2010-12-15_REVISION - C1981019 - Laserfiche WebLink

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area to produce a gentle camber on the top of the fill which will direct runoff to the West Taylor West Tributary and the West Taylor East Tributary Ditches. 22. Response Not Accepted. The following is the Division's original adequacy question for your reference (please note that two additional questions have been asked in the following paragraph, based on the Division's third and fourth comments, as a result of the new designs submitted): Colowyo has provided a new Map 45 - South Taylor Fill, which shows the East Taylor and West Taylor Fill plans and cross-sections. This plan view information (less the cross-section details) for the East Taylor and West Taylor Fills is also shown on Exhibit 7, Item 20, Figures 1 C-4 and 1 C-5 - West Taylor Pond Drainage and Figure 1 of the Shannon and Wilson report. There are, however, two discrepancies between Map 45 and Figures 1C-4 and 1C-5 and Figure 1 of the Shannon and Wilson report with regards to the plan view for the East Taylor Fill. First, the configuration of the topography lines of the temporary overburden stockpile on the East Taylor Fill is different in the figures as compared to the map. The northwest corner of the temporary overburden stockpile is approximately a 90° angle on Map 45. The same corner of the temporary overburden stockpile on the West Taylor Pond figures and in the Shannon and Wilson report is more of a point. There is also a difference in the southeast corner of the temporary overburden stockpile plan. On Map 45 the southeast corner is basically a flat area, connecting with the southwest and northeast corners of the pile. In the West Taylor Pond figures and in the Shannon and Wilson figure the temporary overburden stockpile again comes to a point. Second, the toe of the East Taylor Fill on Map 45 and Figure 1 of the Shannon and Wilson report is not well defined as such. The plan view on the map and Figure 1 shows the toe of the pile ending abruptly at the 7,700 foot elevation line and not toeing out to a point as shown on Figures 1C-4 and 1-C5 (where the East Taylor East Tributary Ditch and East Taylor West Tributary Ditch meet up). There is a distinct toe for the West Taylor fill on Map 45 and all of the aforementioned Shannon and Wilson figures. Please review the plan view for the East Taylor Fill on Map 45, Exhibit 7, Item 20, Figures 1C-4 and 1C-5 and Figure 1 of the Shannon and Wilson report and make the necessary changes/corrections to the temporary overburden stockpile configuration and the toe of the permanent fill. Based on the Division's review of the materials and information submitted in response to the Division's original question 22 (above), Colowyo has not addressed this question. First, in the response Colowyo states that Figures 1C-4 and 1C-5 of Exhibit 7, Item 20 have been revised. These figures were not included in the 1 June 2010 Colowyo submittal. Second, Colowyo states that the large, flat toe of the East Taylor Fill, ending at the elevation line of 7,700 feet, is correct. Colowyo further states that this toe will be approximately 400 to 500 feet wide. Based on a review of the East Taylor Fill, cross-section A-A' shows that the final toe of the fill is at an elevation of approximately 7,550 feet of elevation. This cross-section shows that if the fill was to end at the 7,700 foot elevation point, there would be a drop-off of approximately 200 feet to reach the original ground surface. Further, a review of Map 41A - Watershed Boundaries for Hydrologic Modeling-South Taylor Area, shows the fill toeing out at an elevation of approximately 7,550 feet, at the confluence of the East Taylor West Tributary Ditch with the East Taylor East Tributary Ditch. Additionally, there are contour ditches shown on the face of the East Taylor Fill (on Map 41A) at elevations of 7,700 feet and 7,600 feet, which would not be possible if the fill toed out at 7,700 feet as depicted on Map 45. Third, Colowyo has added what appears to be a large drain or notch to the East Taylor Fill. This drain or notch is on the southwest edge of the fill (south of the E-E' cross- section line and east of the A-A' cross-section line). Fourth, cross-section E-E' shows that between approximately station 60+00 and station 70+00 the East Taylor Fill will gradually rise from an elevation of 8,050 feet to an elevation of 8,150 feet and back down again to approximately 8,050 feet. (Cross-section C-C' also depicts this hump from approximately