FILE PHOTO

Image Credit: SUBMITTED/City of Kelowna

Continued use of road salt could spell bad news for local agriculture, aquatic life and drinking supplies if a better alternative isn’t found soon. Fortunately, studies in Waterloo have shown that it’s not too late to reverse the damage.

In 1975, chloride levels in the Okanagan Lake were just 1.5 milligrams per litre (mg/L). The results this September showed that levels have increase four times since then to 6.04 mg/ L.

Although the lake is still far from the 150 mg/L guideline levels that would make the water harmful to aquatic life, salinity levels have been increasing year by year because of road salt.

READ MORE: Okanagan Lake is slowly getting saltier

Heather Larratt at Larratt Aquatic Consulting said the increased salinity of the lake is a marker of human impact on the local environment.

“Mostly it's road salt that is the big player,” Larratt told iNFOnews.ca. “When we look at the concentrations of salt… we see that it's increasing year over year against the flushing rate of Okanagan Lake.”

According to Larratt, it takes an estimated 65 to 70 years to get a full exchange of water in the Okanagan Lake, and the rate that we are currently adding salt is exceeding that rate of flushing.

“It's a signal of how much effect we are having on the lake as communities,” Larratt said. “Whatever we do in the watershed ends up in the lake and we're all living downstream of what we do in the watersheds.”

Dr. David Rudolph, professor of hydrogeology at the University of Waterloo, has researched the widespread and surprising effects of road salt on the environment. He told iNFOnews.ca that salt is a "forever compound" because it does not break down naturally in the environment.

“It's one of the reasons why the oceans are so salty,” Rudolph said. “Salt doesn't go away… It tends to accumulate and, in the environment, if it accumulates in in areas that that are sensitive, such as drinking water and surface water, which are the things we've been looking at, that's a real critical situation.”

Salt is an important and useful compound that most life depends on, Rudolph said. However, it can cause major problems if it gets in the wrong areas.

“If we irrigate with water with a little bit of salt, over time it builds up in the soil and the soil progressively loses its ability to support crop growth,” Rudolph said.

Water quality changes from road salt can also lead to algae blooms, which could have a significant impact on summer recreational activities like lake swimming.

“That tends to get people, when it gets to a recreational issue,” Rudolph said. “People aren't as worried about a little bit of salt in their water… However, in a long period of time it can affect your health. It corrodes all the water distribution systems. It's a major issue.”

READ MORE: iN VIDEO: Salt, sand or spray? That is the question every snow day in Kelowna

Rudolph and his colleagues studied well fields in the southern Ontario Regional Municipality of Waterloo, which suffered heavy groundwater contamination from road salt. The study showed that the salt contamination is reversable. By using best management practices over a six-year period, chloride levels were reduced by 40% to 60%, the only problem was the length of time it took to reduce them.

“Unfortunately, things move so slowly in the subsurface. It took 40 years to get to this point and, if we stopped applying salt now, it would take another 40 years before we'd lose it,” Rudolph said.

After decades of research, Scandinavian countries like Finland found that reducing salt was a more viable, sustainable solution than completely replacing it with expensive alternatives. They were also able to divert road salt away from groundwater and surface water, Rudolph said.

“They have a natural system of aquifers where they pump their groundwater that allows them to isolate places that are very vulnerable,” Rudolph said. “So, they haven't completely reduced the salt or removed the salt, but they've taken steps to remove the impact.”

In Kelowna, the city is stocked up on calcium chloride and sand for the winter ahead, Infrastructure Operations Department manager Geert Bos told iNFOnews.ca.

“We're all well aware that the federal government has labelled (road salt) as a pollutant and especially for us here… in the Okanagan water basin,” Bos said. “It's very important when we use salt that we use the amounts that are just needed for treatment and not overuse it at all. We don't take that responsibility lightly.”

Usually, during light flurries, the city uses a liquid de-icing agent called calcium fluoride on roadways. Only later when temperatures get much lower and layers of ice and snow need to be broken down, is rock salt used.

“Then, from a maintenance perspective, we like to use like a mix of sand and salt,” Bod said. “The sand provides traction and that allows us to cut back on the salt use a little bit.”

The city has used alternatives like sugar beet liquid in the past, Bos said, although it hasn’t proven successful. Partly due to the mess left behind by the brown sticky substance and partly because of the negative impact it can have on natural water.

“If that beet juice makes its way into local waterways what it does it basically changes the biological oxygen demand on the water,” Bos said. “It derives the oxygen from the water and in turn that will impact the flora and fauna around the creeks and our lake.

"While salt is not ideal, beet juice is not ideal either. So, we always have to look at new technologies and stay up to speed with what's going on.”

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