Aquatic Weed Control

Providing aquatic weed control to Seattle,
Olympia, Tacoma, Bremerton & Puyallup.

Whitworth Pest Solutions is recognized as being one of the few pest control companies in Washington State with the knowledge and expertise to perform aquatic weed control. Aquatic weeds can invade rivers, lakes, wetlands and estuaries. These weeds –such as yellow iris, milfoil, reed canary grass, etc.-- can cause both ecological and economic damage by destroying fish and wildlife habitat (such as blocking salmon runs), interfering with navigation and flood control, stopping recreation like swimming and fishing, and reducing property values.

An example of one of the benefits we provided with an aquatic weed control treatment: Whitworth had treated a stream to control aquatic weeds that were choking a small stream running through a city here in the Puget Sound area. The result was summed up by a quote from a local city engineer. After the treatment had taken effect, he stated that "Whitworth should take some pride in assisting this water-body to repair itself. I've received eight phone calls since yesterday from people astounded at the number of fish coming up the 'ditch.' Appreciate your help." (See the before and after pictures of this project on the right).

Aquatic weeds are very hard to control. In Washington State, controlling them is highly regulated. A special license issued by the State Department of Agriculture is required before anyone can treat aquatic weeds in “waters of the state.” These waters are broadly defined as any water standing in the soil. It does not apply to things like swimming pools or ornamental ponds with concrete or plastic bottoms.

The state also regulates the herbicides that are allowed to be used. Not all pesticides registered for use in water are legal in this state. Even with the proper license, most treatments require a special Department of Ecology permit. Obtaining this permit is a long, complicated process, taking 60-90 days. Once all the requirements are met, we have a variety of effective herbicides to tackle your aquatic weed problems. We can treat ponds, ditches or lakes.