FUTURE DIRECTIONS OF RESEARCH ON ROAD SALT CONTAMINATION IN AQUATIC SYSTEMS

During the past several decades, the observed ever increasing concentrations of road salt contamination in the drinking water supplies, streams, ponds, and lakes creates urgent concerns about the future state of water quality, its impact on the environment, human health, and the health of aquatic life. In many areas, the continuing rate of chloride buildup is estimated between 1 and 6 ppm of Cl per year. When projecting these rates of increasing concentrations into the near future most water supply aquifers in the regions where road salt is applied as the winter de-icing chemical will become contaminated above the SMCL for Cl within 5 to 20 years.

Future research on the extent of road salt contamination must include studies on road salt retention within the aquifers, understanding of pathways of mild electrolyte solutions in the subsurface, deeper aquifer pathways of these solutions, hydraulic conductivities of mild electrolytes, mechanism of electrolyte percolation in a variable density water column and its dependence on electrolyte composition and temperature. We will present several critical (preliminary) findings based on field aquifer studies at several locations in the eastern part of Massachusetts where significant road salt contamination may lead to severe problems in the near future.