An aquatic herbicide will be applied Monday to the waters of the swim beach and boat harbor at Gene Coulon Memorial Beach Park and at Kennydale Beach Park to treat milfoil, an aquatic non-native weed that flourishes in Washington.

An additional treatment is possible Wednesday, if the work isn’t completed Monday.

Milfoil is a feathery weed that can tangle people, boat propellers and fishing lines. It chokes out native plants and spreads rapidly to new areas and has few natural controls. Once established it is difficult to remove through mechanical removal efforts and aquatic treatment is the most effective solution.

The process includes applying an aquatic herbicide below the surface of the water, which then settles on the plants.

Gene Coulon Memorial Beach Park swim area and Kennydale Beach Park will be closed on June 15, 2009, in order to conduct the application. The product used for this application is safe and is authorized by the Washington State Department of Ecology. Aquatechnix LLC, the contractor conducting the application, has notified area residents and has posted signs.