willow mulberry Is there too much salt in Sudbury’s water
Public meeting in Sudbury on Monday will tackle that question
Concerns about road salt leaching into our drinking water, and elevated levels of salt in our lakes, have prompted the Greater Sudbury Watershed Alliance to organize a meeting next week.
The watershed alliance is hosting a panel discussion on road salt on Monday at the Vale Living with Lakes Centre on Ramsey Lake Road. and the public is invited to this open forum to learn more about the growing problem of road salt entering into our freshwater lakes, rivers and aquifers.
Increasing sodium and chloride levels from road salt is a cause for concern, especially in water bodies, such as Ramsey Lake, that are sources of our drinking water, the alliance says.
Scientists and municipalities across North America are struggling to find solutions to the problem of chloride and sodium used to de ice paved surfaces. There are few mitigation methods and currently there is no practical way to remove salt from our drinking water or the environment.
How do we balance the need to protect our water bodies with the need to keep roadways and parking lots safe?
The discussion will focus on how to answer this question, especially with regard to Ramsey Lake, which is a main source of drinking water for more than 50,000 Sudbury residents. Its sodium levels are approaching three times the level at which the medical officer of health must be notified.
Additionally, the lake’s chloride levels are rapidly approaching a level that can harm aquatic life.
The watershed alliance will host a panel of experts from the science community to discuss the road salt issue. Panel members include John Gunn, Canada research chair for stressed aquatic systems and director of the Living with Lakes Centre; and Charles Ramcharan, an associate professor in the School of the Environment at Laurentian University.
Tony Cecutti, the city’s general manager of infrastructure services, said Friday the city launched in 2006 a salt management plan to monitor and address the salt on roads and in water bodies.
“Council adopted a maintenance standard at that time that involved a substantial reduction in road salt usage,” he said. “The salt management plan has done two things: it’s limited the number of roads that actually get salt . There was more widespread use of salt before the salt management plan was in place. The second thing we’ve done is we’ve managed the use of that salt, so we control the rates of application much more accurately than in previous times. We monitor and measure the amount of salt we use.”
Cecutti explained the city only salts roads considered class 1 3 arterial and some collector roads while class 4 6 roadways get sand. Class 4 6 roads meander through subdivisions and form the local road network.
Where the city does use salt, it has adapted its application techniques, which means less salt is wasted or ends up in ditches,
curbs or snowbanks. The city now adds a wetting agent to the salt so that it sticks to the asphalt.
“Wetting agents substantially enhance the ability of the salt to stay effective and stay on the roadways,” Cecutti said.
The city also applies liquid salt directly to thoroughfares.
“We make a brine and use this a lot for our bridges,” he said. “It’s basically a very similar product to what you would use for pickles. It’s a similar process.”
Cecutti said liquid salt is very effective in areas where icing is a concern, such as streets with high humidity.
Some municipalities have begun using beet juice as a wetting agent. While it could be effective, Cecutti said there would be no cost savings for city hall.
“I think the theory is that some citruses are pretty sticky,” he mused. “We haven’t tried it but I can only imagine. If the intent is to keep the salt on the road, then beet juice would certainly be very sticky and it would stay there.”
As Cecutti pointed out, the city only uses salt until the asphalt reaches a temperature of 12 C. At that point, they begin using sand (which is mixed with a little salt to prevent it from clumping) in order to create a sandpaper effect on roads. Sand is used on all class 4 6 roads, as well as sidewalks.
Cecutti said the city is “very conscious of the impact of urbanization” on lakes and he agrees salt in water bodies is a bad thing whether or not they are sources of drinking water. But so far, Ramsey Lake is actually not doing too badly. The city tests its drinking water routinely.
“From the 1980s to 2010, we saw modest increases. The salt concentration in Lake Ramsey was between 50 and 58 parts per million of sodium,” he said. The acceptable standard is 200 ppm. “Since we’ve had the salt management plan we’ve seen the levels stop and even drop. The measurements we took last year were in the mid 50s. Even after a couple hundred years the number wouldn’t change that much, even if we stopped salting today. Once sodium through salting is introduced into your system, there’s so much in the watershed it’s unlikely you’re going to see much significant change either way in the foreseeable future.”
Anything more than 20 ppm and the city has to notify the medical officer of health, who then relays the information to doctors and nurse practitioners, who may have patients on reduced sodium diets. Cecutti said the medical officer of health was notified back in the 1980s.
“Frankly, at 50 ppm in your drinking water, a piece of chicken from the grocery store in a raw state is going to have a higher concentration of sodium than the drinking water. In your balanced diet, you need to be concerned, but in and of itself it’s not the most important issue for health. The medical officer of health is well aware of the number and they’re not concerned in terms of being able to communicate with physicians. . It looks like our efforts have stabilized now.”