Mayo puts campus on low salt diet
Talking about winter precipitation this early in the season can make people a little salty.
Last winter was the snowiest on record in Rochester. Despite that, Mayo Clinic used 60 percent less salt to de-ice its campus paved surfaces than was used the previous winter.
That’s not a small task under a regular burden. Mayo grounds maintenance crews are responsible for 15 miles of sidewalks, more than 300 doorways, more than 800 outdoor steps and about 120 acres of parking lots and roadways.
Salt is still the cheapest and most efficient way to melt ice from paved surfaces. However, its widespread use hurts the environment. Salty water threatens freshwater fish and other aquatic species. Chloride, from road salt runoff and other sources, is building up in Minnesota waters.
A teaspoon of salt will permanently make 5 gallons of water toxic to aquatic plants and animals. According to the Minnesota Pollution Control Agency, 21 Minnesota lakes, 21 streams and four wetlands have unacceptable chloride levels.
As MPCA and the Minnesota Department of Transportation try to balance road safety with environmental concerns, Mayo’s grounds maintenance crews’ efforts got both entities’ attention.
It also garnered Nick Queensland, Mayo grounds maintenance supervisor, and the grounds maintenance crews a 2019 environmental leadership award from the Fresh Water Society in Minnesota.
Queensland gave a presentation to state officials at the Fresh Water Society's fall road salt symposium .
Queensland explained how calibrating spreaders on wide surfaces, creating a low-salt brine liquid solution and being judicious about where salt is spread cut back usage. He took an MPCA course on smart salting and began applying tactics he learned from that. Although there isn’t one single tactic that led to the overall reduction in salt use, an overall strategy to apply salt where and when needed and keeping the amount used to a minimum reduced salt use by 60 percent from the previous winter and 72 percent less than used the year before that.
Those little changes make a big difference on a large campus.
That means little changes from many people can also make a big difference. Reducing use of salt, timing use of it and using it only where needed in minimal amounts is something everyone can do. For businesses that want to learn larger scale strategies, the MPCA offers three levels of smart salt training .
However, the MPCA doesn’t presume to have all the answers and strategies for maintaining safe walkways and roadways while reducing salt use. If you have found ways to reduce use and want to share them, MPCA water pollution prevention coordinator Brooke Asleson is all ears. She can be reached at: Brooke.Asleson@state.mn.us.