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The slide is located along a southwest facing slope situated immediately above Pond 16 and a riprap lined* <br />d;a*age channel that flows into the northeast corner of Pond 16. It is our understanding that the water that is <br />flowing in the drainage comes from the overflow in Pond 16A, as well as from a series of failed monitor wells <br />(Series 24) that were installed in the southeastern portion of the failure and south of Test Hole 5 (TH-5) in <br />2001. It is our understanding that the wells were drilled to depths ranging from 238 to 418 feet below the <br />existing ground surface so that the groundwater quality of the aquifers situated below the Wadge Coal seam <br />could be monitored. It is our understanding that the casing in upper portion of the wells ruptured between the <br />winter of 2002 and the spring of 2003. It appears that the well casings were sheared off at depths ranging <br />from 17 to 26 feet beneath the existing ground surface. We also understand that water was flowing under <br />artesian pressure from the ruptured wells and that an underdrain system was installed so that the water coming <br />from wells could be collected and diverted into Pond 16. <br />It appears that a considerable amount of site grading, consisting of cuts on the uphill portion of the haul road <br />and the placement of fill materials on the downhill side of the haul road, was required during the original <br />construction. It is our understanding that during the reclamation of this section of the haul road, the fill <br />materials placed in the lower portion of the roadway embankment were moved uphill and used to fill in the <br />roadway cut. <br />Based on our observations, it appears that the head scarps for the slide are situated in the areas that were <br />reclaimed after the haul road was abandoned. The head scarps appear to range from approximately 600 to 650 <br />feet in length and anywhere from 3 to 8 feet in height. The approximate location of the larger/upper head <br />scarp is shown in Figure #2. The debris flow from the slope failure has encroached into the eastern and <br />northeastern sections of Pond 16. It is our understanding that some additional site grading has taken place in <br />this area since the original slope failure occurred to try and repair the slide. However, the previous site <br />grading does not appear to have stopped or slowed the rate of movement. In fact the amount of movement in <br />the slide area has increased substantially over the last 1 % years. Based on our observations, it appears that the <br />failure has increased in size since our first visit to the site last summer (2008). <br />A rip rap lined drainage channel that discharges into the Pond 16 is located east of the pond and southeast of <br />the failed area. Water was observed to be flowing in the drainage channel in an east to west direction at the <br />time of our site visits. It appears that a debris flow related with the slope failure has encroached slightly into <br />the northwestern side of the drainage since last summer. <br />The vegetation in the slope failure area was sparse due to the previous site grading operations. However the <br />vegetation along the undisturbed slopes situated to the west, north and east of the failed area is heavily <br />vegetated with weeds, grasses, deciduous shrubs and scrub oak brush. <br />• <br />Job Number: 08-8099 NWCC,1nc. Page 3