Aquatic Noxious Weed Control General Permit

This permit controls freshwater and marine noxious weeds in Washington. It covers the indirect discharge of herbicides, adjuvants, and marker dyes into estuaries, marine areas, wetlands, along lake shorelines, rivers, streams, and other wet areas.

An indirect discharge occurs when there may be incidental overspray — spray that goes beyond the intended area — or dripping of a chemical from the treated plants into waters of the state.

We issue statewide coverage under this permit to the Washington State Department of Agriculture (WSDA). Individuals or entities may contract with WSDA to be Limited Agents for riparian and emergent noxious weed control projects statewide.

Although the current permit has expired, it is still in effect and treatments can continue until a new permit is issued. We plan to release an updated draft permit for public comment in late 2026, and issue a new Aquatic Noxious Weed Control general permit by Spring 2027.