Salt Management

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Salt is a major water quality concern. The salt we spread on the ground does not go away. Some of this salt soaks into the ground to mix with groundwater, the water we drink. Once the salt is in the water, there is no easy fix to remove it.

How you can help keep salt out of groundwater

When everyone uses a little less, together we can make a difference.

What you might not know about salt

  • Environmentally friendly ice melters contain salt and are not water friendly
  • Current water and wastewater treatment does not remove salt from water. Removing salt requires desalination, an expensive and energy intensive treatment.
  • Salt (sodium chloride) does not work when colder than -10 C

What the Region of Waterloo is doing

Why salt is a water quality concern

  • Once salt is in the water, there is no easy fix to remove it
    • Current water and wastewater treatment does not remove salt from the water
    • Removing salt requires desalination which is extremely expensive and energy intensive
    • Including desalination as part of the treatment process would also result in much higher water costs for the community
  • The Ontario Drinking Water Objectives for chloride is 250 mg/L
    • This is when a salty taste may be detectable by some people
    • The Region of Waterloo must mix groundwater from different wells to lower the chloride levels
  • Chloride levels from salt are increasing in groundwater wells
    • The image below compares chloride levels in Region of Waterloo municipal groundwater wells between 1998 and 2018
    • The orange and red dots are groundwater wells with chloride levels near or exceeding the 250 mg/L limit

Map showing chloride levels at Region of Waterloo municipal supply wells

Educational resources

Research projects and studies

  • Do road salt reduction strategies improve groundwater quality? Results from a long-term study by the Region of Waterloo and City of Kitchener on how best management practices influence chloride levels at Greenbrook municipal drinking water wells. University of Waterloo Water Institute Research article.
  • Salination as a driver of eutrophication symptoms in an urban lake, University of Waterloo, Canada Centre for Inland Waters, City of Richmond Hill. Accelerating urban growth worldwide has been blamed for declining water quality of freshwater environments, including the eutrophication of lakes and other surface water bodies. Eutrophication can pose serious risks to drinking water sources and may ultimately cause the die-off of aquatic life. Eutrophication is generally assumed to be driven by the human-enhanced supply of phosphorus, but recent research out of the University of Waterloo found that at Lake Wilcox (a small lake in southern Ontario), eutrophication symptoms persisted even after external phosphorus inputs were reduced. So, what is causing this deterioration in water quality? Follow up article Time to Act: Road salts are stressing our urban lakes by Global Water Futures.
  • Snow and Ice Control for Parking Lots and Sidewalks, University of Waterloo. Addresses the common question winter maintenance contractors face each winter: what are the right snow and ice control methods, materials, and amounts of material that should be applied under specific winter weather conditions?
  • Evaluation of Organic Anti-icing Materials for Winter Maintenance, University of Waterloo. Evaluates and compares the capacity of three organic and semi-organic anti-icing liquids and conventional sodium chloride brine to improve pavement friction relative to an untreated control
  • Specifying Salt Management Best Practices in Parking Lot Winter Maintenance Contracts, Toronto and Region Conservation Authority. Provides guidance on how to develop parking lot snow and ice management contracts that encourage the use of best practices for salt management established by Environment Canada and other organizations such as the Transportation Association of Canada.
  • Friction and Parking Lots, Lake Simcoe Region Conservation Authority. Friction testing show us that bare pavement is safest, as it has the highest friction value, and that the over-application of salt does not translate to safer conditions. The takeaway from this is that if you achieve bare pavement in a reasonable amount of time with little to no residual salt, you applied the right amount.
  • Year-round monitoring of chloride releases from three zero-exfiltration permeable pavements and an asphalt parking lot, University of Toronto and Toronto Metropolitan University Toronto. The study provided insights into the behaviour, retention and release of Cl− from traditional and permeable hardscape surfaces and possible avenues for Cl− attenuation, source control and aquatic habitat conservation.
  • Salty summertime streams - road salt contaminated watersheds and estimates of the proportion of impacted species, University of Toronto.

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