RIO DE JANEIRO — Latin America’s largest garbage dump has a case of gas.
As an estimated 90 million tons of trash decompose in Rio de Janeiro’s Jardim Gramacho landfill, it emits thousands of cubic feet of methane and other gasses. Dump manager Lucio Vianna believes the flammable byproducts will soon be a formidable source of energy.
“The energy potential is really significant,” said Vianna, who has managed the city-owned dump for two decades.
With the help gas wells drilled into the landfill, Vianna expects by 2012 to be sending some seven hundred thousand cubic feet of garbage gas every hour to a nearby power plant, which is owned by the state-controlled energy company, Petrobras. City officials say that’s enough to replace half the natural gas used by residents and business in the entire state of Rio de Janeiro.
The transformation from garbage pile to power source will be a revolutionary one for what may be Rio’s biggest eyesore. Jardim Gramacho’s trash mountain commands a view of Rio tourist attractions like the sugar loaf mountain and, in the distance, the city’s iconic statue of Christ.
The dump opened in the late 1970s, when environmental concerns weren’t high on politicians’ agendas. A marsh beside a Rio de Janeiro’s famous Guanabara Bay seemed as good a place as any to dump a city’s worth of trash.
“At that time, environmental laws didn’t exist for landfills,” Vianna said.
For nearly 20 years the huge, open-air trash plateau spilled further and further into the wetlands and the surrounding bay. When Vianna arrived in the 1990s, he helped to mitigate this environmental damage, sealing off and treating sludge that once leaked out into the bay and walling in the garbage.
After these changes, the only direction to dump was up. Standing atop Gramacho’s 130-foot man-made mountain on a recent morning, Vianna said, “From here down 40 meters, its just trash.”
When he began working at Gramacho, Vianna knew right away he wanted to harvest the gas it produced. It took two decades, but the World Bank funded feasibility studies, and the city of Rio gathered the funds to get the project underway. Vianna says it’s the biggest project of its kind not just in Brazil, but in all of Latin America.
Once the system is finished, 278 wells will riddle the landfill like a pin cushion. Each well consists of a perforated pipe, sunk 65 feet into the garbage, and lined with gravel at the bottom.
“In this way, you’re creating a path for the gas,” Vianna said.
The methane-rich gas is piped from each well to a central location at the dump where it is burned on site, turning it into heat and carbon dioxide. That alone is enough to earn the facility U.N. carbon credits because carbon dioxide is 20 times less potent than methane as a greenhouse gas.
But for Vianna, the most exciting part of the project is yet to come. When the facility station is finished, it’ll purify the gas so it can be burned in power plants. And he says the income earned from selling the gas will help re-train those who make their living recycling trash on the landfill.
Just in time, too, because next year the dump is set to close. A place that was once home the Rio’s castoffs will may soon become a key part of how the city meets its needs.
“What I see today, all of this,” Vianna said, “is the reality of the future.”