Viewpoint: Hold the salt, pleaseThere’s been a lot of talk in the press lately about the salt we use to keep our roads and parking lots safe in the winter.
By: Angie Hong, South Washington County Bulletin
There’s been a lot of talk in the press lately about the salt we use to keep our roads and parking lots safe in the winter.
While good old-fashioned salt is the deicer of choice for many municipal road crews and private parking lot maintenance companies, it threatens lakes, streams and even groundwater drinking resources. Only one teaspoon of salt is enough to pollute five gallons of water, and a single 50-pound bag of salt can contaminate over 10,000 gallons of water. When you stop to consider that approximately 15 million tons of salt are applied every winter in the United States, it quickly becomes apparent just how dangerous of a problem salt can be.
It is mistaken to frame discussions about winter salt use as a debate between public safety and natural resources protection when in fact, nothing could be further from the truth. Chloride concentrations in watersheds harm fish and wildlife, along with benthic organisms at the base of the food chain. The presence of salt in aquatic ecosystems also releases toxic metals from sediment into the water column and impairs distribution and cycling of oxygen and nutrients. In addition to these immediate impacts, the gradual accumulation of salt in our environment threatens our future drinking water availability.
Chloride that enters our environment tends to stay there — and almost all of it eventually migrates to surface or ground waters. While raingardens and stormwater ponds help to remove many stormwater pollutants, chloride is not one of them. Salt in the environment is a lot like sugar in your morning coffee. Once it’s there, it’s almost impossible to remove.
A major effort is underway to help public road crews and private parking lot maintenance companies employ a more scientific approach to deicing winter roads and parking areas. Led by a variety of partners, including the Minnesota Pollution Control Agency, Fortin Consulting and the University of Minnesota Local Technical Assistance Program (LTAP), the goal is to reduce the amount of salt used without risking public safety. As the recent stretch of subzero weather has reminded us, dry rock salt is almost completely ineffective when it is colder than 10 degrees outside. Local businesses and municipalities are being trained to pre-treat roads when storms are forecasted, precisely measure the rate of salt and chemical application (and use salt alternatives when necessary) and target salt to the areas that need it the most – intersections, hills and curves.
As a local resident, you can help by limiting the amount of salt you use on your own sidewalk and driveway and cleaning up any remaining salt after ice thaws. In addition, you are the eyes and ears to remind local cities and businesses how important it is to use salt sparingly. For more technical information, there is a parking lot and sidewalk maintenance manual available at http://www.pca.state.mn.us/publications/parkinglotmanual.pdf.
Angie Hong is an educator for the East Metro Water Resource Education Program. Contact her at (651) 275-1136, extension 35 or firstname.lastname@example.org.