The Columbia Irrigation District applies aquatic herbicides and algaecides to the entire irrigation canal system in accordance with Washington State Department of Ecology, Permit No. WA0991000. The purpose is to minimize aquatic weed and algae growth to maintain unrestricted water flow within the delivery system. Products used will be Cascade (Dipotassium Salt of Endothall), Nautique (Copper Ethylenediamine Complex and Copper Triethanolamine Complex), Captain and Captain XTR (Copper Ethanolamine Complex), Copper Sulfate Crystals (Copper Sulfate Pentahydrate), Green Clean Pro (Sodium Carbonate Peroxyhydrate), Sonar H4C (Fluridone) and Sonar A.S. (Fluridone).