Lake Tapps to Get Second Round of Milfoil Treatment

After a successful first run of milfoil treatment, Lake Tapps will undergo a second round this August, according to a Cascade Water Alliance press release.

The nonprofit lake owner began a multi-year program last year to reduce the amount of milfoil in the lake – a recent study shows that the treatments, stretched across 400 acres, have been successful.

Eurasian Water milfoil is a non-native, invasive aquatic plant that spreads rapidly, crowds out native plants and forms dense surface mats in Lake Tapps. 

“The 2011 treatment plan calls for treatments on Monday, Aug. 15 and Tuesday, Sept. 6 with an option to do an additional small quantity should we notice other areas that we missed from a boat survey to be conducted in mid-August,” said Jon Shimada, Cascade’s Capital Projects Director.  If other areas are added, there will be a third treatment date in late September.”

The treatment will consist of applications of Sonar PR (Fluridone) as used last year, with the addition of Renovate OTF (Triclopyr.) The Renovate label states, “there are no restrictions on use of water in the treatment area for recreational purposes, including swimming and fishing;” however to prevent eye irritation, the State Department of Ecology imposes a 12-hour restriction on swimming after treatment.

Cascade awarded the 2011 contract for milfoil treatment to Aquatechnex, the same contractor who conducted the 2010 treatments.  Aquatechnex will perform herbicide treatment to approximately 100 acres of the lake this year.

The State Department of Ecology requires a 10-day notice period per treatment application. Homeowners in affected areas will be notified at their property that treatment will be done.