Water Contamination Caused By Road Salt Runoff
As winter turns into spring, Lake Superior faces an increasingly worrisome problem: contaminated water runoff. Snow and ice from all over Duluth, Minnesota stream into waterways, bringing chemicals and bacteria along for the ride and straight into Lake Superior. Perhaps the most troublesome chemical is potassium chloride, commonly known as salt. The more than 200,000 tons of salt used to prepare roadways for driving in Minnesota dump into the vast body of water. After years of this abuse, Lake Superior is becoming too salty. Potassium is able to dissolve in water, but chloride is too weak of a base to completely dissolve in water and causes the same effects one sees using chlorine in a pool. While chlorine is necessary for sanitizing swimming pools, the microorganisms and marine life found in Lake Superior can only tolerate low levels before dying. In fact, high levels of chloride cause water to be undrinkable and toxic. Ingesting water with toxic amounts of potassium chloride can lead to high blood pressure, dehydration, and strain on key vital organs, including kidneys and heart. A vast body of water, such as Lake Superior, will likely never be fully contaminated; however, surface areas and areas close to water runoff are already contaminated, effectively contaminating drinking water.
University of Minnesota Duluth’s Natural Resources Research Institute (NRRI) has been researching alternatives to potassium chloride as road salt and found one expensive but green alternative: potassium acetate. Potassium acetate is approximately seven times as expensive as potassium chloride, costing $75-90 per mile as opposed to $10 per mile for sodium acetate, reports MnDOT. Not only would potassium acetate not harm the environment, it would be more effective at sub zero temperatures than potassium chloride and could potentially preserve infrastructure. Most importantly, potassium acetate is not poisonous for our water systems, unlike potassium chloride. Researchers are continuing their work to establish the most efficient method of icing roads while protecting our waterways and ecosystems in Duluth, Minnesota, hopeful to cleanse our waters nationwide.