For the last several months, organic waste deposited in bins by participants in the town of Princeton’s composting program has not gone to a farm or a facility that composts the waste — instead the food and other organic materials have gone to an incinerator in Tullytown, Pa.

The incinerator is a “waste-to-energy” incinerator, where garbage is burned and the resulting heat is used to turn water into steam that drives turbines to generate electricity.

Residents in Princeton who participate in the town’s composting program pay an annual fee of $65 to do so. The program is also subsidized by the municipality. In an email Princeton Mayor Liz Lempert wrote that was sent out by Access Princeton, the town’s community relations and communications department, to some participants in the program early Saturday morning, residents were informed that the composting bins contain too much prohibited material and thus Princeton’s organic waste is, in fact, not being composted. The news was cushioned in a “good news, bad news” email about a grant awarded to the municipality last winter by Bloomberg to improve the food waste program.

Lempert hopes the town, one of 35 national finalists, will receive funding from Bloomberg to build its own food waste composting facility in Princeton.

“The bad news is that two weeks ago, we learned that Princeton’s composting bins contain too much prohibited material – mostly traditional plastic garbage bags and ‘compostable’ utensils – to be accepted at the farm utilized by our hauler,” Lempert wrote. “Since being notified of this several months ago, the hauler has been taking Princeton’s material to the waste-to-energy incinerator in Tullytown, Pa, in Lower Bucks County.”

According to the email, Princeton officials have been working with composting hauler Premier Food Waste Recycling, a subsidiary of Central Jersey Waste, to find a suitable location for Princeton’s organic waste. A farm about 80 miles away in Pottstown, Pa. was identified as a possible location for Princeton’s food waste. A trial delivery was sent to Pottstown last week, Lempert wrote.

“This arrangement is at risk because of the number of plastic bags in last week’s trial delivery,” Lempert wrote. “Clearly, we need to do a better job working with our composters to improve the content of our food waste in order to keep this important program viable. Discussions continue with the Pottstown farm, and, with your help, we hope to demonstrate our food waste stream is clean enough to be a valuable resource.”

If the municipality is unable to find a suitable solution, the composting program will be shut down, and the town will get a refund from the waste hauler.

Participants in the composting program should not place plastic items in compost buckets. Use paper grocery bags or compostable bags with the Biodegradable Products Institute seal on the box. These bags are available at McCaffreys, Whole Earth, Ace, and online. Utensils, even those marked as compostable, are not allowed in the bins because they do not break down quickly enough.

A full list of acceptable items can be found here.

In October of 2014, officials in Delaware ordered that an industrial composting site near the Port of Wilmington be shut down because of widespread odor complaints from residents, stockpiling problems, and fire risks.The Delaware composting site was the largest food waste recycling facility on the East Coast, and was used by businesses and municipalities from New York to Washington DC, including Princeton.

In early 2015, Planet Princeton wrote a story raising questions about where Princeton’s food waste was being hauled after the closure of the Delaware composting facility. At the time, officials said the location information would be available soon. Planet Princeton then filed an Open Public Records Request for more information. Officials had narrowed down the possible location to a few farms in South Jersey and Pennsylvania at the time.

Lawrence Township also has a composting program and uses the same hauler as Princeton. Residents there pay $17 a month to participate in the program.