CIUDAD NEZAHUALCOYOTL, Mexico – An afternoon wind whips up small tornados of acrid dust across mounds of earth that resemble an ancient burial ground.

Only what’s buried here on 75 acres just outside Mexico City is the capital’s first large-scale compost plant. The city recently shuttered the last landfill it operated and on a piece of unused land at the site, started composting.

City officials tout the facility as the largest in Latin America and one of the largest of its kind in the world.
Each day, tractor trailers filled to the brim with organic garbage – the rinds, peels, pits, meat and bones and other natural materials that amount to the city’s leftovers – dump their cargo here, where the waste is buried, aerated, mixed with microorganisms, monitored for temperature and “cooked” into compost over a period of 40 days.

Mayor Marcelo Ebrard oversaw the closing of the sprawling landfill, the Bordo Poniente, in December. His administration has been working to find alternatives for disposing of the roughly 12,600 tons of trash the city generates daily.

Since the plant came online at the start of the year, the city is now composting roughly 80 percent of its organic waste, according to Ricardo Estrada, who directs the city’s recycling and composting programs.

That’s an important figure, he said, given that 40 percent of Mexico City’s trash is organic. In more developed countries, the trash mix includes far less organic matter and much more dry, inorganic material, such as plastics, aluminum, cardboard and other packaging, he said. Mexico’s trash is very “wet” by contrast.
The city has plans to eventually sell the compost to agricultural producers in and around the city, but so far it’s not up to farming quality. For now, the city is using the compost to fertilize green spaces including parks and medians.

“It’s going to be a resource that we didn’t have before,” Estrada said.

Mexico City dabbled with the idea of composting for nearly a decade before committing to developing a plan two years ago, Estrada said. One obstacle was that the powerful city sanitation workers union couldn’t see the benefit of separating out the organic trash – when they dedicated most of their time to separating out recyclables, which could be sold. Now, at the plant, the city pays each tractor-trailer 50 pesos, or about $3.60, per ton of organic material.

“People weren’t convinced that composting was an alternative,” said Estrada. “All the systems had been focused on recycling.”

Now the city just needs to work out what to do, long-term, with all the trash that remains after the compost and recyclables are weeded out. For now, it’s destined for dumps in nearby Mexico State – at least until those communities decide they no longer want the capital’s waste.