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This page lists environmental documents prepared by the King County Wastewater Treatment Division that are currently available for public review.

The listed documents are mainly threshold determinations and checklists prepared under the Washington State Environmental Policy Act (SEPA statute, RCW 43.21C; SEPA Rules, WAC 197-11). Other environmental documents prepared by the Wastewater Treatment Division, such as documents prepared under the National Environmental Policy Act (NEPA), may also be listed.

Local, state and federal regulations mandate the ways in which agencies must notify the public that environmental documents are available for public comment. These may include mailings, signs and/or newspaper notices. The Wastewater Treatment Division typically makes the documents available in local libraries and upon request. This web page is another way in which the division provides notice and copies of these documents.

You may view and download an electronic copy of each listed document by clicking on the associated link. Information on how to provide comments on each document listed below is included in the document. 

Documents currently available for public comment

Title of proposal: Coal Creek Trunk Maintenance Hole 25B Protection Project

Description of proposal: The King County Wastewater Treatment Division (WTD) proposes to temporarily protect an existing sewer pipeline maintenance hole (MH-25B) that has become exposed due to erosion of the adjacent stream bank along a segment of Coal Creek. MH-25B is currently at risk of being damaged during a high streamflow event, which could result in pipe failure and sewage release into Coal Creek. WTD is therefore proposing to stabilize approximately 80 linear feet of adjacent stream bank by installing four bendway weirs (also known as rock barbs) to redirect streamflow, stone toe protection to prevent erosion, and streambed mix for salmon habitat. Construction is anticipated to last approximately two weeks, during which time the contractor will use a portion of the Red Cedar (also known as Upper West Coal Creek) Trailhead parking lot, and the gravel ramp to the sediment pond for construction staging. WTD proposes to temporarily close the parking lot and trail system within the construction work limits from Monday through Friday, and reopen them on the weekends with construction equipment, construction staging areas, and the work area near MH-25B fenced off. WTD is currently designing a larger project, the Coal Creek Trunk Upgrade Project, which is anticipated to enter construction within the next five years and will permanently remove MH-25B and the temporary protection measures proposed by this project.

Issue date: June 11, 2020

Comment deadline: June 29, 2020

Download document and view instructions to comment: DNS and Environmental Checklist

Clean Water Plan SEPA scoping comment period extended - now ends July 19, 2020

You're invited to comment on the scope of the Draft Environmental Impact Statement (EIS) for the Clean Water Plan

A public comment period for the scope of the Draft EIS under the State Environmental Policy Act (SEPA) review of the Clean Water Plan is open through 5 p.m. on June July 19, 2020. Visit our online open house to learn more about the Clean Water Plan, SEPA scoping, and how to submit a SEPA scoping comment.

The SEPA review process is designed to help agency decision-makers and the public understand how a proposed action or plan will affect the environment. On May 20, 2020, King County Wastewater Treatment Division (WTD) issued a Determination of Significance and Request for Comments on the Scope of the Programmatic EIS for the Clean Water Plan. This formally began the SEPA scoping public comment period for the Clean Water Plan.

To make a formal SEPA scoping comment, submit your comment via email or regular mail:

Email to:

Mail to:
Katherine Fischer
Environmental Programs Managing Supervisor
King County Wastewater Treatment Division
201 S Jackson Street, MS: KSC-NR-0505
Seattle, WA 98104-3855