Iowa City set to receive $4 million grant to improve composting facility

IOWA CITY — The compost facility at the Iowa City Landfill and Recycling Center is set to get a $4 million upgrade through funds from the EPA’s Solid Waste Infrastructure for Recycling grant program.

Among the planned upgrades are the purchase of a compost turner, resurfacing the existing five-acre compost facility and adding two additional acres.

With the new upgrades, city staff expect the facility to be able to process more food waste, increase the amount of usable compost produced and quicken the composting process.

The city is working on finalizing a contract with a consultant for the design process and hopes to put the project out to bid in spring 2025. There is no official timeline for project completion yet.

Iowa City’s facility, located at 3900 Hebl Ave. SW, serves the entirety of Johnson County as wells as Kalona and Riverside.

Compost turner expected to improve efficiency

Under the current process, once food or yard waste is dropped off, it gets ground up and lined up into rows. The rows are then lifted by an end loader truck and moved to the next row, which mixes the piles up.

This process, which is called turning, helps speed up the decomposition process by incorporating more air, shifting microbes and distributing moisture.

The compost is turned once a month and Iowa City Resource Management Superintendent Jen Jordan said it takes around two to three hours to complete each row.

A compost turner would allow for the compost to be turned once a week and Jordan said would greatly reduce the amount of staff time and fuel required for turning. The city has yet to finalize which specific turner it plans to purchase.

“They basically bite into the rows with a scoop and just lift it up and fluff it, or lift it up and move it to the next row … What the difference is, instead of biting into it and having to lift it and move it over, the turner will actually just roll over it in place and fluff it up as it goes,” said Jordan about how a new compost turner will impact operations.

With the current machine Jordan said it takes about a year from when food waste is brought in to when it’s compost that’s ready to be sold. Jordan said the aim is to shorten the process to three to four months with the new compost turner.

In addition to turning, landfill staff regularly test the compost for heavy metals. Once the compost is near the end of the decomposition process it’s screened again and sits for a month to return to ambient temperature. The compost can typically get up to 132 degrees Fahrenheit during the process.

Currently about 15,000 tons of food and yard waste is processed each year and the new turner is expected to process at least 5,000 additional tons.

But Jordan is hoping that the city can double the amount of waste the facility currently processes, though that could depend on the capability of the new turner.

“It may be a little bit optimistic, but that’s OK. I will aim for the stars,” said Jordan.

The city sells the compost for $20 a ton and has regularly sold out throughout the last decade, said Jordan. For the 15,000 tons of food waste that comes in, the city can make 3,500 tons of compost for use.

“A chunk of that's waste that we don't process with the compost. But it's not a one for one ratio by any means … It's more like this is what comes in, this is what can go out,” said Jordan.

Future outreach efforts in the works

Though the city has yet to start construction for the project, it’s been a focus of staff for the past few years.

Prior to applying for the grant in early 2023 the city had already set aside around $300,000 for improving composting operations at the landfill.

“I think that was kind of the linchpin for the funding. We showed we're already working on this, but we can do so much more ” said Jordan.

Due to limits on capacity Jordan said that there’s been points where the facility has had to limit food and yard waste from businesses. With the planned upgrades Jordan said the idea is to be able to take in more food waste from existing partners and reach out to more.

“I'd like to ask that there'll be a huge push for reaching out to grocery stores and restaurants in particular to help them sort out the material and figure out how to get it to us,” said Jordan.

Iowa City offers curbside compost collection to residents. Businesses and other county residents are required to bring the compost to the landfill.

Comments: megan.woolard@thegazette.com