2010-12-21_REPORT - M1977004 - Laserfiche WebLink

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Homestake Pitch Reclamation Project 2010 Geotechnical Observations Indian Creek and Tie Camp Creek Waste Rock Dumps 1. Indian Creek Waste Rock Dump a) "10800" Level Site Description: Identical to that of past reports for 1996 through 2009. 2010 Observations: The 2010 observations are similar to those reported for this area during the past fourteen years. Visual inspection of the area has revealed no evidence of settling or slumping of the rock dump material in 2010. Drainage channels are functioning as designed. ___J b) "10780 -10650" Level Site Description: Identical to that of past reports for 1996 through 2009. 2010 Observations: The 2010 observations are similar to past observations. Visual inspection of the area has revealed no evidence of settling or slumping of the dump material in 2010. Drainage channels are functioning as designed. ..' c) "10650 - 10600" Level Site Description: Identical to that of past reports for 1996 through 2009. 2010 Observations: Unlike 2009 when no water was detected in Piezometer IC10630. In 2010, a thin veneer of water was noted at various times from mid-May to October following spring snow-melt and summer rain storms. To be realistic the moisture was only noted because the measurements were taken out to the next decimal point. Overall, this piezometer has never shown more than a foot of water following snow melt and it normally dries up by mid-summer. As noted in previous reports, in October 2001, an obstruction was removed from Piezometer IC10600, allowing it to be used once again for the collection of water level data. In 2010, a rise of 6.84 feet of water was recorded, which was slightly less than the rise in 2009 and 2008. The water level then dropped back to a normal range by mid-July as it has in the past. This condition is similar to other piezometers in the Indian Creek dump, and is deemed as an acceptable seasonal variation. The water level increases in 2005 through 2010 were a result of heavy snow pack and wet spring conditions. d) "10725 -10525" Level Site Description: Identical to that of past reports for 1996 through 2009. The minor overlap between this level and other bench designations reflects the original bench configuration. 2010 Observations: Piezometers IC10600 and IC10525 bound this area. In 2010, the water level in Piezometer IC10525 increased by 6.60 feet in early May through June and, similar to Piezometer IC10600, dropped back to normal levels in late-July. This behavior is very similar to that of past reports from 1996 through 2009. In 2010, the average water level in ICI 0525 was 225.8 feet bgs, in a total dump thickness of. approximately 229 feet at this location,.