Thursday, May 15, 2014 at 4:00 PM
When it comes to doing what’s best for the environment, compost is king. But sometimes it doesn’t fit into city life. Garbage disposals offer a simpler solution for getting rid of food scraps, but how do they stack up?
GANZER: When you’ve got a handful of potato peels or cucumber skins or perhaps last week’s smelly leftovers...what do you do with them? Where do you put them?
That question was on the mind of our science producer Anne Glausser and she wrote about it in a recent QUEST article, now up online.
So Anne, where do you put your food waste?
GLAUSSER: Well, that’s the question that got me started with this article. I know, from an environmental perspective, I should compost. Composting returns the nutrients from all that organic matter back into the soil and finished compost is great to add to your backyard garden.
But the problem is, I don’t really have a backyard and I certainly don’t have a garden. I live in a 2nd story apartment, I’ve got neighbors, they’ve got dogs, it just doesn’t make a lot of sense for me to compost.
So I thought there must be a contingent of people like me out there who are busy and it’s just not convenient or even possible to compost. And statistics bear this out: Americans only composted some 5 percent of the nearly 40 million tons of food waste generated in the states in 2012.
So I wanted to see what the next best option might be for disposing of food scraps.
GANZER: So if you’re not going to compost, that kind of leaves you with sticking them in the trash or sending ‘em down the garbage disposal. What’s a better choice?
GLAUSSER: Short answer is it’s probably a wash. But the longer answer is: it really depends on your city’s infrastructure. So I talked with a guy out of the U of Michigan who specializes in food lifecycle analysis, and after telling me I really should be composting, he told me that some cities have the facilities to put those food scraps from the garbage disposal to good use.
GANZER: How’s that work?
GLAUSSER: Well, when you grind up food in the garbage disposal, it goes to the same place as the water you flush down your toilet. That whole mess goes to the wastewater treatment plant which will separate out the solids. Some facilities will then treat those solids to kill the pathogens and offer it to farmers and others as a soil amendment. It’s full of nitrogen and phosphorous and other nutrients that help crops grow.
GANZER: Huh. And this happens in Ohio?
GLAUSSER: Yeah, about 40% of the state’s sewage sludge ends up on ag or park land.
And some wastewater treatment plants go even farther and will capture the methane gases released from decaying sewage sludge—which, don’t forget, has your food scraps mixed in it—and use this gas to run their operations or even feed energy into the grid.
The Northeast Ohio Regional Sewer District doesn’t but the wastewater treatment plant in Lakewood, for instance, does.
GANZER: So if your wastewater treatment plant turns sewage into fertilizer or renewable energy…that’s a reason to send your food scraps down the garbage disposal?
GLAUSSER: Yeah in that case it’s probably better than sending them to the landfill because when organic waste decays in the landfill, it releases methane into the atmosphere and that is a potent greenhouse gas and contributes to global climate change. And it takes up landfill space.
GANZER: Interesting, so you kind of have to do a lot a homework if you really want an answer on what to do with your food scraps.
GLAUSSER: Right. But there is one more option out there, beyond the trashcan or garbage disposal. A growing number of cities are offering curbside composting. So like in Seattle and San Francisco, they’ll pick up your food scraps just like they pick up your recyclables. That’s not an option here in Northeast Ohio yet, but there is a fellow in the Detroit Shoreway area who plans to offer curbside compost pickup via bicycle, but you’ve got pay him and it’s not a city service.
GANZER: Huh, a clever spin on the urban ag movement.
GLAUSSER: Yep and if I can add just one more thing that the lifecycle scientist said to me about this whole issue?
GANZER: Yeah, sure.
GLAUSSER: He challenged me to think more upstream, and buy less food in the first place. So it doesn’t sit in the frig and go to waste. His phrase was, “don’t binge-shop.”
GANZER: So have you taken the advice to heart?
GLAUSSER: I’m getting there. No Costco runs for me in the near future, and I may even sign up for this bicycling compost service, you never know.
GANZER: Thanks Anne.
GLAUSSER: Thank you.
Food scraps can also be utilized on a commercial scale. In Ohio, the local energy company quasar gets food scraps on an industrial scale from restaurants and universities, even sports stadiums, and converts it into renewable energy (biogas). And there’s a local Oberlin-grad who runs Groundz Recycling which has partnered with all sorts of local businesses and chains, like Dunkin’ Donuts, and will take their food waste and coffee filters, and compost it in piles across the city.
Community/Human Interest, Science
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