Monday, January 10, 2022

Road salt use is enough to raise salt levels in drinking water

Via the New York Times, this interesting set of factlets (emphasis mine) 
Salt has been used to de-ice roads in the United States since the 1930s, and its use across the country has tripled in the past 50 years, Dr. Hintz said. More than 20 million metric tons of salt are poured on U.S. roads each winter, according to an estimate by the Cary Institute of Ecosystem Studies in New York, and the environmental costs are growing.

...Road salt is made from sodium chloride, the same chemical found in table salt. Of all salt consumed in the United States, about 43 percent is used for highway de-icing, according to the U.S. Geological Survey in 2020.

Ms. Kelly said the accumulation of salt in drinking water reservoirs in some places was harming people on low-sodium diets.

A 2018 study of wells in Dutchess County, N.Y., found that sodium concentration in wells reached levels as high as 860 milligrams per liter — much higher than the federal and state recommendation that levels not exceed 20 milligrams per liter for people on very low-sodium diets and 270 milligrams per liter for people on moderately restricted sodium diets.

 That's a lot of salt!


  1. Just last week after a small snow here and seeing salt on parking lots, I got to wondering where all this salt ends up.

    Interesting that there is so much salt in well water. The house I have now is the first one I've lived at with a well, and we had to have a new well drilled last year. Being a curious person, I did some looking into well construction and talked to the driller. My impression was that the liner is supposed to keep ground-level contaminants out. But, I suppose changes to well construction, depth, and local geology probably impact this (our first well, drilled in 1963, had I believe only 30 feet of liner; I think the new well has 140 feet of liner).

  2. it is also bad for cars, they rust alot faster. You can compare used car prices, using Kelly's Blue Book, and you will notice significant price difference in older models - the same make, year, mileage - between states where they use salt on the roads, and the states where they don't

  3. urea does not have this problem and works even better than salt. Except that it is more expensive, and a too good fertilizer, causes algal blooms later in the spring

    1. From a water quality perspective, urea really should not be used. I'd like to see softer anion usage, though the costs are much higher. IIRC, sodium and/or potassium acetate is used for airport runways and deicing planes as it works faster and doesn't pit concrete and blacktop like sodium chloride. I think sodium and/or potassium formates are also approved for use by the FAA but I am not sure if they are favored over the acetates.


looks like Blogger doesn't work with anonymous comments from Chrome browsers at the moment - works in Microsoft Edge, or from Chrome with a Blogger account - sorry! CJ 3/21/20