National Pollutant Discharge Elimination System (NPDES) Permits
The Washington Department of Ecology (Ecology) developed National Pollutant Discharge Elimination System (NPDES) permits for the use of aquatic pesticides in lakes, rivers, estuaries, and irrigation canals in Washington State in response to a Ninth Circuit Court decision, Talent Irrigation District v Headwaters, Inc. The permits were developed between July 2001 and June 2002. Ecology has delegated authority from EPA to enforce the Clean Water Act in Washington State.
Permits are required for any application in, or adjacent to water, including mosquito control, where the objective is to control larvae in water. It includes wetlands with standing water. If the application is made when the ground is dry, no permit is needed unless residue remains when the ground is wet. This creates a difficult situation for the use of persistent herbicides in seasonally wet areas.
Four general NPDES Permits were developed:
- Aquatic Plant and Algae Management – in lakes and ponds
- Irrigation System Aquatic Weed Control Permit
- Mosquito Control Permit – issued to mosquito control districts
- Noxious Weed Control Permit – for the control of noxious and quarantine list weeds along lake and river shorelines, in rivers, wetlands, and estuaries. Coverage is issued to the State Department of Agriculture.
Three individual Permits were developed for unique circumstances:
- Fish Management – issued to the Washington State Department of Fish and Wildlife for the use of rotenone in lakes.
- Invasive Moth Control – issued to the Washington State Department of Agriculture for control of various moth species, including gypsy moth.
- Oyster Growers Permit – issued to the Willapa Bay/Grays Harbor Oyster Growers Association for ghost shrimp control.
- Non-native Invasive Aquatic Animal and Marine Algae Management General Permit (This permit was developed because of concerns about zebra mussels, marine algae, Caulerpa and other invasive species.)
According to the Department of Ecology, these permits are intended to:
- Ensure those pesticides that have the lowest risk to human health and the environment are used.
- Reduce uses and amounts of pesticides.
- Track uses of pesticides.
- Assure that public notifications and postings occur when waters are treated.
- Monitor levels of pesticides in the water after treatment.
More information about NPDES permits can be found on the Ecology website.