February 15, 2012
By Bob Hodgins
Smart about Salt executive director

Terry MurphyAs I was out walking my dog and pondering the topic for this month’s article, I came upon a thick layer of salt spread around a city bus stop that made me realize it might be time for an article on application rates.

This is always a gritty topic, since there is no accepted standard or even agreement on the quantity of salt to put down on parking lots and sidewalks. Fortunately, there is an ongoing study at the University of Waterloo that hopefully will answer this question with some solid science. In the meantime, there is a lot of experimentation going on.

In Ontario, there is considerable concern about the effect excessive salt use is having on our drinking water. It was this concern in the Regional Municipality of Waterloo that led to the development of the Smart about Salt program. As well, since the Walkerton disaster, the Ministry of the Environment and conservation authorities have been working on provincial plans to protect drinking water supplies.

Rock salt has been identified as one of the threats to water supplies that needs to be addressed. Eventually every ounce of salt we put down ends up in our water. So, while we need to use salt to maintain winter safety, it is also important that we are responsible and use only the right amount to achieve safe conditions.

In our training, we encourage snowfighters to have three different application rates: a light rate for frost and light snow falls, a medium rate for normal snowfalls and a heavy rate for heavy snowfalls and colder temperatures. But what are the correct rates?

Snow and ice control contractors who are certified under the Smart about Salt program, report annually on their salt use. Last year the average application rate that was reported was 53 grams/square metre, which is 11 pounds per 1,000 square feet, or 490 pounds an acre. Everyone likes to use different units of measure. The highest reported rate was over twice this average, with the lowest less than half this average rate. The Region of Niagara has stipulated rates that are the same as its road application rate for parking lots and sidewalks, claiming to have eliminated the incidence of slip/falls at the targeted locations.

My article entitled, ‘Rock salt doesn’t melt anything’ (December 2011) talks about the benefits of liquids. When using liquid de-icers, the amount of salt used is significantly less with enhanced safety under the right conditions.

We have a responsibility to maintain safe conditions during the winter, but we also have a responsibility to protect our water supplies for now and into the future. There are many contractors who have been diligent about their salt use and reduced their rates by using pre-treated salt, liquid de-icers, or simply dialling back the spreaders. Clearly the people maintaining the city bus stops could learn much from these responsible snowfighters.
You can learn more at www.smartaboutsalt.com or email Bob Hodgins at smartaboutsalt@bell.net.