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Vantage to Pomona Heights Chapter 4 230 kV Transmission Line Project FEIS Environmental Consequences PAGE 4-17 With the implementation of RDFs described above, impacts to special status plant species and potential suitable habitat are anticipated to include 0.5 mile of no identifiable (e.g., developed and agricultural land), 1.2 miles of low impacts, and 0.7 mile of moderate impacts. 4.2.4.2 Route Segment 1b General Vegetation Construction of Route Segment 1b would result in long-term disturbance of approximately 33.8 acres of vegetation. The majority of long-term disturbance, 28.4 acres, would occur in areas classified as sagebrush/perennial grassland (Table 4.2-4). Long-term disturbance would also occur to annual (1.7 acres) and perennial (3.1 acres) grasslands, rabbitbrush/annual grasslands (0.5 acre), and quaking aspen (Populus tremuloides; 0.1 acre). Short-term disturbance would occur to approximately 19.2 acres of vegetation. General vegetation impacts are similar to those described above for Route Segment 1a/NNR- 1. Disturbance would be minimized by RDFs described above that are designed to reduce impacts to vegetation resources. RDFs include using existing public roads to access structure sites, minimizing blading and disturbance to plant communities, revegetating following construction, and implementing a Noxious Weed and Invasive Plant Management Plan. Refer to Section 2.3 - Required Design Features Common to Action Alternatives for a complete list and description of RDFs. With the implementation of RDFs, long-term impacts to vegetation from the construction of Route Segment 1b are anticipated to be: 1.1 miles of no identifiable, 5.1 miles of low, and 6.4 miles of moderate. Special Status Species and Priority Habitats No federally listed plants are known to occur along Route Segment 1b (Table 4.2-5). Nuttall’s sandwort (Minuartia nuttallii ssp. fragilis) and snowball cactus (Pediocactus nigrispinus) were documented during special status plant surveys along Route Segment 1b, as described below, and WNHP data indicate that Hoover’s tauschia (Tauschia hooveri) occurs within one mile of Route Segment 1b (Table 4.2-5). No WNHP priority ecosystems are known to occur or would be disturbed through construction of Route Segment 1b. Approximately 57 percent (138.2 acres) of federal lands within this route segment were surveyed for special status plants (Table 3.2-3). The remaining un-surveyed area consisted of 103.7 acres of inaccessible federal lands and 1.9 acres of non-federal lands. As not all land within the route segment corridor was surveyed, impacts could occur to special status plant species. Long-term disturbance would occur to potential habitat for special status plants, including 5.1 acres of suitable, 5.4 acres of marginal, and 0.8 acre unsuitable habitat. RDFs described above for Route Segment 1a/NNR-1 would also be implemented during construction and maintenance of Route Segment 1b to minimize impacts to special status plants. With the implementation of RDFs, impacts to special status plant species and potential suitable habitat are anticipated to include 0.9 mile of no identifiable, 5.0 miles of low impacts, and 6.7 miles of moderate impacts. Nuttall’s Sandwort Nuttall’s sandwort is a BLM Sensitive and a Washington Threatened species. This species is found in Oregon, California, Nevada, and Grant County, Washington. Within the region, two populations occupying approximately 884 acres are known to occur. One occurrence of Nuttall’s sandwort was documented during the special status plant surveys along Route Segment 1b. This occurrence consisted of approximately 10 individuals scattered throughout 34 square feet. Approximately 0.1 acre of long-term disturbance and 0.4 acre of short-term disturbance in known occupied habitat are anticipated to occur along this route segment, less than 0.1 percent of the known occupied habitat of Nuttall’s sandwort in the region. As all potential habitat was not surveyed, additional Nuttall’s sandwort occurrences could be