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Vantage to Pomona Heights Chapter 3 230 kV Transmission Line Project FEIS Affected Environment PAGE 3-264 FIRE REGIME CONDITION CLASS DESCRIPTION FRCC 2 Ecosystems with moderate (33-66%) departure. Fire regimes have been moderately altered from their historical range. The risk of losing key ecosystem components is moderate. Fire frequencies have departed from historical frequencies by one or more return intervals (either increased or decreased). This results in moderate changes to one or more of the following: fire size, intensity and severity, and landscape patterns. Vegetation attributes have been moderately altered from their historical range. FRCC 3 Ecosystems with high (>66%) departure from reference conditions. Fire regimes have been significantly altered from their historical range. The risk of losing key ecosystem components is high. Fire frequencies have departed from historical frequencies by multiple return intervals. This results in dramatic changes to one or more of the following: fire size, intensity, severity, and landscape patterns. Vegetation attributes have been significantly altered from their historical range. Sources: NIFTT 2010; Menakis et al. 2004 Fifty-two percent of the Project study area is within FRCC 2 (moderate departure from reference conditions), 17 percent is within FRCC 3 (high departure), and eight percent is within FRCC 1 (low departure). The remaining 23 percent of the Project study area is within the category agriculture, barren, urban, or water and were not assigned a FRCC. Based on FRCC classifications, it appears that the Project study area has experienced moderate to high alteration from historic conditions. In summary, the entire Project study area historically experienced fire return intervals of 35 to 200 years with a mixture of low to high severity fires (Fire Regime Groups III and IV), but, according to FRCC classifications, only eight percent of the Project study area has current fire regime conditions within the historic range of variability (FRCC 1); 69 percent of the Project study area has a moderate or high departure from historic conditions (FRCC 2 and 3). The FRCC data does not specify whether fire frequency (and/or intensity) have increased or decreased. 3.12.2.4 Fire Risk Factors Wildland fire ignitions in the Project study area could occur through natural causes (i.e., lightning) and human activities (e.g., transmission line operation and maintenance activities, recreation, military training). The wildland fire ignition risk associated with vegetation depends on the amount of fuel present and fuel continuity. The wildland fire ignition risk would be higher in areas with established populations of cheatgrass and other non-native annual species. Annual grasslands and noxious weeds are present in the Project study area, primarily associated with Route Segments 1a/NNR-1, 1b, 1c, 2a, 2b, 2c, 3c, NNR- 2, NNR-3, NNR-4 and Manastash Ridge (MR) 1. Operation and maintenance activities on the existing transmission lines within the Project study area have the potential to ignite wildland fires through the generation of sparks or heat from maintenance activities (e.g., welding) and maintenance vehicles and equipment coming into contact with flammable fuels. In addition, wildland fires have the potential to affect the operation of the proposed Project facilities and, consequently, the reliability of the transmission system in the region. Smoke and hot gases from a large fire under or near a power line can create a conducting path between conductors and the ground, initiating arcing resulting in flashovers. Fires can also damage steel support structures and overhead conductors and can destroy wood pole support structures. The NNR Alternative parallels Pacific Power’s existing Pomona-Wanapum 230 kV Transmission Line for 31.1 miles. From 1995 to present, the Pomona-Wanapum 230 kV Transmission Line has not experienced any instances of line outage due to smoke or fire damage (DeNuccio 2011). PacifiCorp’s Union Gap-Midway 230 kV Transmission Line is located near Route Segments 2a, 2b, 2c, and 2d. During 1995 to 2011, the Union Gap-Midway 230 kV Transmission Line had two instances of lightning striking transmission line structures. In July 2008, lightning struck the top of a pole and damaged it and in July