The (American) Okanogan County Noxious Weed Control Board has applied to a national environmental agency to treat Eurasian water milfoil with an aquatic herbicide, much to the dismay of the (Canadian) Okanagan Basin Water Board.
Osoyoos Lake is located in Osoyoos, British Columbia and Oroville, Washington; making it an international lake. The Boundary Waters Treaty states that shared waters “shall not be polluted on either side to the injury of health or property on the other.” Osoyoos mayor Stu Wells feels the potential risks to the ecosystem, drinking and agricultural water intakes are unknown and may violate the treaty.
Canadians have moved away from aquatic chemical control for milfoil decades ago, they rely upon aquatic weed harvesting, rototilling, and hand-pulling to control the milfoil. Wells says all that is stopping their weed harvesters from cutting the milfoil on the American side of the lake is an imaginary line.