Clean Composting Turning Waste into an Asset
May 27, 2010 08:23PM
Discarded vegetable ends, eggshells, coffee grounds and lawn clippings… most of us throw away a huge amount of compostable material. What could be a significant environmental asset, if transformed into nutritious garden soil, has become instead a major environmental problem.
The U.S. Environmental Protection Agency reports that yard trimmings and food residuals together account for 26 percent of our total municipal solid waste stream. Also, unnecessary food waste doesn’t just happen at home—it’s a fact of life for most restaurants, stadiums, convention centers, hotels, schools and anywhere else people gather to eat.
Choosing to turn scraps into rich fertile soil, courtesy of beneficial bacteria and fungi, has multiple advantages. It creates rich humus for high-yield crops, works to suppress plant diseases and pests and limits the need for chemical fertilizers. Those same organic scraps have a devastating effect on the environment when they are trapped in oxygen-starved landfills. Due to their highly compacted nature, organic waste is not able to fully decompose and releases methane—a global warming gas that’s 25 times more damaging to air quality than carbon dioxide.
Part of the challenge is that there’s no widespread collection system in place to encourage or require municipal composting. Unlike the bottles and cans we place in handy curbside bins, or the newspapers and cardboard we tie and separate for recycling trucks, food waste doesn’t yet have designated places to be taken to. A few cities are changing that model, but others are slow to follow.
Seattle was the first to require households to compost food waste; San Francisco was the first to add businesses and restaurants. These progressive cities provide green compost carts for food scraps, including meat, bones, seafood and dairy plus soiled paper, like tea bags, coffee filters and greasy pizza boxes; and yard trimmings including grasses, branches and leaves. All of these can thus be safely diverted from landfills.
But where city collection of compostable materials is not yet a reality, clean composting at home is an answer. Whether in an urban apartment or a suburban home, composting has never been simpler.
“Keeping your pile aerated is key to keeping it odor-free,” counsels Elle MacKenna, a home improvement contractor and design consultant. “A good mix of materials will allow oxygen in, keeping smells away and helping your pile compost quicker.” She suggests adding moist, shredded newspaper or thin cardboard to give some variety to the compost make-up.
Farmer Annie Farrell, of Millstone Farm, in Wilton, Connecticut, which specializes in heirloom, organic vegetables and heritage (pure-bred) chickens, sheep and pigs, says composting at home is as simple as investing in three metal or plastic garbage cans designated for the purpose of food waste and yard scraps.
She sets the three cans off the ground using cinder blocks, drilling half-inch holes into the cans to allow air to circulate.Next, she layers foliage clippings, food matter and old newspapers in what she describes as a “lasagna-like mix,” in bin number one. As the mixture begins to decompose, she dumps it into the second bin, followed by the third bin when it’s almost ready for use. (Using multiple bins to “turn” the compost also allows oxygen in, an essential part of the process.) Farrell likes to use bungee cords to secure the lids to prevent animals from getting in.
Other store-bought variations on composting bins range from compact ceramic, bamboo and stainless steel crocks and pails for indoor storage to outdoor tumblers (for easy turning) and stackable “worm bins” that can hold up to 90 gallons. When worms are enlisted, composting goes by the name of vermiculture.
Worms—ideally, red worms, which do well in confinement and eat more than their own weight in food each day—produce the most fertile garden soil. They also speed the process of breaking down waste into soil, while helping to keep smells at bay. Kids also are more likely to get involved when adults enlist the help of a few hundred wiggling allies.
Brita Belli is the editor of E – The Environmental Magazine.