SPRINGFIELD, Mo. — With these winter weather conditions, salt is one of the first things people think to buy and pour on sidewalks, driveways, and entranceways. The City of Springfield and MoDOT also use salt, among other products, on roadways. But salt can be a concern for the environment if used in large quantities as it eventually makes its way into waterways.
Sarah Davis, the stormwater specialist with the City of Springfield Environmental Services, says salt increases conductivity in local streams. Conductivity, she explains, refers to the amount of dissolved materials within the water. High salt levels in streams can accumulate over time and disturb the life cycles of macroinvertebrates, the little bugs that make up the base of the aquatic food web.
But Davis says this is not a huge concern in Springfield, since our winters in this area are not too severe. In northern communities that receive much more snow and ice, cities have to apply much more salt to roadways each winter. However, she says the city recognizes it’s still a concern and takes steps to minimize the impact of the salt application on local streams, including using liquid calcium chloride, which helps minimize salt scatter.
Davis says the city uses a combination of rock salt and liquid calcium chloride for de-icing. Beet juice is also used to minimize clumping of the material. The liquid calcium chloride helps shorten the reaction time of the rock salt and provides melting at lower temperatures. It also decreases the “bounce and scatters” effect when salt hits the road, which keeps more salt on the road and out of roadside ditches.
Davis says the city waits until the snow is falling to start applying salt. This keeps salt from immediately washing into our streams if it’s just raining.
In the 1990s, the Springfield was using the nationally recommended rate of 500 pounds of rock salt per lane per mile, but based on research done at this time, it was determined that an effective level of ice and snow removal for public safety could be provided using a rate of 300 pounds per lane mile. The city says it continues to experiment with alternative products to minimize pollution.
What can you do at home?
Our best advice is to follow the directions on the bag when applying salt and don’t over-apply. More doesn’t always mean better!
You can also use sand or kitty litter for traction.