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Open standpipe piezometers were installed in boreholes B-3 and B-7. At B-3, the standpipe was <br />screened from 89 to 99 feet below ground surface to measure deep water levels within the bedrock. <br />The B-7 standpipe was screened from 12.5 to 22.5 feet below ground surface. <br />Inclinometer casing was installed in the following boreholes: B-4, B-5, and B-8. The purpose of <br />these traditional inclinometers was to measure slope movement within the colluvium. The depths to <br />which the inclinometer casing was installed ranged from 25 to 35 feet below ground surface. <br />2.1.2 Construction Phase Investigations <br />Samples of colluvium were collected on August 27, 2010, while stripping colluvium during <br />construction of the buttress. These bucket samples were shipped to Soil Engineering Testing for <br />laboratory testing. <br />MCC's Coal Preparation Plant (CPP) generates coal refuse material that has been and will continue <br />to be placed in the RPEE waste rock pile. The CPP processing produces a refuse that is coarser than <br />some previously available refuse materials on site. Refuse material from the initial operation of the <br />CPP was placed and compacted in the existing Refuse Pile Expansion (RPE) area, located northwest <br />of the RPEE. Samples of the newly generated coal refuse were collected from the RPE on January 4, <br />2011. Four representative samples (each sample consisting of a 5 -gallon bucket) were collected from <br />the upper 18 inches at various locations. After sample collection, photographs were taken of the <br />sample to document the overall gradation of the material. The coarser material (diameter greater than <br />3 inches) was then separated from the sample and placed in a separate container. Both sample <br />containers were weighed to determine a total sample weight in addition to the weights of the coarse <br />and fine fractions. The coarse sample fraction was placed back in the RPE while the fine sample <br />fraction was shipped to Soil Engineering Testing for analysis. <br />In addition to the investigation work and instrumentation installation performed in 2009 and 2010, <br />traditional inclinometers and vibrating wire piezometers were installed in the buttress and in the <br />RPEE waste rock pile in 2012. These included two inclinometers in the colluvium buttress (I12-03 <br />and I12-05) and one in the refuse (I12-04). The inclinometer casings at these locations have <br />deformed to the point where readings are no longer possible. Inclinometer I12-03 was replaced with a <br />ShapeAccelArray (in-place inclinometer using MEMS sensors) and it is functioning properly. Nested <br />vibrating wire piezometers were attached to the traditional inclinometer casings (two at each <br />4 <br />PAMpls\06 CO\26\06261003 MCC Refuse Pile Site Review & Permit\WorkFiles\Permit Application\2014 Revision\Exhibit 82 2014-05- <br />29.docx <br />