BIDDEFORD — Last week Mark King, an environmental specialist and director of the Maine Compost School, spoke to members of the School Committee to detail the ins and outs of composting programs, as the city’s school system prepares to craft one of its own.

School Superintendent Jeremy Ray said that the school system’s recycling program has been a success, and implementing a composting program is the next logical step in the schools becoming more environmentally friendly.

“One of the things we began working on this summer was the recycling of paper, and I would say ”¦ we’ve been fairly successful with the recycling of paper,” he said. “The next step is to talk about composting through the lunch program. That process is a little bit more involved than dealing with paper.”

King acknowledged that the process of composting can be taxing at times, but if done correctly, he said, a composting program is a very rewarding asset to a community.

“In order for this to work, it affects everyone,” he said. “And it’s not just everyone within the school; it goes beyond that. When the kids go home, it affects their families. It affects the community.”

King also explained that a composting program provides an opportunity for educating and involving children from kindergartners to high school students.

“There’s an opportunity for (students at) every level to learn something from this process,” he said.

For example, said King, K-2 pupils could draw pictures of the bacteria and insects that are part of the composting process; middle school students could weigh their school’s compost piles to determine how much organic material they’re keeping out of the waste stream; and high school students could track their piles’ temperatures and learn the science behind composting ”“ a science that, according to King, isn’t very complex.

“It’s, in essence, a process that happens every single day,” he said. “All we’re trying to do is maximize the opportunities for the process to work and optimize the performance of the microbes doing their activities.”

King explained that for composting to work well, only a few things are needed: organic materials, which are the food scraps you’re composting; “bulking material,” which can be anything from sawdust to leaves to horse manure; and a moist, hot environment. Once the ingredients are mixed, the bacteria go to work, he said, using nitrogen from the food scraps to grow and reproduce, and carbon from the bulking material for energy. The metabolic activity of the bacteria generates heat, which speeds up the process of decomposition.

King said that the ideal temperature for composting is between 130 and 140 degrees Fahrenheit, adding that Maine’s cold winters won’t disrupt the process, nor do the high temperatures present the risk of a fire starting.

“Once the piles start cooking, ambient temperatures do not affect the process, as long as you have 1 cubic yard in volume,” he said.

In the same vein, compost piles that are exceptionally large can become too hot and catch fire, said King, citing an experience he had with composters who keep piles that are 9,000 cubic yards, which often catch fire. But the piles the school system would maintain, he said, would, in the most extreme case, only start to smolder and turn to ash.  

Once the composting process is complete, said King, the soil-like material makes a great addition to any farm or garden.  

“Hopefully we can get support from the community,” he said. In other places where there are composting programs like the one Biddeford’s school system hopes to start, the compost is added to a community garden, he said.  

Last fall, the kitchen staff in Biddeford’s schools participated in studies to determine how much organic material is generated by the schools, said Ray. Moving forward, he said, the school system will soon start to explore possible locations where composting bins could be stored, as well look into which methods and materials would be best for the schools.

Mayor Alan Casavant said in an email on Monday that creating a composting program within Biddeford’s school system would be the first step in realizing citywide composting operations.

“Composting is the next logical step for the city in terms of waste reduction,” he said. “Creating a composting program within the schools not only begins the process, but educates our young in the importance of waste reduction and recycling. It would be the foundation of a citywide project that would occur down the road.”

— Staff Writer Angelo J. Verzoni can be contacted at 282-1535, ext. 329 or [email protected].