Washington, Oregon, Idaho, and Wyoming

TtEC prepared an Exhibit F-IV Environmental Report (ER) to support an application to the Federal Energy Regulatory Commission (FERC) for a Certificate of Public Convenience and Necessity to construct natural gas pipeline facilities in Washington, Oregon, Idaho, and Wyoming for the Northwest Pipeline Corporation. Technical information in the ER was presented in the format typically used by the FERC’s environmental staff to prepare and present results and conclusions for environmental analyses of pipeline projects. The ER was supplemented with technical appendices that provided the basis for and supported its content. The ER was formatted in this manner to aid the FERC and other cooperating federal agencies in the assessment of the environmental effects of the proposed project.

The project involved construction and operation of 170 miles of pipeline loop, 7 miles of new pipeline, and 88,239 horsepower (hp) of compression at 4 new and 12 existing compressor stations. The pipeline facilities crossed lands under the jurisdiction of several different agencies including the Bureau of Land Management (BLM) and US Forest Service. Major issues that were evaluated included detailed route variation analyses to determine the best location for the pipeline and above-ground facilities; mitigation plans to minimize impact on residences near the proposed route; and procedures to reduce impact on wetlands, water bodies, and soils. In addition to preparing the ER, we conducted all air quality modeling necessary to obtain state air quality permits for the new and additional compression, and managed all cultural resource surveys and report preparation for Northwest Pipeline Corporation.

Project Highlights

• Worked with federal and state agencies to accomplish multi-jurisdictional permitting requirements.
• Managed the preparation of an Exhibit F-IV Environmental Report.
• Developed mitigation plans to minimize impacts to residences along 170-mile route.
• Proposed procedures to reduce impact on wetlands, water bodies, and soil.
• Conducted air quality modeling required to obtain state air quality permits.
• Managed cultural resource surveys.