Springs around the Lake Wingra Watershed are highly salted and getting more so with every application of road salt and other ice melters to our highway system, according to a recent study.
As we reported in a earlier post, chloride concentrations in Wisconsin streams are high not just in the winter but all year round. Now, a 2012 study by the Friends of Lake Wingra (FOLW) of Lake Wingra watershed springs also found high springtime chloride concentrations in some of Madison’s shallow groundwater supplies.
Road Salt Monitoring Project
Chloride concentrations is select springs around Lake Wingra were measured in 2012 by Bannerman and Merrill of the Friends of Lake Wingra (FoLW) in cooperation with the Water Action Volunteers Program (WAV), sponsored by the UW Extension and the Wisconsin Department of Natural Resources.
The chloride sapling conducted by FoLW was part of the WAV’s Urban Road Salt Monitoring Project, that looked at streams throughout the state and shallow groundwater (springs) in the Madison area. (Madison area streams such as Pheasant Branch, Nine Springs Creek, and Starkweather Creek, were also sampled to measure chloride concentrations and results for these stream studies can be found here.)
Spring (Shallow Groundwater) Sampling
The Wingra Watershed findings were described by FoLW in its November, 2012 Newsletter and published in the November, 2012 paper by Bannerman, “Sources of Chloride to Lake Wingra” The WAV/FoLW report on its study of chloride concentrations in select springs (shallow groundwater) can be found by clicking here and are summarized below.
Rex Merrill and Roger Bannerman sampled a subset of springs five times each from March 8, 2012 through June 6, 2012. The springs sampled (with the spring names used in the study followed in parenthesis the springs names used in the blog) were: Cadwallader Washburn Spring; Nakoma Duck Pond (Duck Pond Springs); Wheeler Circle Springs (Council Springs); Arboretum Sand Boil (Dancing Sands Springs); and Arboretum Big Spring.
“Chloride levels at the Cadwallader Washburn Spring always exceeded the Enforcement Standard (ES= 250 mg/l) for groundwater quality, although the other springs had much lower average chloride levels, three of them had values close to the DNR’s Preventative Action Limit (PAL = 125 mg/l) for groundwater quality.” Click here for the full FoLW Newsletter story.