To Salt or Not to Salt?

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Created on Thursday, 01 May 2014 12:24
Written by Meaghan Meachem

saltstoryWritten by Student Meteorologist Curt Olson

AROUND THE NEK - With the harsh winter the Northeast Kingdom experienced this year, road crews were forced to dump upwards of 22,000 tons of road salt onto Kingdom roadways. But now with warmer temperatures and the snow melt, what happens to that extra salt left over on the roads?



Most of the salt running off into drainage finds its way into local streams and rivers. As the salt mixes with the water it breaks up into sodium and chloride ions. Sodium is harmless to the environment, but the chloride is a major concern as high levels in water can hurt local ecosystems and kill marine life. For humans, drinking water with high levels of chloride can cause damage to internal organs. But why use a product that can potentially put us at risk?

The Vermont Agency of Transportation (Vtrans) says they use salt rather than sand because it is more effective. Sand has a higher maintenance cost because it clogs up drains and builds up on road shoulders requiring crews to remove it. Vtrans only puts down a small amount of salt at a time so as the salt breaks down only a small amount of chloride goes into streams and rivers
According to Ben Copans, the watershed coordinator in St. Johnsbury, chloride levels in local streams and rivers have been increasing without the help of road salt. The Watershed Management team runs water quality tests to look for damaging levels of chloride through a process called macro invertebrate sampling. Nets are used to catch bugs that are unable to survive in certain levels of chloride. The number and type of bugs caught is then compared to what is usually found to determine how much chloride is in the water. According to Mr. Copans, road salt is more likely to impact local rivers that are near more developed areas. Copans said, "the NEK will need to use a lot more road salt in order to impact the environment around here."

Long term effects for rivers and streams with high levels of chloride include a decrease in aquatic life. This includes plants and fish, along with posing a threat to any wildlife that may drink from the water source. Eventually chloride levels in streams and rivers will return back to safe levels as chloride free water from river heads make their way into the streams and rivers.

For now it is best to stay out of rivers and streams as this is the time when chloride levels are the highest. Most people will choose to stay out of the water as water temperatures are just above freezing.