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Simply put, composting
is nature's way of recycling. Organic material such as plant matter and food
scraps get decomposed by soil-dwelling insects, earthworms, bacteria and fungi.
At a composting facility (or in a bin), organic wastes are layered and mixed
periodically to aerate the pile. As the material heats up, the waste breaks
down into rich, dark humus. This nutrient-dense soil is ideal for gardeners
and landscapers.
In the year 2000,
MIT's Environmental
Programs Task Force (EPTF) initiated a pilot food composting program at
Walker Memorial cafeteria. According to the EPTF 2001 annual report, this
program was later expanded to include Baker House and Next House, two residential
campus-dining facilities. The report states that the amount of food residuals
collected per month stands at nearly 9 tons, or 92 tons total per year.
Despite these recent
efforts, composting at MIT remains the exception rather than the rule. In
fact, we are somewhat wary of the optimistic statistics given in the EPTF
report. In talking with the managers and head chefs at each of the dining
venues, we found that many were unaware that a composting program at MIT even
exists, not to speak of participating in such a program. Of the five facilities
included in our project, Next House and Walker are the only ones currently
involved in limited composting of organic kitchen scraps and unserved food.
In no venues is there composting of post-consumer "tray waste."
Ideally, pre-consumer
leftovers (unserved food) should be donated to local homeless shelters or
foodbanks. But because of OSHA safety/health regulations, some leftovers are
ineligible for donation. At Next House and Walker, this food is added to the
compost collection bin---a large yellow garbage can labeled "Compost
Only." Once a day, a truck from Herb's Disposal picks up the compost
and hauls it away to Weston Nurseries in Hopkinton, MA.
A wide-scale adoption of composting
by MIT's dining services could potentially divert tons of waste per year from
landfills. This action would be both environmentally and economically sound:
it currently costs the school $150 per ton to haul trash away to the landfill.
Meanwhile it costs only $70 per ton to haul away compost. The expense of composting
could be driven down even further if MIT would build an on-campus composting
facility. (Although we have not researched the space and cost such a project
would entail, it would have the three-fold benefit of lowering transportation
costs, reducing transportation emissions, and signaling MIT's commitment to
environmentally friendly practices.)
In addition to the obvious savings of landfill space, composting benefits the atmosphere and soil as well. In its comprehensive annual report on the environment, the EPA concluded that "composting, when managed properly, does not generate CH4 (methane) emissions. (Well-maintained compost piles maintain an environment with adequate moisture and oxygen to encourage aerobic decomposition of materials.) Moreover, the composting process leads to the formation of stable organic compounds that, when added to soil, dramatically enrich its nutrient value. This has a "multiplier effect" as better soil begets more plants---which are in themselves natural carbon sinks.
Composting is an easy and low-tech
way to turn garbage into 'gold.' But in order for the decomposition process
to work properly, the compost pile must be kept free from contaminating non-organic
materials. When composting programs fail, it is often because people fail
to sort their trash adequately and there aren't resources to screen for contaminants.
While the problem of compost contamination
is significant, it is certainly not insurmountable. It should be dealt with
in a way appropriate to the particular dining facility. At Baker and Next,
for instance, which both offer reusable tableware, students' trays are shuttled
on a conveyor belt back into the dishroom. It may be simpler and more efficient,
in this case, to train a few kitchen staff members in organic/ non-organic
trash sorting rather than relying on students to do so.
At other venues, such as Walker
and Lobdell, which use primarily disposable dishes and utensils, trays are
often emptied into trashcans by the students themselves, making sorting by
staff difficult to impossible. One solution would be to require (or at least
encourage) people to dispose of all biodegradable tray waste in a separate
"organics" receptacle adjacent to the normal trash and recycle bins.
While this approach is more vulnerable than staff-sorting to compost contamination,
it has the added benefit of getting more people actively involved in the composting
process, thus making them more aware of our daily environmental impacts
Here we offer some suggestions
to MIT dining services for both short-term and long-term composting implementations.