Whether on snowy and icy Minnesota roadways or in the water softener in your home, salt use is common in daily life. Two University of Minnesota experts are available to discuss the lasting effects of salt use on natural resources and simple ways to be smarter with salt.
Andy Erickson, a scholar with the Center for Transportation Studies and research manager at the St. Anthony Falls Laboratory, discusses the impact of road salt and new and improved options for de-icing.
Sara Heger, a researcher and instructor in the Water Resources Center and an adjunct assistant professor in the Department of Bioproducts and Biosystems Engineering, discusses the often-overlooked water softeners — another significant contributor to salt in our waterways.
Andy Erickson, Ph.D., P.E.
“We started putting salt on roads to melt snow and ice in Minnesota in the 1950s, and the concentration of salt in our lakes and groundwater has increased significantly ever since. This has affected the diversity of plants and animals in our lakes, streams and rivers. Some local drinking water wells have begun to taste salty, forcing communities to dig deeper wells and our water utilities to increase treatment at a substantial cost.
To reduce this impact, Minnesota has implemented Smart Salting training for road salt applicators and source reduction training for cities. The state also funded research into road salt alternatives, including use of less harmful chemicals, pavement technologies that don’t require road salt, and improved plowing and snow removal techniques that require less ‘anti-icing’ chemicals.
Some of the biggest remaining contributors to the road salt problem are private applicators, and residents and property owners who salt parking lots, driveways, and sidewalks. These areas are often drastically over-salted to prevent slips and falls, and research shows that too much salt can be just as dangerous for slips and falls as the ice it’s trying to melt. There are many resources to learn how to properly apply the right amount of salt for safe passage of cars and people, including the Statewide chloride resources.”
Sara Heger, Ph.D.
“Much of Minnesota has hard water, characterized by high calcium and magnesium concentrations. Water softeners are commonly used to remove these minerals, providing benefits like improved lather and reduced staining on washed dishes and clothing. Most household water softeners are ion exchange softeners that use sodium chloride salt to remove hardness. This sodium chloride is eventually discharged to wastewater treatment plants or septic systems where it can reach ground or surface waters. Data shows chloride levels in some surface waters are increasing and pose an emerging environmental concern for aquatic life.
Road salt is the primary contributor in many cases, but approximately 100 wastewater treatment plants that discharge to surface waters have elevated levels of chloride and are negatively impacting water quality. Our work shows that water softeners are the largest source to these wastewater treatment plants.
Homeowners can make a difference by using less salt to soften their water. This can be done by replacing timer-initiated softeners, which waste salt as they regenerate whether it is needed or not. Newer, efficient models can be installed that utilize demand-initiated regeneration based on the amount of water used. Other options to reduce salt usage include checking if your softener is set appropriately for the water hardness and usage, only softening the hot water within the home, and considering more efficient systems or non-salt based alternatives. You can find more information on water softening from the U of M’s Water Resources Center.”
Sara Heger, Ph.D. is a researcher and instructor in the Onsite Sewage Treatment Program in the Water Resources Center, a scholar for the Center for Transportation Studies, and an adjunct assistant professor in the Bioproducts and Biosystems Engineering department. Her areas of expertise include decentralized wastewater, septic systems, water softeners, chloride management and milk house wastewater.
Andy Erickson, Ph.D., PE, is a Research Manager at St. Anthony Falls Laboratory, a scholar for the Center for Transportation Studies, and a registered professional engineer in Minnesota. Erickson's research pursues an understanding of water quality in urban and agricultural watersheds, assessment and maintenance of stormwater treatment practices and developing new stormwater treatment technologies such as the Iron-Enhanced Sand Filter.
About the Center for Transportation Studies
The Center for Transportation Studies at the University of Minnesota is a national leader in transportation research, engagement and education. CTS collaborates with public-sector, industry and academic partners to shape transportation systems that are sustainable, serve the needs of all users, support a strong economy and improve our collective quality of life. Learn more at cts.umn.edu.
About the Water Resources Center
The University of Minnesota’s Water Resources Center provides leadership in freshwater management through cutting-edge research, educational opportunities for students and professionals, and community outreach. Authorized by Congress as one of the nation’s 54 water resources research institutes, the WRC also connects the research expertise at the University to research problems at the national level. The Water Resources Center is a unit of the College of Food, Agricultural and Natural Resource Sciences and University of Minnesota Extension.
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This story was originally shared on UMN News