Staff's final environmental impact statement recommended approval to replace the majority of the delivery capacity of Northwest Pipeline's existing 268-mile-long, 26-inch-diameter pipeline. The project would also construct and operate 79.5 miles of new 36-inch-diameter pipeline in 4 separate loops in Whatcom, Skagit, Snohomish, King, Pierce, and Thurston Counties, Washington.

Northwest's proposed mitigation, and the FERC staff's additional mitigation recommendations, it would be an environmentally acceptable action. The principal reasons are:

  • 99 percent of the proposed loops would be within or adjacent to Northwest's existing right-of-way and 93 percent of the proposed loops would be within Northwest's existing permanent easement;
  • Northwest would abandon the existing 26-inch-diameter pipeline in place in the locations along the non-looped portions of its system, which would eliminate disturbance to 188.5 miles of the right-of-way with the exception of the activities that would occur to isolate the 26-inch-diameter pipeline from other system components;
  • Northwest would submit documentation of concurrence from the WDOE that the project is consistent with the Washington Coastal Zone Management Program before construction;
  • Use of a Horizontal Directional Drill method would avoid disturbances to the beds and banks of the North Fork Nooksack, North Fork Stillaguamish, and South Fork Stillaguamish Rivers and associated wetlands/riparian areas; and
  • Northwest would implement approved waterbody crossing and compensatory wetland mitigation plans to minimize and compensate for unavoidable stream and wetland impacts.
  • Cover Letter
  • Table of Contents
  • Executive Summary
  • Section 1
  • Section 2
  • Section 3
  • Section 4
  • Section 5
  • Additional Documents in eLibrary

Note: Maps and figures that contain Non-Internet Public information are not included in above electronic files.

This page was last updated on May 14, 2020