Laserfiche WebLink
• 1998 GEOTECHNICAL DRILLING PROGRAM (MR#246) <br />SYLVESTER GULCH FACILITIES AREA <br />SCOPE OF WORK <br />Mountain Coal Company (MCC) proposes to complete additional geotechnical drilling in <br />Sylvester Gulch. This drilling program includes two deep coreholes and eleven shallow <br />boreholes. <br />coreholes: The two coreholes are proposed to be drilled on drill roads previously <br />constructed. Therefore, no new roads or drill pads will be required. The projected depth <br />of each hole is 700 feet. The holes will be drilled using continuous coring methods. <br />Hollow stem augers may be used or temporary surface casing will be installed in the <br />overburden to case it off while drilling. Once the overburden is drilled and "cased" off, <br />wire-line continuous coring methods will be used to drill and sample the rock. The <br />diameter of each corehole will be approximately 5 inches. <br />Lost circulation zones are anticipated during drilling due to the frequency of joints and <br />bed plane breaks in the rock. Water from Sylvester Gulch will be supplied to the coring <br />operation for the first corehole, and from sedimentation pond SG-1 for the second <br />corehole. The fresh water will be containerized in plastic stock-type tanks and no <br />dischazges will occur from the site. The fresh water in the stock tanks will be mixed with <br />• drilling mud (separate from the water source), and then pumped down the hole. Any <br />return (which is unlikely) will be recirculated back into the plastic tanks or back down the <br />hole. <br />Upon completion of the corehole, it will immediately be abandoned with cement grout <br />emplaced with a tremie pipe, as required by Rule 4.07.3. <br />Boreholes: The eleven boreholes are planned in the vicinity of the Sylvester Gulch <br />Substation and the Landing #2 Road, which aze azeas that have been previously <br />disturbed. Therefore, no earthwork or topsoil removal will be required prior to beginning <br />the drilling. The purpose of this investigation is to provide MCC's consultant, Barr <br />Engineering, with additional site specific data to design permanent stabilization for the <br />substation azea and the Landing #2 Road. Angering, soil boring, and coring methods will <br />be utilized to gather the necessary information from the boreholes. Water is expected to <br />be required in the coring process, and will be handled as described above for the <br />coreholes. <br />• Exhibit 69 July 1998 <br />cxh69mr246.doc <br />