Ways that urbanites can turn their waste into compost

By Nina Shen Rastogi
Tuesday, June 22, 2010

I live in an apartment in the city with zero outdoor space, and I don't have any plants that would benefit from compost. Is there any reason at all, then, why I should be composting my food scraps?

In a word: Yes. Let's say you composted all your scraps and then made the (admittedly sort of strange) decision to throw the resulting compost in the trash. The planet would still come out ahead. That's because composting has two important benefits, aside from creating a nutrient-rich soil additive. First, the process causes food waste to shrink by about 80 percent as it decomposes. Throw your compost away, then, and you'll still be reducing the volume of garbage going to your landfill. Second, proper composting can help reduce greenhouse gas emissions generated by your trash.

Rotting food that's left out will tend to generate carbon dioxide and water as it decomposes. But that reaction -- whether it happens in a compost pile or on your countertop -- requires plenty of oxygen. In a tightly packed landfill with no oxygen, those same apple cores and carrot peelings will produce methane, a greenhouse gas that's 21 times more potent than carbon dioxide. According to Sally Brown of the University of Washington, some European waste facilities reduce the volume of their trash and its potential for methane generation by using a kind of partial composting before sending it to a landfill.

Of course, it's much better to find some more practical use for your compost. Judging by conversations the Lantern has had with folks who are happily letting food rot in their apartments, getting rid of excess compost doesn't seem to be a serious problem. Schools or community gardens, strangers on Craigslist or friends with rooftop gardens may be able take the stuff you don't want. In New York City, for instance, residents can apply their home-brewed compost to any street tree in the city, according to Tara DePorte, program director of the Lower East Side Ecology Center. (She also notes that people tend to overestimate how much compost they'll actually end up with.) Just take some time to figure out what you'll do with the end product before you commit to a composting regime.

The bigger question is how much time or money you're actually willing to put into the process. If you're not already getting up close and personal with dirt on a regular basis, a worm bin, which seems to be the most popular choice for indoor composters, might fall outside your comfort level, though the Lantern recently visited a gentleman who keeps a plastic tub full of worms and decomposing waste in his apartment bathroom, and she was amazed at how fresh the place smelled. (There were a few errant fruit flies.) But vermicomposting definitely requires care and upkeep. If your building-mates are amenable, you might consider installing a communal bin and divvying up the work.

Meanwhile, electric composters such as the NatureMill promise to make the process completely hassle-free. The NatureMill uses five kilowatt-hours a month -- about as much as running a room air conditioner for five hours -- which the company claims is less than a diesel-burning garbage truck would use to haul away the same amount of trash that the mill can process. As an added bonus, the machine can apparently handle meat and dairy items, which are verboten in most home compost systems.

The major downsides: The unit is pricey -- $299 for the cheapest model -- which can be hard to swallow when even a relatively fancy, ready-made worm bin costs about $75, plus worms. (You can also make your own pretty cheaply.) In addition, it's unclear how much you'd have to compost before you earned back the environmental cost of building the metal-and-recycled-plastic machine in the first place. (Bokashi fermenters are another relatively new option for indoor use, but you have to bury the pickled waste they produce before it's safe to apply to plants, so it's not likely to be a good choice for a garden-phobic urbanite.)

If none of these options is feasible for you, look into outsourcing your compost. The Lantern, for example, has a paper bag of wilted lettuce and withered pears sitting in her freezer; this Saturday, she'll take the package to her local greenmarket, whence volunteers will cart such scraps to farms and gardens around the city. Schools and community gardens may accept kitchen scraps for their compost piles, too. Just make sure to check the regulations in your area, lest you inadvertently get the recipient in trouble: Back in 2008, a Los Angeles woman who took food scraps from a local restaurant ran afoul of a regulation barring people without a permit from taking material generated off-site and putting it on an open compost pile.

Of course, as the Lantern noted in her last column, reducing the amount of food waste you create in the first place is even better than composting. So be sure to check this space in two weeks, when the Lantern will share your best ideas for how to churn out less food waste. If you haven't already done so, submit your best tips, tricks and recipes to ask.the.lantern@gmail.com.

Is there an environmental quandary that's been keeping you up at night? Send it to ask.the.lantern@gmail.com. Read previous Green Lantern columns here.

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