In Minnesota winter comes with snow, cold and rough driving conditions. To try and prevent a complete breakdown of Minnesota’s main transportation method, driving, municipalities do what they can to make sure that residents can get from point A to point B safely.
In Red Wing and Goodhue County salt is used to keep ice and snow levels down, but both the city and county try to avoid an overuse of salt. Goodhue County Public Works Director Greg Isakson explained:
“The best option to reduce the use of salt is to prevent slick roads by preventing the snow from sticking to the road in the first place. If we are expecting wet snow that will stick to the roads, we ‘pretreat’ the roads by laying down a coating of salt/water brine to the hills and intersections the day before the snow. This brine will help prevent the snow from bonding to the roads and greatly reduces the work it takes to scrape it off the road. If snow accumulation is expected over night we will mobilize the crew early so they can get on the roads and scrape the snow before the morning commuters pack it down.”
Red Wing also uses an anti-icing process. Public Works Director Rick Moskwa specified, “The city also uses a treated salt when temperatures are 20 degrees and falling.” Salt’s effectiveness declines at the temperature drops. By the time the air temperature is about 10 degrees, untreated salt is more or less useless.
The public works departments are in a position where they need to keep roads clear and safe while also working to decrease the amount of salt that is used in the winter.
“We have made a lot of improvements to our snow fighting program over the past few years,” Isakson said, “which we feel maximize the road clearing benefits of using salt, such as pretreating the roads, plowing early and using other products when they work better.”
The brine also helps lower the amount of salt used because it both activates the salt and prevents it from blowing off the street, resulting in the need for additional salt.
Moskwa said that the city is working to reduce how much salt is used on roads, but there is a direct correlation between the amount of snow used and the type of winter the community experiences.
Modern technology has been a useful tool in monitoring how roads are treated. Moskwa said:
“Crews also calibrate trucks each year to make sure that the trucks are putting down the correct amount of salt. Trucks are also equipped with road sensors to monitor pavement temperatures and GPS so staff can see where and how much salt is being used. Salts totals are then uploaded into Cartegraph so staff can see how much each snow event costs.”
For both the county and city’s public works departments, the challenge last winter was the amount of time required to clear snow. According to Isakson:
“The large blizzards of last year required the crews working long hours to keep the roads open. It is more difficult to plow snow off the roads when the road ditches are full of snow since there is nowhere to put the snow. If the snow banks creep up to the road shoulders the winds can easily blow the snow into the road and block the travel lanes, which then compounds the problems.”
While local governments have seen a reduction in the levels of salt used on roads, simply reducing salt is not enough. The Minnesota Pollution Control Agency has reported that salt has been detected in several lakes, streams and rivers, Isakson notes.
“Salt in our waters is not natural and if the levels get too high, our plants and animals will be adversely affected. This salt comes from fighting snow and ice on our highways, city streets, commercial lots, sidewalks and driveways. Another source of this salt is from water softeners, he said.
"Prior to this MPCA report, there has not been a lot of talk about the adverse impacts of using salt to fight snow and ice. At some point, the public as a whole will need to make a decision concerning fighting snow and ice. Either we keep using inexpensive rock salt and deal with more salt in the lakes, streams and rivers; or we use other products that need additional equipment, employees and are a lot more expensive than salt; or we get used to driving on roads that not cleared to the level they are today.”