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<br />methane gases to the surface. Although their occurrence is not likely, <br />• either of these hazards has a potential of causing significant impacts <br />to .vegetation, wildlife, soils, and visual resources. <br />CI?I reports it has experienced no subsidence to date from its <br />mining operation. Ho+•;ever, retreat mining at the Orchard Valley i;ine <br />was attempted in only one panel. Serious roof falls occurred and as a <br />result the panel was abandoned before it was fully retreated. <br />kegulations in 30(CFR): <br />underyround mining activities <br />prevent subsidence and protect <br />surface lands. Implementation <br />impacts of subsidence. <br />• <br />Paleontology <br />211.31 and 30(CFR): 817.21 reouire that <br />be planned and conducted to control or <br />and ~i~dlntaln the value ar~d use of the <br />cf these regulations will minimize the <br />hlir,ine may damage or destroy any paleontologic resources which <br />exist on the tract. <br />Mineral Resources <br />kn esti~~~ated 28.5 million tons of coal lie in-place in the D seam <br />on this tract. Underground mining practices for the roof conditions of <br />the area would allow the recovery of i2 feet of the fetal thickness cf <br />the seam. Therefore only about 18 million of the 28.5 miilion uns can <br />be coraidered as mineable. The mine layout and the room-and-pillar <br />mining methods proposed by C~,+i +,ould recover 5.6 million tcns during the <br />8 years or" mining. This represents an estimated 3i percent or' the total <br />mineable reserves and only 20 percent of the totai in-place reserve;. <br />As a result of the proposed action approximately 80 percent of the <br />in-place reserves and 70 perceni of the mineable reserves en tine tract <br />would be lost dae to the limitations of current minima teci-~nology and <br />would probably be unavailable for future mining if technoiogy is not <br />improved. The current status of underground mining technology rakes the <br />loss of the majority of this coal unavoidable. Coai mining would not <br />affect later development of other mineral resources. <br />Water Resources <br />The proposed action +•~ould not increase water consumption for mining <br />purposes at the Orchard Valley t9ine. Existing +•~ater use +vouid be con- <br />tinued at established levels for .a period of eight years. <br />Caving of overburden caused by retreat room-and-pillar mining may <br />cause r"racturing of overlying rocks followed by some subsidence. If open <br />• <br />