COMPOST
HAPPENS
at MIDDLEBURY COLLEGE
An Introduction to Middlebury College's
Passively Aerated Windrow System
Why compost?
Middlebury College
- Diverts 75% (300 tons/year) of college food waste from the landfill, protecting the
environment and avoiding tipping fees;
- Turns food residuals into compost for soil amendment in campus landscaping and vegetable
production;
- Reduces stress on the county's water treatment plant;
- Uses composting as a vehicle for education and research within the college.
A History Lesson
Middlebury College has been composting since 1993. when the college was awarded a state grant to expand its recycling program.
A waste audit revealed that the heaviest component of the college's waste was food,
while the greatest volume component was cardboard. Encouraged by the results of the audit, the College considered composting.
Several short term solutions, such as trucking waste to other composting facilities,
were implemented and then finally replaced by the on-campus passively aerated windrow
system (PAWS).
The Passively Aerated Windrow System (P.A.W.S.)
P.A.W.S. is unique because air is brought through a pile of compost through passive
means, eliminating the need to actively turn the piles.
The compost recipe is made up of the following layers placed on top of a concrete
pad:
- bed of manure and wood chips to sponge up moisture
- perforated PVC pipes laid perpendicularly to the windrow, with the ends sticking out
to passively aerate the compost pile
- food waste and paper products
- six-inch top layer of dry manure to seal in odors
Each windrow is left to sit for 12-16 weeks to complete the decomposition process.
Reproduced with permission from On-farm Composting Handbook NRAES-54, published by the Natural Resource, Agriculture, and Engineering Service, Cooperative Extension, 152 Riley-Robb Hall, Ithaca, New York 14853-5701. (607) 255-7654.
Why the P.A.W.S system?
- Low start-up costs
- Low operating costs
- Little staff time, or special skills, are required
- Minimizes odors and pests
The Composting process
Step One: Staff separate pre- and post-consumer food waste from garbage in the dining
halls.
Step Two: A specially-designed truck empties toters and brings the food waste to a
storage container at the composting site.
Step Three: The container is emptied onto a concrete pad. Wood chips and horse manure
are added, and PVC pipes are laid through the pile.
Step Four: Finished compost is used as soil amendment on campus and in a student research
greenhouse.
Materials Needed
- Pre-consumer food prep scraps, post-consumer food residuals, waxed cardboard, paper
towels, napkins, and food prep wastepaper,
- Truck to transport compost that is specially designed to lift toters from food service
areas,
- One large preliminary food waste storage container,
- At least one acre of land,
- Concrete pad,
- Manure and wood chips
- and Perforated PVC pipes.
Contact Information
Assistant Director
Maintenance and Operations
Service Building
Middlebury College
Middlebury, VT 05753
ph: 802-443-5003
cushman@middlebury.edu
Environmental Coordinator
Environmental Affairs
23 Adirondack View
Middlebury College
Middlebury, VT 05753
ph: 802-443-5043
aseif@middlebury.edu
More about Middlebury College COMPOSTING
Middlebury College as a liberal arts institution is committed to environmental mindfulness
and stewardship in all its activities.