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Indicator Type: Environmental Condition
The River Pesticide Index provides general information about the pesticide contamination of Alberta rivers. It does not attempt to measure the risk to aquatic life or drinking water sources. The index uses pesticide data collected at 24 Long-Term River Network (LTRN) monitoring sites throughout the province. It takes into account which pesticides were detected, how often they were detected, and at what concentrations. Over 50 pesticides are routinely analyzed. These include herbicides, insecticides, and fungicides used in agricultural and urban settings of Alberta. Of these, a subset of 17 commonly applied pesticides is used to generate the Index. Pesticides are sampled at LTRN sites four times a year during the open water season.
The River Pesticide Index is a component of the general River Water Quality Index (indicator). It rates the quality as "Excellent", "Good", "Fair," "Marginal" or "Poor", based on the presence of pesticides. Follow this link to learn more about the rating system.
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What does the indicator show?
The 2005-2006 Pesticide Index rating ranges from good to excellent for most long-term river monitoring sites. This indicates that pesticides are detected fairly infrequently and at low concentrations in Alberta rivers. Two of twelve LTRN monitoring stations, one each on the Battle and Bow Rivers, received a rating of fair. This indicates more frequent pesticide detections, higher concentrations, or both, at these two sites.
A number of Alberta rivers, such as the Bow and Oldman, are sampled at multiple locations and can be assessed on a reach-by-reach basis. Not surprisingly, Pesticide Index ratings tend to decline as rivers flow through regions of significant urban or agricultural development. This is an indication that such areas are contributing pesticides to the river. Conversely, northern rivers, such as the Smoky, Wapiti, Peace, and Athabasca, rated excellent in 2005-06. This likely reflects less development and lower pesticide usage in that area of the province.
Important reasons for pesticide contamination relate to the overall quantities used, the wide distribution of application sites, and the behaviour of pesticides in the environment. Pesticides are relatively persistent, water soluble, and volatile man-made compounds. This means they could potentially be transported from application sites (via runoff, percolation, and wind action) and introduced to surface waters, shallow groundwater, and the atmosphere. Low levels of several pesticides often occur at the same time in water. The risk posed by these mixtures to various water users is unclear.
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Why is this indicator important?
Pesticides are designed to adversely affect certain plants and animals. Hence, their presence in rivers may be of significant concern. Direct impacts on aquatic life and human health remain unclear. However, because rivers provide water for aquatic life and for human applications, such as drinking water, irrigation, and stock watering, the occurrence of pesticides in our rivers may pose risks to these various uses.
The River Pesticide Index is typically a measure of non-point source contamination, which has a potential impact on surface waters across the province. It is relevant to the protection of aquatic ecosystems and drinking water sources. These are identified as goals in Alberta's Water for Life strategy.
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What actions are being taken?
The use of pesticides is regulated. Adherence to Codes of Practice, public education about alternative methods of pest control, and proper pesticide use and disposal can help reduce surface water contamination. More information about pesticide management is available from Alberta Environment's website.
The pesticide market is a very dynamic one. New pesticides are introduced continually, while others are phased out or lose popularity. To ensure that the monitoring program adequately reflects pesticide use, Alberta Environment regularly reviews sales records and updates the list of pesticides being monitored in surface waters.
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Links to additional information
Overview Of Pesticide Data In Alberta Surface Waters Since 1995: http://environment.gov.ab.ca/info/library/7614.pdf
Focus on Pesticides: http://environment.gov.ab.ca/info/library/Focus_On_Pesticides.pdf
Alberta Environment's Pesticide Management Program: http://www3.gov.ab.ca/env/protenf/pesticide/index.html
More information on the River Pesticide Index can be found through the Alberta Environment Surface Water Quality website at: http://www3.gov.ab.ca/env/water/swq/
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Feedback
E-mail the SOE Coordinator: SOE.Coordinator@gov.ab.ca or complete this short on-line questionnaire to provide your feedback: http://www.zoomerang.com/
survey.zgi?p=WEB224DW6P3E2K.
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