Geoff Hill, 67, of Belgrade, first became interested in composting on April 22, 1970 — the first Earth Day — as a way to improve the health of the planet. In the early 1990s, he took a course with the University of Maine Cooperative Extension to earn the title of Master Composter and joined the Maine Compost Team, a group that won the gubernatorial Teamwork Award during his time of service, between 1992 and 1997. He made headlines 20 years ago for teaching then-Governor John McKernan how to compost at the governor’s mansion in Augusta as part of a statewide push to increase recycling. A regular presenter at composting workshops and farmers markets, he has preached compost’s virtues to hundreds. We called him recently to ask about composting lobster shells, the dirty secret behind Chinese rice and schooling Governor McKernan.

TO BEGIN: “It can be very simple. Collect your vegetable and fruit waste and mix it with something as simple as leaves and grass clippings. Don’t mess with meat. Don’t mess with fish waste.”

WEIRDEST COMPOSTABLE MATERIAL: Ground up shellfish, including lobster shells, crab shells and mussel shells. Hill said some operations Down East grind them up and mix them with sawdust to give them an extra calcium kick.

THE MASTER’S OWN COMPOST?: Hill doesn’t have a vegetable garden himself, so he ships it to the garden of a friend, and gets his pick of tomatoes in exchange.

MAINE’S MOST UNIQUE COMPOST: An operation in Unity that turns sewage sludge into compost. It gets its raw material from area communities and mixes the sludge with sawdust in large cubicles heated to 160 degrees with forced air. “They have a bucket loader that helps to turn the rows and you can see the steam coming off, it’s so hot.” Compost from human waste, he said, shouldn’t be used on a vegetable garden, but it can be used to grow grass, hay, ornamental plants or fruit trees.

DANGER, DANGER: “Occasionally, someone makes a mistake and either puts in dog or cat waste or cat litter. That should not go in because dogs and cats eat meat. Any animal that’s a carnivore, you don’t want to mix their waste into your compost pile, if you’re going to use your finished compost for a vegetable garden.”

CAN VEGANS OR VEGETARIANS COMPOST THEIR OWN WASTE FOR GARDENS?: No way. Whether they eat meat or not, E. coli “bacteria is an integral part of our bodies,” which is just one of many bacterial concerns. “You just have to stay away from that.”

MOST COMMON COMPOSTING MISTAKE: “Some people throw their food scraps in a pile outside their home and expect it to compost, but it just rots. You really need yard waste, like leaves, to provide that carbon.”

CULTURAL TRADITION THAT WOULDN’T CUT THE MUSTARD IN MAINE: “In China, for their rice, they mix in human waste with their rice paddies. Here, you don’t do direct application of any human waste.”

THE MESSAGE HAS CHANGED OVER 20 YEARS: More people are interested in keeping animals away from their home compost piles. “Some people don’t care, but others do.” To overcome the objection, Hill has begun recommending people use seal-able plastic containers to discourage the wildlife. “I’m not saying it’s animal-proof, but it’s animal-resistant anyway, so it can keep out some of the critters.”

REDUCING YOUR WASTE: The average household can subtract 15 to 30 percent from their household waste by composting their kitchen scraps.

MAINE’S ADVANTAGE: “We have plenty of leaves in Maine. If you’re one of those rare people that don’t have them in your yard, get them from a neighbor or get them from your transfer station.”

THE SECRET RECYCLABLE: “We talk a lot about recycling our paper and metal or plastic, but we don’t talk as much about our food waste.”

THE GREAT COMPOSTING DEBATE: Some experts say compost is best when it’s derived from pure leaf litter— no kitchen scraps needed. But Hill says that’s coming from the wrong perspective. “I don’t agree with that at all. My purpose is to recycle as much of the waste stream as possible. If you only compost the leaves, it’s missing ingredients. To me, mix in the food waste and the coffee grounds and the eggshells — it increases the nitrogen content of your compost, which in turn increases the nitrogen content in your vegetables. That’s a better thing.”

ON TEACHING GOV. MCKERNAN TO COMPOST: “People gave me a hard time about that, ‘photo op, photo op.’ I don’t care if it’s a photo op or not. They asked me and I went, just to get the message out.”

IS MCKERNAN STILL COMPOSTING?: I’d love to know that. I suppose I could call him and say, ‘By the way John, this is Geoff. Are you still composing?’ He’d say ‘Geoff who?'”

HOW TO SEPARATE FINISHED COMPOST FROM THE NEW STUFF IN THE BIN?: “It’s an interesting problem. The more questions you ask, it gets more complicated, doesn’t it? I have two compost bins. When one is pretty much filled up, I let that one sit and I start with my second.” He said some bins have drawers in the bottom that allow for removal of the finished product.

COMPOSTING’S FUTURE: As pressures increase to reuse and recycle to subtract things from the waste stream, composting will become a way of life for increasing numbers of people. “Massachusetts just enacted a law that businesses that produce more than a certain amount of food tonnage have to fine a way to compost it now, to keep it out of landfills.”

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