Technology, logistics challenge food-scrap composting efforts in Wisconsin


This article was created by Wisconsin Watch.

The University of Wisconsin-Madison used to have a successful composting program that was very popular until recently.

The university began collecting food scraps from campus cafeterias in 2009 to send to West Madison Agricultural Research Station to be composted. Clean Fuel Partners LLC purchased the anaerobic biodigester in 2018. The university started bringing its scraps to it. The waste was then converted to methane, which is used as fuel.

The company changed its focus and it ended its partnership with UW–Madison. Travis Blomberg is the UW-Madison campus resource coordinator and uses manure instead of food. This change also ended Madison’s attempts to compost food scraps across the city.

According to the state Department of Natural Resources, 1.2 million tonnes of materials could be diverted annually from landfills to be composted. The DNR states that about three quarters of this is food waste. This methane is a dangerous greenhouse gas.

It is not just the university and city that struggle to keep large-scale food waste composting going.

Only 7% of the 1,000 largest cities in the nation have a municipal curbside compost program that accepts food waste — representing Contamination can cause severe problems

UW-Madison’s composting program suffered a number of setbacks before it was forced to close down. This included contamination of the waste stream.

The West Madison Agricultural Research Station’s composting system churns organic waste and aerates it in long rows. Blomberg stated that the system was unable to process non-compostable materials, such as plastic bags, metal, and packaging, in the food streams from the university.

The university tried to clean the stream of its food waste by recruiting students to conduct trash audits at campus cafeterias, and training staff to sort food and run it through a pulper.

However, campus waste caused problems. Paper containers and napkins slow down the system and light objects were blown away. Also, the agricultural station had to repair tractor tires that were punctured by silverware and thrown into compost bins.

Blomberg stated that contamination occurred in “front of house” materials, which were food scraps left behind by cafeteria customers. Blomberg said that contamination of non-compostable items with food waste collection is “always an problem” and “the program was not perfect.”

Blomberg stated that the university signed up to the anaerobic digester in 2018, which separates food from contaminants using a depacker machine, when the opportunity presented itself in 2018.

Blomberg stated that while we can do all we can, there isn’t an industrial composter nearby that (wants) the material.

Municipal composting falters

Madison, like UW-Madison has been involved in several food composting projects — all of which were unsuccessful.

Residents could drop off food scraps at three locations in the most recent city program. The material was then sent off to a biodigester, which extracted methane. The program was ended when the biodigester started extracting methane only from cow manure. This is the same change that brought an end to UW-Madison’s program, according Bryan Johnson, the city’s recycling coordinator.

Two curbside composting programs were previously tried by the city. However, they failed due to the labor-intensive nature of the program and contamination of food scraps. Johnson stated that among the items that were contaminated were towels, coat hangers, toys for children, and even a deer skull.

Madison is now giving food scrap recycling another chance. The U.S. Department of Agriculture grant enabled the city to open two food waste drop-off locations at farmers’ markets this summer. These scraps will be sent to the Neighborhood Health Solutions farm near Fitchburg for composting. The South Madison and East Side farmers markets will be open through Oct. 25.

Johnson stated that the operation is still small but that he plans to increase the number of sites. The two-site initiative has already collected nearly 8,000 pounds worth of food scraps. He said that although it is not much, every ton worth of compost is “a win.”

The city plans to collaborate with Dane County’s Sustainability Campus, a proposed landfill waste disposal project that is slated for Yahara Hills Golf Course. This will allow the city to host a large-scale program in the long-term.

Johnson stated that despite all the failures along the way, Johnson is still optimistic. “I know that we will do it. It’s taken much longer than anyone expected.

Minnesota ahead on composting

Minnesota has many municipal composting programs, including some that pick up organic material curbside. The Ramsey/Washington County Recycling and Energy Center in Minnesota intends to start curbside food scrap collection before the end of 2023. Junalee Ly, a UW-Madison grad, is the center’s leader.

Ly explained that residents will be able to collect their food waste from the two counties in thick compostable bags. They can then dispose of it the same as normal garbage or recycling.

She said that “our program is unique because we rely on existing collection infrastructure and trash haulers don’t need to change how they deliver their service.”

Lamensky, DNR’s solid waste coordinator, stated that food scraps collection programs are more common among densely populated areas, particularly along the coasts. These areas have limited land areas so landfills may be more costly than composting.

One bright spot in Wisconsin is yard waste composting. In Wisconsin, a landfill ban on yard trash was implemented in the 1990s. This has led to more than 200 municipal composting programs that turn an estimated 200,000 tons of leaves, grass clips, and small bits of brush each year into compost which is usually given away free of charge. Ironically, this makes composting food waste in the state more difficult.

She stated that (Food waste compost) is often a more lucrative product but that it is difficult to justify buying (food scraps), compost in a state where there is a lot of free yard waste compost.

The lack of infrastructure in Wisconsin causes municipal programs such as Madison to fail to get off the ground. Lamensky stated that confusion can result from the on-and-off attempts to compost food, which could increase the risk of contamination in the recycling waste stream. She advised that if in doubt, toss it.

Subscription services dominate

Even though Madison is not able to sustain a comprehensive composting program, there’s a market for private companies that can turn food scraps into soil.

In the Madison area, at least three services are offered — Curbside Composter and Earth Stew. Green Box CEO Ben Stanger founded the company to meet a growing demand in the area. Green Box members pay $24 per month.

Stanger stated, “There are a lot young people who have sustainability (as an objective) generally but also food and waste more specifically as something they want to concentrate on.” Stanger said, “I’d like them to have this in a convenient, easy, and inexpensive way.”

Lamensky stated that subscription-based services such as Green Box continue outnumbering municipal programs in the state. This is because private companies are able to “move more quickly,” bypassing bureaucracy which can slow down implementation.

She said that the DNR offers technical support to Wisconsin municipalities, waives reviews, and waives standard licensing fees in order to encourage start-ups.

State laws in some states and municipalities encourage food scrap recycling from landfills. Minnesota has a statutory goal to recycle 75% of its wastes by 2030. Wisconsin doesn’t have a benchmark, but DNR has set a goal of reducing food waste 50% by 2030.

Lamensky believes that despite the difficulties, more municipalities will try it.

She said, “And when there are more examples here in Wisconsin,” she added.

Remediating waste at its source

UW-Madison has begun a pilot program to bring composting back on campus. Blomberg stated that material will be limited to the “back of the home” food scraps of the university’s four largest food-waste generators, which make up more than half the food waste on campus.

Blomberg stated that the pilot program is temporary and that vendors have not been able to provide long-term composting facilities.

The university is also looking for ways to reduce food waste. A team of students obtained money through the Green Fund, an initiative that funds student-led projects to address environmental problems on the UW Madison campus.

This project uses digital scanners to scan food in trash bins so that the university can adjust its food purchase.

Jacob Breit, a senior member of the project team, stated that the solution is simple, inexpensive, and cost-effective.

Blomberg agreed with Blomberg that minimizing waste is the best solution.

He said that the bigger question was “Why are we producing so many food wastes in the first place?” That’s a valid concern.

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