ENSIA:
“A recent study of 371 lakes in North America — most in the northern states and southern Canada — showed chloride concentrations rising in more than a third. More than two dozen were nudging toward levels harmful to aquatic life. Extrapolated to all lakes in the U.S. northern Great Lakes and Northeast regions, about “7,770 lakes may be experiencing elevated chloride concentrations, likely due to road salt runoff,” the study concludes.
U.S. road maintenance departments have been spreading salt on streets and highways to melt snow and ice since the 1940s, but the use of salt skyrocketed over time — from 0.15 metric tons (0.16 tons) per year during the 1940s to about 18 million metric tons (19.8 million tons) per year today. Road salt use is common and growing throughout Canada, Europe, Japan, China and even South America. As much as 60 million metric tons (66 million tons) may be applied worldwide each year. Unlike chemicals that break down into less harmful compounds, road salt persists and may remain in water and soil for years, until it eventually is diluted and carried away by moving water...
...the biggest single change to use less salt is switching to liquid solutions. The brine spreads more evenly, stays put and begins working immediately because the salt is already in solution. As a result, spraying liquid brine is more effective while using less salt.”
