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Vantage to Pomona Heights Chapter 4 230 kV Transmission Line Project FEIS Environmental Consequences PAGE 4-64 construction activity to predetermined spatial limits, including restrictions on use outside of the Project ROW; whenever possible, locations of the new transmission line structures will be in sync with the adjacent existing transmission lines; adhering to reasonable speed limits in construction and maintenance areas; closing and revegetating new or improved access roads that are not required for ongoing maintenance activities; to avoid providing food subsidies to ravens or other predators, food waste will be kept in covered receptacles and removed daily; and perch deterrents will be used within four miles of active leks. 4.3.3.2 General Wildlife Collisions Construction, operation, and maintenance of the proposed Project have the potential to cause biological disturbance through wildlife injury or mortality from collisions or interactions with construction and maintenance equipment and transmission line structures. Potential direct mortality from construction equipment includes collision with animals and crushing of nests or dens. Bird collisions with overhead wires typically involve large, less maneuverable species such as pelicans or species that fly at high speeds and low altitudes such as ducks (California Energy Commission [CEC] 2002; Manville 2005; PacifiCorp 2006). Other factors that influence the likelihood of collisions with transmission lines include the habitat type where lines are located, age of birds as juveniles are more likely than adults to collide with lines, and environmental characteristics (e.g., visibility, weather, time of day). Collisions are more likely to occur in areas with high concentrations of birds in close proximity to transmission lines (CEC 2002; PacifiCorp 2006). Available literature indicates that waterfowl, including ducks, geese, swans, cranes, and shorebirds appear to be most susceptible to collisions when transmission lines are located near wetlands (Erickson et al. 2005; Faanes 1987; Anderson 1978). In general, raptors are considered less susceptible to collisions with transmission lines than other groups of birds; however, an increased risk of collision occurs where there are repeated flights across transmission lines, especially during bad weather or while pursuing prey (Avian Power Line Interaction Committee [APLIC] 1994 and 2006; Manosa and Real 2001). RDFs would be incorporated and implemented to minimize wildlife injury and mortality associated with the proposed Project. Specific RDFs to reduce collision risk would include: installing bird flight diverters in locations with known avian collision mortality; installing markers on any new fences constructed or repaired in Sage-Grouse habitat; moving vehicles and equipment at slow speeds; restricting construction vehicle movement to pre-designated locations; avoiding construction or maintenance activities within four miles of active Sage-Grouse leks from February 1 to June 15; avoiding construction during the bird nesting season when possible or conducting pre-construction clearance surveys and buffering active nests by at least 100 feet; and avoiding mowing the Project ROW during the bird nesting season. Pacific Power’s Bird Management Program Guidelines include protocols for documenting the incidence of mortalities from collision with transmission lines, contacting the appropriate resource agency and additional actions to be taken to reduce mortalities such as installing bird flight diverters and marking static wires in sensitive areas when warranted (PacifiCorp 2006). A Wildlife Protection Plan identifying specific measures to protect wildlife resources would be developed and incorporated into the POD. Electrocution Raptor electrocution on transmission lines has received substantial attention and has resulted in the development of ‘avian-safe’ and ‘raptor-safe’ design guidelines for new transmission lines (APLIC 2006; APLIC and USFWS 2005). Research has indicated that most avian electrocutions occur on low-medium voltage lines (4 kV to 69 kV) on which conductor spacing is small and can be bridged by large birds (APLIC and USFWS 2005). The industry standard for avian protection includes a minimum horizontal separation of 60 inches between conductors (APLIC 2006). This separation is intended to allow sufficient clearance for eagles; however, applying this standard would also help protect smaller birds, including ospreys, hawks, owls, wading birds, and songbirds (PacifiCorp 2006). The proposed Project, a 230 kV transmission line, would have a horizontal separation between conductors of 230 inches (19.5 feet) and