The permit covers 16 irrigation districts that use pesticides to control aquatic weeds and algae growth in irrigation systems. The permit is required by the Washington State Water Pollution Control Act.
Ecology’s updated permit tightens the limit for the discharge of copper from irrigation systems. Copper kills aquatic weeds, however it also harms fish and other forms of aquatic life. Copper can damage the function of fish gills. It also interferes with the ability of migratory salmon and steelhead to find their spawning streams.
The permit also provides specifics to irrigation districts that use pesticides about where they should monitor water quality.
Any short term toxicity to aquatic organisms is allowed under the terms of the permit and the water quality modification provisions to perform essential activities that promote effective water delivery.
This permit does not authorize a violation of the surface water quality standards, or any other applicable state or federal regulations. Ecology may require any person seeking coverage under this permit to obtain coverage under an individual permit instead.
The determination of whether or not a pesticide is a pollutant under the Clean Water Act is still before the courts.
On November 21, 2006, the U.S. EPA issued a final rule entitled “Application of Pesticides to Waters of the United States in Accordance with FIFRA [Federal Insecticide, Fungicide, and Rodenticide Act].”
This rule replaces the draft interpretive statement the EPA issued in 2003 concerning the use of pesticides in or around waters of the United States.
The EPA rule states that any pesticide meant for use in or near water that is applied in accordance with the EPA-issued FIFRA label, is not a pollutant under the Clean Water Act. Therefore, such applications are not subject to NPDES permitting.
The rule has been appealed and will be heard in the coming months by a U.S. District Court.
After the EPA issued this rule, the Department of Ecology met with stakeholders to seek input on how Ecology should regulate the use of pesticides until the rule appeal concludes. Ecology also provided the public with a three week comment period.
Stakeholders affiliated with each of the seven affected permits - mosquito, noxious weed, aquatic plant and algae, irrigation, oyster growers, fish management, and invasive moth - sent comments to the Department of Ecology. The majority of comments requested that the state agency continue issuing joint NPDES/state permits to regulate aquatic pesticide applications.
The Department of Ecology warns users that any application of pesticide to surface waters of the state requiring NPDES permit coverage that is found not to be covered under either the general permit or an individual permit may be subject to potential enforcement action.
The new permit replaces and revokes the permit Ecology issued on April 10, 2002, and that expired on May 10, 2007. The official title of the revised permit is Irrigation System Aquatic Weed Control National Pollutant Discharge Elimination System (NPDES) and State Waste Discharge General Permit.