On average, 5 million tonnes of road salts are used each year as de-icers on roadways in Canada. Due to concerns about the large quantities of chlorides being released to the environment, road salts underwent a comprehensive five-year scientific assessment under the Canadian Environmental Protection Act, 1999 beginning in 1995. The road salts assessment covered the chloride salts — sodium chloride (NaCl), calcium chloride (CaCl2 ), magnesium chloride (MgCl2) and potassium chloride (KCl) — as well as brines used in road de-icing/anti-icing and dust suppression, the salt portion of abrasive mixtures and ferrocyanide additives.

Road salts enter the environment through losses at salt storage and snow disposal sites and through runoff and splash from roadways. The assessment report, published on December 1, 2001 concluded that high releases of road salts were having an adverse effect on freshwater ecosystems, soil, vegetation and wildlife. The publication of this report initiated the risk management process to address the risks posed to the environment by road salts.

To assist Environment Canada with this complex task, a multistakeholder working group was formed, which included members from provincial and municipal road authorities, federal and provincial governments, industry, environmental non-governmental organizations and related associations (see the list of working group members at the end of this Code). This working group worked together over a two-year period towards the development of the Code of Practice.

The Transportation Association of Canada worked in parallel to the working group to produce the Syntheses of Best Practices. The syntheses are a detailed resource on winter maintenance practices and supplement the recommendations made within the Code.

The main objective of the Code of Practice is to ensure environmental protection while maintaining roadway safety. There are two main recommendations in this Code:

1. The development of salt management plans, based on a review of existing road maintenance operations, identification of means and goal-setting to achieve reductions of the negative impacts of salt releases; and

2. The implementation of best management practices in the areas of salt application, salt storage and snow disposal, as outlined in the Transportation Association of Canada’s Syntheses of Best Practices.

Monitoring and reporting aspects are also included in the Code. The information collected will play an essential role in evaluating the progress achieved.

This Code of Practice does not address the use of road salts on parking lots and private properties, use as dust suppressants or use of ferrocyanide additives. These applications are being addressed separately by Environment Canada.

When applied, the recommendations made within this Code will result not only in benefits to the environment, but will also have the potential to result in benefits to road authorities, including more efficient operations, improved roadway safety and savings in material usage. Since the beginning of the assessment process, many road authorities across Canada have taken early actions to improve their salt management practices. Case studies documenting the resultant benefits of these practices, as well as other related information on road salts management, can be found on Environment Canada’s road salts website at http://www.ec.gc.ca/nopp/roadsalt/.