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potential storage area of asbestos. See Exhibit C-1. This overburden will be obtained from stripping <br />for the sediment pond and the portions of the Phase 1 & 2 mining areas that contain clean <br />overburden. The mining areas have also been selected to be outside a 200' perimeter from the <br />potential asbestos dump area. The clean overburden will be permanently placed in the staging area <br />to provide a safe working area that can also be later used as an industrial site. <br />Prior to mining Phase 1, a sediment pond of approximately 1.0 acre in size will be excavated on the <br />east central part of the permit azea, as shown on Map C-2. A depression will be cut from the <br />existing terrain to an average depth of 4', therefore, a volume of 4.0 acre feet will be excavated. The <br />northern portion of this silty overburden will be tested for contamination according to the <br />Contingency Plan. If it is contaminated, it will be brought to one of two designated areas north of <br />the staging area for land farming, as agreed to by the CDPHE and as shown on Map C-2. The <br />overburden will be tested on site using portable TPH (total petroleum hydrocarbon} meters to detect <br />the presence of contamination. All areas will be flagged or marked for removal to the farming area <br />or the staging area. Fruita Marketing and Management and the CDPHE will handle the ]and <br />farming of all overburden moved from the site. Since this material will never be brought back to the <br />mine site, it will not be part of the mine permit area. Material determined to be free of <br />contamination will be placed in the staging area, as explained above. It is expected that 3.S ac ft of <br />the 4.0 ac ft excavated will be clean and can be placed in the staging area. Details of the pond <br />design are given in the Section 8 of [his mine plan discussion. The sediment pond will have a gated <br />steel discharge structure that can be easily shut to keep the water in the pond in case any <br />contaminated water from the refinery is found. <br />Therefore, in order to cover the staging area with 2.8 feet of overburden, the total volume needed is <br />13.5 ac x 3.0 ft = 37.8 ac ft. - 3.5 ac ft (from sed pond) = 34.3 ac ft from Phase 1 and from Phase 2. <br />Since much of [he Phase 1 area was previously excavated to make an evaporation pond, the top of <br />the gravel was reached in some places but sediment has partially filled the pond over many years. <br />For this reason, the average silty overburden to be removed from Phase 1 is 2.S feet. This is a <br />volume of 2.5' x 12.6 ac = 31.5 ac ft. Therefore, the amount needed to complete the filling of the <br />Gilsonite Pit 1/04 8 <br />