Tijuana Sewer Plant Stirs Up High Hopes : Novel Treatment Project to Begin Soon; Low Cost, Low Maintenance Benefits Cited

On a barren, eroded hillside, a former dump site, engineers and planners from both sides of the U.S.-Mexico border are attempting to spawn a dramatic change in attitudes toward waste. In the process, they envision a future long-term solution to the decades-old problem of sewage in the border area.

“We need to end the waste of sewage,” said Carlos de la Parra Renteria, a Tijuana engineer educated in both Mexico and the United States, as he stood on the wind-swept hillside overlooking this border city. “It’s time to put sewage to use as a natural resource.”

De la Parra heads a novel, experimental sewage-treatment project, now nearing completion, that has attracted attention on both sides of the international boundary line.

Reclaim Waste Water

The idea: Collect and treat sewage in small, low-maintenance, low-cost neighborhood plants, using as little costly electricity as possible. Rather than being dumped at sea, the reclaimed water would be utilized in a variety of ways, among them irrigation for parkland and greenbelts in this crowded city where open space is at a premium.

Apart from its singular view of sewage as a potential resource, the pilot project here is also an unusual example of cross-border cooperation--it was largely financed with a California state grant--on an issue that has historically been a source of international divisiveness.

Eventually, its advocates say, the plant here could be a model for dozens of similar facilities in Tijuana and elsewhere in Mexico--maybe throughout the Third World. Its advantages--low cost, minimal maintenance and the reclamation of water, a vital resource--make it a natural alternative to the expensive, high-technology waste treatment systems prevalent in the United States and other developed nations, supporters say.

“I think it’s terribly important,” said Patricia McCoy, who heads a volunteer group trying to preserve the Tijuana River estuary, a natural marine habitat in southern San Diego County that is threatened by sewage from Tijuana. “This (the plant) is one of the best rays of hope I’ve seen in a long time.”

Others are not so sanguine, suggesting, among other things, that the treated water will not meet U.S. health standards, yet may end up flowing into the United States, like so much current Tijuana waste.

‘Not a Solution’

“I’m sure it’s a perfectly feasible idea, but it’s not a solution,” said Ladin Delaney, executive officer in San Diego for the California Regional Water Quality Control Board, a state agency that oversees waste water matters. “We’re not against that type of plant . . . but we’re afraid the (treated) water will just come right back across the border, and its quality is not good enough to be discharged in the United States.”

Supporters of the project say the quality of the reclaimed water meets U.S. and Mexican health standards. Moreover, they assert that there will be ample uses for the water in Mexico, meaning it will not end up north of the border.

“It really is just a step away from being a solution,” said Alan Sakarias, an official of the Environmental Defense Fund, a nonprofit, New York-based conservation group that is helping to manage the project. “It’s a unique opportunity to get some use out of sewage . . . We’re designing a treatment plant that you don’t need four years of college to operate.”

In its literature, the project sponsors refer to the huge, U.S.-style treatment plants as costly “dinosaurs of engineering” that are particularly impractical and wasteful in places like Mexico, with its ongoing financial crisis, and in other funds-poor Third-World settings.

To Open Soon

The pilot project here is being built on a 23.5-acre, treeless stretch of land sloping down from Tijuana’s Mesa de Otay and overlooking the neighborhood known as Colonia Buenavista and the paved channel of the sewage-clogged Tijuana River. Last week, workmen were busy completing the final stages of the project, which is scheduled to open formally late this month or in April.

Within a year, planners hope to have transformed the barren site into a novel park, complete with dozens of fruit and shade trees, freshwater marshes with bulrushes, picnic areas and a man-made lake complete with a waterfowl nesting area. The water used will be reclaimed sewage, odorless and more than 99.9% pure, according to project managers.

“At the moment,” noted De la Parra, “if you want to plant a tree in Tijuana, you get laughed at, because there’s no water. The only way to expand park space is through recycled water.”

