Temporal Variability in Groundwater Hydrochemistry Induced by Salt Water Intrusion at a Road Salt Facility

Road salt application and storage for winter maintenance has heavily affected groundwater quality in surrounding areas. Groundwater samples from 70 monitoring wells in 20 clusters were collected monthly or quarterly at a salt/storage facility from 1997 to 2008. All the samples were analyzed in the laboratory for constituents of major anions, cations and total inorganic carbon. The hydrochemical characterization of groundwater shows cation exchange induced by salt water intrusion plays a key role for groundwater hydrochemical evolution in shallow and middle water groups. Ten years observation indicates shallow well contamination was being reduced by the relative pure recharge from ground surface, whereas, middle well contamination was accumulating due to salt water percolating. Most of the deep wells were still under natural generated stage and controlled by rock weathering process. The contamination of groundwater at this glacial till drumlin is a slow process and influenced by well locations and aquifer hydraulics.