MINNEAPOLIS (WCCO) – The Minnesota Correctional Facility in Stillwater has been feeding more than 1,600 people a day, three meals a day.

So, the prison has considerable food waste.

To reduce the amount of food hauled away in trucks, Stillwater has a begun a year-round composting program. The key to the program’s success is little and wiggly: worms.

In a custom-made steel bin, in a heated building, more than a hundred pounds of worms earn their keep by turning waste food into fertilizer.

Coffee grounds, egg shells and all sorts of fruit and vegetable waste are placed in the bin, with a little sand. Like birds, the worms need grit in their diet to digest food.

“The worms don’t actually eat the food, they eat the decaying process,” said Douglas Johnson, who works at the facility.

A hose at the bottom of the bin collects what is called “worm tea.” It is saved in a large barrel, and during the growing season, it is diluted 50 to one in a watering truck.

“The by-product of this is an organic fertilizer that we’re then able to spray on to our bushes and our trees and our grass,” Johnson said.

The bin is cleaned occasionally, and the solids that are removed from it can also be used as fertilizer.

Future plans include at least two more bins, and a process to remove salt, which kills the worms. That would allow waste meat to go into the bins with the veggies.

“Right now we’re in what we would call, probably, the infant stages of the process,” said Michelle Smith, the prison warden.

As the composting project continues, the worms may help break down other things in the bins, like brown paper towels.