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• We took 18, four inch core samples around Edgewood College campus (see map). |
Soil Pollution:
Sodium Chloride
Concentration in the Soil
on Edgewood College's
Campus
by:
George Sapon
Nate Zellner
• Over the last few decades, road salt has been used in the maintenance of Madison’s streets, highways, sidewalks, and driveways.
• The large amount of road salt used has accumulated in the ground and has raised the amount of chloride within the soil. Has the amount of road salt reached harmful levels for our environment?
• Has Edgewood College’s campus been victim of excessive amounts of road salt?
• The soil located farther away from parking lots, streets, and sidewalks will have less of a chloride concentration than that of soil in near proximity of parking lots, streets, and sidewalks.
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• We took 18, four inch core samples around Edgewood College campus (see map). |
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• We submerged each soil sample in 1,000mL, stirred, and used a hand held probe to test conductivity in uS/g. |
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• For the second set of samples we used the HACH chloride test to find mg/L of chloride. |
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| • Soil samples by Monroe Street and
the Mazzuchelli rain garden showed unusually high conductivity.
• The soil sample taken by the natural spring shows a relatively high conductivity within all four inches of the core sample. • Samples taken in a fully “encurbed” grass area, such as the Dericci parking lot and parking garage, had a relatively low conductivity. • Though supposedly isolated from possible salt contamination, we have concluded that the rain garden contained high conductivity because of people shoveling snow on to it. |
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| • The Edgedome prairie runoff entrance was
excessively high in both conductivity and chloride.
• Conductivity is a measure of all ions within the soil. There is strong correlation between conductivity and chloride of the sample taken from the Edgedome prairie runoff entrance. |
Implications & Recommendations
• Research indicates that most of the vegetation damage is due to chloride ions rather than sodium ions.
• Harmful effects on vegetation include browning and falling leaves, stem dieback, stunted or abnormal growth, or premature death.
• Some of the effects are obvious because there is no vegetation growing where salt is excessive (picture of Edgedome prairie runoff entrance).
• We recommend cutting road salt use dramatically and using a sand/salt mixture of 20:1.
John Hausbeck, City of Madison Road Salt Report
Department of Natural Science, Edgewood College
Jim Lorman, Edgewood College Professor
Tricia Mangold, Road Salt Use for Winter Maintenance