According to a 2011 waste characterization study done at the Iowa City Landfill and Recycling Center, about 25 percent of what goes into the landfill is organic material. Food waste makes up about 15 percent of what goes into the landfill each year, or about 18,000 tons each year. In an effort to reduce waste and produce quality compost for the community, the Landfill has a commercial composting facility for yard waste and other organics.
The tip fee for commercial organics is $24 per ton, which is less than the cost of landfilling the material. Check with your solid waste hauler for hauling costs.
The materials must be 100 percent organic; no contamination is allowed or the load is treated and charged as trash. Materials must arrive unbagged, in paper bags or in pre-approved biodegradable, compostable bags that meet ASTMD6400 certification. The Biodegradable Products Institute has a list of ASTM D6400 certified bags at http://www.bpiworld.org/BPI-Public/Approved.html.
Yard waste is banned from Iowa landfills and must be cleanly sorted. No chemically treated or painted lumber, railroad ties, mixed construction waste or other debris or contamination is allowed in the wood waste or yard waste piles.
What is acceptable?
Yard waste, including:
- garden waste, including fallen apples, pumpkins, etc.
All food waste, including:
- fruit and vegetables
- meat (raw or cooked, including bones) seafood (raw or cooked, including shells)
- grains, bread and baked goods
- dairy, eggs, coffee grounds/filters
- mixed plate scrapings
- wood produce crates
- floral waste
- leftovers past the point of re-serving
- spoiled foods
- paper that has been in contact with food:
- parchment bakery tray liners
- pizza boxes
- uncoated paper plates
What is not acceptable?
- any trash or other contaminants
- plastic, metal, glass
- foil- or plastic-coated paper
- plastic packaging
- plastic straw wrappers, stir sticks
- waxed paper or waxed cardboard (most often it’s actually plastic-coated)
- chemically treated or painted wood
Industrial food-related or organic waste:
Contact Recycling Coordinator Jennifer Jordan for more information about composting industrial food-related organic waste.
How does commercial composting work?
Commercial composting at the Iowa City Landfill is as simple as it gets—materials are composted in open-air windrows just like they would be in a back yard bins, but much larger. The Iowa City Landfill takes in about 7,500 tons of organics each year—yard waste, leaves and some food waste. From that, around 3,000 tons of finished compost is produced and sold each year.
Incoming materials are ground up, piled in long open-air windrows and turned monthly to encourage microbial and bacterial breakdown of the organic matter. The temperatures are taken in each windrow twice per week to ensure that the temperatures reach a minimum of 132 degrees Fahrenheit for at least two weeks, the minimum temperature and time needed to kill any harmful bacteria and weed seeds. Once the compost is done “cooking,” it is screened and must cure for 30 days. Overall, it takes about six to eight months to make compost at the landfill. The compost is sold in bulk at a cost of $20 per ton.
Environmental benefits of food waste diversion and composting
- Composting can significantly reduce the amount of organic material ending up landfills.
- In a landfill, organic materials break down over about 30 years and produce landfill gas, which is about 49 percent methane. Methane is a greenhouse gas that is about 21 times more harmful to the environment than carbon dioxide. While the Iowa City Landfill captures and flares the landfill gas, it is environmentally preferable to avoid the production of landfill gas.
- For the past several years, the Iowa City Landfill and Recycling Center has regularly sold out of compost. Diverting more organics for processing into compost would help meet the community's growing demand for more compost.
For information on the Environmental Protection Agency’s Food Recovery Challenge, including free webinars, visit http://www.epa.gov/foodrecoverychallenge/.
Want to reduce food waste and compost at home?
Learn more at https://www.icgov.org/foodwaste.