Laserfiche WebLink
1100318 R0T0 0811 JRW1 28 <br />Area H. Boring EXAP-1 encountered artesian groundwater conditions at a <br />depth of 14 feet during drilling. At the conclusion of drilling, the <br />groundwater level had stabilized at between 7 and 8 feet below ground <br />surface. Boring EXAP-1 did not encounter the Sawatch Formation to the <br />maximum depth drilled (67 feet), which was much deeper than anticipated in <br />this region based on discussions with quarry staff. Boring EXAP-2 <br />encountered the Sawatch Formation at a depth of about 62 feet and <br />groundwater at an approximate depth of 68 feet. At the conclusion of <br />drilling, the groundwater level had also stabilized at between 7 and 8 feet <br />below ground surface. The depth to the Sawatch Formation was again much <br />greater than anticipated based on prior information. Boring EXAP-3 did not <br />encounter any moist or wet material during drilling to a total depth of 70 feet. <br />By the next day, however, groundwater levels had risen to a depth of 42 feet <br />below ground surface. <br />The May 2011 field investigation significantly added to the overall understanding of geologic <br />and groundwater conditions in the Pikeview Quarry. Key findings and results of the May 2011 <br />field investigation include: <br /> Borings EXC-1, EXC-2 and EXC-4 all encountered clay beds in the upper <br />fine-grained member of the Sawatch Formation that could be correlated <br />between the top of the quarry and the floor of Area H. <br /> Rock core samples from EXC-1 through EXC-4 and EXB-1 through EXB-3 <br />permitted the development of a detailed stratigraphic column and correlation <br />of stratigraphy between different parts of the quarry. <br /> Groundwater conditions measured in the various borings performed in the <br />April and May field investigation, as well as open shot holes dating from <br />2008 permitted an understanding of the groundwater conditions across the <br />site, including a recognition that shallow groundwater was present near the <br />toe of the Pikeview Landslide in Area H. Data from borings EXB-1 through <br />EXB-3 provided critical information on the depth of fill material place in the <br />south end of Area H circa 2008.