Winter weather has struck hard this year, and many people and municipalities are pouring on the road salt. According to the National Research Council, we Americans dump between 8 million to 12 million tons of salt on our roads per year. Massachusetts, New Hampshire and New York report the highest level of salt use, with New York weighing in at 500,000 tons per year. The New York State Department of Transportation requires a road-salt application rate of 225 lbs. per Lane-Mile for light snow and 270 lbs. per Lane-Mile for each application during rapidly accumulating snow.
When you consider that there are approximately 6,000 mi. of paved roadways near NY watersheds, you begin to see how all that road salt adds up. Some roads may get up to 300 tons of road salt per Lane-Mile each year. Recently, many scientists have begun to study the effects of so much road salt on ecosystems, water quality, public health and road quality. Here are a few things you should know before you break out that sodium chloride, the most commonly used deicer.
— Salt destroys soil structure by killing some soil bacteria. This allows more soil to erode into streams, taking the salt with it. Salt erosion contaminates drinking-water supplies to levels that exceed standards.
— Salt doesn't evaporate or otherwise get removed once applied, so it remains a persistent risk to aquatic ecosystems and to water quality. Approximately 55 percent of road-salt runs off with snowmelt into streams, with the remaining 45 percent infiltrating through soils and into groundwater aquifers, according to a 1993 study.
— Salt slowly kills trees, especially white pines, and other roadside plants. The loss of indigenous plants and trees on roadsides allows hardier salt-tolerant species to take over.
— Salt can change water chemistry, causing minerals to leach out of the soil, and it increases the acidity of water, according to Dr. Stephen Norton, a professor of Geological Sciences at the University of Maine.
— Elk, moose and sheep eat road salt, causing "salt toxicosis" where they lose their fear of vehicles and humans, causing many fatal encounters.
— Salt cracks animal paws, making house pets particularly susceptible.
— Road salt seeping into drinking water changes its flavor, and supplies the excess dietary sodium associated with hypertension.
— Salt corrodes metals like automobile brake linings, frames and bumpers, and can cause cosmetic corrosion. To prevent this corrosion, automakers pay almost $4 billion per year.
— Salt can penetrate concrete to corrode the reinforcing rods causing damage to bridges, roads and cracked pavement.
Canada is considering classifying conventional deicers as toxic substances under the Canadian Environmental Protection Act. California and Nevada restrict road-salt use in certain areas to reduce damage to roadside vegetation. Massachusetts is using alternative deicers to prevent contamination of drinking water. New York State is considering doing the same to protect New York City's watershed.
There are alternatives to sodium chloride that are relatively harmless to the environment and still get the job done. Calcium magnesium acetate and potassium acetate are two chloride alternatives currently available. They are much more expensive than road salt, but if you factor in the loss of wildlife, soil erosion, water quality and corrosion, these alternatives start to look like a real bargain.
Shawn Dell Joyce is an award-winning columnist and founder of the Wallkill River School in Orange County, N.Y. You can contact her at [email protected] To find out more about Shawn Dell Joyce and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com.