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Herbicide Sprayed in Pine Chee Wetland

During July 2010, an herbicide called Milestone (a.k.a. Aminopyralid) was sprayed by the company at various sites for noxious weed control. At the Pine Chee site, OHA staff noticed that Canada Thistle plants (Cirsium arvense) growing in and near the water had been sprayed, as evidenced by curling and yellowing of the leaves.

While Milestone is a good choice of herbicide, being registered under the EPA’s Reduced Risk Pesticide initiative, the label clearly states: “Environmental Hazards: Do not apply directly to water, to areas where surface water is present… It is a violation of Federal law to use this product in a manner inconsistent with its labeling."

OHA has notified the company as well as Ecology and Fish and Wildlife, and the company has instructed their spraying contractor to leave an appropriate corridor in the future. They are looking into manual pulling of weeds in the wetland areas. OHA will continue to monitor noxious weed management on the Pine Chee and Myers Creek mitigation sites.  
   Thistle sprayed in wetland
Thistle growing in water, 
sprayed with Milestone

Herbicide sprayed in wetland