The road salt (usually sodium chloride) applied on our streets, sidewalks, and driveways to make winter driving and walking easier, does not just disappear once the storm is over. It mixes with melt water or rainfall and washes down the storm drain where it ends up in Madison lakes, the groundwater, and eventually our drinking water wells.
The Friends of Lake Wingra (FoLW) and many others have, for years, been advocating for reduced road salt use because of its likely impacts on our lakes. Now comes another piece of evidence in the road salt discussion. According to a new report, one result of over 50 years of road salt use by the City of Madison, is a continual rise in chloride levels in our watershed and lakes. This finding from the 2012 Road Salt Report prepared by Environmental Protection Lead Worker from the Department of Public Health for Madison and Dane County, Rick Wenta, and his colleague Kirsti Sorsa, the environmental technical services supervisor.
This fact plus a thorough discussion of road salt use practices and procedures in Madison and the implications for environmental and public health, are reported by Yilang Peng, a writer for Madison Commons in a piece entitled “Road Salt Lingers in Madison’s Watersheds and Drinking Water.”
Among the key points reported in Peng’s story and based upon the 2012 Road Salt Report, are these:
- Road salt use began in Madison in 1959.
- “The total road salt use (in Madison) reached 7,716 tons in the 2011-2012 winter, double the volume used in the winter of 1982. It peaked at 17,993 tons in the winter of 2007-2008, a particularly snowy season.”
- “In 2012, average chloride level in Lake Wingra reached 115 mg/L, a 130 percent increase over the preceding three decades. Chloride in other Yahara Lakes – Monona, Mendota, Kegonsa, Waubesa – is accumulating at a higher rate, though the current levels are much lower than Lake Wingra’s concentration,”