WSR 10-06-103


[ Filed March 2, 2010, 6:34 p.m. ]


Announcing Permit Modification of the General Permit for

Aquatic Weed Control in Irrigation Systems

On March 17, 2010, the department of ecology (ecology) is modifying a general permit that covers pesticide use in irrigation systems. The permit is called the "irrigation system aquatic weed control national pollutant discharge elimination system (NPDES) and state waste discharge general permit." The modification to the permit allows the use of the pesticide endothall. Endothall is an alternative to acrolein, the pesticide that irrigation districts historically used but is being phased out.

Purpose of the Permit: The permit covers the discharge of pesticides used in irrigation systems in Washington state. Pesticides are used to control plant and algae growth. Under the Washington State Water Pollution Control Act, a permit is required to discharge pollutants that alter the biological or chemical characteristics of a water body. The permit addresses these legal requirements and regulates the discharge of pollutants to protect water quality in Washington.

Ecology issues a general permit in place of a series of individual permits for similar[ly] permitted activities. Individual activities that receive coverage under the general permit must comply with the terms and conditions of the permit. The permit covers irrigation districts and other irrigation water suppliers who apply for coverage under the permit. The permit applies statewide. The modified permit will be effective on April 17, 2010.

Public Comments: Ecology held a public comment period from January 6, 2010, to February 19, 2010. Ecology held a public workshop and public hearing in Yakima on February 9, 2010. Ecology is issuing the final permit after considering all public comments.

Changes From the Draft to the Final General Permit: Ecology made numerous changes to improve clarity and readability of the permit. Ecology made two significant changes to the permit based on public comments:

Changed the effluent limitations in Condition S5.B4.

Clarified the scope of the endothall plan in Condition S5.B10.

Applying for a Permit: The modified permit covers the same irrigation districts covered by the 2008 permit. The following entities have permit coverage:

1. Cascade Irrigation District

2. Columbia Irrigation District

3. East Columbia Basin Irrigation District

4. Ellensburg Water Company

5. Kennewick Irrigation District

6. Kittitas Reclamation District

7. Naches-Selah Irrigation District

8. Quincy-Columbia Basin Irrigation District

9. Roza Irrigation District

10. Selah-Moxee Irrigation District

11. South Columbia Basin Irrigation District

12. Sunnyside Valley Irrigation District

13. Union Gap Irrigation District

14. Wenatchee Reclamation District

15. Westside Irrigating Company

16. Yakima-Tieton Irrigation District

New or currently nonpermitted facilities may obtain coverage under the permit by submitting a complete permit application to ecology. Application forms are available from ecology.

Requesting Copies of the Permit: You can request copies of the permit, fact sheet, and application by contacting Andrew Kolosseus, Department of Ecology, P.O. Box 47600, Olympia, WA 98504-7600, phone (360) 407-7543, fax (360) 407-6426, e-mail

The permit and fact sheet are also available on-line at

Appeal Process: You may appeal the permit within thirty days. Pursuant to chapter 43.21B RCW, appeals must be filed with the pollution control hearings board and served on the department of ecology within thirty days of receipt of the permit.

Your notice of appeal must be filed with the Pollution Control Hearings Board, 4224 6th Avenue S.E., Rowe Six, Building 2, P.O. Box 40903, Lacey, WA 98504-0903.

Your notice of appeal must also be served on Department of Ecology, Appeals Coordinator, P.O. Box 47608, Olympia, WA 98504-7608.

In addition, please send a copy of your notice of appeal to Andrew Kolosseus, Department of Ecology, P.O. Box 47600, Olympia, WA 98504-7600.

Washington State Code Reviser's Office