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Pesticide Applications into Surface Waters

Pesticide applications into surface waters

The Oregon Department of Environmental Quality requires a permit for any pesticide application in, over or near water. Two general permits regulate pesticide use. The 2000-J is a new general permit for pest control within irrigation district boundaries. The 2300-A Pesticide General Permit provides coverage for a variety of pest control applications that typically reach water. Information about permit coverage is provided below. These general permits should result in long-range, benefits to water quality.

Pesticide use in irrigation systems (2000-J)

The 2000-J general permit regulates the use of pesticides for weed and algae control within irrigation system boundaries. Permit coverage is available for operators of irrigation systems formed as Irrigation Districts under ORS Chapter 545, Water Improvement Districts under ORS Chapters 552 and Water Control Districts under ORS Chapter 553 and any irrigation system operating under an individual permit. Registration is required to receive coverage under this general permit.

2000-J Permit and supporting information

Pesticide General Permit 2300-A

2300-A general permit regulates pesticide applications made in, over, and near water. Examples of treatment objectives regulated under this permit include insect control, plant and animal control, conservation, habitat, recreational and economic management. 

2300-A Permit and supporting information

Application information

To help operators complete the application for registration and satisfy the permit recordkeeping, notification and reporting requirements, DEQ has mapping tools and GIS layers available.

​​The U.S. Environmental Protection Agency issued a final rule in November 2006 that clarified two specific circumstances in which a Clean Water Act permit is not required before pesticides are applied. The two situations are when pesticides are:

  • applied directly to water to control pests, including mosquito larvae, aquatic weeds and other pests in the water

  • applied to control pests that are present over or near water where a portion of the pesticide will unavoidably be deposited to the water in order to target the pests effectively.

In effect the rule meant that pesticides legally registered under the Federal Insecticide, Fungicide, and Rodenticide Act for application to or near aquatic environments, and legally applied to control pests at those sites, were not subject to NPDES permit requirements. The rule became effective Jan. 26, 2007. Challenges to the rule were filed in 11 circuit courts around the country. The challenges were consolidated for hearing in the Sixth Circuit Court. On Jan. 7, 2009, the Sixth Circuit Court ruled that NPDES permits are required for:

  • all biological pesticide applications and

  • chemical pesticide applications that leave a residue or excess pesticide in water

When the applications are made in or over or near U.S. waters. The court ruling affects DEQ because EPA authorizes DEQ to issue NPDES permits and conduct the compliance and monitoring for these permits.

The Sixth Circuit Court gave EPA two years to develop a general permit so that by April 9, 2011, the regulated community was required to be covered under the pesticide general permit. EPA requested and received an extension on the court-ordered date. NPDES permits were required by Oct. 31, 2011. EPA issued the permit on Oct. 31, 2011.

EPA’s Pesticide General Permit covers discharges in areas where EPA is the NPDES permitting authority, which include four states (Massachusetts, New Hampshire, and New Mexico), Washington, D.C., all U.S. territories, most Indian Country lands, and federal facilities in four additional states (Colorado, Delaware, Vermont, and Washington).


Beth Moore
General Permit Coordinator