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C~ <br />• <br />• <br />FINDINGS <br />SITE DESCRIPTION The project site ties in the southwest Quarter of the southwest Quarter <br />of Section 27, Township 105, Range 98W of the 6th Principal Meridian, Mesa County, Colorado. More <br />specificalh• the site is located on the northern limits of the old town site of Cameo and is bounded on the south <br />be• the Coal Canyon Drainage Channel, on the north by the Coal Canyon Road Access and is southwest of the <br />existing Roadside North Portal Coal Mine. The site is approximately %: mile west of the Public Service Power <br />Plant and the Government Highline Canal. <br />The topogaphy of the existing site is relatively flat with the ponds being excavated below the original Bound <br />surface. The original Bound topography slope to the south, southeast, being located on alluvial plain/fan of Coal <br />Canyon Creek. This alluvial fan adjoins the Colorado River flood plain, which is approxirately'/. mile to the <br />cast, with the active (low channel of the Colorado River being located approximately'/: mile southeast of the site. <br />The actual drainage in this general area is quite variable, due to construction of the ponds, the access road into <br />Coal Camon and other features on the site. The improved drainage chazacteristics of this site include the borrow <br />ditches along side the Coal Canyon access road and minor berms associated with the pond construction, all of <br />which direct.the surface drainage on the north side of the.Coal Canyon Drainage Channel, toward the east. <br />Surface drainage on this site can be described as farr and subsurface drainage can be described as good to <br />excellent. <br />GENERAL GEOLOGY AND SUBSURFACE DESCRIPTION <br />The geologic <br />materials encountered under the site consist of in excess of 15 feet of alluvial sands, silts, sandy and silty clays <br />with variable amounts of gravel and boulder size fragments of sandstone, siltstone, mudstone and shale. Some <br />strata of this alluvial fan appear to have been placed by ancient debris flow activity from Coal Canyon. This <br />coarse grained debris material is o[tcn times enwuntercd in a low density, very permeable condition. Some of <br />these debris flow strata exhibit significant compressible characteristics and occasional slight metastable <br />(collapsible) characteristics. Our observations of the existing embanlanent, some of the floor azea of the existing <br />Pond 12 and the lower skrpes within the Coal Canyon Drainage Channel indicate that significant piping of water <br />from the pond and embanlonent area is presently occurring. Several of the pipe channels, near the Bound <br />surface, were observed to be in excess of 2 to 4 inches across in the largest dimension. These areas of piping <br />were observed to be present around the lazger gravel and boulder fragnents and in particular in zones of large <br />concentrations of boulder fragments. The geologic and engineering properties of the materials found in our 3 <br />4 <br />