Pesticides and Water Quality

Proper handling, use, and disposal of pesticides are critical for preventing adverse impacts on water resources. Environmental pollution can occur when pesticides enter surface and ground water systems through misapplication, movement of treated soils, irrigation return flows, runoff from urban and agricultural land, storm water runoff, and leaching through soils. It is important to know the pesticide and soil properties to help avoid water contamination. Your local NRCS Soil Conservationist can provide you with more site specific pesticide and soil properties information. For additional information and links to publications on this topic, visit:

National Water Quality Program,

Idaho State Department of Agriculture,

Oregon Department of Agriculture,

Washington Department of Agriculture,

Water Quality Related Databases

State and county offices of the USDA-Natural Resources Conservation Service will provide decision aids and risk assessment tools to predict groundwater and surface water vulnerability to pesticide contamination. The decision aids utilize pesticide properties and soil types to help predict site-specific vulnerabilities.

Clean Water Permits for Certain Pesticide Applications

A permit is required for certain pesticide applications in, over, or near waters of the State and/or United States. A National Pollutant Discharge Elimination System (NPDES) pesticide general permit and a Notice of Intent (NOI) may be required before an aquatic application or pesticide application near waterways. Be sure to check the state and federal regulations.

Idaho: Idaho Department of Environmental Quality issues NPDES permits under the Idaho Pollutant Discharge Elimination System.