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But there’s a new frontier in recycling. It involves turning leaves, grass clippings – even food garbage – into compost. The waste becomes a rich soil additive that’s sold to farms and gardeners. Burlington, Vermont has one of the biggest operations in the Northeast. But it may be closed soon. The problems it faces offer lessons in large scale composting. As part of a collaboration with Northeast stations John Dillon of Vermont Public Radio reports.
It starts at a trash drop off site in downtown Burlington. Residents line up to toss cardboard, bottles and cans into bins. Mary Western has something slimy in a white plastic grocery bag.
“It’s usually pretty gross in here," says Western. "So the only thing I have to take home is a dirty bag.”
Western dumps two weeks worth of kitchen garbage – bits of lettuce and carrot peels – into a plastic bin. She's glad that what she throws away will eventually be re-used in farms and gardens.
Mary Western’s kitchen scraps will eventually end up here, in a large county-run composting site in Burlington.
“This is a little bit of cabbage that escaped from the pile and now is somewhat frozen," says site manager site manager Dan Goosen. "But once it gets mixed back into the pile it will be unrecognizable, that one probably within days. Let’s just see what this pile is doing for temperature.”
As an earth mover turns the six foot high rows, Goosen sticks what looks like a three foot long meat thermometer deep into a pile. The temperature gauge spins rapidly. Even on this subzero January day, the compost steams from its own internal heat.
“It’s about 150 degrees Fahrenheit. And that’s been here maybe a week,” says Goosen.
The heat comes from the bacteria that’s breaking down the organic matter. It takes about eight months for the waste to be fully transformed into rich, dark organic material that Goosen calls black gold. He says the compost adds nutrients and micro-organisms back to the soil.
“That’s a very important part of any soil structure, and something that’s missing in a lot of soils that have seen a lot of pesticides, or herbicides or tilling.”
And it’s not just good for the soil. Tom Moreau is general manager of the Chittenden Solid Waste District, which runs the Burlington facility. He says composting saves costly landfill space, and reduces pollutants such as methane gas and leaking chemicals known as leachate.
"All those issues … a lot of it really comes down to how much organic matter you have," says Moreau.
For Moreau, the equation is simple -- the less organic matter, the fewer problems in a landfill. The Burlington site is one of the biggest compost operations in the Northeast. Connecticut also has a large-scale facility and smaller ones are located in Massachusetts, New York and Maine.
While composting has benefits, there are challenges as well, including odor problems and community acceptance, and the impact on the environment.
Nora Goldstein is editor of BioCycle Magazine that covers the industry. Goldstein says the Northeast hasn’t seen a lot of growth in large scale composting in recent years. But she says there are long term gains.
“The payback over 10 years, because of using the compost to help manage our stormwater, getting the food waste out of the landfill, we can reduce methane emissions," says Goldstein. "All those factors together, you end up further ahead.”
And another problem surfaced recently when tiny amounts of chemicals linked to cancer were found in the Burlington compost. Polycyclic aromatic hydrocarbons come from air pollution. They’re absorbed by leaves and then concentrated in the compost.
Nora Goldstein says more research is needed because this pollutant is everywhere in the environment.
"You can detect it," says Goldstein. "Is it really a hazard because it is so ubiquitous? It’s in the leaves, it’s in the streets, it’s in the dust that comes into our homes."
The district is suspending compost sales, even though it’s not known if there’s a risk to the public. Still, the Chittenden Solid Waste District, which runs the enterprise, wants to continue to keep organic material out of the waste stream. So it’s considering building another large compost operation in a different location.