Title
Road deicing and Groundwater Chemistry in Water Management Areas 03 & 04, New Jersey
Presentation Type
Event
Start Date
27-4-2019 8:45 AM
End Date
27-4-2019 9:24 AM
Abstract
Multivariate, time series, and regression analyses of major ion concentrations were performed on a decadal basis for field data of the 1960s, 1980s, 1990s, 2000s, and 2010s to determine if there is a statistically significant increase in calcium, chloride, and sodium relative to other major groundwater ions in New Jersey’s Water Management Areas 03 (Middle Passiac River Basin, MPRB) and 04 (Lower Passaic River Basin, LPRB). For the MPRB, sodium and chloride levels were found to be increasing at different rates. There was no significant correlation between chloride and sodium, or between chloride and total dissolved solids. The groundwater facies showed little to no change through time. Sodium and chloride showed only slight to moderate increases from the 1960s to 2010s in the groundwater. Groundwater in the MPRB is relatively free of road deicing salts, probably due to the combination of low deicing application and the occurrence of the low-permeability bedrock of basalts, gneisses, and granites.
Comparatively, sodium, chloride, and calcium concentrations increased at substantially greater rates in the LPRB. Plots of sodium versus chloride, and calcium versus chloride showed strong correlations, suggesting an observable relationship between the ions individually produced by the applied deicing salts (NaCl and CaCl2). Additionally, calcium showed no correlation with sodium, suggesting the lack of an intermolecular relationship between the two deicing agents. These observations indicate that road deicing application in the LPRB has contaminated the underlying groundwater. The high urbanization, high road density, and the permeable bedrock are considered to be responsible for the contamination.
Road deicing and Groundwater Chemistry in Water Management Areas 03 & 04, New Jersey
Multivariate, time series, and regression analyses of major ion concentrations were performed on a decadal basis for field data of the 1960s, 1980s, 1990s, 2000s, and 2010s to determine if there is a statistically significant increase in calcium, chloride, and sodium relative to other major groundwater ions in New Jersey’s Water Management Areas 03 (Middle Passiac River Basin, MPRB) and 04 (Lower Passaic River Basin, LPRB). For the MPRB, sodium and chloride levels were found to be increasing at different rates. There was no significant correlation between chloride and sodium, or between chloride and total dissolved solids. The groundwater facies showed little to no change through time. Sodium and chloride showed only slight to moderate increases from the 1960s to 2010s in the groundwater. Groundwater in the MPRB is relatively free of road deicing salts, probably due to the combination of low deicing application and the occurrence of the low-permeability bedrock of basalts, gneisses, and granites.
Comparatively, sodium, chloride, and calcium concentrations increased at substantially greater rates in the LPRB. Plots of sodium versus chloride, and calcium versus chloride showed strong correlations, suggesting an observable relationship between the ions individually produced by the applied deicing salts (NaCl and CaCl2). Additionally, calcium showed no correlation with sodium, suggesting the lack of an intermolecular relationship between the two deicing agents. These observations indicate that road deicing application in the LPRB has contaminated the underlying groundwater. The high urbanization, high road density, and the permeable bedrock are considered to be responsible for the contamination.