The Tacoma-Cascade Pipeline would involve constructing a buried approximately 20-mile-long, 42-inch-diameter pipeline and ancillary features to convey drinking water from the Tacoma Water Second Supply Pipeline (SSP) to Cascade’s Bellevue-Issaquah Pipeline (BIP).  The Preferred Alternative would originate at a point along the SSP and continue northerly through the cities of Covington, Renton, and Issaquah, and unincorporated King County before reaching its northern terminus at the BIP.  The Tacoma-Cascade Pipeline would be the first principal project feature of the Cascade Regional Water Supply System to be constructed.  Once the link between SSP and BIP is constructed, the full water supply that Cascade has purchased from Tacoma Water and Covington Water District can be delivered to Cascade's Members. 

An Environmental Checklist was prepared for the Tacoma-Cascade Pipeline in July 2006. Following review of the Environmental Checklist, the Cascade SEPA Official determined that the Tacoma-Cascade Pipeline was likely to have a significant adverse impact on the environment and that an EIS would be required. A Determination of Significance and a Request for Comments on Scope of EIS was issued on July 21, 2006. The Draft EIS was then prepared and a Notice of Availability and Request for Comments on the Draft EIS was issued on December 21, 2006, with comments due on February 2, 2007.

FINAL ENVIRONMENTAL IMPACT STATEMENT

The Final Environmental Impact Statement (Final EIS) for the Tacoma-Cascade Pipeline has been prepared and has been distributed in compliance with the State Environmental Policy Act under Chapter 43.21C RCW.  The Cascade Water Alliance is the project proponent and lead agency. 

The Final EIS discusses the need for the project, alternatives considered and their associated environmental impacts and planned mitigation measures, and provides the comments received on the Draft EIS and Cascade’s responses.  Some text changes have been made as a result of the comments received on the Draft EIS as well as editorial corrections or clarifications.  The Final EIS includes all of the information contained in the Draft EIS and, thus, is a standalone document.    

Final EIS
Final EIS Figures
Final EIS Appendices

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Archives:

DRAFT ENVIRONMENTAL IMPACT STATEMENT

The following Notice of Availability and Request for Comments on the Draft Environmental Impact Statement has been prepared for the Tacoma-Cascade Pipeline in compliance with the State Environmental Policy Act under Chapter 43.21C RCW.  Cascade is the project proponent and lead agency. 

Notice of Availability/Request for Comments & Draft EIS
Figure 2-1 to Draft EIS
Figure 2-2 to Draft EIS      
Figure 2-3 to Draft EIS
Figure 3-1 to Draft EIS
Figure 3-2 to Draft EIS
Figure 3-3 to Draft EIS
Figure 3-4 to Draft EIS
Figure 5-1 to Draft EIS
Figure 5-2 to Draft EIS
Figure 5-3 to Draft EIS
Figure 5-4 to Draft EIS
Figure 5-5 to Draft EIS
Figure 7-1 to Draft EIS
Figure 8-1 to Draft EIS
Figure 11-1 to Draft EIS

Click on the links below for documents pertaining to the Tacoma-Cascade Pipeline Project:

Letter 1 - Request for Comments

Letter 2 - Request for Comments

SEPA Checklist / DS / Request for Comments on EIS

Figure 1 to SEPA Checklist

Figure 2 to SEPA Checklist

Figure 3 to SEPA Checklist

Figure 4 to SEPA Checklist

NOTICE OF WITHDRAWAL FOR THE CENTRAL SEGMENT
TRANSMISSION PIPELINE PROJECT

On February 1, 2006, Cascade Determined that the proposed Cascade Regional Water Supply System ­ Central Segment Transmission Pipeline (Central Segment) was likely to have a significant adverse impact on the environment. Pursuant to the State Environmental Policy Act (Chapter 43.21C RCW), Cascade's Responsible Official issued a Determination of Significance (DS), called for an environmental impact statement (EIS) and requested scoping comments from the public. The public, agencies, and affected tribes were given until March 16, 2006, to comment on the DS. Cascade also held scoping meetings (March 16, 2006) in relation to the proposed Central Segment, its impacts, and the scope of the EIS.

Cascade has since determined to combine the Central Segment project with a proposed North Segment pipeline for the purpose of conveying drinking water from the Tacoma Second Supply Pipeline to Cascade Members (the Tacoma-Cascade Pipeline) and withdrew the Central Segment project, and the corresponding environmental documents relating to the same. Cascade will issue the necessary environmental threshold determination on the Tacoma-Cascade Pipeline project when feasible.