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The core retrieved from the hole will be approximately 3" in diameter although smaller diameter <br />core (17/8") may be used in some instances. The outer diameter of the cored portion of the hole <br />will be 6 inches or less. <br />Modification of Drill Holes to Surveillance for Water Levels <br />AL proposes to convert exploration hole SST -2 to an E Seam water monitoring site if mineable <br />thickness of E Seam coal is present. Due to the high potential for unmineable coal to be present at <br />that location, AL proposes to delay construction of the water monitoring well until the hole is <br />drilled and a determination on mineability of the resource is completed. The necessary permit will <br />then be obtained from CDRMS for the monitoring well installation. <br />For the other exploration sites, the FS, BLM, and CDRMS will be notified if significant water <br />flows are encountered during drilling. At that time, it will be determined whether a monitoring <br />well installation would be prudent. <br />No significant water -bearing bedrock or aquifers are anticipated to be encountered. The Mesa <br />Verde Formation is known to contain limited water bearing sandstones, and no known bedrock <br />aquifers exist. If significant quantities of water are encountered, the appropriate regulatory <br />officials will be notified and if so directed, the hole may be completed as additional water <br />monitoring well. <br />Drill Hole Identification <br />For reference, the identification of the holes will change upon initiation of drilling. <br />Pre -Drill ID <br />Completed Hole ID <br />SST -1 <br />XXSST-1 <br />SST -2 <br />XXSST-2 <br />SST -3 <br />XXSST-3 <br />SST -4 <br />XXSST-4 <br />SST -5 <br />XXSST-5 <br />SST -6 <br />XXSST-6 <br />SST -7 <br />XXSST-7 <br />SST -8 <br />XXSST-8 <br />SST -9 <br />XXSST-9 <br />SST -10 <br />XXSST-10 <br />XX = Year hole was drilled; e.g. Hole 18SST-8 would have been drilled in 2018. <br />Drill Hole Abandonment Methods <br />The hole plugging method described in 43 CFR 113484. 1 (a) or Colorado Division of Reclamation, <br />Mining and Safety (CDRMS) Rules at 4.07.3, states that each open hole will be plugged with <br />cement from bottom to 50 feet above the uppermost thick coal seam and from 50 feet below to 50 <br />feet above any aquifers encountered in the hole. The remainder of the hole is to be filled with an <br />approved completion mud, gel, cuttings, or cement. A suitable plug will be placed 10 feet below <br />the ground surface to support a cement plug to within 3 feet of the ground surface. The surface <br />casing will be cutoff below the ground surface and an appropriately labeled monument marker set <br />on the ground surface above the hole. AL may elect to fill the hole in its entirety with cement. See <br />Figure 2. <br />10 <br />