Because of low purchase price and ready accessibility, road salt (sodium chloride) is the most commonly used de-icing chemical, and its use on highways has increased steadily since the 1940s. New York State is the largest user of road salt in North America, and the amount of road salt used in the Adirondack Park greatly exceeds the inputs of other regionally important pollutants like acid deposition. Yet, despite this higher input we know comparatively little about the effects of road salt on Adirondack ecosystems. Road salt has the potential for significant negative effects on forest and aquatic ecosystems that may be on par with or greater than those reported for other regional pollutants. Much research has been done on road salt, and its general effects on forest, soil, and water resources are well documented, but questions remain on the significance of road salt compared to other pollutants, and additionally little research has been done that can be used directly by agencies and municipalities to improve winter road management practices to reduce the environmental impacts of road salting.
The objectives of this work are to understand the effects of road salt application rates (tons of salt per km of road) on soil fertility and water quality and to develop practical information to aid agencies and municipalities in selecting management practices that reduce the impacts of road salt on forest and water resources.
Water quality is being monitored intensively on a network of 15 streams in the Adirondack Park representing a broad range of road salt application rates. The data is being used to develop relationships between road salt application rate and water quality response that managers can then use to help choose and justify alternative road salt application rates to meet water quality objectives. Results are being communicated at meetings, and will be comunicated in journal articles and in a special forum devoted to winter road management. Though the focal region is the Adirondacks, because road salt is widely applied across the Northern Forest region and Adirondack soils and geology are similar to others in the region, the results will be widely applicable.
Funding for this project is provided by AdkAction.org, the Lake Champlain Basin Program, and the North Eastern States Research Cooperative. Note, this project was a follow on to a study we conducted with lake data that showed increased cation loss from watersheds with road salting (see promotion).