Aquatic herbicide application is planned for portions of southern Black Lake, in Kootenai County, Idaho between July 11 and July 13, 2017, weather permitting, in the areas outlined below. Please refer to maps and water use restrictions below for additional information about these treatments.
NOTICE OF 2017 BLACK LAKE EURASIAN WATERMILFOIL TREATMENTS
June 15, 2017
Dear property owners and lake users,
Eurasian watermilfoil has been identified as a significant invasive species within Black Lake, Idaho and is known to negatively affect the beneficial uses of a waterbody. As such, an aquatic herbicide treatment is planned for portions of Black Lake between July 11 and July 13, 2017, weather permitting. The treatment timing was selected to maximize treatment efficacy which is when milfoil is actively growing. Up to 43 acres of the lake will be treated with liquid endothall (Aquathol K, EPA Registration # 70506-176). Please see the following website for information on the endothall herbicide. http://dnr.wi.gov/lakes/plants/factsheets/EndothallFactsheet.pdf
Certain water use restrictions will be in effect for households using lake water located up to 600 ft from treatment areas for at least 12 days depending on herbicide residues. The following water use restrictions apply:
Potable Water: Functioning potable water intakes must be turned off until endothall levels are 0.1 parts per million (ppm) or less by laboratory analysis. Results of laboratory analyses will be posted approximately two weeks after the day of treatment.
Irrigation: There is no restriction on use of water from the treatment area to irrigate established grasses.
Recreational Use of Water in treatment Area: There are no swimming or fishing restrictions within the treatment areas.
Animal Consumption: Do not intentionally use water from the treated area for animal consumption until laboratory analysis indicates that restrictions are lifted. This does not apply to incidental exposure of animals to treated water. Again, laboratory analyses will be posted on the applicator's website listed below.
Home owners near treatment areas who use water from the lake for drinking or irrigation are advised to not use lake water until herbicide residue samples indicate that levels in the water are within acceptable use levels as described above.
A week or two weeks after treatment you can expect to see milfoil within the treatment areas turning brown and losing foliage. Please contact Ben Scofield, Water Resources Specialist with the Coeur d’Alene Tribe’s Lake Management Department (208-686-6206) or David Armes, Terrestrial Resource Specialist, Avista (509-495-2796), with any questions.
Areas within solid yellow lines will be treated with aquatic herbicides for Eurasian watermilfoil between July 11 and July 13, 2017, weather permitting.
Areas highlighted in yellow will have water use restrictions in effect after treatment.
Water use restrictions will be in effect for potable use purposes after treatment. Additional information will be provided after herbicide treatment has occurred and when water use restrictions have been removed.
Yellow Polygons - Planned treatment and water use restriction area
Red Polygons - Treated and water use restriction area
Green Polygons - Treated area with no water use restriction