May Willison ’23 Studies Geochemical Properties of Springs
May Willison ’23 is a Geology major working with thesis advisor Sue Swanson. She studies the geochemical properties of springs and their importance to spring dwelling organisms.
My thesis focuses on the concentration and distribution of common pollutants across the discharging area of Cadiz Spring, Monroe, Wisconsin. Two common pollutants in Wisconsin are nitrates and chlorides. One source of nitrate pollution is fertilizers applied to agricultural lands. Sometimes this leads to nitrogen-rich runoff entering surface water or excess nitrate can leach through soil and enter groundwater. Chloride pollution often comes from the use of road salts. When road salt melts, chloride-rich runoff can also enter surface water or infiltrate to groundwater. Excess nitrate and chloride in an ecosystem can lead to a decrease in biodiversity and an increase in invasive, non-native species.
I aim to study how common pollutants vary in concentration across the discharging area of Cadiz Spring. This information will be helpful in determining how many samples are necessary to adequately describe the geochemistry of a spring, as well as in determining the overall health of the spring ecosystem. Cadiz Spring is a seepage-filtration spring in which water bubbles through sediment and collects in pools along a stream. The discharging area of Cadiz Spring is approximately 6 m by 6 m. It is an ideal location for this research because detailed geochemical data for the spring do not exist. In June of 2022, I collected water samples and water depth, temperature, specific conductance, and pH measurements from over 200 positions in the spring. The water samples were then tested for nitrate and chloride concentrations. I will be using ArcGIS and spatial analysis to map and characterize the distribution of nitrate and chloride across the spring pool.