Language selection

Government of Canada / Gouvernement du Canada

Search

Water monitoring pilot program for pesticides

On this page

About the pilot program

Health Canada's Pest Management Regulatory Agency conducted a pilot monitoring program for 2 years, from April 2022 to March 2024. We worked in collaboration with Environment and Climate Change Canada (ECCC) and Agriculture and Agri-Food Canada (AAFC).

We're using the data we collected to better inform future pesticide re-evaluations and special reviews. Making these data available to the public increases understanding and awareness.

The pilot program also serves as a model for:

Water monitoring sites

Provincial and local partners, including members of Indigenous communities, worked with us and ECCC and AAFC to collect samples.

We collected water samples from 2 types of water sources at various locations across Canada.

Surface water samples from sources such as rivers, streams, wetlands and lakes were collected 2 times a week, when feasible, during the growing season. At some locations, we collected samples throughout the year.

Groundwater samples were collected from public wells in Ontario once in the fall of year 2, and from 4 wells in Prince Edward Island every 2 weeks throughout year 2.

We chose sampling sites for the pilot program that met 1 or more of the following criteria:

In year 1 (2022 to 2023), data are available for 86 surface water sites.

In year 2 (2023 to 2024), we collected samples from:

Figures 1 and 2 show the locations of the surface water and groundwater sites. The sites are shown together with Canadian agricultural lands, based on AAFC's 2022 annual crop inventory.

Figure 1: Surface water sites
A map showing the locations of the surface water sites for years 1 and 2.
Figure 1 - Text description

This map of Canada shows the location of agricultural lands in 2022 (in green). Most of the lands are in southern Ontario and Quebec and the Prairie provinces.

The dots on the map show the locations of the surface water sites. The 3 colours for the dots correspond to the year that samples were taken.

Blue dots are sites that were only monitored in year 1:

  • 1 in British Columbia
  • 36 in Saskatchewan
  • 14 in Ontario
  • 1 in Quebec

Purple dots show the 73 surface water sites that were added in year 2:

  • 17 in British Columbia
  • 5 in Alberta
  • 11 in Saskatchewan
  • 20 in Manitoba
  • 8 in Ontario
  • 3 in Quebec
  • 4 in New Brunswick
  • 3 in Prince Edward Island
  • 2 in Newfoundland and Labrador

Yellow dots show the 34 sites monitored in years 1 and 2:

  • 4 in Alberta
  • 7 in Saskatchewan
  • 2 in Manitoba
  • 10 in Ontario
  • 4 in Quebec
  • 4 in Nova Scotia
  • 3 in Prince Edward Island
Figure 2: Groundwater sites
A map showing the locations of the groundwater sites for years 1 and 2.
Figure 2 - Text description

This map of Canada shows the location of agricultural lands in 2022 (in green). Most of the lands are in southern Ontario and Quebec and the Prairie provinces.

The blue dots show the groundwater wells monitored in year 2:

  • 77 in Ontario
  • 4 in Prince Edward Island

Laboratory analysis

Health Canada's pesticide laboratory developed a liquid chromatography method to analyze:

In year 1 of this pilot program, our lab analyzed:

In year 2 of this pilot program, our lab analyzed:

To analyze the increased number of samples collected in year 2, some samples were sent to AAFC's London Research Development Centre laboratory. AAFC's lab analyzed:

We also sent some samples taken in both years to the University of Guelph's Agriculture and Food Laboratory. This lab analyzed the samples for glyphosate, 4 other pesticides and 6 transformation products.

Samples analyzed

In year 1:

Data are available for 1,205 samples in Open Data.

In year 2:

Data are currently available for about 3,650 samples. More will be released when they become available.

Explore the results

You can check out all year 1 and initial year 2 results on our Open Data portal.

You'll find information on:

Also check out our interactive water monitoring for pesticides dashboard for interactive summaries on:

Pilot program limitations

There were some program limitations that can affect the interpretation of the results.

Limitations related to site selection

We relied on partners for collecting samples. Working with these partners, we chose sampling sites based on existing water monitoring networks, with an emphasis on those located in agriculture areas. We also considered sites that were sampled for pesticides in other monitoring programs.

Site types included lakes, large rivers, watersheds and small streams next to agricultural lands, and some groundwater wells.

The concentration of chemicals detected in a sample can be affected by a number of factors, such as:

To select sites for future sampling, we will take a science-based approach, using:

This approach helps us identify areas where there might be a higher risk of pesticides moving to water.

Comparing results to reference values

Groundwater samples are only compared to the human health reference values. This is because groundwater samples are considered drinking water sources for pesticide risk assessments.

Surface water samples, which are used for both human health and environmental risk assessments, can be compared to both human health and aquatic life reference values.

Note: Other jurisdictions have their own benchmarks or reference values, which may be different from ours.

Other pesticide data

In addition to data from this program, pesticide concentrations are available from other sites across Canada.

Here are a few examples of Canadian pesticide data available online:

Our partners

We owe the success of this program to many partners, including the following federal, provincial, local and Indigenous organizations:

Related links

Page details

Date modified: