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Home    Residents    Open Spaces (Parks)    Herbicide Use on Town Property

Herbicide Use on Town Property

The Town must consider a range of challenges and issues when implementing vegetation and pest management in landscape and park environments, including:

  • Health, Safety, and Water Quality
  • Aesthetics versus Need
  • Education and Notification
  • Administrative and Political
  • Construction and Disturbed Sites
Health, Safety and Water Quality

Issue: The Town should ban all pesticide use because of the potential for impact on human health and environment.

Response: Nuisance, noxious, and restricted weeds and various insect pests are invasive species that cause significant threat to our agricultural crops, urban forest, the environment and its associated ecosystems. Many of these invasive species are required to be controlled or destroyed by law. Integrated pest management promotes utilizing the best strategy and practices to address a specific pest problem, which includes using pesticides when necessary. Banning pesticides would reduce the number of management tools available allowing some of these invasive species to spread beyond control by other methods. Minimal concentrations of chemical can be effective when used properly and at the right time during the growing season.

Issue: There are concerns that the products presently used by the Town represent long term and potentially dangerous hazards to individuals using public lands.

Response: Herbicides are a very useful tool for weed control and are especially helpful on sites where weed infestations are severe. There is extensive scientific evidence that herbicides are very safe when applied as intended following instructions for use. As severe weed infestations can be extremely detrimental to the environment and agriculture industry, finding the right balance between chemical use and acceptable weed levels is instrumental. The Town's “Right to Know” bylaw warns users of the area intended for treatment. Herbicides will only be applied when restricted or noxious weeds are present, or when nuisance weeds exceed the acceptable levels.

The Pest Management Regulatory Agency of Health Canada is the governing body that approves and grants registration for pesticides in Canada. Prior to receiving Federal registration, the manufacturers are required to demonstrate the products do not pose a significant health risk, as long as they are used in the manner for which they were registered. The Town only uses pest control products that have received Federal registration.

Of far greater concern is the frequency and improper application of pesticides by residents who are not trained in proper pesticide application procedures and are not aware of potential harmful human health and environmental impacts. Of particular concern is the application of herbicides prior to storm events which may not provide enough time for the product to break down and become chemically inert. As a result, pesticide products enter the Sheep River and can have adverse affects on aquatic health. The percentage of herbicide loss following a storm event can be significant. One study found up to 90% of the herbicide 2,4- was lost in storm water runoff after being applied a few hours before a storm event (Hall et. al, 1995)2.

Issue: Children that use tot lots and playgrounds and sports fields cannot comprehend pesticide warning signsand as a result are likely targets for secondary pesticide exposure.

Response: Town maintained tot lots and playgrounds are not to be treated with pesticides. The maintenance practice will be to hand-pull or dig all weeds from turf and gravel areas. Open Spaces may trial a super-heated steam system to treat weeds in chemically sensitive areas. The IPM Plan recommends a 15 meter “pesticide-free” buffer zone be maintained around playgrounds and tot lots. Sports fields will be closed for maintenance should a herbicide application be necessary. Signage will be posted as per the “Right-to-Know” bylaw.
 
Aesthetics versus Need

Issue: There may be a perception the Town may indiscriminately use pesticides.

Response: The frequency of pesticide application on Town land depends on turf health, vigor and quality, location, and maintenance standards and type of park or public land. The maintenance standard for different public lands determines the efforts needed to maintain that site. The Town does not indiscriminately use pesticides. Indiscriminate use of pesticides contradicts the provincial Environmental Codes of Good Practice for pesticide applications and is subject to prosecution by the provincial government.

Issue: There is a perception that nuisance weeds such as dandelions are not invasive and do not pose a threat to municipal public lands.

Response: Nuisance weeds are, by definition, common species that can be found throughout Alberta that cause significant economic losses, but are so biologically suited to Alberta that they cannot be eradicated. Weeds are generally opportunistic and symptomatic of growing conditions not adequate to support desirable species. Unhealthy turf and exposed soil areas are susceptible to weeds. Many of the turf grass mixes used are better suited to irrigated sites. Periods of drought can send turf species into dormancy, allowing weeds to flourish will little competition. Cultural maintenance practices such as top dressing, aerating, fertilizing, and necessary irrigation are required to keep traditional turf resilient from weed infestation. Where appropriate, especially on non-irrigated sites, native and non-traditional turf mixes should be considered to provide healthy ground cover resistant to weeds.

Issue: The lists of pests are not all inclusive in the provincial regulations and civic bylaws.

Response: The IPM Plan will continue ongoing efforts towards determining pest categories and tolerance levels of various pests within the Town. Initial pest management objectives within the plan will be based on the legal pest definitions in the Agricultural Pest Act and Weed Control Act. Further review of these pest species will be determined in future IPM program reviews and in consultation with professional expertise of the Provincial Weed Inspector.

Education & Notification
Issue: There are few formal educational opportunities which would enable communities to understand the methods and principles needed to participate in pest management of civic or private landscapes.

