Kahnawake draws raw water from the same St. Lawrence River source as multiple Quebec municipalities flagged in new pesticide research, raising questions about contamination levels in the community’s independent water system.
The Mohawk territory operates its own water services, unlike other Indigenous communities near large towns that depend on neighboring municipalities such as Chateauguay for supply. Mark Morris, a water plant operator with the Mohawk Council of Kahnawake’s Public Works Unit, acknowledged that elevated readings could exist locally given the shared intake source. He emphasized that any levels detected so far remain within Quebec and Health Canada standards.
Weekly testing conducted by Public Works covers temperature, pH, turbidity, iron, alkalinity, water hardness, ultraviolet transmittance percentage, and aluminum. Meanwhile, Kahnawà:ke Shakotiia’takéhnhas Community Services’ Environmental Health Services handles contaminant screening for substances including pesticides.
July testing revealed s-metolachlor concentrations below 0.2 micrograms per liter, according to Morris. A copy of that report was requested but not immediately made available.
Provincial pesticide and herbicide use continues to climb. Rehn, from Vigilance OGM, argued that federal regulators should focus on restricting contaminants at the source rather than forcing municipalities to upgrade treatment infrastructure. Five separate pilot projects since the 1990s have tried and failed to address the problem through facility modifications, Rehn noted.
The advocacy group pushes for mandatory agronomic prescription as the solution for s-metolachlor. This approach functions like a doctor’s note, giving farmers limited access to a pesticide only under specific conditions.
Atrazine offers a compelling precedent. The herbicide has been banned in Europe for two decades, but Canada shifted to mandatory prescription status in 2019. The result: sales dropped 94 percent.
Rehn said the same treatment should apply to other pesticides deemed dangerous.
Health Canada and provincial environment or health ministries did not respond to requests for comment.
