While many states in the Ninth Circuit Court Districts have moved away from requiring NPDES permits to apply aquatic herbicides, Washington’s DOE remains committed to using this permitting program to manage the use of aquatic herbicides. This permit was initially required because of a legal decision in the Ninth Circuit Court in 2001. This past year, the US EPA amended the Clean Water Act to exempt the application of aquatic herbicides from the need for this permit. Ecology has not adopted that position.
Those that treat irrigation deliver systems can view the new permit and learn more about it from this press release.