Wintertime in much of America is characterized by snowstorms, freezing temperatures, and hazardous driving conditions. As a result, many municipalities use salt, which lowers the freezing point of water, to deice roads and make them safer for motorists.
Salt is the country’s most popular deicing agent because it is inexpensive and there is an abundant natural supply. In fact, so many communities salt their roadways that this practice uses about 10 times the amount of salt used in the country’s food production process. Some estimates put the annual amount of road salt at about 22 million tons, or roughly 137 pounds per person.
Unfortunately, all this salt has an effect on the environment long after the snow melts. Road salt dissolves, and its components, chloride and sodium, are carried away by runoff and ultimately end up in rivers, lakes, and streams. They can even contaminate the drinking water supply.
While salt may seem harmless, many communities recognize that it has a negative effect on the environment. For example, Canada classified road salt as an environmental toxin in 2004, leading it to adopt alternative dicing methods. The United States is also beginning to choose alternatives, but there is no legislation yet regarding this issue.
This article will explore the environmental risks of road salt as well as effective salt alternatives.
Environmental Impact of Road Salt
Most people know that road salt wreaks havoc on cars, causing rust and degrading roadways to the point that they are riddled with potholes. However, salt runoff also adversely impacts water, soil, and plants.
Salt-contaminated runoff is responsible for increased concentrations of both sodium and chloride in numerous bodies of water. In fact, a study conducted in a New York stream from 1986 to 2005 indicated that road salt was to blame for 91 percent of the sodium chloride in the local watershed. These elevated salt levels can adversely affect water circulation because salt impacts the density of water and keeps oxygen near the surface, which can be detrimental to aquatic life that resides in deeper waters. It’s estimated that approximately 40 percent of urban streams in America have higher-than-safe levels of chloride and pose a real danger to wildlife.
The dehydrating effects of road salt have been shown to kill plants and trees. Even more worrisome, the Department of Environmental Conservation in New York reports that road salt has the ability to damage plants up to 650 feet away from a road.
Road Salt Alternatives
Despite the abundant supply of road salt, some municipalities are searching for alternative deicers in an attempt to reduce the use of salt and combat its effects on the environment. Some of these alternatives are more effective than others, yet they all represent a positive step towards reducing environmental hazards.
One road salt alternative that is gaining popularity in some metropolitan areas is beet juice. When mixed with salt, this substance effectively melts snow and ice at lower temperatures than is possible with salt alone, thus reducing the amount of salt needed to deice roads. Additionally, beet juice reduces corrosion of road surfaces and cars because it is less acidic than salt.
In Wisconsin, some communities have been experimenting with adding cheese brine to salt as an alternative to pure road salt. Cheese brine helps salt adhere better to the roads, which in turn melts the ice faster. A study conducted by Wisconsin’s Polk County Highway Department reported that use of cheese brine reduced salt usage by 30 to 40 percent.
Another salt alternative, calcium magnesium acetate, is being studied by Dutch University researchers as a possible alternative to road salt. This deicer is harvested from organic waste like grass and household compost materials. Though it looks promising, it cannot be considered a cost-effective alternative just yet due to the difficulty in removing the acetate from the organic waste.
Many areas have discovered that pretreating the roads ahead of a storm is a better strategy than spraying salt on top of existing snow and ice. By doing so, it’s possible to limit snow and ice buildup and reduce salt use, thereby making post-storm clean up easier. Other municipalities have experimented with mixing road salt with water and sand or gravel for easier spreadability and improved traction.
With so many alternatives to road salt available, every community should be able to find a way to reduce its use of salt. Some research has also indicated that better road maintenance could help reduce our dependence on road salt. Regardless of the method used, it is worth it to consider safer deicing alternatives.