Response: Different levels of cooperation and participation from residents will result from apparent contradictory messages received from various sources internal and external to the community. The IPM Plan will continue to assist in establishing consistent messages and delivery of IPM information and educational programs on the Town's IPM Plan and how homeowners can utilize IPM principles and practices on their properties.

Issue: The concern is that the present notification system does not adequately address all potentially susceptible open spaces and parks users.

Response: The IPM Plan provides public notice on pesticide applications. Community areas and residents receive a 24 hour pre-notification of herbicide applications and 48 hour post-notification through warning signs posted at the main entrances to residential areas and directly at the site where applications will occur.

Issue: How are staff trained in IPM?

Response: Most staff involved in implementing the program bring with them post-secondary training including IPM and cultural management practices. Additional education is provided as needed to Town staff, committees, and Council to help in decision-making about IPM strategies and implementation plans. The IPM Plan recommends establishing regional cooperation and continued participation in external educational training programs for Town employees, developers, and private contractors involved with various aspects of pest management.

Administrative and Political Implications

Issue: If the Town hasn't had an IPM Plan until now, were herbicide and other treatment applications in previous years really necessary? Why do we need an IPM plan if we're already practicing IPM strategies?

Response: Although there was no formal departmental IPM program in place, the Town has utilized different management strategies within their operational units that are fundamentally IPM based. However, there is a real need to have IPM standards and practices implemented to ensure that appropriate landscape maintenance standards are met and pest assessments are conducted prior to treatments.

Issue: Periodically the Town has received interest from individuals/groups that have expressed interest in the Town or their parks and open spaces areas to be “pesticide-free.”

Response: The IPM Plan would establish a framework to encourage and facilitate community involvement in park maintenance and seek opportunities to establish reasonable park plans to reduce or eliminate pesticide use.

Issue: Information regarding pest management is not consistent or coordinated with the Towns in the region. The Towns need to become leaders in environmentally sound pest management to assist in the preservation and protection of urban and rural landscapes as well as the overall aquatic health of the Sheep River watershed.

Response: The IPM Plan would establish a framework to develop and encourage other Towns in our watershed implement this or a similar IPM program. The IPM Plan also encourages public education campaigns and educational materials to inform residents of current and alternative pest management practices.

Transportation, Construction and Disturbed Sites

Issue: The railway and school bus routes provide mechanisms for weeds to be introduced and transported out of the community, creating a potential impact on rural lands. The school bus parking areas have frequent scentless chamomile infestations and the railway line also transports weed seeds.

Response: The railway has a linear impact on the Town of Okotoks providing a mechanism for weeds to be transported into the community and provides a means for weeds to be transported out of the community. This means that rural landscapes can be adversely impacted by weeds originating within the Town and vice versa. Similarly, school buses have also had the potential to transport weed seeds. It is recommended that these areas are regularly inspected and actions are taken to remove weed infestations to avoid impact on rural landscapes.

Issue: Increased development within the Town has increased disturbed soil areas susceptible to weed infestation as well as introduced soils and potential weed seeds. These areas become unsightly and contribute to the noxious and nuisance weedproblem on both urban and rural landscapes. The large quantities of new trees and other plant materials used in new communities also pose a risk to introduce pests. Regular inspections of new plantings on municipal lands are essential to maintaining pest free urban environments and supporting IPM strategies.

Response: From a weed perspective, greater management and control of disturbed soil areas and fill is needed by developers. Okotoks' General Design & Construction Specifications are updated annually to accommodate this goal. Site inspections and orders to control weed growth should be conducted and issued on a regular basis. In minimizing risks of pests, the Town will support and encourage nursery suppliers join forces with the Domestic Phytosanitary Certification Program (DPCP). This is a program developed by the Canadian nursery industry and supported by the CFIA (Canadian Food Inspection Agency) promoting clean nursery stock.

How Does the Town Determine When Herbicide will be Applied?

Open Spaces assesses all manicured turf areas for weeds. The method for sampling is a 1m2 sampling quadrant. The quadrant is tossed out onto random, yet representative, areas of the turf and the number of weeds counted. Five samples are taken on small sites, ten on large sites. Sports fields are sampled separately from surrounding park areas. The acceptable level of weeds is <15% (or 15 weeds/m2). Where weed coverage >15%, the site is prescribed for herbicide control.

As weeds tend to proliferate in unhealthy turf or non-irrigated turf, other Integrated Pest Management (IPM) practices need to be considered. The dominant turf species in manicured turf is Kentucky Blue Grass, which has a high water requirement. The fall of 2008 and spring of 2009 have received very low precipitation, which keeps Kentucky Blue Grass in a more dormant state, with less active growth. When the grass is dormant, the weeds have less competition and have a better chance to take over.

Aside from increased irrigation, IPM measures that may help turf resist weeds include:

  • seeding in more drought tolerant turf species
  • aerating to allow moisture to penetrate more deeply
  • increasing organic matter in soil by topdressing with compost

All of these practices are being utilized where budget and resources permit.