On Tuesday, May 4, a qualified aquatic herbicide contractor will treat Eurasian watermilfoil on the north, east, and southeastern sections of the lake with Florpyrauxifen-benzyl (brand name ProcellaCOR). The work is funded by a Department of Ecology grant.
Lake residents and lake users have reported that these aquatic plants restrict movement and make it difficult to boat or fish, and the decomposing plants smell unpleasant when they die off in the fall. Water quality in the lake has also been impacted; low oxygen levels can trigger increased nutrient release from lake sediments. These conditions have historically led to toxic algae blooms on Lake Ballinger.
To address the problem, a citizen steering committee has recommended an integrated aquatic vegetation control plan, including the use of selective aquatic herbicide. The herbicide chosen was selected for the minimal risk to people and animals, and has been approved by the Environmental Protection Agency (EPA) and the Washington Department of Ecology for use in potable water sources.
No restrictions on swimming and fishing in the lake are required. A previous herbicide treatment in the lake in 2019 on the north and west side of the lake was extremely effective, reducing the amount of Eurasian watermilfoil by 80% across the lake. The goal of this invasive control effort is to encourage a more balanced native plant community, improve overall lake water quality, and support recreational activities.
Today the herbicide contractor will post all lakefront property within 400 feet of the treatment area (including the Mountlake Terrace boat launch and swimming beach) with notification and information regarding the herbicide treatment.
The city reminds you to always check your boats and fishing gear when you enter or leave the lake; remove all plant fragments and place them in your yard waste container.
For more information, please contact Stormwater Program Manager Laura Reed at firstname.lastname@example.org or (425) 361-8713.