Water Quality photo identifier

Water Quality Program

Willapa Bay - Grays Harbor
Burrowing Shrimp Control - Imidacloprid

Shellfish growers from Willapa Grays Harbor Oyster Growers Association (WGHOGA) have requested a permit to use the pesticide imidacloprid on burrowing shrimp in Willapa Bay and Grays Harbor. Before considering the permit, we have assessed the potential environmental impacts from the use of the pesticide on tidelands.

We have compiled our findings in a formal report, officially referred to as a draft Supplemental Environmental Impact Statement. We are seeking public review and feedback through Nov. 1, 2017. Two public meetings have been scheduled in October – one in Lacey and one in South Bend.

Get involved

Submit public comments on the Draft Supplemental Environmental Impact Statement Sept. 18 through Nov. 1.

We also encourage you to learn more about the environmental review of this proposal and submit formal comments in person at an upcoming public hearing:

Saturday, Oct. 7 – South Bend

  • Open house: 12 p.m.
  • Public hearing: 1 - 3 p.m.

South Bend High School
400 E First Street
South Bend, WA 98586

Tuesday, Oct. 10 – Olympia

  • Open house: 6 p.m.
  • Public hearing: 7 - 9 p.m.

Lacey Community Center
6729 Pacific Ave. SE
Olympia, WA 98503


Supplemental environmental review findings:

  • Immediate adverse, unavoidable impacts to juvenile worms, crustaceans, and shellfish to the areas treated with Imidacloprid and the nearby areas covered by incoming tides.
  • Limited impacts bay-wide, but that there is significant uncertainty about the cumulative impacts and other unknown impacts to other marine invertebrates and life cycles.
  • Little known direct risk to fish, birds, marine mammals, and human health.
  • Potential indirect impacts to fish and birds if food sources are disrupted.
  • There are still knowledge gaps about Imidacloprid. Further research is needed.

We are currently pre-decisional in our process, which means we have not made a decision about whether to deny the permit application or develop a draft permit approval. Information gathered during this public comment period will inform our decision of how to proceed. We plan to make that decision in fall 2017.

What’s different this time around?

The current proposal is similar – but not identical – to the one submitted by WGHOGA to use imidacloprid in 2015. The applicants propose treating less acreage – 485 acres in Willapa Bay and 15 acres in Grays Harbor – as opposed to 2,000 acres across the two bays in the previous permit. They also propose in this application to treat tidelands with hand or ground equipment as opposed to aerial spraying. The 2015 permit was withdrawn at the growers’ request and never used.

There is also new information to consider when evaluating the potential environmental impacts of this proposal. New research has been released by scientists and government agencies. Several new risk assessments have been completed in North America and Europe providing the best available up-to-date science. There is also a growing public concern about Imidacloprid, which is a neonicitinoid pesticide.

As part of the environmental review process for the current application, we have considered and evaluated new research and analyses that were not available during the previous environmental review. This supplemental review incorporates the most current scientific information available into the full Environmental Impact Statement that was originally adopted in 2015.

New Current proposal application process

The growers completed and submitted an application for the required National Pollution Discharge Elimination System (NPDES) permit, and applications for two Sediment Impact Zone authorizations for areas in Willapa Bay and Grays Harbor in April 2017.

These permits regulate a source of pollution in water (in this case, the discharge of a pesticide) and set rules for the discharge, such as containing that pollution to a specific area and requiring that the effect of the discharge is at or below a minor adverse biological effects level.

New review, new decision process

This new, independent permit application will go through the full, normal regulatory process.

This process breaks down into three distinct phases: review of the environmental impacts, a decision on whether or not to develop a permit, and the permit development process.

First phases in the process:

  • Environmental review
    We made a determination of significance and adopted the full Environmental Impact Statement from the previous 2015 permit. Now that our draft of the supplemental Environmental Impact Statement is complete, it is ready for public review and comment.
  • Public input on environmental review We are here"
    We are holding a 45-day public comment period on our Draft Supplemental Environmental Impact Statement. This will include public hearings, stakeholder and tribal briefings, and other opportunities for review and input. We will consider and respond to all comments before adopting our final review of environmental impact.
  • Permit decision point
    At this point, we will consider everything we learned from our environmental review and determine whether or not to proceed with the permit development process. To decide to draft a permit, we must determine the proposal will meet the regulations and environmental impacts from the use of Imidacloprid can be avoided or mitigated enough to be a safe option to control burrowing shrimp.

If we decide the proposal cannot be sufficiently conditioned to be in compliance with the regulations (for example, the proposal has too many acute, unavoidable environmental impacts), we will deny the application and the process will end. If we determine the proposal can be conditioned to meet all the requirements in the regulations, we will continue with the permit development process.

Environmental review process

We have the responsibility to evaluate projects that may have a significant environmental impact under the Washington State Environmental Policy Act. We are evaluating this proposal to determine whether there will be potential to harm the environment.

We prepared an Environmental Impact Statement for the 2015 permit process, and we will supplement it with the most up-to-date research and information available. The Supplemental Environmental Impact Statement – ibuilds on the Environmental Impact Statement from 2015. It compiles new research and information that wasn’t available to us when we prepared the 2015 Environmental Impact Statement.

Current proposal application documents:

To stay informed on opportunities to comment on this process, please join our Aquatic Pesticide Permit ListServ.


Email: burrowingshrimp@ecy.wa.gov
Derek Rockett, Water Quality Program
Washington State Department of Ecology
Southwest Regional Office
PO Box 47775
Olympia, WA 98504

2015 Permit and SIZ Documents

Oysters in basket after harvest

Aquatic Pesticides Contacts

Aquatic Pesticide Permit ListServ

Focus Sheet: Control of burrowing shrimp on shellfish beds in Willapa Bay and Grays Harbor

Blog: Ecology has received a new request to use Imidacloprid to control burrowing shrimp

Public involvement calendar

Submit comments online