The United State’s Geological Survey recently released yet another study, this one focusing on the salinity of streams. The study concerned hundreds of streams which were tested to determine if they were above federal standards in terms of salinity. The study found that a large percentage of streams across the country are excessively salty due to the salting of roads in the winter.
The study used data from twenty different states, including: Alaska, Washington, Nebraska, Iowa, Illinois, North Dakota, Pennsylvania, Ohio, Wisconsin, Rhode Island, Vermont, New Jersey, New York, Connecticut, Maine, Massachusetts, Minnesota, New Hampshire, Indiana and Michigan. The data included 1,329 wells and 100 surface water basins.
The federal standards in question are in place in order to assure the protection of aquatic life. Above certain levels, aquatic life is drastically impacted by salinity. Insects are often the first species impacted by the salinity, which then works its way up the food chain impacting other species. In addition, the salinity can harm plant growth, impact reproduction and even harm the diversity in the waterway in question.
Over forty percent of all streams tested were above the federal standard levels. Not surprisingly, the highest concentrations of chloride, a component of salt, was found during the winter when road deicer is prevalent. During these winter months, some of the streams tested were twenty times the federal standards.
Groundwater showed little impact from the salt being used on roadways. Drinking water samples were generally acceptable as well as only two percent had high salinity levels. Overall, the salinity of the waters tested were greater in urban areas versus rural areas tested.
Road deicing is not the only cause of the increased salinity, however it is considered the main culprit. Other things impacting the salinity of waterways include: septic systems, water softeners, farms, salt leaching from landfills and wastewater treatment plants.