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Environmental Impact Statements (EISs)

Final Environmental Impact Statement on the Phoenix Expansion Project (Docket No. CP06-459-000)
Issued: September 21, 2007

The staffs of the Federal Energy Regulatory Commission (Commission or FERC); the U.S. Department of the Interior, Bureau of Land Management (BLM); the U.S. Department of Agriculture, Forest Service (FS); the U.S. Department of Transportation, Office of Pipeline Safety; the U.S. Department of the Interior, Bureau of Indian Affairs; and the Navajo Nation, collectively referred to as the Agency Staffs, have prepared a final environmental impact statement (EIS) on the natural gas pipeline facilities proposed by Transwestern Pipeline Company, LLC (Transwestern) in the above-referenced docket.

Transwestern proposes to construct 24.6 miles of new 36-inch-diameter pipeline loop along the existing San Juan Lateral (Loops A and B) in San Juan and McKinley Counties, New Mexico; 259.3 miles of new 42- and 36-inch-diameter lateral pipeline (the Phoenix Lateral) in Coconino, Yavapai, Maricopa, and Pinal Counties, Arizona; 1.4 miles of new 24-, 20-, 16-, and 6-inch-diameter lateral pipeline connecting the Phoenix Lateral to meter stations; and other associated facilities. Transwestern would also perform minor piping modifications at two existing compressor stations in San Juan County, New Mexico and Mohave County, Arizona, and would acquire an undivided interest in the existing 36.7-mile-long, 24-inch-diameter East Valley Lateral, which extends between Pinal and Maricopa Counties, Arizona.

The EIS was prepared to satisfy the requirements of the National Environmental Policy Act.

The Agency Staffs conclude that the proposed project, with the appropriate mitigation measures as recommended by the FERC staff, would be an environmentally acceptable action. The principal reasons are:

    • 86 percent of the proposed pipelines would be within or adjacent to existing rights-of-way;

    • The project would be consistent with or in conformance with all identified comprehensive plans;

    • Transwestern would implement its Upland Erosion Control, Revegetation, and Maintenance Plan; Wetland and Waterbody Construction and Mitigation Procedures; Restoration Plan; Spill Prevention and Response Procedures; Blasting Procedure; Trenching and Wildlife Guidelines; Migratory Bird Plan; Dust Control Plan; Fire Prevention and Suppression Plan; Forest Service Access Management Plan; Horizontal Directional Drilling (HDD) Plan; Unanticipated Discovery Plans; and Site-specific Residential and Structural Implementation Plans to protect natural and cultural resources and residential areas during construction and operation of the project;

    • Transwestern would implement all site-specific stipulations in the Plan of Development that would be developed by the BLM, the FS, and the U.S. Department of the Interior, Bureau of Reclamation;

    • Use of the HDD method would avoid disturbance to the bed and banks of the San Juan River and associated riparian areas. If the HDD fails and the alternative wet open-cut method were used, the short-term impact of a wet open-cut crossing would be environmentally acceptable and the terms and conditions that are expected to be included in the U.S. Fish and Wildlife Service's (FWS) Biological Opinion would ensure that the project would not jeopardize the continued existence of the Colorado pikeminnow and the razorback sucker;

    • The appropriate consultations with the FWS, the State Historic Preservation Offices, and Native American tribes would be completed before Transwestern would be allowed to begin construction in any given area; and

    • An environmental inspection and mitigation monitoring program would ensure compliance with all mitigation measures that become conditions of the FERC Certificate and other approvals.

    The FERC Commissioners will take into consideration staff's recommendations and the final EIS when they make a decision on the project.