Irrigation System Aquatic Weed Control NPDES General Permit

The Washington State Department of Ecology issues general permits for the application of herbicides to control aquatic weeds in irrigation water conveyance systems. Ecology wrote the last permit in March 2008.

During the revision process Ecology used a Permit Advisory Committee to gather input from the stakeholders. Once they completed their reviews, Ecology held a public comment period on the draft permit from November 7, 2007 to January 11, 2008.

Note: unless otherwise specified, the files below are available in Adobe Acrobat (.PDF file) format. To view and/or print PDF files, you first will need to download and install Adobe Acrobat Reader.

Proposed Permit Modification

The Washington Department of Ecology (Ecology) is proposing to modify the permit in early 2010 to allow the use of the pesticide endothall. More information will be added to this website soon.

Washington State Register Notice

For more information please contact:

Andrew Kolosseus
Washington State Dept. of Ecology
Water Quality Program
PO Box 47600
Olympia, WA 98504-7600
(360) 407-7543
Email: Andrew.Kolosseus@ecy.wa.gov

Last updated November 2009