Western Electricity Coordinating Council Common Corridor Criteria

1. Western Electricity Coordinating Council Common Corridor Criteria Land Managing Agency Perspective

2. WECC Reliability Criteria • Derived from North American Electric Reliability Council (NERC) Planning Standards (WSCC-S2) • Performance based rather than prescriptive • Rule of thumb: 1,500 feet or the minimum span length • A Mean Time Between Failure (MTBF) of 300 years • Risk Factors • Tower falling into an adjacent line • Snagged shield wire dragged into adjacent line • Aircraft flying into more than one circuit • Fire or smoke shorting more than one circuit • Lightning strikes affecting more than one line

3. Risk Mitigation • Lightning mitigated by shield wires • Fire and smoke mitigated by ROW vegetation management and increased spacing • Tower fall, snagged shield wire, and aircraft strikes mitigated by increasing spacing distanceHowever, significant fines, penalties, and capacity de-ratings can result from N-2 failures despite the use of mitigation measures. Thus, spacing decisions come down to the level of the utility’s risk aversion

4. The BLM’s Corridor Policy • “In order to minimize adverse environmental impacts and proliferation of separate ROWs, the utilization of rights-of-way in common (corridors) shall be required to the extent practical . . . “ (Federal Land Policy and Management Act, Section 503) • “Whenever possible the BLM will manage ROW use . . . through a system of designated corridors.” To minimize the proliferation of linear facilities. (BLM Manual 2802.1 B.1)

5. The BLM’s Corridor Policy • The Energy Policy Act of 2005 : • Directed agencies to designate energy corridors by January 14, 2009 • Assumed corridor use would streamline permitting • Use of designated corridors preferred but not mandatory • Screened at a high level of resource review - - site-specific analysis still needed.

6. The Issues • Definitions - - • WECC “Common Corridor”: Contiguous lines with centerline separation less than the longest span length. (Does not apply to the last five spans entering a substation. • BLM’s corridor definition is more variable. • Width on the order of thousands of feet • Multi-modal • Prescribed boundaries, but some variability in interpretation

7. The Issues • Performance based standards • Lack of identified distance results in variable distances that are difficult to justify or explain to general public • Different companies use different separation criteria • Rationale becomes even more difficult when public realizes regulatory body is self-regulating • Distance separation is the simplest (and likely the least expensive) mitigation to apply, thus it is the first proposed and most often used. But there are equipment and operational mitigations. These are complex and difficult to explain and critique to the public

8. The Issues • Believability of the once in 300 year frequency for N-2 events • Difficulty in explaining wide separation when people see lines close together but do not understand their function in grid operation and performance • Perception that WECC does not care about environmental impacts, effects to land values or its use. “We only deal with reliability. It’s not our job.”

9. The Most Important Issue • Disconnect between WECC rating process and Federal environmental analysis process - - only the planned rating (phase 2) is available during the environmental analysis and not for all alternatives studied • Land managing agencies seek to minimize environmental impacts. • Habitat fragmentation • Intrusion of structures onto the landscape • The closer the proximity of high voltage lines to property, the greater the devaluation • There is need to analyze the trade –off of the degree of decreased reliability against reduced environmental impacts