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West Elk Mine <br />1. The healing and sealing potential for stream channels discussed in Section 2.05.6 conflicts <br />with short-term stream diversion not to mention stream diversion after 20 years; and <br />2. No water was observed upstream from the azea where the beaver ponds were located, <br />beyond where the Oliver No. 2 mining could have had an impact. Consequenlly, there <br />was not a perennial flow for the beaver habitat in the canyon when Mr. Dunrud observed <br />the beaver ponds in the mid-1970s. It is not known what happened to the source of water <br />to the beaver ponds; the beaver had already moved out. <br />MCC now owns the water right to the first east fork of Sylvester Gulch-the water right <br />previously owned by the Bear family. Therefore, the puzzling decrease in flow (perhaps the flow <br />was intercepted by a permeable formation or natural fractures exposed by stream erosion) should <br />only concern the current owner of the water right. <br />Methane Concentrations in the Oliver No. 2 Portal Area <br />Methane was also encountered in the portal area of the Oliver No. 2 Mine during exploration <br />drilling for the State Highway 133 roadbed: Boyd Emmons, State Coal Mine Inspector, stopped. <br />drilling in one hole north of the Oliver No. 2 portal when 100 percent methane was detected. It <br />was 14 to 15 days before CDOT could remove steel from one hole (Boyd Emmons, Oral <br />Communication, November 6, 1996). According to Emmons, methane still is likely to be present <br />in the roadbed. <br />~' -. Water and Methane Potential in the B-Seam-O&verNo. 2 Mine Area <br />Based on the history of mining the Oliver No. 2, water and methane also tray locally be expected <br />to be encountered during the muting of the B-Seam in that area at least. Apparently most of the <br />water and methane encountered in the Oliver No. 2 Mine was present in fractures, joints, bedding <br />planes, or in permeable rocks near the coal seam mined. However, with about 250 feet of shale, <br />siltstone, and sandstone between the B-Seam and the E(DO-Seam, the extent and volttme of water <br />and methane cannot be predicted without drilling. <br />One drill hole located near the mouth of the unnamed drainage west of Box Canyon, near the <br />haulageway of the Oliver No. 2 Mine, was observed to exhaust gas and water vapor in a volume <br />of 5 to 10 cubic feet per minute (5-10 cfm) at atmospheric pressure during field studies in October <br />1996. The shut-0ff pressure was estimated to be 20 psi. The source of the methane and water <br />vapor was reported to be mainly from the A and B-Seams. This would indicate that water and <br />methane may be encountered during mining of the B-Seam in the Oliver No. 2 Mine area. <br />Potential Im. pact of Water ou Subsidence in West Minin¢ Areas <br />As discussed in a previous section, Geologic Factors Influencing Subsidence, the moisture content <br />of the caved and downwarped rocks controls the amount of subsidence that can be expected. In <br />• <br />2.05-129 Revised Jun. 1995 PR06; IN6RN03; RevisedJan. 1998 PR08 <br />