Lafayette College has a new, $150K commercial composter. Here's how it works

• Lafayette College in June placed a commercial composting vessel on campus
• The vessel can hold 1,200 pounds of material
• Compost created is spread on the college’s farm, used to grow food for the dining halls

EASTON, Pa. — Composting at Lafayette College works as a cycle, or loop, of food sustainability, Melissa Adamson said.

“The dining hall collects food scraps, then the food scraps get turned into compost,” said Adamson, Lafayette’s climate action and circularity manager. “The compost goes to the farm, and the farm grows the food for the dining hall.”

Lafayette’s campuswide composting program has grown this year after the college bought and began using a $150,000 commercial composting vessel.

Situated in the 900 block of Bushkill Drive, the large, bright red box looks much like a shipping container, but has an auger inside that turns food scraps and wood chips into usable compost.

With students feeding the machine during shifts each week, the vessel doesn’t only serve as a sustainability effort, officials said, but also as an interdisciplinary learning tool that gives students hands-on experience.

“As an institution of higher education, we’re constantly thinking about being responsible environmental stewards,” said Delicia Nahman, Lafayette’s director of sustainability.

“We’re also trying to craft opportunities for students to be part of the process so that they can work on something tangible to understand the theory,” she said.

Food in landfills

Composting isn’t new. Researchers have found clay tablets from the Akkadian Empire, the first ancient empire of Mesopotamia, from about 2350 B.C., that were the first to describe “making” compost for agricultural use, according to the Compost Research and Education Foundation, a nonprofit based in Virginia.

In the United States, George Washington and Thomas Jefferson “frequently corresponded about farming matters,” including soil fertility and composting, according to the foundation.

However, even after centuries (and even millennia) of successful composting efforts, it hasn’t caught on with the general public, at least in the United States.

Of the 66.2 million tons of wasted food generated during 2019 in the food retail, food service and residential sectors across the county, only 5% was composted, according to the Environmental Protection Agency.

“In the U.S., food is the single most common material sent to landfills, comprising 24.1% of municipal solid waste,” according to the agency.

“When yard trimmings, wood and paper/paperboard are added to food, these organic materials comprise 51.4 percent of municipal solid waste in landfills.”

According to the EPA, “When we send food and other organic materials to landfills or combustion facilities, we throw away the valuable nutrients and carbon contained in those materials.

“By composting our food scraps and yard trimmings instead, and using the compost produced, we can return those nutrients and carbon to the soil to improve soil quality, support plant growth and build resilience in our local ecosystems and communities.”

The state Department of Environmental Protection’s website includes a listing of food waste composting locations. There are three listed for the Lehigh Valley.

‘As intentional as possible’

After a crew of 10 Lafayette students collect five-gallon buckets of food scraps from dining halls on campus, Adamson explained, they drive them to the composting vessel, tucked neatly under a wooden awning near the campus’ public safety and facilities building.

Called an Earth Flow, the vessel was made by Green Mountain Technologies, a Washington-based company that works on solutions for commercial composting.

While the vessel was placed in June, research into it started almost four years earlier, in 2019.

The vessel can handle up to 600 pounds of food waste a day, Adamson said. Because the recipe for compost includes a one-to-one ratio of food scrap and wood chips, the vessel can hold 1,200 pounds of material.

Over the summer, the college piloted the vessel using scraps from local businesses, Nahman said. When the semester started, the vessel already was up and running and ready to make compost.

All the buckets are weighed before being dumped into the vessel, along with wood chips, Adamson said. The auger within runs slowly, moving on a chain from side to side and back to front to mix the material and create compost.

“The aeration is so crucial,” she said. “It helps everything to be broken down.”

A decade in the making

One day last week, Wednesday, condensation had built up on the window workers used to dump the scraps and chips. When Adamson opened it, a warm, rich smell of earth and decay wafted out.

Temperatures stay incredibly warm inside the vessel, she said — about 130 degrees is the sweet spot.

Thick pipes run from the far side of the vessel to the college’s old Earth Tubs, which act as a biofilter to capture any gasses created during the process, she said.

The Earth Tubs, a smaller-scale method, were the start of the college’s composting journey more than a decade ago.

While the idea to start a composting program at Lafayette started a year earlier, all of the college’s food service locations during the 2009 spring semester began to use fully compostable packaging and cutlery.

At the 2010 graduation, students wore compostable graduation gowns and caps that were collected, shredded and composted in the Earth Tubs at Bushkill Commons, according to the college’s website.

“We’re trying to be as intentional as possible,” Nahman said.

She said the new, much larger vessel has about a 20-year lifespan.

Students are encouraged to think up ways to streamline the process even further as part of their scholarship, she said. For example, an engineering major could come up with a plan to run the vessel only using solar power.

There currently is a mechanical engineering project focused on creating a lift to more easily add wood chips to the mix, Adamson said.

After the compost is delivered to LaFarm at the Metzgar Field Athletic Complex, it needs to cure before it’s spread. Officials plan to test the soil each year to measure its health.