Laserfiche WebLink
25 percent slopes, map units 68C and 68D. Soil cores#7 and 8 were mapped as Aaberg silty clay, 25-65% slopes, <br /> map unit 35F. In Section 17, soil cores#10, 11 and 12 were located within the Binco silty clay loam, 3-25 percent <br /> slopes, map units C 10 and D10. A narrow inclusion of Cumulic Cryaquoll soil was observed in the small drainage <br /> channel bisecting the ventilation pad area in Section 17(Map 2S). <br /> Maximum rooting depth at soil core #2 (Cumulic Cryaquoll) was observed into the seasonal high water table. Soil <br /> mottling within the soil profile is a good indication of the depth of the seasonal high water table that can fluctuate <br /> with the season and by year. Enhanced vegetation growth and plant species adapted to mesic and riparian sites was <br /> also evident adjacent to soil core #2. Unconsolidated stream-laid sediments were observed at 25 inches and <br /> exhibited free water within these unconsolidated gravels and coarse sands. Similar soil characteristics were <br /> observed in the small drainage channel bisecting the ventilation pad area in Section 17(Map 2S). <br /> The maximum rooting depth at soil core #9 (Menbar series)was observed to a depth of 47 inches with a significant <br /> decline in roots noted at shallower depths due to calcareous root restricting horizons. Unconsolidated stream-laid <br /> sediments were observed below 105 inches and exhibited free water within these unconsolidated gravels and coarse <br /> sands, however, no indicators of AVF soil characteristics were evident in this soil core within the rooting zone. <br /> While this colluvial material may overlay water-bearing unconsolidated alluvial strata, these colluvial materials are <br /> at a sufficient depth and contain shallow, calcareous root restricting horizons that prevent any subirrigation <br /> potential. Reduced vegetation growth and production at this sampling site were evident from the plant species that <br /> are more adapted to semi-arid, non-sub-irrigated sites. The field survey observed a distinct soil, vegetation, and <br /> topographic boundary between the AVF and the upland portion of the study area containing the proposed <br /> ventilation shaft facility access road. <br /> Soil core descriptions, surface vegetation, and topographic relief indicate that the existing AVF boundary (as <br /> previously defined in Exhibits 7b, 42a, and 46) along Fish Creek in Section 11 should be relocated as shown on <br /> Map 1 S. Approximately 800 feet of proposed road corridor in Section 11 has been relocated upgradient <br /> approximately 100 feet to follow an existing abandoned farmstead access road and avoid potential wetland soils <br /> along the stock pond shoreline. The remaining 6,314 feet of access road corridor From the fenceline at the south <br /> end of the stock pond to the shaft pad have no soil limitations. Soil coring and geologic stratigraphy strongly <br /> suggest that the entire ventilation shaft pad is located on a suitable upland Winevada soil series formed over <br /> fractured sandstone bedrock parent material. While the previous AVF boundary (shown in green on Map 1S) is <br /> located within the southwest corner of the shaft pad, the revised AVF boundary (shown in red on Map 1S) lies <br /> outside of the proposed shaft pad location. Southern and western portions of the 500-foot buffer that overlay the <br /> Fish Creek channel contain AVF and wetland soils (Map IS). No soil mapping activities were performed on the <br /> west side of the railroad corridor within the 500-foot buffer area since pad and shaft construction activities will not <br /> cross the railroad tracks. As construction activities are limited to the ventilation pad and northern and eastern <br /> halves of the buffer area, no AVF or wetland soils will be affected. <br /> The 9-East Utility Borehole project area is immediately adjacent and to the south of the 18-Left Ventilation Shaft <br /> Road. Previous soil mapping did not include this area, so the most recent soil mapping (NRCS, 2006) and soil <br /> descriptions for this area was obtained and reviewed. The soil types to be affected by disturbance are similar to <br /> those for the nearby 18-Right Vent Shaft disturbance(as discussed above), and include the Rabbitears loam, 3 to 12 <br /> percent slopes (68C), and 12 to 25 percent slopes (68D), and the Winevada-Splitro complex, 3 to 25 percent slopes <br /> (X8D). Soil depths (A and B1 horizons to gravel or clay) range up to 26-inches (68C), 22-inches (68D), and 38- <br /> inches (X8D), respectively. The site-specific soil mapping and soil descriptions have been added as Exhibit 16C, <br /> Appendix 4, for reference. <br /> MR 17-304 2.04-50.2 01/12/17 <br />