Jardim Gramacho, Brazil (CNN) -- Dozens of garbage pickers pounce on the black and white trash bags as they tumble out of the latest truck to dump its load at the summit of the Gramacho landfill.
Steam rises as they pull out cans, bottles, cardboard, paper and bits of metal -- anything that can be recycled.
If you throw something out in Rio de Janeiro, there is a 70 percent chance it will end up here, on the other side of the scenic Guanabara Bay in one of the biggest garbage heaps in Latin America.
"I've been working here for 30 years," says Tiago, an elderly man with just a few teeth left. "Back then it was just a mangrove swamp. Now it's a mountain, a mountain of garbage."
Some 2.4 million tons of urban waste has been buried in the Gramacho landfill every year for the last three decades.
"I make enough to eat rice and beans every day," says Tiago.
He is one of 1,300 scavengers who work two shifts, 24 hours a day, picking through the garbage as vultures fight for their share.
Soon, they'll be out of jobs.
Engineers have already started drilling a network of 300 wells in the massive landfill to extract methane generated by the trash.
It's pumped down the hill to the Novo Gramacho plant where carbon dioxide and nitrogen are separated out.
"We're installing 30 kilometers of pipes," explains Eduardo Levenhagen, the plant's director.
For now, they're burning the methane. But by April next year it will be pumped to a nearby refinery owned by the state oil monopoly Petrobras, providing 10 percent of the refinery's power.
"Instead of using natural gas from the wells we have offshore we are using (methane) from the landfill, which is renewable," says Levenhagen.
He estimates the plant will provide methane for the next 15 years, generating carbon credits for Novo Gramacho.
"That's the most important thing for us," he says.
Gramacho will close down for good in 2012 as the methane is extracted.
It will be replaced by smaller, more modern landfills, good news for the environment but a bittersweet end for the garbage pickers who make their living here.
They can earn between $400 and $2,500 a month, decent wages, although the working conditions can be very difficult.
Gramacho was established in 1970 and soon attracted hundreds of scavengers. In the 1990s, the job of "recycler" was formalized and the number of people authorized to work in the landfill was closely regulated.
Paula is 32 years old and has been working in Gramacho for nine years. She has a bright smile and is wearing a plastic shower cap and dangly silver earrings.
She says the landfill workers have become like an extended family.
"We all work in the same place, we laugh, we sleep when the sun goes down, one person helps another," she says.
"We'll all have to find something to do. Recycling is what I know, but if I have to sweep streets, I'll sweep streets," she says. "The important thing is to keep working."