Food waste composting is cooking in Minnesota — and helping curb climate change

Americans waste more than one-third of available food. And that out-of-date salad or mushy banana tossed in the garbage contributes to increased emissions of methane, one of the most potent climate-warming gases.

Local governments across Minnesota are mandated by law to increase recycling of organic waste and they are expanding composting programs to keep food out of landfills.

Controlled composting of the material reduces emissions of greenhouse gases that occur when organic material rapidly decays in a landfill.

At the Pope-Douglas organics recycling facility about a half hour west of Alexandria, food waste from five counties is turned into compost.

Environmental Programs Manager Nathan Reinbold stands inside a large hoop style building open on both ends. He explains the computer controlled compost site “is pretty much state of the art as far as composting goes in Minnesota currently.”

A garbage truck loaded with organic waste from Morris, 25 miles away, dumps bags of compostable paper products and food next to a pile of rotting meat and vegetables, used paper towels and a few grease-stained pizza boxes.

The food waste is mixed with wood chips, grass clippings and leaves in concrete bins. A computer monitors air flow through the pile to speed the process and raise temperatures high enough to kill any pathogens.

The controlled decay also limits the odor from rotting food.

“It’s kind of sweet, it almost smells like a pipe tobacco or something,” said Reinbold.

Food waste makes up about 20 percent of garbage headed to landfills in Minnesota, and as much as half of municipal garbage is compostable. Burying that waste in a landfill is problematic.

“The number one reason is methane generation,” said Reinbold. “It’s not good to landfill food waste organics, it’s one of the largest contributors to methane.”

The Environmental Protection Agency says municipal solid waste landfills are the third-largest source of methane emissions from human activities in the country.

Composting is one solution.

In densely populated metro areas, curbside food waste recycling is feasible. That’s not the case in rural areas.

Counties collect food waste from bins at large sites such as schools, hospitals or restaurants.

Separating food waste into recycling bins is “not a heavy lift” said Jen Pastian, executive chef at Pike and Pint Grill in Alexandria. The restaurant has food waste bins where dirty dishes are cleaned and next to the area where food is prepared each day.

Pastian sees no downside to recycling the food other than perhaps the bins behind the restaurant get “a little smelly” in the summer.

At the Fabled Farmer restaurant in Fergus Falls, owner Rebecca Lacheur has always tried to recycle food waste, but found it a challenge until Otter Tail County recently started an organics recycling program.

“We have two garbage cans that they supplied us with that are specifically for the compost and they come and pick that up once a week,” she said. “So it’s really convenient.”

For now, there’s no charge for the program, so the only cost is the compostable bags she uses, and a small amount of time spent training staff on what to put in the compost bin.

The waste collected in Otter Tail County is hauled to the Pope-Douglas compost site.

But Otter Tail County is also encouraging back yard composting rather than picking up residential food waste.

“It’s actually not cost effective or really environmentally correct to have a big truck driving around the county picking up the stuff,” said Solid Waste Director Chris McConn.

So the county provides residents with a back yard compost bin and a stainless steel bucket to collect food waste in the kitchen.

“A big part of our program is the county doing nothing other than supporting citizens with good education and some supplies,” said McConn who added it can be a challenge to convince people with busy lives to take the extra time keep food out of the trash.

Fergus Falls resident Zach Stach is sold on composting the food scraps in his household of eight people.

“On the counter we keep what my kids call a yuck bucket. That’s where we put all the organic food scraps,” he explained. “If you let it sit too long, it does kind of start to stink a little bit.”

So they typically dump the bucket in the back yard composter twice a week, said Stach. He uses the finished compost in his vegetable garden.

There are different rules for back yard food composting because temperatures don’t get as high as in a controlled commercial compost site. Stach avoids putting meat scraps and dairy products in the bin.

While food waste composting is an important tool in reducing landfill methane emissions, state officials say it's not the best solution.

“Could that food waste have been prevented just by changing policies, changing management, how food is prepared, how it’s transported?” said MPCA Sustainable Materials Management Unit Supervisor Mark Rust.

“If you prevent food waste, the greenhouse gas and energy impacts are so much greater than even if you rescue it, compost it or do other things with it,” said Rust.

Food rescue takes excess food out of the waste stream and finds a new use for it through food shelves or other distribution systems.

A Northfield nonprofit is developing one of the first carbon credit programs for rescued food to help fund those efforts. The Community Action Center collects and distributes 250,000 to 350,000 pounds of food each year.

“I think easily it could become a consistent $25,000 to $45,000 revenue stream for our food shelves alone,” said Executive Director Scott Wopata, who expects the carbon credit for rescued food to be finalized later this year.

“I think the real excitement grows when you start thinking about how many food shelves are across the state of Minnesota,” said Wopata. “How can we bind them all together? And what does that type of revenue stream look like when we bring all of our aggregate data together, and potentially collectively bargain on a bigger scale?”

Most rescued food is from grocery stores or large institutions. But about half of all food waste comes out of residential kitchens.

“Households have a huge opportunity to participate in climate change mitigation efforts,” said MPCA Sustainable Materials Management Specialist Tabitha Birdwell.

While reducing carbon dioxide emissions will have a long term effect on reducing climate change, scientists say reducing methane emissions will more quickly slow climate warming.

“So in the short term, if we can do measures that would significantly reduce how much methane we're emitting through the food waste process, we can significantly impact how much climate change we have,” said Birdwell.

The MPCA wants to cut food waste in half by 2030. Counties have mandated goals to increase recycling of organic material.

Rust wants individual consumers to understand they can contribute to to cutting food waste.

“Take a look at what you’re buying, take a look at what you’re throwing out. Are you finding that maybe because you’re so busy, your purchasing habits aren’t lining up with your consumption habits?” he said. “There may be simple things that you can do that can have a cumulative impact, especially if a lot of people are starting to think about that.”

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