Combining the Badger State's love for dairy with practical winter solutions, a Wisconsin county is revolutionizing road maintenance by swapping conventional salt for a surprising yet sustainable alternative: cheese brine.
The use of traditional road salt in Madison has been a source of concern for city officials due to its disadvantageous environmental effects, including water pollution, soil degradation, infrastructure corrosion and health risks to both aquatic ecosystems and human populations.
The city of Madison responded to concerns by reducing salt routes for the 2024 winter season by 6%. This reduction, estimated to cover over 50 miles of Madison’s roads, prevented approximately 270 tons of salt from entering local waterways.
However, this reduction is not without its challenges.
On average, 60 people die and 6,000 more sustain injuries in Wisconsin each winter due to accidents on roads covered in ice, snow and slush, according to the UW-Madison Police Department.
When temperatures dip below 20 degrees Fahrenheit in Madison, the city turns its de-icing focus from salt toward sand. At those temperatures, the chemical process that typically melts snow slows down significantly, rendering the traditional method of road salt less effective.
Navigating through campus in these conditions presents its own challenges.
“Walking through campus and the mess is no joke,” said Hannah Koury, a UW-Madison student. “My shoes are constantly covered in what looks like mud, and it leaves a trail in every building I enter. We have to be extremely careful when walking because if you're not, you find yourself slipping in front of everyone.”
Cheese brine poses a potential solution to some of the issues presented by road salt and sand.
Derived from the cheese-making process, this dairy byproduct addresses multiple environmental concerns associated with traditional salt use. Apart from its environmental qualities, cheese brine boasts a lower freezing point than water.
Polk County, located in northwest Wisconsin, adopted cheese brine in 2009.
"In 2008, I started working on using salt brine from F&A Dairy in Dresser, Wisconsin, for snow and ice control," said Polk County administrator Emil Norby. "We were seeking a cost-effective measure to reduce salt and salt sand usage during winter while maintaining efficiency."
Cheese brine’s adoption led to significant material savings, with a 30% reduction in costs, amounting to approximately $90,000 in the first year alone, according to Norby. This success prompted further exploration of cheese brine's potential benefits.
Initially, the Department of Natural Resources (DNR) was concerned about the high levels of biochemical oxygen demand (BOD) in cheese brine. High levels of BOD in water are a key indicator of poor water quality and can affect both the environment and health, according to the Environmental Protection Agency.
After obtaining a conditional grant of low hazard exemption permit from the Department of Natural Resources in 2009 that would allow them to use the salt brine on highways, Polk County proceeded with testing, according to Norby.
The testing phase involved comparing the effectiveness of cheese brine-treated roads with those treated conventionally with salt or salt sand mixes. Results indicated that cheese brine-treated roads exhibited quicker response times and clearer conditions, even in extreme temperatures, he said.
“It was a win-win for both Polk County and F&A Dairy,” Norby said. “The tests showed that the use of the salt brine saved money within our snow and ice control budget, and not only was there material saving, but a quicker reaction time for the melt aided in clearing highways.”
