Pesticides Sampling in the Upper Thames River WatershedÌý

The ÌÇÐÄÖ±²¥ (UTRCA) has recently begun a partnership with the (PMRA), a branch of Health Canada. The PMRA is responsible for the regulation of pesticide products in Canada.ÌýIt also assesses the risks to both human and environmental health associated with the use of pesticides.Ìý

The UTRCA and PMRA partnership has initiated the Canadian Water Monitoring Program for Pesticides (CWMPP), which allows the UTRCA to monitor pesticide levels in surface water by collecting samples twice weekly at three different subwatersheds:ÌýÌý

• Gregory Creek near Cherry Grove,ÌýÌý
• Otter Creek near St. Mary’s,ÌýÌý
• and Fish Creek near Prospect Hill.ÌýÌý

These sites were selected due to their proximity to areas with significant agricultural activity and human influence. Anthropogenic factors (human-caused actions and processes that impact the natural environment)Ìýcan increase the likelihood of pesticides movement into water bodies. Whenever possible, sampling is aligned with rain events to accurately capture any runoff that may occur.Ìý

The data collected through the CWMPP will be analyzed for pesticide concentrations and be made publicly available through the . This information will support science-based decision-making and help guide future regulations of these chemicals.Ìý

Much of the land within the watershed is used for agricultural purposes, where pesticide application is a common practice used to enhance crop productivity. However, the use of pesticides may pose both environmental and health risks if not managed correctly. The objective of PMRA is to keep risks to a minimum (e.g., preventing/limiting exposure) while still allowing the use of these chemicals to reach the required crop yield.Ìý

Pesticides used on crops can enter surface water sources via run off. If applied too heavily to a field, or if there is a heavy rain event immediately after application, this runoff can carry any excess pesticides to the nearest surface water source. There is also a possibility of pesticides binding to soil particles that may be washed away and into the surrounding water bodies. The PMRA is interested in the concentrations of pesticide concentration in non-target environments, as many waterways reside within or adjacent to farm fields and are therefore more susceptible to contamination. This is particularly true if the pesticides are being improperly applied.Ìý

According to the , risks vary depending on chemical composition, as well as the level and duration of exposure. Pesticides are beneficial for controlling unwanted pests and supporting food production but minimizing risks to both human and environmental health should be a high priority.ÌýÌý

Several best management practices can aid in reducing the amount of pesticide contamination in surface water. Some of these include:Ìý

• Assessing site characteristics of the land on which they are being used (slope, soil condition, amount of organic matter, location of water sources etc.),Ìý
• Preventing spills,Ìý
• Avoid application before a heavy rainfall,Ìý
• Implementing buffer zones, andÌý
• Storing and disposing of these chemicals in a safe manner.Ìý

For more information, viewÌýÌý

By participating in this project, UTRCA can enhance our water quality monitoring programs and fill in knowledge gaps. A more comprehensive data set will also allow for evidence-based decision-making regarding water quality within our watershed, therefore keeping the environment safe, and in turn, protecting human health.Ìý