How can salt impact our drinking water?

One of the biggest impacts to water quality is from using salt in the winter. In Waterloo Region, most of our drinking water comes from groundwater.

Although groundwater is naturally protected, it can still be impacted by activities at the surface. The salt we put on the ground doesn't go away after it melts the ice. It may soak into the ground to mix with groundwater or drain into a storm basin that empties into a local stream or pond.

Overtime, the salt we put on the ground can end up in our drinking water and cause it to taste salty.

The image below compares chloride (from salt and ice melters) levels at Region of Waterloo well sites in 1973 and 2014. The Ontario Drinking Water Objective for chloride is 250 mg/L. A salty taste is detectable at this level.

Chloride levels maps for Region of Waterloo well sites


What can I use instead of salt?

Salt includes all products with chloride. This includes most ice melters and de-icers as well as products labelled environmentally friendly. 

Sand, grit or non-clumping kitty litter are good choices for traction or when it's too cold for the salt to work. For sand, look for a product with little (less than five per cent) or no salt.

However if you want to melt the ice, alternatives to salt that do not impact water are hard to find.

No matter what you use to melt ice, clear the snow first and only use salt on icy areas following product directions for application rate and working temperature. Learn more with these snow and ice clearing tips

Why do we use salt?

Salt is an effective tool for removing ice by lowering the freezing temperature of water.  Instead of freezing at 0 Celsius water turns to ice at a much lower temperature when salt is added.

However it's a bit more complicated. Reducing salt use is what we call a wicked problem with many factors to consider.
  • Liability is one of the biggest reasons we often see too much salt.  When you're afraid of being sued if someone falls, it can be tough to use less salt even when that's all that's needed.
  • Community expectations for bare pavement
  • Weather forecasts help to determine when to use salt. But forecasts can change resulting in using salt when it isn't needed. And more freezing rain from Climate Change also means more ice and more salt.
  • Using the right tools and equipment for the job can make a big difference.  For roads, the snow plows are equipped with tools that help spread the right amount of salt. However these tools are not readily available for parking lots and sidewalks.
  • Training is not required to use salt and there are no industry standards outlining best practice
  • Design of buildings and parking lots may not consider winter and the potential of creating icy conditions
  • Lack of awareness about the issue. Salt on the ground can be seen as part of our winter landscape. We don’t typically think of salt as a pollutant to water.