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' The site is steep,with natural slopes varying from 15 to 40 percent. Near vertical es rpments <br /> occur in several areas on the site. The terrain is very rocky with a south aspect. The oils are <br /> generally very shallow(less than 10 inches deep)to shallow (less than 20 inches in d pth) and <br /> coarse textured, which are reflective of the parent materials they are derived. The geologic <br /> material and underlying layers consist of mixed igneous and metamorphic rocks. It is these <br /> geologic materials,primarily granite but also small amounts of amethyst, that is the principal <br /> reason for the rock quarry. <br /> ' The natural vegetation of the site includes pinyon and juniper trees, with sagebrush, r ibbitbrush, <br /> and several species of native grasses understory. The percent of bare ground for undi urbed <br /> conditions is about 60 percent. <br /> ' Due to the steep, rocky slopes of the site, this area does not have any significant valu for <br /> livestock grazing or agricultural use. The principal beneficial uses of the site include wildlife <br /> ' habitat and rock mining. The current reclamation plan specifies that the final use of tf is site after <br /> mining operations are completed shall be for wildlife habitat. <br /> ' SECTION 3.0 OBSERVATIONS <br /> The existing 60,000±cubic yard stockpile of minus 3-inch material has south facing s opes with a <br /> ' nearly uniform slope gradient. The gradient is about 40f percent. The stockpile has I leen <br /> undisturbed for approximately 10 years. Since that time,the stockpile has been succe sfully <br /> revegetated. Despite the"harsh"growing conditions of the steep south exposure of d a site,the <br /> ' stockpile exhibits good vegetative cover of rabbitbrush, four-wing sahbush, sagebrus , <br /> wheatgrasses, smooth brome, yellow sweet clover, and pinyon,juniper, and ponderos i pine trees. <br /> This vegetation was planted during the past several years during mining operations. ignificant <br /> ' surface erosion or any mass wasting on or along the stockpile has been minimal. <br /> A low area currently exists along the "back"(north) side of the stockpile area. Some onding of <br /> water was noted during the site investigation. (A rainfall storm of about 0.25 inches curred the <br /> ' evening before the site investigation in Grand Junction.) A high point has been consti ucted near <br /> the left center at the top of the pile. Runoff from the west side of the highpoint drains vesterly <br /> toward the natural drainage. The natural drainage lies about 350 feet to the west of th high <br /> ' point. Runoff from the east side of the high point drains easterly to a point near the er d of the <br /> stockpile. A small gully is forming near the lower east end of the stockpile. <br /> At the east end of the stockpile, an 18-inch CMP has been installed to drain surface rLL ioff <br /> southerly toward the CDOT right-of-way. Runoff then travels along CDOT's cut ditc on the <br /> north side of the Highway for approximately 130 yards to a 48-inch CMP culvert under the <br /> thighway. At this point, runoff travels under the highway to East Creek. <br /> The highwall area appears to be relatively stable. The height of the highwall area vari s from 40 <br /> to 60 feet, depending on the location one is measuring. The highwall is best described by near <br /> vertical steps with several benches. The highwall is characterized by some loose rock that will <br /> break off with time from further weathering processes. The detached rock will roll downward to <br /> the bottom of the steep slopes of the highwall. Some benching of the highwall area has occurred <br /> 1 during the mining operations. The highwall area does not have any vegetation, as no sod exists <br /> on the near vertical escarpment. <br /> ' 4 <br />