Numlock Sunday: Chris Ingraham on a stadium-sized pile of rock salt

Photo by kim giseok on Unsplash

By Walt Hickey

Welcome to the Numlock Sunday edition.

This week I spoke to Chris Ingraham, who is a senior reporter at the Minnesota Reformer and wrote “A year’s worth of Minnesota road salt, visualized.” Here's what I wrote about it:

Minnesota sees a lot of snow and has a lot of roads, and that combination means that the state is on the hook for a whole lot of salt. The Minnesota Pollution Control Agency estimates that 445,000 tons of salt are applied to paved surfaces every year, a massive pile of salt that would have the profile of an NFL stadium, a cone 160 feet high and 500 feet wide, if all put in a single heap. That’s got consequences beyond keeping the roads clear, as a teaspoon of salt is sufficient to pollute five gallons of water; 50 of the state’s notoriously ample lakes and streams are listed as impaired due to high levels of chloride, and 75 more are getting dangerously close.

We spoke about the sheer volume of salt that goes onto roads, what…