Collection of surface water samples and ancillary data for the Canadian Water Monitoring Program for Pesticides in priority Ontario watersheds.

Health Canada (HC) evaluates the risks to human health and the environment associated with the use of pesticides and regulates pesticide products in Canada under the Pest Control Products Act. In the interest of increasing the availability of real-world data for use in pesticide risk assessments, HC coordinates the Canadian Water Monitoring Program for Pesticides (CWMPP). As part of this program, water samples are analysed to determine the concentrations of pesticides present in Canadian waters. Federal laboratories will analyse approximately 200 chemicals (i.e., pesticide active ingredients and transformation products) in water from various regions across Canada. Ancillary data and expert advice assist in improving our collective understanding of any patterns observed or any potential levels of concern. October 26, 2026: Added Q&As.