May 15, 2019

Suggestions About Restarting Princeton’s Composting Program

To the Editor:

It was a curiously satisfying and energizing experience to attend the recent meeting on the composting program covered in Town Topics (May 1, pg. one), and observe residents, municipal officials, and staff enthusiastically exchanging ideas and information in order to solve an intractable, difficult problem: how to deal with … our garbage. Such are the times in which we live!

It was encouraging to hear that every effort is being made to restart the composting program. It would be worthwhile to invest extra funds to re-establish this same program, which might be expanded by using a per-bag trash disposal fee to encourage waste minimization and participation in the organics collection program.

There seemed to be considerable enthusiasm for accepting the gift of a biodigester from the MetLife Stadium. While in general one might not want to look a gift horse in the mouth, in this instance great skepticism is warranted. For example, this equipment might accommodate a small expansion in the program which had about 1,000 participants, but could not cope with all the waste generated by about 7,000 homes, much less that from restaurants and apartment dwellers.

One person mentioned the challenge of odor emissions; many people seemed to dismiss this concern since the plant would be located near the sewage processing plant. This is unwise. We knew people who lived near the sewer plant who objected vociferously to any sewage plant smell. Waste processing equipment is usually installed in an airtight building kept at negative pressure, with exhausted air carefully deodorized. The cost of a specialized enclosure is not included in the overall plan, nor was a service contract mentioned. It would also be important to understand why MetLife wants to give this piece of equipment away.

It would seem that if Princeton wants to move to a system that is more involved than residential sorting and remote composting, it should be to one that is much more capable and less problematic than a biodigester.

Such a system does exist and is widely used in Europe as well as in one town in the U.S. (Martinsburg, West Virginia) with another (Rensselaer, N.Y.) in the permitting process. This is important, as one does not want to be the first to suffer through an unknown permitting procedure with state and federal authorities.

The new plant uses mechanical biological treatment (MBT) of unsorted municipal solid waste (MSW) to produce a renewable solid fuel at about 50 percent efficiency. Trash is screened in a large rotary drum; plastic bags are broken open and water content reduced with fresh and recirculated warm air; only heat generated by the decomposing organic material is needed. The processing equipment is housed in an airtight, negative pressure building and the contract stipulates, among other guarantees, that there will be no off-site odor.

This plant capacity is much larger than what is needed by Princeton, and should be regarded as a regional (Mercer County?) solution to the MSW challenge.

This higher technology MBT approach is probably more expensive that a crude “landfill” operation, but well worth the extra investment considering the negative impact of piling up mixed waste in large mountains for the next generation to deal with.

Al Cavallo
Western Way