The permit – called the Irrigation System Aquatic Weed Control General Permit – covers 17 irrigation districts in Eastern Washington. The permit is required by the Washington State Water Pollution Control Act.
The modified permit would allow the irrigation districts to use the pesticide endothall at a more effective rate so it can be used instead of acrolein. Endothall is a less toxic alternative to acrolein. The draft permit reduces and eliminates the use of acrolein, where feasible.