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Vantage to Pomona Heights Chapter 3 <br />230 kV Transmission Line Project FEIS Affected Environment <br /> PAGE 3-297 <br />3.15.4.3 Route Segment 1c <br />Route Segment 1c continues along the northwestern foothills prior to turning south and traversing the <br />Yakima Ridge. In addition to ephemeral creek washes, there are three landslides mapped along this route <br />segment alignment along the northwestern foothills. Recent movement was not evident in aerial <br />photography; however, to maintain the stability of these features field review and determination of BMPs <br />for this area would be prudent. Traversing Yakima Ridge, the route segment crosses an inactive thrust <br />fault evidenced by exposed strata along the northern ridgeline. As the route segment alignment continues <br />to Route Segments 2a, 2b, and 2c along the southern foothills, ephemeral creek washes continue to pose a <br />hazard. <br />Route Segment 1c corresponds to 231.3 acres of soils with high water erosion potential, 0.0 acres of soils <br />with high wind erosion potential, and 261.6 acres of soils with low soil restoration potential. <br />3.15.4.4 Route Segment 2a <br />Route Segments 2a, 2b, and 2c parallel Yakima Ridge along its southern foothills as shown on the <br />Geohazards Map in Appendix A. No significant geologic hazards are present along Route Segment 2a. <br />Ephemeral creek washes are present, but there are no landslides or fault lines mapped along Route <br />Segment 2a. <br />Route Segment 2a corresponds to 41.4 acres of soils with high water erosion potential, 0.0 acres of soils <br />with high wind erosion potential, and 13.9 acres of soils with low soil restoration potential. <br />3.15.4.5 Route Segment 2b <br />No significant geologic hazards are present along Route Segment 2b. Ephemeral creek washes are <br />present, but there are no landslides or fault lines mapped along Route Segment 2b. <br />Route Segment 2b corresponds to 373.9 acres of soils with high water erosion potential, 0.0 acres of soils <br />with high wind erosion potential, and 334.3 acres of soils with low soil restoration potential. <br />3.15.4.6 Route Segment 2c <br />No significant geologic hazards are present along Route Segment 2c. Ephemeral creek washes are <br />present, but there are no landslides or fault lines mapped along Route Segment 2c. <br />Route Segment 2c corresponds to 904.4 acres of soils with high water erosion potential, 0.0 acres of soils <br />with high wind erosion potential, and 210.0 acres of soils with low soil restoration potential. <br />3.15.4.7 Route Segment 2d <br />Route Segment 2d traverses south to north over Yakima Ridge terminating at the Columbia River at the <br />bottom of Umtanum Ridge. This route segment is in the vicinity of three active, though Class B <br />(undefined age), faults. It is also in the vicinity of several landslides features. Recent movement was not <br />evident in aerial photography; however, to maintain the stability of these features, field review and <br />determination of BMPs for this area would be prudent. <br />Route Segment 2d corresponds to 274.7 acres of soils with high water erosion potential, 0.0 acres of soils <br />with high wind erosion potential, and 147.1 acres of soils with low soil restoration potential. <br />3.15.4.8 Route Segment 3a <br />Route Segment 3a is a short segment (approximately 750 feet long) of the proposed transmission line that <br />extends from the existing Vantage Substation to the northeast where it would tie into route segments 3b <br />and 3c. No active faults, mapped landslides, or areas of liquefaction susceptibility correspond to Route <br />Segment 3a according to the Geohazards Map provided in Appendix A.