Aquatic Mosquito Control Permit - NPDES General Permit

What is the purpose of this permit?
This permit allows government entities and individuals to discharge insecticides into state waters to control mosquitoes and ensures water quality is protected. It is a combined National Pollutant Discharge Elimination System (NPDES) and State Waste Discharge General Permit.
Who issues this permit?
Department of Ecology
What activities require this permit?
The application of mosquito larvicides or adulticides to state waters requires permit coverage, whether it is a direct or indirect discharge. For example, a direct discharge is the application of larvicides directly to surface water, while an indirect discharge is the settling of adulticides onto surface water even though the water was not the target area. Government entities and Mosquito Control Districts may hold one permit coverage that covers their entire jurisdiction. Commercial applicators must get separate permits for each waterbody they treat or group who hires them. To find out the specific activities that trigger this permit, see Special Condition S1 on page 3 of the current permit or page 35 of the fact sheet. You can download both documents from the Aquatic Mosquito Control General Permit website.
How much will this permit cost?
There is no fee to apply for permit coverage. After Ecology approves your application and issues permit coverage we will send you a bill for the annual permit fee, which is currently $500. Permit fees change over time, so please check the Permit Fee Schedule in WAC 173-224-040.
Where can I get the application for this permit?
The application is called 'Notice of Intent (NOI) Application Form for Coverage Under the Aquatic Mosquito Control General Permit' is online and can be accessed at
Do I need to include anything with my application?
Applicants must submit a completed and signed SEPA checklist unless SEPA is completed at the local level. If SEPA is completed at the local level, include:
  • A completed and signed SEPA determination.
  • A map of the area and location(s) you are proposing to treat.
  • An Integrated Pest Management Plan, if using adulticides.
Is the decision on my permit dependent on anything besides the information in my application?
When making the decision on your application, Ecology will consider the laws and rules that apply and the contents of your application. In addition, the permitting process includes public participation. This means the public may submit comments to Ecology (during the 30-day public comment period) to support or oppose your proposed activity. If any comments are received, Ecology must review and respond to the comments and consider them when making the decision to issue or deny permit coverage.
How long will it take to review my application?
Generally, 45 to 60 days, which includes the 30-day public comment period. See the Permit Timeliness Results below for average processing times. WAC 173-226-200 and RCW 90.48.170: Application for permits shall be made at least 60 days prior to commencement of any proposed discharge or permit expiration date, whichever is applicable. Ecology can issue coverage on the 38th day following receipt of a complete application and the publication of the first public notice in a newspaper of general circulation in the county.
Where do I submit my application?
You must apply for the permit online, through Secure Access Washington (SAW), and submit a signed hardcopy of your application to Ecology. See the "Notes" section for more information on applying through SAW.

      Department of Ecology
      Water Quality Program
      Attn: Aquatic Pesticide Permit Manager
      PO Box 47600
      Olympia, WA 98504
How long is my permit valid?
Ecology permits are issued for a 5 year period. During that 5 year span, your permit is valid from the day your permit coverage is issued to the day the permit expires at the end of the 5 years. Coverage may be cancelled before the end of the 5 year period by submitting a Notice of Termination or for failure to pay your yearly permit fee. Coverage should only be cancelled if the pesticide discharge you are permitted for is no longer going to occur.
What is the appeal process for the permit?
An order, permit, license, or decision can be appealed within 30 days from the “date of receipt” of the decision. The appeal process is governed by RCW 43.21B and WAC 371-08. “Date of receipt” is defined in RCW 43.21B.001(2). Get more information on the Pollution Control Hearings Board web page.
Notes / Comments:
You must apply for the permit online, through Secure Access Washington (SAW), and submit a signed hardcopy of your application to Ecology.
      The permit application is available online through Secure Access Washington (SAW). Applicants must register for a user account through SAW, and then apply for access to the Secure Service for the pesticide permit they are going to apply for. This initial set up takes longer than filling out a paper application, but reduces time and paperwork in the long run by allowing applicants to submit applications and annual reports as well as updates online. Get the instructions for how to apply for aquatic pesticide permit coverage on the Aquatic Mosquito Control General Permit wep page.
          Get your SAW user account at
              A signed hard copy of each application or annual report is required to be submitted to Ecology to satisfy Environmental Protection Agency reporting requirements.

                    Department of Ecology
                    Water Quality Program
                    Attn: Aquatic Pesticide Permit Manager
                    PO Box 47600
                    Olympia, WA 98504
                For additional help, please contact the Ecology staff listed at the bottom of the Aquatic Mosquito Control General Permit web page.
                Legal Authority:
                Permit Timeliness Results

                Permit Timeliness data collection is in response to a State Auditor’s Performance Audit and RCW 43.42A. Each regulatory agency developed a plan to improve permit clarity, predictability, and timeliness. Each agency considers the customers experience to ensure permit assistance is simple to use, easy to access, and designed in a customer-friendly manner. Agencies report progress to the Governor’s Office for Regulatory Innovation and Assistance (ORIA). ORIA prepares and distributes reports, with participation from the State Auditor’s Office and Results Washington. See latest report here:

                All permits submitted for reporting were entered into this Regulatory Handbook. Here are the results of the performance data:

                Estimated Time Required By the Agency to Process a Permit Application (Definition)
                Average number of days from Receipt to Complete: 1
                Maximum number of days from Receipt to Complete: 1

                Estimated Time Required By the Agency to Issue a Permit Decision (Definition)
                Average number of days from Complete Application to Decision: 1
                Maximum number of days from Complete Application to Decision: 1

                (Summary results based on 6 submittals in 2023)

                Where can I get permitting assistance?
                Web page URL:
                Subject matter expert phone: Contact Information is available at the bottom of the permit web page.
                Department of Ecology
                300 Desmond Drive
                PO Box 47600
                Olympia, WA 98504-7600
                Telephone: (360) 407-6000
                Triggering Questions:
                • Do you plan to apply aquatic pesticides to control larval or adult mosquitoes?
                * Permit information last updated 1/3/2024