A 2020-2021 waste characterization study commissioned by the Wisconsin Department of Natural Resources (DNR) has found that organics account for roughly 30 percent of the state’s landfill waste by weight.
As reported by the Wisconsin State Journal, the study states the broad organics category accounted for about 1.3 million tons. An estimated 924,900 tons of paper, including cardboard, compostable and office paper, comprised about 21 percent of the landfills’ tonnage. That was followed by plastic at about 17 percent, or 745,600 tons.
The study, for which samples were collected in the fall of 2020 and spring of 2021 by Long Beach, California-based environmental consulting and contracting firm SCS Engineers, was completed by filtering through 200 pounds of waste collected at 14 landfills and one solid waste transfer station.
Casey Lamensky, solid waste coordinator for the DNR, told the State Journal that the 14 sites represent 72 percent of the state’s municipal and general solid waste. Crews collected 398 200-pound samples from those locations.
“Then those samples were hand sorted into 85 different waste categories to give us a percent total that each of those categories represents in our landfills in 2020,” she said.
This is the third study of its kind, and the first since 2009, Wisconsin Public Radio reported.
Lamensky said organic materials in landfills are compressed with other waste to open up space. But that compression pushes out oxygen, which helps break down food. Without oxygen, food is broken down by other microorganisms.
“And those microorganisms off-put methane, which is a greenhouse gas that’s 28 times more powerful than CO2,” she said.
Aside from food waste, the State Journal reports there were several marked improvements since 2009 that the study acknowledged, including a reduction in roofing shingles showing up as solid waste. This can be partially credited to recycling efforts that use old shingles in road-building.
Another example is likely due to Wisconsin’s law to recycle electronics that went into effect in 2010, according to the DNR. Compared to 2009, when the study was last conducted, the weight of landfilled TVs and monitors dropped 85 percent this time around.