The Impact of Road Salt on Water Quality in the Adirondacks
What is Road Salt?
Road salt is the same substance as table salt, but it is left in large crystals rather than being pulverized into a powder that can fit through the holes of a shaker. These large crystals act as grit to improve automobile traction on frozen surfaces, and above 10 degrees Fahrenheit, salt melts ice and snow to expose clear pavement. On average, state snowplow drivers drop 37 tons of road salt per lane-mile per year on state highways in the Adirondacks. More than six million tons have been applied to the Park’s roads since road salt was first used in 1980.
Hidden Dangers: Road Salt in Adirondack Waters
Road salt does not evaporate or disappear; it remains on the road until it dissolves or is physically removed. Dissolved salt drains into nearby water or seeps into the soil, where it can reach aquifers (subsurface water supplies). Studies in the Adirondack Park have found that salt loadings have had significant impacts on lakes and ponds, as well as drinking water wells near treated roadways, resulting in adverse impacts to human and ecosystem health, including:
- Toxic Soils: Trees near roadways where salt is frequently used can exhibit leaf burn, the browning of needles or leaves.
- Water Quality: Slow-moving streams, ponds, or lakes with only seasonal outflow can be particularly affected by salt runoff. As the level of salt increases, the density of the water also increases. This can disrupt natural annual mixing cycles during which the surface water and its abundance of oxygen are transferred to deeper portions of lakes. When this cycle and exchange of oxygen is disrupted, oxygen is decreased, and aquatic plants and animals struggle to survive.
- Drinking Water: The Adirondack Watershed Institute and partners have tested over 500 private drinking wells in the Adirondack Park. Sodium levels in more than half of the wells that receive state road runoff were found to exceed New York State’s water quality guidelines.
- Air Pollution: Road salt dramatically increases particulate air pollution.
Low Sodium Diet: Reducing the Use of Road Salt while Maintaining Road Safety
For more than 25 years, the Adirondack Council has been working to raise awareness of the damage road salt can cause and to advance solutions. The Council worked with members of the NY Legislature in the 1990s to raise awareness of road salt corrosion and ecosystem damage. In 2009, the Council published Low Sodium Diet, an analysis of winter road maintenance practices, negative impacts of salt pollution, and recommendations for road salt reduction and alternatives. Over the next decade, the Council partnered with AdkAction to host the three road salt reduction conferences at Paul Smith’s College and worked with partners to help the state pilot road salt reduction methods.
In 2019, the Adirondack Council partnered with elected officials, AdkAction, the Adirondack Watershed Institute, the Ausable River Association, the Lake George Association, and partners from local municipalities to draft and advance the Randy Preston Road Salt Reduction Act, which established the Adirondack Road Salt Reduction Task Force and the parameters of its work. The bill was signed into law in late 2020.
The Adirondack Council continues to push for comprehensive solutions, including the establishment of a blue-ribbon commission to set enforceable goals via a Park-wide road salt management program.
