Somewhat lost in all the hype about the heavy snows and frigid temperatures much of the country has had this winter, and the frustration with a pothole epidemic and treacherous roads and sidewalks, is that we may be applying record amounts of road deicing chemicals, primarily salt (NaCl). A couple of recent articles in the New York Times highlighted how much salt we’ve been using. From an article on February 16, 2014, it was reported that Chicago has already spent $25 million for plowing and salting, $5 million more than budgeted. That’s with half of February and all of March still to come; in a typical March, Chicago gets about 7 inches of snow. Other data from that article: Pennsylvania is using road salt at a pace 24% ahead of normal, and Maine has already spent almost 40% more than they do in a normal year.
New Jersey is also suffering. In a February 19 story, it was reported that the state is almost out of road salt, and is having difficulty getting new shipments from Maine due to some government bureaucracy snafu. As of February 11, New Jersey had used 373,000 tons of salt, compared to the 258,000 tons they used in all of 2012-2013. I’m not sure, but I think those figures may only refer to roads salted by the state DOT, and might not include county and municipal road salting. It almost certainly doesn’t include parking lots.
During a snowy winter, there is great public pressure to keep the roads cleared and safe. We don’t think about how all that salt is going to end up in our water bodies. The water operator in Aurora, IL, reported that after a rain event in January, the water they were withdrawing from the Fox River, their primary source of drinking water, was saltier than they had ever measured. We’ll have a big slug of salt coming down our streams and rivers this winter and spring, and a lot will also recharge our shallow aquifers.
Here's a link to a 5-minute "lightning talk" I gave last year on the increasing salinization of our water resources due to road salt runoff: http://youtu.be/JUt4J1z3VgI
