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<br />iii iuiuiiiim iii <br />COLORADO WESTMORELAND INC. <br />P. O. Box E, Paonia, Colorado B142B ~ 303-527-4135 <br />Pugust 17, 1984 <br />RECEIVED <br />Mr. Robert Liddle AUG 12 ~yb4 <br />Colorado Plined Land l~clanation Division MINED LAND RECLAMATION DIVISION <br />423 Centennial Buildirg Colo. Dept. of Natural Resources <br />1313 Sherman Street <br />Denver, CO 80203 <br />Isar Bab: <br />II~closed are the results of Q~lorado Westrnoreland Inc .'s (d~I) 1984 <br />semi annual subsidence survey perfunnai during July, 1984. Al though sta- <br />tions 28 through 51 were emplaced during October and reported in December, <br />1983, (34I requests that the July, 1984 data be used as bawl ine information, <br />due m potential instrument error. <br />Safety and production concerns necessitated postponirx~ the development <br />atxl extraction sequence beneath stations 42 through 51. 'Ihe 2E-1N panel off <br />9 r;ast is tentatively scheduled bor July, 1985. <br />Extension of the line of monuments 38 through 41 is planned approxi <br />mately 1200 ft. east to ensure undeemining of subsidence stations above the <br />4N,8E~8N panel, the additional monuments will be emplaced during the autumn <br />1984 survey, and will allow flexibility in panel design and alignment. Osr- <br />rent sequencing projects the 4N~N-8E panel tD be extracted by February, <br />1985, and definitive subsidence data will be available crnunencing July, <br />1985. <br />I7avelopnent mining has daninatEd activities during 1984 with the excep- <br />tion of retreat mining Eton January through June iti the 9E-1N panel. the <br />East Mains, SN-8E, and 8N-BE bbrth Intala?s have all been advanced during the <br />first half of 1984. <br />Walk-wet inspections detected possible subsidence-induced pension <br />cracks over the 2:i~tE panel , al though widespread mass-wasting feah~res <br />inclusive of scarps, slides, etc., are present througtout the permit area. <br />Glgoing monimring will dethrnine the cause of these features. Ab addi <br />tional subsidence-related features sere identified wet the 1, 2, and 2 1/2 <br />West panels, and the existing features are continually being sealed by <br />natural processes. Subsidence features sere rot located above the SE, 9E, <br />7E, 6E, SE, 4E, 3E, 2E, and lE panels. <br />Mine infLo~s continued to be shall, alttpugh slightly larger than pre- <br />vious years, undoubtedly related to snocpack and runoff conditions experi <br />erx: ed during spring , 1984 . <br />• <br />St1DEID14RY DF <br />WESTMOREL4ND <br />C04L COMP4NY <br />