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Spring 2008 Subsidence and Geologic Field Observations <br />Box Canyon, Apache Rocks, and South of Divide Mining Areas <br />• 4.0 OVERVIEW OF SPRING 2008 FIELD STUDIES <br />This subsidence report is the first of two reports to be generated during the 2008 calendar year. <br />Biannual reports were initiated in the spring of 2007. According to the permit, such reporting is <br />to be submitted to Colorado Division of Reclamation, Mining and Safety (CDRMS) by April 301'' <br />(spring) and October 31St (fall). However, springtime observations are regularly hampered by <br />limited access due to snow or muddy conditions as occurred this year. For example, persistent <br />snowstorms and snowpack prevented field observations this April while prolonged cooler <br />weather caused additional snow and muddy conditions throughout much of May. This inability <br />to complete field observations was reported to CDRMS via letter dated May 1, 2008. Due to <br />these weather conditions, the earliest access occurred in early June (and even then under stormy, <br />blustery conditions that included snow squalls). <br />This spring report describes the field observations made on June 4 and 5, 2008, which <br />represented the second time that most of the subsidence monitoring areas have been observed <br />is during the spring. The areas visited were much wetter than that observed during subsidence <br />observations prior to 2007. <br />Subsidence observations were conducted in the Box Canyon, Apache Rocks, and SOD mining <br />areas. Field observations were made from a 4-wheel drive vehicle and by foot travel to <br />efficiently complete the required work. <br />C7 <br />Prior field observations and experience in the West Elk Mine area during field studies over the <br />last twelve and one-half years' (1996 to 2008 inclusive) indicate that subsidence features (cracks <br />and bulges) are most visible on roads and trails, where the ground is more compact and free of <br />Annual subsidence and geologic hazard reports are kept at Mountain Coal Company, LLC and at the Colorado <br />Division of Reclamation, Mining, and Safety, as well as exhibits to the permit document (Exhibits 60, 60A, 6013, <br />and 60D). <br />831-032.790 Wright Water Engineers, Inc. Page 11 <br />August 2008