Traditionally, treated waste water is dumped, usually in rivers and seas. The notion of reclaiming sewage water and using it for other purposes is not new: It has been employed with some success, notably in St. Petersburg, Fla., said Sakarias of the Environmental Defense Fund.

Apart from irrigating parkland, officials said the water could also be used for a variety of other purposes, including firefighting and street cleaning. It will not be drinkable; nor will it be used in direct contact with edible crops.

‘Ranch Technology’

Underscoring the interest here, the Mexican minister of environment, Manuel Camacho Solis, is scheduled to dedicate the facility. He has referred to the engineering concept as tecnologia de rancho --literally, “ranch technology,” an allusion to its simple but efficient design.

The plant features little pumping; most of the treated waste and the reclaimed water will flow downhill via gravity. Consequently, electric costs are estimated at less than $100 a month, planners say; labor and maintenance expenses are also limited. Total estimated operating cost for a six-month period: $4,050.

That is because of its low-technology design, officials say. Sewage treated at the plant is tapped from an overloaded sewage line, which often discharges raw waste into the Tijuana River. The sewage is channeled through the facility’s three basic treatment elements: a fine screen, or hydrosieve, where coarse solids are trapped; a filter, known as a biofilter, that separates more impurities, and a settling tank, or clarifier, where heavy clumps of material sink and are collected. Collected compost is slated to be used as fertilizer for non-edible plants.

Despite its low-technology approach, those who have witnessed frequent breakdowns of Mexican sewage systems are suspicious. “Any mechanical plant like that requires substantial maintenance, and they’ve had problems in the past operating simple pump stations,” said Ladin Delaney of the California Water Quality Board.

Currently, the facility is geared to treat only about 250,000 gallons a day--a tiny percentage of the more than 20 million gallons of sewage generated daily in Tijuana. However, advocates say its capacity can be tripled; moreover, if the approach is successful, engineers have identified 30 other potential sites for future facilities. Where the money would come from for such expansion remains a question.

In Mexico, the facility is run by El Colegio de la Frontera Norte, an academic institute that studies border issues. De la Parra, a staff member of El Colegio, notes that Tijuana’s rapid growth and need for sewage treatment means that officials here must make some difficult decisions.

‘Choice to Be Made’

“All these areas that used to be on the outskirts of the city are now heavily populated,” De la Parra said as he stood on the site of the future plant, pointing to the swelling colonias on the city’s periphery. “There’s a choice to be made: Build more big systems or decentralize.”

A much ballyhooed, $20-million treatment facility that opened near the Pacific Coast here last year has suffered a major breakdown. Mexican officials are talking about building another mega-plant on the city’s fast-growing east side, drawing opposition from U.S. groups concerned about additional pollution to the Tijuana River.

Along the border, sewage is an oft-politicized issue: U.S. officials have even threatened to block aid if Mexico does not take steps to prevent cross-border pollution. Mexican authorities, in turn, have pointed to many examples of U.S. pollutants, such as smelter emissions and pesticides, that have befouled Mexican territory.

The idea for the novel plant here goes back to 1983, when engineers, conservationists and others concerned about the problem of border pollution began to seek alternative means of treatment. After the idea was formulated, backers secured a $260,000 grant from the California Coastal Conservancy, a state body worried about damage to the Tijuana River estuary in San Diego. After operations at an initial plant on the U.S. side of the border, Mexican workers began building the Tijuana facility last November.

As the grant money dwindles, project sponsors are looking for other funding sources, such as foundations, that will allow for future expansion. Whatever happens, however, the plant should be operating shortly, they say, and, within a year, a model park should be a reality in the foreboding landscape sloping down from Tijuana’s Mesa de Otay.

“I don’t see what other alternative there is 10 or 15 years down the line,” says the confident De la Parra, surveying the construction site where the plant is being built. “Once we start doing it, it’ll catch on.”