While you’re excavating your sidewalk from beneath a foot-deep slab of snow, take it easy on the de-icer and rock salt.
First, de-icers can contain a variety of salt compounds, which can be harmful and/or corrosive to plants and pets. Second, when the glacier on your driveway melts, the water can whisk those salts into the street, the storm drain and directly into streams, creeks and even groundwater. Depending on where you live, these are potentially sources of drinking water.
The EPA suggests sodium in drinking water is safe up to 20 parts per million. But a 2008 study in Duchess County, N.Y., (which receives a lot more snow, and thus uses more salt), showed that on average, the drinking water wells contained twice that amount. The Cary Institute of Ecosystem Studies issued a report in December 2010 that gives a fuller explanation of the problem, including the fact that in rural and particularly snowy areas, (e.g. the Carolina mountains), it can take years for the salts — which can be toxic and corrosive to aquatic life — to flush out of the environment.
If you need another reason to be suspicious of fracking in North Carolina, Scientific American reported in 2015 that states which have oil and gas drilling often use the salts from those operations in their road brine. The chemical soup then flows off the roadways and can enter water supplies. Imagine if these types of salts were used on roads near coastal waters, estuaries and sounds — as well as North Carolina’s many lakes. For example, US Highway 64 runs over Jordan Lake; Highway 50 over Falls Lake, and Highway 150/I-77 over Lake Norman.
The takeaway: Falling on the ice is a good way to pull up lame, so safety is paramount. However, don’t use more de-icer than you need, and if possible, let the sun work its magic.