Zostera japonica management on commercial clam beds in Willapa Bay General Permit

We issue coverage under this general permit when shellfish growers decide that using an herbicide (imazamox) to control the non-native eelgrass Zostera japonica on their commercial clam beds is a method they want to use. Zostera japonica is a class C noxious weed that may be controlled on commercial clam beds, which do not include geoduck and oyster beds. Physical and mechanical methods of Zostera japonica control are not regulated by this permit.

This permit is a combined National Pollutant Discharge Elimination System (NPDES) and State Waste Discharge General Permit. The permit was last modified on April 5, 2017, and expired on May 2, 2019.

Permit Reissuance

We announced the draft Zostera japonica Management on Commercial Clam Beds in Willapa Bay General Permit (permit) on Sept. 18, 2019. Comments on the draft permit documents were accepted from Sept.18, 2019 to Nov. 4, 2019​. The comment period is now closed. We plan to make a final decision on whether to issue this permit in early 2020. We will publish a Response to Comments as an appendix to the fact sheet to address comments submitted during the public comment period.​

In addition, we have a blog post that explains more about this permit.

Comments we recieved

Comments submitted during the comment period may be viewed through the online comments system.

Workshops and hearings

We hosted two workshops (one as a webinar) immediately followed by public hearings. During the workshops, we explained changes proposed and answered questions. The hearing began after the public workshop and ended when all individuals who wanted to provided their oral testimony. 

Permit documents

Join our listserv to receive email updates about aquatic pesticide permit work.

Annual reports and pre-treatment plans

NOTE: The following information provides annual operations report information. We recently re-developed our Water Quality permit database (PARIS). Soon, these reports will be transitioned to, and only available through, PARIS. They will no longer be posted here. Reports posted here will be removed once they are available through PARIS.