After last week's snow and current warmer temperatures melting the snow, run-off water will be pouring into local streams and rivers. The next few days will carry tons of ice-melting salt and other contaminants into our water supply. In trying to keep roads safe, the Louisville Metro Public Works Department has spread 15,000 tons of salt since last week's snowstorm. That's close to the 20,000 tons that metro road crews apply in a normal winter. High concentrations of salt are not good for the environment, but the trade-off is a need to have safe highways.
The flushing that is expect to occur in the next few days, with many inches of snow melting, also sends other contaminants such as sodium chloride, calcium chloride and potassium chloride into waterways. And those leaking fluids such as oil and gas from cars and trucks, bits of rubber from tires and soot from exhaust also contribute to storm-water pollution. The contaminants in the snow, along with salt, are bound to end up in waterways.
Regulators call this "nonpoint-source pollution" because it doesn't come from an industrial pipe or other plant discharge. But added up, along with sediment from disturbed landscapes, it's considered even more of a problem than what comes from industrial sources as stated by the Day.
The salt flush can be a particular concern because it can change water chemistry,
making it harmful to the gills of fish and other aquatic life, making breathing harder or impossible. Salt has damaged trees especially cedars. It all depends on how much dilution occurs during melting.
Indiana environmental regulators are trying to educate highway department officials and others who apply de-icing salt to minimize the amount used and the chances of salty runoff getting into surface water, said a spokesman for the Indiana Department of Environmental Management in the Day.
Different types of salts have different environmental effects.
Alternatives to sodium chloride tend to be more expensive, or they cause other problems.
Previously used (coal ash) cinders from various companies, and sand. But it was dirty, and complaints from people wanting their living room carpets replaced.
Some environmentalists also have complained that cinders are toxic.
Using sand can plug storm drains and cause air pollution problems after the snow melts.
Some communities have chosen to stop using salt because of environmental concerns.
But in those communities motorists expect to drive on snow.
People expect their streets to be treated and back to dry/black pavement directly following a snowstorm.