How does the City use herbicide?

Yes.  Any staff member who applies restricted-use pesticides or uses power equipment to apply pesticides on public land is required by state law to be a Certified Public Operator. Mercer Island staff are certified through the Washington State Department of Agriculture and required to complete continuing education training through organizations such as the King County Noxious Weed Program and the Washington State Cooperative Extension Integrated Pest Management Program.  Pesticide certification ensures that staff follow best management practices for proper use and handling of herbicides, ensuring safety of the applicator and the public, and minimizing risk or exposure to off-target species. Currently, eighteen City staff members are licensed by the state.

No.  When the use of glyphosate (the active ingredient in Roundup) is the best fit for the target species, the City uses an aquatic formulation of glyphosate that contains no surfactants.  A surfactant is a chemical additive to herbicides that helps the herbicide stick to the leaves, which increases a plant’s uptake.  POEA (i.e. polyethoxylated tallow amine) is a surfactant known to be harmful to aquatic organisms, including amphibians, at high concentrations. For this reason, the City has elected to eliminate the use of POEA.  In many cases, the City adds an aquatic-approved surfactant to their treatments to ensure the treatments have maximum efficacy.

All herbicide applicators are required to follow regulations for notification on the herbicide label. The City posts signage at entrances to each treated area that includes the date, time, and chemicals applied for at least 24 hours following the application.