Composting in New York City

08 Jun, 2013

by Elizabeth Royte, via OnEarth.org

Sometimes I bike and sometimes I walk, but either way I’m a tree-hugging, 350.org-supporting, vegetarian Brooklyn cliché — hauling a week’s worth of kale stems, shallot skins, and daikon peels to my local greenmarket for compost collection. I feel sheepish about fulfilling a stereotype, but at least I’m joined on my weekly march by tens of thousands of others around New York City who share my feelings about the earth: we know that these scraps converted to compost will nurture the soil that grows our food and other plants. (The wonkier among us understand that compost also increases soil’s carbon-storage capacity, helps to retain soil moisture, reduces the use of artificial fertilizers, and improves soil structure and texture.) And so we don’t mind terribly that our bags of waste take up valuable space in our freezers (the best place to store them until market day), or resent hiking this stuff a half mile, or more, to a collection site no matter what the weather brings.

Food and other organic material (by which I mean yard waste and prunings) make up a whopping 25 percent of New York’s residential waste stream: that’s a huge amount to potentially divert from landfills and incinerators. Compost it instead and we’d be saving the city money (New York spends more than $330 million a year hauling waste to landfills) and avoiding the generation of the greenhouse gas methane, which is produced when organic material rots in the airless confines of a dump.

Not too many people consider the biochemical fallout of their banana peels, but solid-waste managers across the nation are beginning to see organics collection as the next frontier, after recycling, in reducing their waste streams. Today, more than 160 American communities, serving more than 1.2 million households, have programs for separating organics from the trash — an increase of more than 50 percent since 2009.

Yes, most of these communities are in California, Washington, and Oregon (places accustomed to collecting yard waste during a long growing season), but New York is poised to get on board. Last month, Mayor Michael Bloomberg announced a pilot program for collecting organic material from the curbsides of several Staten Island neighborhoods, a couple of homeless-services agencies in Brooklyn, three high-rises in Manhattan, and 72 schools in two boroughs. Should the two-year pilot succeed — with high participation rates and the diversion of significant tonnages — the program will roll out across the city. My days of toting rotting food to market may be numbered.

The city tried this once before, with an organics-collection pilot in the 1990s. That program compared participation in my brownstone neighborhood, which is almost comically progressive and green-leaning, with the high rises of Starrett City, a public-housing project on the southeastern fringe of Brooklyn. My neighborhood diverted 41 percent of the food in its waste stream (not great); Starrett City diverted almost none (worse). A study found that collection wasn’t efficient (trucks weren’t maxing out); contamination was high (thanks to a lack of education and little supervision of the bins); and many buildings complained they didn’t have space for another collection container. Everyone worried about stench and pests (perhaps forgetting that food scraps had been nestled in their garbage bags all along).

So what will be different this time around? Lots, according to Ron Gonen, New York’s deputy commissioner of sanitation, recycling, and sustainability. “There’s been a cultural shift, people are more aware of waste and its impacts.” We’ve also got better food-scrap containers, which keep vermin out and smells in; better compostable bags; and better building managers. “The ethos has changed in the real-estate community,” Gonen says. “Developers understand that smart environmental decisions can reduce their costs.” And potentially attract green-leaning tenants.

Perhaps the biggest challenge for New York will be finding facilities to accept what it collects. The city recently solicited a request for proposals from organics processors, and is seeking an operator that can handle 100,000 tons of material a year. Nearly a decade ago, I visited California’s Jepson Prairie Organics, which happens to annually convert exactly that amount of material into high-quality compost. Over 15 acres, grinders, bulldozers, front-end loaders, augers, and screeners roared and hummed. Depending on the material’s stage of decomposition, the air was redolent of pig farm, mold, fungus, or loam.

It’s hard to imagine siting this type of operation within the New York city limits. But note that most people in the food-scraps game try hard to avoid the word “compost” in favor of the phrase “organics collection.” That’s because the city’s food waste might not be piled and prodded across a swathe of land but instead shoveled into tall enclosed tanks for anaerobic digestion, in which microorganisms devour food and other scraps, producing gases (mostly methane) that can be collected and used to fuel turbines and make electricity, or compressed into liquid fuel. Anaerobically digesting just 50 percent of the food waste generated each year in the U.S., says the Environmental Protection Agency, would produce enough electricity to power 2.5 million homes for a year. (The process also leaves behind material that can be used for fertilizer.) Says Rhodes Yepsen, a compost expert who consults for BioCycle magazine and Novamont, which makes biodegradable plastic bags, “The highest and best use for food scraps is to first make energy, and then compost what’s left.”

Traditional compost operations are cheaper to build than anaerobic digesters, and therefore more common among cities that collect food waste. But that could change as cities spread closer to areas zoned for industrial activity, neighbors grow fussy about odors, and processors seek tax credits for producing sustainable energy.

It’s too soon to say what the future of food-waste collection in New York City will look like, but for individual residents it’s likely to start with scraping plates into a counter-top container, which they would empty into larger brown bins they’d set on the curb for collection. The department of sanitation would deliver the scraps to transfer stations, from whence they’d be hauled to regional compost and digestion sites. “We like the idea of making links with upstate communities and the city-to-farm connection for an organics partnership,” says NRDC’s New York City environment director, Eric Goldstein. You’ll also see more verdant parks, green spaces, and private lawns, Goldstein says, “since free compost would periodically be made available to participants, including parks, in the program.”

With 1.2 million tons of organic material in its waste stream, the city will likely use several processing sites and methods. One can imagine a biodiverse system that includes everything from anaerobic digestion to traditional compost operations, backyard static piles in neighborhoods with yards, community drop-off sites, and even indoor worm bins, for the obsessively hyper-local. No single system will meet all the city’s needs — residential and commercial, high-rise and low. But with so much organic material out there, the opportunity to do some good for both the planet and the city’s bottom line is vast.

It may take some time for cranky, impatient New Yorkers to get used to the idea of segregating their food scraps, but Gonen isn’t worried. “If you make it convenient for people, and teach them that this is an important issue, they will eventually change their behavior.” Twenty years from now, he says, “people will shake their heads and say, ‘You were spending $100 million a year exporting food waste to landfills and allowing it to emit methane into the atmosphere? What were you thinking?’”

Originally published at OnEarth Magazine, reposted with permission.

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