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Vantage to Pomona Heights Chapter 1 230 kV Transmission Line Project FEIS Purpose and Need PAGE 1-8 conditions and plan adequate redundancy in the system (e.g., through construction of multiple transmission lines and locating multiple lines in wide geographically diverse transmission corridors) to meet expected system reliability performance. These standards and criteria define both the expected level of event severity (single and multiple line outages) and acceptable performance requirements. In part, the standards require transmission providers to evaluate multiple adjacent outages and, when applicable, the outage of all lines in a corridor to ensure the outage does not result in a cascading and uncontrolled loss of generation stations and outages of customer loads. While these standards and criteria exist for performance and reliability, it is the responsibility of the transmission provider, based on operational history and experience, to plan, design, and site transmission projects to meet system performance requirements and manage reliability, risks, and costs. In 2007, Pacific Power participated in a regional transmission system planning study to address reliability issues within the Mid-Columbia transmission system. To address these issues, the Mid-Columbia utilities including BPA, Grant County Public Utility District (PUD), Chelan County PUD, PacifiCorp, and Puget Sound Energy worked together with the Northwest Power Pool - Northwest Transmission Assessment Committee (NTAC) to perform a detailed screening of the transmission system exposure to overloading (NTAC 2007). As a result of the study, system reinforcement projects or upgrades were identified to address system conditions and overloading. This proposed Project was a reinforcement project that was identified for Grant, Benton, and Yakima counties to ensure reliability of the transmission network in the Mid-Columbia area. The regional transmission study determined that loss of the existing Pacific Power Pomona-Wanapum 230 kV transmission line would result in a significant load shedding exposure on the transmission system and would also impact other transmission providers in the Mid-Columbia area with overloads of their existing transmission components. Based on 2007 loads and system activity during high load periods in the Yakima Valley, loss of the Pomona-Wanapum 230 kV transmission line would result in the need to shed up to 167 megawatts (MW). This load shed would occur through five different substations and would represent 33 percent of the 500 MW load in the Yakima area. The regional transmission study showed that an outage of the Pomona-Wanapum 230 kV transmission line would result in redistribution of electrical flow across the BPA and Grant County PUD parallel transmission systems that also feed into Pacific Power’s Yakima load area. This redistribution would result in loadings well above the acceptable limits of many existing transmission components on the other systems, putting the regional transmission system at risk of failure. The transmission system planning studies determined that an outage of the Pomona-Wanapum 230 kV transmission line would result in the overload of three Pacific Power high voltage transmission lines and two BPA high voltage transmission lines, potentially causing service interruptions in the Yakima Valley. The regional planning study showed that the addition of a Vantage to Pomona Heights 230 kV transmission line would eliminate the redistributed loads and the overloading of the adjacent transmission system and would ensure continued reliable and efficient service to the Yakima Valley. 1.4 LEAD AND COOPERATING AGENCIES 1.4.1 Bureau of Land Management It is the mission of the BLM to sustain the health, diversity, and productivity of the public lands for the use and enjoyment of present and future generations. The BLM’s Spokane District is the lead federal agency responsible for preparation of this FEIS and project oversight and compliance with the requirements of NEPA and other applicable laws and regulations. The BLM’s Spokane/Coeur d’Alene District Manager is the Authorizing Officer (AO) responsible for the decision on whether to issue the requested BLM ROW and, if issued, the applicable terms, conditions, or other stipulations. The BLM AO