The University of Michigan (U-M) Grounds & Waste Management Services provides vermi-composting (a.k.a. worm bins) to selected offices and departments to compost small quantities of food waste in employee lunchroom areas.


Applicable Regulations


Overview of Procedure
Ten University offices were provided with a worm bin to compost employee food scraps and lunchroom waste. The plastic boxes (1' x 1' x 2') are partially filled with shredded newspaper bedding and a pound of red worms. Bins are kept aerated and moist for ideal composting conditions. Food scraps are buried under the bedding, and worms aid in the decomposition process. Every 4 - 6 months, the finished compost and worm castings are harvested. Employees are welcome to use the compost for gardens or houseplants.


Waste Minimization Procedure
A covered container is kept in the break room in which employees place their food waste. Items such as banana peels, apple cores, coffee grounds, and other vegetative leftovers are acceptable. Items such as meat, fish, dairy or oils are not acceptable because they will cause foul odors to develop in the compost. The food waste material is added to the bin each day. Compost material is stirred periodically to ensure aeration and distribution of moisture, as the moisture tends to migrate toward the bottom.


Known Limitations
The worm composting bins only work well for small-scale operations. Bins can handle between three to five pounds of food waste per week, or a lunchroom area servicing 15 - 20 employees. The bin requires some maintenance and oversight. Employees must be educated on what to keep out of the bin.


Safety & Health Precautions/Personal Protective Equipment
None needed.


Awareness by staff about alternative waste disposal methods is increased. This raised awareness has encouraged some staff to start composting at home.


The worm bins can only handle a small quantity of food waste. This method would not work for the larger food service operations on campus, unless a much larger and more complex system were installed.

Occasional complaints of insect pests (fruit flies, spring tails, etc.) have been reported, but no serious insect infestations have been linked to the bins themselves.


Project Related Costs
Not available.