4/3/2021 12:11:00 PM New Developments to Reduce Chloride Pollution in Cass County
By Pat Miller for the Cass SWCD
Snow and ice can form a deadly combination for motorists in northern Minnesota, and among those helping to minimize the dangers are the local, county and state highway departments.
The weapons the highway departments utilize include sand, salt and salt brine. Each has its particular benefit in the fight against icy roads and, both economically and ecologically, salt brine has become a go-to option when the conditions are right.
"Every winter is different, and this winter we haven't had to use a whole lot of salt," said Cass County Engineer Darrick Anderson. "Salt usage is very weather dependent so it is hard to compare (use) year to year. It takes some salt to make brine but, the concept is, if you are using 20 to 30 percent less salt, it should, in essence, decrease our budget for salt use by that amount."
In many situations, brine actually is more effective at clearing the road than is the combination of salt and sand.
"If you imagine a bunch of salt and sand that you just throw onto the road, if that road surface is dry, the salt and sand can blow to the side as the traffic goes by," Anderson said. "It is estimated that as much as 20 to 30 percent of that salt can bounce right off the road and onto the shoulder.
"But, if you put a little bit of water with it, the salt (brine) will stick to the pavement, more salt is being activated and there are more benefits to the road."
And to the environment.
According to the Minnesota Pollution Control Agency (MPCA), road salt is a major source of chloride entering the state's lakes, streams, wetlands and groundwater. Once that chloride reaches the water, the only way to remove it is reverse osmosis, which currently is not an option because of the prohibitive cost.
A recent University of Minnesota study found that 78 percent of salt applied for winter maintenance in the Twin Cities metro area is either transported to groundwater or remains in the local lakes, streams, wetlands, groundwater and soil. High concentrations of chloride can kill fish, invertebrates and even some plant species, according to the MPCA. Pets and wildlife that drink the water or eat nearby plants can also be at risk.
Eliminating salt from the winter road maintenance tool box is not a viable option because, currently, there are no cost-effective alternatives that are effective at melting ice on paved surfaces, according to the MPCA. Reducing the amount of salt through the use of brine, however, is more environmentally friendly.
Reducing salt in the environment is among the goals of Cass County and Hubbard County, and their Soil and Water Conservation Districts. The Leech Lake River Comprehensive Watershed Management Plan, which is funded for implementation with dollars dedicated from the Clean Water Land and Legacy Amendment through grants administered by the Minnesota Board of Water and Soil Resources, was developed through their partnership, according to Cass County Environmental Services Director John Ringle. To meet the plan goals, the partnership was able to allocate $30,000 to Chloride Reduction Projects in both Counties.
In Cass County, according to Ringle, its share of the funding was coupled with an additional $45,000 from the Cass SWCD Local Capacity fund to purchase salt brining equipment for the County Highway Department to allow it to reduce the winter chloride use by up to 30 percent throughout the entire county.
"This is a great example of being able to utilize Legacy Funding in a very expedient manner, to do something that might not have happened as quickly without this additional assistance, that benefits everyone in the county and helps protect our resources," said Cass County Commissioner Neal Gaalswyk.
"The SWCD has helped us out a lot with the 'One Watershed, One Plan' focus, and one of their goals is to reduce the chloride in the environment," Anderson said. "We have the same goals, and by them helping us fund our own brine production, and by us having brine more readily available in all of our shops, our hope is that we can reduce our salt usage as well.
"The SWCD definitely helped us fund this project, and so did the County Board through the capital budget program. The SWCD essentially purchased the tanks for the brine and the capital plan paid for the building plus all the plumbing and electric that goes in it. This definitely is a good partnership."
Other entities have also benefitted from the partnership.
"The County also is providing brine to Shingobee Township, the City of Walker and, eventually, even to Turtle Lake Township," Anderson said. "Those three partners have purchased salt from us in the past (at cost) and they have indicated that they are interested in using our brine as well."
From the minnows swimming in Leech Lake to the motorist traveling the Cass County roads, everyone is benefitting from the brine project. And, hopefully, more projects are on the way.
"With the help of the recent development of a Leech Lake River Watershed Comprehensive Management Plan, and funding earmarked by the Clean Water Land and Legacy Amendment through a grant from the Minnesota Board of Water Soil Resources, when the opportunity to improve Leech Lake Watershed water quality surfaced, the Cass SWCD was eager to do its part," Ringle said. "Additional funding from the LLRCWMP is available on a biennial basis to assist landowners and cooperating agencies in the wise use, conservation and management of the watershed's natural resources."
For more information on the SWCD and its projects, contact the Cass SWCD at the County Environmental Services office at (218)547-7241.