Aquatic Plant & Algae Management General Permit

We issue the Aquatic Plant and Algae Management General Permit to allow the in-water and shoreline (roadsides, dikes/levees, and ditch banks) management of noxious weeds, native nuisance plants, and algae. The permit also allows for phosphorus inactivation treatments. The permit allows the use of a specific list of aquatic-labeled herbicides, algaecides, biological water clarifiers, adjuvants, marker dyes, shading products, and phosphorus inactivation products into the freshwaters of Washington.

The permit is a combined National Pollutant Discharge Elimination System (NPDES) and State Waste Discharge General Permit.

Join our listserv to receive email notifications about this permit.

Permit documents

Modifications to the 2016 Permit

We propose modifying the current permit to allow the use of additional tools to control aquatic plants, algae, and noxious weeds. These tools include:

• Three herbicides.
• One algaecide.
• Two phosphorous inactivation products.
• Adjuvants registered by the Washington State Department of Agriculture (WSDA).

We accepted comments on the modified permit documents from Nov. 7, 2018 until Dec. 21, 2018. We will publish a Response to Comments as an appendix to the fact sheet to address comments submitted during this period. We plan to make a final decision on this permit modification by June 5, 2019.
  1. Draft Modified Aquatic Plant and Algae Management General Permit
  2. Fact sheet
  3. 2017 Supplemental Environmental Impact Statement
  4. Public notice of modified draft
  5. Sign templates

Workshops and hearings

On Dec. 10, 2018, we hosted both a webinar and an in-person workshop immediately followed by public hearings in Lacey, WA. 
View the presentation from our workshops

During the workshops, we explained the proposed modifications to the permit and answered questions. During the hearings, people were given the opportunity to provide oral testimony and written comments on the proposed changes. Written comments received the same consideration as oral testimony.

Only the portions of the permit revised during this permit modification are available for comment.                                          

Modificaciones al Permiso

Ecología propone modificar el Permiso General para el Control de Plantas Acuáticas y Algas. Este permiso regula el uso de herbicidas, alguicidas, adyuvantes, y productos para la desactivación de fósforo para el control de hierbas tóxicas, plantas nativas molestas, algas, y fósforo en aguas superficiales en el Estado de Washington. 

Para obtener más información acerca del permiso general modificado, comuníquese con Stacey Callaway al 360-407-7118. Para información en español, comuníquese con Gustavo Ordóñez al 360-407-6619.

Additional documents