Lake Ballinger being treated with herbicides to control invasive aquatic weeds

Pesticides will be distributed from an air boat
Photo courtesy City of Mountlake Terrace

Reporting from MLTNews.com

Beginning Wednesday, July 24, the first of three treatments of aquatic herbicides was applied in Lake Ballinger to control lake weeds, the City of Mountlake Terrace said.

In recent years, Lake Ballinger, across SR 104 from Shoreline, has become infested with invasive aquatic weeds, including Eurasian watermilfoil, fragrant water lilies and curly leaf pondweed. The thick aquatic plant beds that cover most of the nearshore area have negatively impacted boating, swimming, and fishing in the lake. Invasive weeds have also reduced water quality.

To address the problem, a steering committee of local residents has recommended a control plan including use of burlap bottom barriers and aquatic herbicide applied to 50 percent of the lake during summer 2019. (See more about the plan in an earlier story.) Lake Ballinger will be treated with aquatic herbicides three times between July 24 and Sept. 15, 2019. A motorized boat has been permitted on the lake in order to complete this project.

Treatment will be applied to the western shore of Lake Ballinger and the northeastern section near Ballinger Park fishing dock/boat ramp, the city said. These herbicides were chosen by the steering committee and have been approved by the U.S. Environmental Protection Agency (EPA) and Department of Ecology for use in potable water sources. 

There are no restrictions on swimming, fishing, or irrigation with the herbicides (SonarOne and ProcellaCOR with active ingredients Fluridone and Florpyraux-benzyl.) The herbicide treatment is regulated under a permit issued by the Washington State Department of Ecology.

This project is intended to support a more sustainable lake environment through reducing the quantity of invasive aquatic weeds, decreasing phosphorus levels, and improving the quantity of dissolved oxygen in Lake Ballinger, the city said.

Lake Ballinger watershed

Lake Ballinger outflow goes to Ballinger Creek and McAleer Creek on the east side of I-5, and Lyon Creek, flowing through Shoreline and Lake Forest Park then into Lake Washington at LFP Town Center.

More background information on the treatments for Aquatic Weed Control in Lake Ballinger can be found in the city’s Integrated Aquatic Vegetation Plan posted on the city’s website.