2012-10-18_REVISION - C1980004 - Laserfiche WebLink

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Mike Boulay -44 October 16, 2012 • The introduction describes "an east -west trending, flat- topped, oval shaped landform that lies across the valley and may be either an old earthen dam structure or a landslide debris pile." • Soil Map Unit I, (which comprises the feature) is identified as "Unnamed fine sandy loam, 1 to 20% slopes ", and is described in subsection 3.2 of the report. Mr. Nyenhuis suggests that the feature is an earthen dam constructed across the valley some decades ago. • Page 5 of the Soil Resource Assessment describes a soils map that was compiled on a topographic base map with a 2 -foot contour interval at approximately 1" = 200'. This map was not submitted with the report for the Division's review. Rather, soil boundaries are outlined on Map 4.4 -2 — Soils Map. The contour interval for this map is 10 feet, which is suitable for the steeper slopes, but results in a loss of topographic detail on the flatter valley floor and makes the subject feature much less distinctive. Figure 2.2 -5 — Haul Road Plan and Profile • The proposed Gob Pile Haul Road will be constructed through the landform in question as it skirts the perimeter of the proposed Coal Mine Waste Pile. The cross - sectional shape of the landform feature is shown clearly in the Profile view, between stations 12 +30 and 14 +80. Appendix W — Alluvial Valley Floor Determination (ERO Resources Corporation) • In the Agricultural Practices section, the report describes a water diversion system constructed "in the late 1800s at the constriction of East Salt Creek ". Photos 1 and 2 show the remains of a concrete wall located in the creek, adjacent to the landform. • The Geology section describes the feature in question as a "Landslide Deposit," concluding that "there is no obvious reason for such a large artificial embankment ". The source of the landslide material is assumed to be the deposit west of the creek and highway. • Figure I of the report shows the study area on a topographic base map with a 2' contour interval, on which the shape and dimensions of the landform are clearly visible. • On Figure 2, the geology of the landform is identified as Qls — Landslide. • Figure 4.1 -2 — Preliminary Alluvial Valley Floor Identification — has been revised substantially with the PR -2 application. All prior versions of this map have identified the landform as "Man -Made Fill ", but on the proposed version, the area is identified as, "Landslide Deposit, from West side of canyon wall."