Adoption of best practices for the environmental
management of road salt in Ontario
M. Stone and J. Marsalek
ABSTRACT
There are increasing concerns regarding the adverse environmental impacts of chloride from road
salts. A web-based survey was conducted to determine how the Code of Practice for the
environmental management of road salts has influenced the adoption of best practices in Ontario,
Canada. The majority of large Ontario municipalities have salt management plans that adequately
address safety and the environment. Most municipalities train a high percentage of permanent staff
but only half of seasonal workers and 21% of private contractors are trained. Most training programs
cover key learning goals defined by the Code of Practice. There is little improvement in the
management of salt-vulnerable areas. Many existing snow disposal sites are poorly designed and do
not manage snowmelt quality. The Code has strongly contributed to the adoption and improvement
of salt management practices in Ontario by helping to standardize practices and advance the rate of
implementation of best practices. Barriers to further implementation of the Code include
understanding the Code, institutional will, liability, limited technical/financial resources and public
expectation of high service levels. Further benefits can be achieved by aggressively promoting the
Code and improving education and training programs for the public, private contractors and staff
of road authorities.
M. Stone (corresponding author)
Department of Geography and Environmental
Management,
University of Waterloo,
Waterloo, ON,
Canada N2L 3G5
E-mail: mstone@uwaterloo.ca
J. Marsalek
Aquatic Ecosystem Management Research Branch,
Water Science and Technology Directorate,
Environment Canada,
Burlington, ON,
Canada L7R 4A6
Key words | Code of Practice, road salt management, salt management plans, salt-vulnerable areas
INTRODUCTION
The necessity to keep highways safe and fully operational in
cold regions has led to the development of advanced winter
road maintenance plans, which include applications of
chemical deicers (mainly road salt, sodium chloride) and trac-
tion agents (sand and grit). The release of road salts to the
environment has been estimated at 18 million tonnes/year
in the USA (Corsi et al. ) and 5 million tonnes/year in
Canada (Environment Canada and Health Canada ). In
addition to annual use, temporal trends in road salt use are
also of interest and indicate a continuing growth, driven by
increasing population. Historically, increases in salt appli-
cations contributed to environmental effects of deicing salts
and the first reports of these effects were reported in the
1970s (Field et al. ; Hanes et al. ). Similar concerns
about road salt effects in Canada (Howard & Hayes ;
Marsalek ; Rokosh et al. ; Mayer et al. ; Oberts
et al. ; Williams et al. ) led to a comprehensive
five-year scientific assessment of the environmental impacts
of road salt to provide a state-of-the-art synthesis of scientific
literature regarding the effects of road salt on the environment
(Environment Canada and Health Canada ). The assess-
ment concluded that, under the road management practices
prevalent at that time, significant discharges of chloride
from road salt were having adverse impacts on freshwater
ecosystems, groundwater quality, drinking water supplies,
soil, vegetation, wildlife and urban infrastructure in many
regions of Canada. Furthermore, road salt impacts in urban
areas were reported to be exacerbated by modern stormwater
management or low impact development (LID) practices,
including infiltration of chloride-laden runoff, use of storage
in ponds, constructed wetlands, and oil and grit separators
(Marsalek ).
174 © Environment Canada 2011 Water Quality Research Journal of Canada | 46.2 | 2011
doi: 10.2166/wqrjc.2011.105
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