VARIATIONS IN ELEMENT RATIOS HELP DISTINGUISH THE EFFECTS OF DILUTION BY MIXING OF INFLUENT GROUNDWATER FROM THE ADDITION OF DEICING CHEMICALS
Throughout the main stream and tributaries, Ca/Mg ranges smoothly from 2 to 20, with the highest values occurring associated with wetlands, kettle ponds, and a perched pond with chloride concentrations higher than 2000 mg/l and close association with a deicer storage facility. In isolated forest watersheds, the Ca/Mg ratio is typically much closer to constant.
Other ion concentrations such as Na and Cl are very highly correlated with a ratio of 1.688 and correlation R2 = 0.996 over a very wide range of concentrations caused by application of road salt deicer. Sodium and chloride also correlate strongly with specific conductance because of their comparatively high concentrations and strong seasonal variation. Analysis of molar concentrations suggests that cation exchange may be affecting sodium contents.