POLK COUNTY, Wis. (WCCO) — Melting ice and snow off the roads has created an unlikely partnership in one Wisconsin County.
A local cheese plant is teaming up with the Polk County highway department to produce a brine they say works like a charm.
In Moe Norby’s office, you might think you’re in the chemistry lab. Plastic bottles and jugs containing various liquids are spread out on top of his filing cabinets.
Lifting a bottle of liquid, Norby said, “the cheese whey itself froze at a lower point than regular salt brine.”
Four years ago, the Polk County highway manager began experimenting with an unusual waste product from a nearby cheese plant. What he stumbled on is sending road engineers running for the mozzarella.
“It’s a win-win for both us and the dairy,” said Norby. “They get rid of their waste product and we get it for free, for just the trucking costs.”
F & A dairy in Dresser turns out thousands of gallons of brine waste in the cheese making process each year. Up until recently, that waste stream was disposed of in treatment plants.
But the high sodium content, around 24 to 25 percent makes the brine the perfect replacement for conventional magnesium chloride — the chemical most often used by highway departments in the pre-treating of road salt.
Highway engineers have found that by wetting rock salt before it is spread onto icy roadways, it activates the salt to work sooner and stay on the road surface longer.
Chuck Engdahl works at F & A Cheese. He smiles when he explained, “we don’t have to send it to our waste plant. We also spray it to irrigate and we don’t have the high chloride content going on our fields.”
With less disposal costs, F & A is saving money on getting rid of the brine. It can turn out about 5,000 gallons per month.
At the county’s maintenance sheds in Balsam Lake, Norby opens the doors to a shed where the brine mixtures are kept.
“That’s our cheese brine tank,” Norby said, pointing to a large tank in the shed.
Polk County used 30,000 gallons of the cheese brine last season during a winter that was relatively mild and required a minimal of plowing and salting.
At just 9-cents a gallon to transport the brine from the dairy to the county, it’s far cheaper than purchasing magnesium chloride.
Most importantly, the department’s experiments with different mixtures has proven the cheese brine works better.
“If we were buying magnesium chloride that’s $1.29 a gallon, in the initial year, we saved $40,000 by not purchasing magnesium chloride and going with cheese brine,” said Norby.
They also did experiments with the amount of salt spread onto Polk County roads and found that because the cheese brine has a lower freezing point, it’s more effective at melting ice.
Bottom line, they cut their salt use by 30 to 40 percent.