Water Monitoring for Pesticides : Dashboard

Concentrations of pesticides from a network of Canadian freshwater sampling locations.

  • Last updated: 2025-09-18

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Key updates

The first 3 tiles provide summary data about the number of sites, samples and chemicals.

The last 4 tiles show the number of samples where a concentration of a pesticide exceeds its aquatic life reference values (ALRVs) or human health reference values (HHRVs).

Sites
Sites sampled

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Sites with detection

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Sites with exceedance

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Samples
Samples collected

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Samples with detection

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Samples with exceedance

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Chemicals
Chemicals analyzed

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Chemicals detected

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Chemicals with exceedance

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Exceedances

Invertebrates
Acute ALRVs

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Chronic ALRVs

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Fish
Acute ALRVs

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Chronic ALRVs

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Plants
Non-Vascular ALRVs

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Vascular ALRVs

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Humans
Acute HHRVs

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Chronic HHRVs

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Notes
  • Length of exposure (for example, long-term or chronic) is not considered in the number of exceedances.
  • A single sample may include multiple chemicals above reference values, but it’s counted as 1 exceedance.
  • Exceedances do not always mean harm and need to be further analyzed in the context of a risk assessment.
  • ALRVs and HHRVs can change based on new scientific information presented in an updated regulatory decision. Please refer to the data changes table to understand changes that have occurred.

Map of sampling sites

Map instructions
  • Click, zoom, or drag the map to see the sampling sites. Hover over or select a site to see the site name, province, and numbers of detections and exceedances.
  • Blue markers indicate sites with exceedances. Black markers indicate sites without exceedances. Greyed-out markers indicate sites that aren’t part of your current selection from the drop-down menus.
  • Some sites are masked to protect the privacy of landowners. To see the masked sites on the map, toggle the checkbox under the map.
  • Use the drop-down menus at the top of the page to select surface sites, groundwater sites, or both.
  • To access data from Quebec please go to Open Data and Atlas de l’eau.
    Notes for data table
    • Toggle between the two data tables by clicking the ‘show watershed data’ or ‘show detection / exceedance data’ button
    • Filter the table using the arrows or type in the ‘filter items’ box.
    • The 'Next' button shows additional results

    Watershed data:

    Detection/Exceedance data:

    • Data presented in this table is linked to the ‘chemical analyzed’ drop-down menu at the top of the page.
    Data table
    Province Site name Samples collected Samples with detection Samples with exceedances Chemicals detected Chemicals with exceedances

    Detections and exceedances by chemicals analyzed (at all sites)

    This bar chart shows the number of times selected chemicals were detected in samples, as well as the number of times they were above the lowest ALRV or HHRV. Hover over the bars for more information.

    Notes for bar graph
    • ALRVs and HHRVs are not available for pesticide transformation products. If you select a transformation product, NA (not applicable) will appear on the graph and in the table for exceedance frequency.
    • In this dashboard, the highest method detection limit (MDL) between the labs for a given chemical is provided in the ‘standardized detection limit’ column. See ‘Understanding the data’ tab for details.
    • The 'Next' button shows results for additional chemicals analyzed.
    Data table

    Pesticide concentrations over time

    To generate the graph, select a single site and a single chemical from the drop-down menus above. The image below is just an example. Hover over the dots for more information. Check boxes to select which ALRV or HHRV you wish to display. Use the time slider or drop-down menu to select the desired time frame of data to display.

    The table and graph change using the date range you select below. Select a date range from the drop-down menu, use the slider to change your date range, or type the dates directly into the 'From' and 'To' boxes.

    Hover over a point, click a point, or see the table below for individual statistics.

    Example graph showing pesticide measurements over time

    Notes for line graph
    • Trace values (identified as T in the graph) are estimates for concentrations that fall between the method detection limit (MDL) and the limit of quantification. The relative error is greater for flagged than for unflagged detections, so use these values with caution.
    • Non-detects (identified as ND above) are data that fall below the laboratory method detection limit and are therefore not quantifiable.
    • ALRVs and HHRVs are not available for pesticide transformation products, so NA (Not Applicable) will appear on the graph and in the table for exceedance frequency.
    Data table

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