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water level monitoring, rc din and need to he sealed and reclaime, The wells were <br />drilled through steeply-dipping unconsolidated mudstones, sitts[ones, and claystones to <br />the coal seam. Depths ranged from 100' to 450' and holes were drilled either vertically <br />or on-dip with the coal seam.. Because they were to be mined through within 5 to ]0 <br />yeazs following completion, small diameter (mostly 2") slotted PVC was used to <br />complete the wells. Unfortunately, some of the wells do not appear to have been properly <br />completed (ie: properly sand-packed and cemented in borehole). In most cases, the <br />casing was stabilized in the hole by a concrete collaz at the surface. <br />A number of the wells were drilled on BLM ]ands, and the BLM has indicated that they <br />will require that the PVC casing be drilled out and the entire borehole be cemented to <br />adequately protect the coal seam. Historically, the mine did not encounter any significant <br />quantities of either methane or water in the coal seam (surface mining was at [he outcrop <br />on a syncline). The mine owner has concerns that the proposed closure requirements are <br />excessive, would be unnecessarily costly to implement, and could result in additional <br />borehole disturbance given the potential for deflection during dri]]hole reaming. Input <br />from a credible "expert" on well closure is needed to evaluate the reasonableness of the <br />BLM requirements and identify any feasible alternatives that would accomplish the <br />objective of sealing an interval of the boreholes immediately above the coal seam to <br />protect the coal resource. <br />Please review the accompanying information, fee] free to contact me with any questions or <br />additional information needs, and then ]et me know what your anticipated time requirements, <br />consulting rate, and irk schedule would be. We appreciate your attention and cooperation. <br />Best <br />cc: <br />If you do not receive all pages, or if there are any problems with this transmission, please call <br />303-938-8878. <br />