SUDBURY -- The Greater Sudbury Watershed Alliance has released new numbers on the levels of sodium and chloride in area lakes.

Samples of tap water were taken from locations around the city, which show the levels of the two elements present in road salt.


Sodium and chloride in Sudbury area lakes

The group says when water systems contain sodium levels higher than 20mg/L, the Medical Officer of Health must be advised, who in turn notifies community physicians. For persons with chronic diseases requiring a sodium-restricted diet, the intake of sodium from drinking water could be significant.

Sodium and chloride levels in surface water

Local watershed advocates say high chloride levels impact aquatic life, specifically zooplankton, which is a significant group of microscopic organisms that graze on algae, including blue-green algae. They say recent evidence suggests that chloride may be more toxic to zooplankton in lakes on the Cambrian Shield. Therefore, a resilient aquatic ecosystem in all three sampled lakes may be threatened.

The City of Greater Sudbury has incorporated best practices in their salt management plan that applies to all municipally-maintained roads, sidewalks and parking lots, and has also indicated changes in snow removal procedures within the Ramsey Lake Watershed.

Meantime, the general public and contractors continue to use road salt improperly and in excess.

"There are alternatives that individuals can use instead of spreading rock salt. People can also significantly reduce the amount they use," said Richard Witham, Chair of the Greater Sudbury Watershed Alliance. "We’ve tried to encourage people who clear parking lots to become 'Smart About Salt certified,' so that they have a much better awareness of the impacts to the environment that the salt produces."

Witham says that Earth Care Sudbury will be hosting a Hold the Salt Breakfast on March 25.

Read the full community information release from the Greater Sudbury Watershed Alliance.