Canadian Consulting Engineer
Road construction and de-icers threaten North American fresh waterEngineering
A report published by the U.S. National Academy of Sciences has suggested that surface waters in the northeastern U...
A report published by the U.S. National Academy of Sciences has suggested that surface waters in the northeastern United States could become so salty as a result of roadway treatments, they may be toxic to freshwater life before the end of the century.
They found streams in Maryland, New Hampshire and New York that were 25% as salty as seawater during the winter. They blame road de-icing and increasing impervious surfaces in suburban and urban watersheds.
Authors of the report was a team of scientists from various U.S. academic and environmental centres, led by Sujay S. Kaushal of the Institute of Ecosystem Studies in Millbrook, New York. Their findings were published in the Proceedings of the National Academy of Sciences of the United States of America on September 20, Vol. 102.
Their summary reads: “Chloride concentrations as a result of deicer are increasing at a rate that threatens the availability of fresh water in the northeastern United States. Increases in roadways and deicer use are now salinizing fresh waters, degrading habitat for aquatic organisms, and impacting large supplies of drinking water for humans throughout the region. We observed chloride concentrations of up to 25% of the concentration of seawater in streams of Maryland, New York, and New Hampshire during winters, and chloride concentrations remaining up to 100 times greater than unimpacted forest streams during summers. Mean annual chloride concentration increased as a function of impervious surface and exceeded tolerance for freshwater life in suburban and urban watersheds. Our analysis shows that if salinity were to continue to increase at its present rate due to changes in impervious surface coverage and current management practices, many surface waters in the northeastern United States would not be potable for human consumption and would become toxic to freshwater life within the next century.”