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Coal Mel6ane DmingQe Projeet - PaneG 16-24 Wet1 Elk Mine <br />1.3.5 Drill and Complete MDWs and Drill and Log Exploration Drillholes <br />1-7 <br />MDWs and exploration drillholes would be drilled from the drill pads constmcted over each of the <br />progressive longwall mining panels. MCC would drill vertical or neaz-vertical MDWs wherever <br />feasible. Where this is not possible due to access or environmental constraints, it may be necessary to <br />drill one or more angled MDWs from a single drill pad to intercept the target locations above the coal <br />seam. The locations of the proposed drill pads and MDWs are shown on Map MI, Project Area <br />Activities With Surface Stipulations. Completion of approximately 70 MDWs and up to 10 <br />exploration drillholes is proposed. Up to 18 MDWs and 4 exploration drillholes would be drilled <br />during each yeaz of the program. <br />MDWs and exploration drillholes would typically be drilled using track-mounted drill rigs and <br />standazd rotary (tticone roller bits) and downhole hammer drilling methods. Drilling circulation <br />media, used to lift drill cuttings from the drillhole and stabilize the hole during drilling operations, <br />would normally include air, water; and biodegradable polymer foams. Gels, surfactants, and <br />bentonite-based drilling muds would also be used to stabilize the drillhole, if necessary. Other <br />materials, including crushed peanut shells, cottonseed hulls, and cedar fibers could also be added to <br />the circulation medium to help seal the walls of the hole to maintain circulation. All drilling fluids <br />and additives that could be used are either naturally occurring inorganic or organic materials or <br />biodegradable compounds. <br />Water for drilling operations would be pumped to individual drill sites from portable tanks using high <br />pressure hose. Drilling water would be obtained from the mine dewatering system or other sources <br />for which MCC has applicable or can obtain water rights. All drilling Euids and cuttings would be <br />contained on the drill pad in mud pits or portable tanks. Earthen berms on the perimeter of the drill <br />pads, designed to intercept and contain runoff from the pad area, would also serve as secondary <br />containment to prevent the release of drilling fluids from the pad area. <br />MDWs would be completed and cased with cemented steel casing, as shown on Figure F3, Typical <br />Methane Drainage Well Construction/Completion. The casing prevents deterioration of the drillhole <br />and maintains an open Flow path for methane drainage. Cementing the casing in the borehole <br />prevents flow of either gas or water in the annulus between the casing and borehole and prevents <br />contamination of ground water or mixing between ground water sources. Control valves would be <br />installed on the surface casing to control methane flow. Blow-out preventets aze not necessary on the <br />well heads since the project area is not a producing gas field, high pressure gas has not been <br />encountered in any previous drilling in the area, and the coal bed methane present is not pressurized <br />and is typically released very slowly under natural conditions. Exploration drillholes would be <br />completed, logged (to obtain information on geology and coal and overburden occurrence and <br />characteristics), and then plugged and sealed, completed as a MDW, or completed for monitoring or <br />other uses acceptable to both the USFS, MSHA, the CDMG, and MCC. <br />Following completion of drilling activities for the MDWs and any exploration drillhole, the size of <br />each drill pad would be reduced by reclaiming all pad areas except those aeeas required Eor MDW <br />operation and access. Generally, this would involve reduction in the pad size from 0.5 acres to <br />approximately 0.05 acres and reclamation of the remainder. One or more of the initial drill pads <br />within each of the three mining districts (Panels 14-175, Panels 18-20, and Panels 21-24) would be <br />used as a staging azea for temporary storage of equipment and supplies for subsequent pad <br />constmction and drilling. For those pads used as staging areas, pad reduction and interim reclamation <br />would be deferred until all drilling was completed in the corresponding mirting district. <br />EnvimnmenlalArretrmenl <br />P.PP/A/rY. GYG/En/Onn //~/n?l:l USFf <br />/t/0}y, <br />