The Value in Our Garbage
The food we don't eat gives us gas. But beyond renewable energy generation, organic waste holds the potential of big benefits for our communities.
Most of the nation's garbage still ends up in landfills, and as much as half of what Americans toss into their trash bins is food waste and other organic material. But increasingly there's recognition of the value in all of that smelly stuff.
Organic waste produces enough biogas that the collection of landfill gas to produce electricity or fuel has become a big business in the United States. And thanks to technological advances, another major use of organic waste, the production of high-quality compost, is increasingly being seen as a key ingredient in long-term community sustainability.
In the near term, there's little question that capturing landfill gas and putting it to use as renewable energy makes sense. The federal Environmental Protection Agency (EPA) lists an array of benefits, including reducing greenhouse gases, offsetting the use of nonrenewable resources, helping to improve local air quality, providing revenues for landfills, and creating jobs and other local economic activity.
But while landfill biogas is a renewable energy source, there's an ongoing debate about whether it's good long-range policy to continue to send organic material to landfills. Landfills are filling up and biogas, after all, can be produced only if the municipal waste stream continues to provide a flow of material to generate it. The landfill waste-diversion goals that states and local jurisdictions are adopting signal that this flow will diminish over time.
In this light, it's worth noting that the EPA has created a set of guiding principles around the highest and best use of food waste, which makes up a significant portion of the organic waste stream. Illustrated as an inverted pyramid hierarchy, the preferences descend from avoiding the generation of waste in the first place to using surplus food to feed people and animals, using food waste for fuels and energy generation and composting it into a nutrient-rich soil amendment. At the bottom is disposal to landfills or incineration.
While composting falls toward the low end of that list, a report by Brenda Platt of the Institute for Local Self-Reliance and Nora Goldstein of BioCycle magazine, to be published soon by the institute, provides a well-researched case for composting's extended benefits, ones that reach well beyond its basic value as a soil conditioner. The authors endorse "a more nuanced hierarchy of highest and best use, one that takes into account scale, ownership, and the level of community engagement."
Such decentralized, locally based use of resources is seen as a cornerstone principle that underpins community resilience. While local water reuse and distributed electricity generation are much more visible to the public, Platt contends that locally based composting is equally valuable for community sustainability. "Unlike recycling," she said in an interview, "composting is inherently local and a place-based industry that takes advantage of a community's existing resources to create jobs." And it has potential as a business development strategy that draws upon local resources.
Today the flow of waste organic material is predominantly a simple stream, from source through consumer to landfill. Using that material to produce renewable energy certainly makes sense as long as the waste stream continues to flow. But in the longer term, programs that advance composting have the potential for diverse benefits -- akin to the rewards that come from managing an entire watershed rather than individual waterways.