plastic bottles. The area is also home to many internationally owned manufacturing plants which are producing mountains of solid waste—tons of the industrial trash is blowing or washing into the local environment.
Romo has devised a simple method of filling plastic bottles with silty soil which hardens inside to form what he calls ‘eco bricks‘. He’s also engineered retaining walls in the canyon lands around the manufacturing centers located in the periphery of Tijuana using everything from eco-bricks to scrap cars to plexi-glass from discarded appliances.
The canyons are arroyos or dry creek beds that seasonally carry water to the Tijuana River which flows south from the U.S. and then west to the Pacific Ocean. As a global manufacturing center and a sprawling metropolis, Tijuana produces tons of solid waste that Romo harvests, with the help of school children, for his green infrastructure projects. One project, in Los Laureles Canyon, upcycled 50,000 car tires and 25,000 plastic bottles, which Romo converted into a giant bioswale.
“We’re talking about materials that can last a long time, but are being used as a product for a short time,” he says. “Instead of putting it in a landfill, we reuse them. It’s appropriate technology. Tires are flexible but strong so they disappear into the landscape as cells for growing plants.”
“Size matters,” he says, adding that his vision isn’t boutique or feel good. These engineered structures are being accepted by government agencies working in stormwater and erosion control. “I can meet the requirements of the Clean Water Act.”
Romo takes invention to the next level by "impregnating" the tires with bacteria and fungi which helps remove pollution while supporting vegetation growth. As plants grow from the ‘green‘ wall, birds in this important migratory route have a rest stop where they can refuel.
Romo’s current project is in Guatemala where Alter Terra is working with school children to upcycle tires and bottles into a road that will use the same technique to build pervious pavers so that transportation routes also provide stormwater capture.
Romo would like to incubate more innovations that redesign and reuse trash as clean water technology. He’s experimenting with green chemistry, or working with a natural process of bacteria found in fungi to render pollutants flowing in water inert.
His work has garnered the attention of officials from the U.S. Fish and Wildlife Service and California’s state assembly, Romo says, where he’s helped craft legislation to treat (and remediate) the bi-national watershed as a shared resource. So, for example, Romo’s working on an upcycled trash boom—using discarded nets and plastic bottles as trash catchment devices stretched across rivers and at outflows to the ocean.
“We’re re-creating a natural system designed to get rid of pollutants,” he says, “and in the process you can beautify the city.”