Public Works Overview of Winter Salt Usage

Our Equipment The City of Mankato's Public Works Department plows 432 lane miles and uses an average of 2,400 tons of salt annually. During a normal snow event the City of Mankato utilizes the following pieces of equipment: 16 plow trucks – ten are set up with Force America 5100’s with temperature compensation systems and two have Force 1500s. Four loaders, one grader, Two 1 ton trucks with plows, three sidewalk and bike path plows and two 1400 gallon brine trucks for pre-treating.

Our System The City’s use of temperature compensation systems (T-Comp) take the guesswork out of knowing how much salt to put down. It computes the minimal amount of salt needed to melt the maximum amount of snow and ice by calculating the road temperature and the air temperature along with the speed of the truck.

Application Process Annually, the City of Mankato’s snow fighting crew prepares for the season by calibrating all equipment to be confident of how many lbs/lane mile of salt and gallons/ton of salt brine are being applied at any given time. Applications range from 90 – 540 lbs/lane mile of salt and pre-wet,at 7 – 10 gallons per ton of brine, depending upon the storm event, pavement surface temperatures along with other factors. Examples: at 30 degrees we use approximately 120 lbs/lane mile at 0 degrees we use approximately 540 lbs/lane mile

What is Brine? Since 2001, prior to each snow event, if surface temps allow, we pre-treat many of our hills, concrete surfaces, sharp corners, bridges, major routes, and other areas to minimize the snow and ice from bonding to the pavement surfaces, reducing the amount of granular salt required to treat after plowing. We partner with MnDot in making the brine, as they have a state-of-the-art machine to create the brine from actual road salt. Road salt is added to the system in a dry form then water is filtered through it to dissolve the salt and create a liquid solution called brine.

Brine Application We apply our brine when pre-treating at around 40 gallons/lane mile. We average approximately 41,000 gallons per year in pre-treating. When temperatures are between degrees and falling, we cannot apply brine to the road surface because it will freeze.

Snow Plowing Along with the use of the 5100’s our entire snow fighting work force has been trained for the proper timing and amounts of chemicals to place during any given storm event by participating in MNDOT Snow and Ice Control Training and internally we have on-going pre and post storm briefings. Each year on Snow Day, all snow plow operators meet and review procedures, drive plow areas and look for any hazards and new streets that have been added.

Training Each fall, the City of Mankato sends up to 12 employees to the MN Fall Maintenance Expo to compete in the Snow Rodeo and to obtain new ideas and better ways of setting up our equipment for future snow events. Fall Maintenance Expo October 8-9, 2014