Using Salts and Deicers Responsibly

When winter storms hit, you might be tempted to pull out that salt to make your driveways and sidewalks safe during snow and ice. Think again! While deicers are an effective safety tool, they must be used responsibly to protect the environment and waters from becoming polluted. A deicer is a substance that melts or prevents the formation of ice, and does so by lowering the freezing point of water and preventing a bond between ice and paved surfaces.

When snow and ice melt, all roadway treatments eventually wash into lakes, streams, wetlands and groundwater. Once present in water, there is no easy way to remove chlorides as no existing stormwater treatment system exists to capture and retain them. Although chlorides may be loosely retained in soils or in water, they can build up at the downstream end of the watershed, or within groundwater.

Since there's no easy or cheap way to remove salt from our environment, we can all do our part to reduce the amount of salt we use with the following tips:

  • Clear snow by shoveling early and often and apply salt only where it is needed.
  • Apply salt after clearing snow and never use salt to “burn off” the snow. It will quickly dilute and requires excess use.
  • If the sun comes out and you can wait, let the sun do some of the work before you apply salt.
  • If it is too cold for your salt to work, or you'd rather not use salt, use traction materials instead. These include sand, native blends of bird seed and zeolite crystals.

One 12-oz coffee mug of sodium chloride or rock salt with a melting temperature of 15° Fahrenheit is enough to treat a 20-foot driveway or ten sidewalk squares. Aim for about three inches between pieces of rock salt. Calcium chloride has a melting temperature of -20° Fahrenheit and should be applied at one third of the rate used for sodium chloride. Be patient and give the salt time to work. The colder it is, the longer it will take for the salt to melt what snow or ice remains after shoveling. All nitrogen and phosphorus salts are illegal in Virginia. Nitrogen salts include urea, ammonium sulfate and potassium nitrate, etc. After the storm, sweep up the extra salt or traction material and use it again next time.

In high concentrations, chlorides can be harmful to freshwater aquatic life. Chlorides also have negative and destructive impacts on infrastructure, as they corrode metal and pit concrete, rust metal vehicle components, kill non-salt tolerant vegetation, and are harmful to soil, pets, and wildlife. They also contaminate groundwater and raise sodium levels in drinking water supplies, which then increases water treatment costs. This winter, try using less salt and help protect Stafford’s environment.