Laserfiche WebLink
Homestake <br />Pitch Reclamation Project <br />2007 Geotechnical Observations <br />Indian Creek and Tie Camp Creek Waste Rock Dumps <br />June. This rise was lower than the 2006 water level fluctuation of 7.4 feet. The 2006 <br />reading was the greatest water level fluctuation since the repair work was completed in <br />1995. The water level began dropping back to its normal range the following month, a <br />condition similar to piezometers on the Indian Creek dump and deemed as an acceptable <br />seasonal variation. In 2007, we will continue to monitor closely the surface conditions of the <br />Tie Camp dump after the spring snow melt. <br />3. Piezometers - 2007General Comments <br />The 2007water level measurements continue to show the normal seasonal variations in the <br />depths to water (and therefore the thickness of the saturated zone at the base of the waste rock <br />dumps). Following the dry conditions of 2001 through 2003, the seasonal variations noted in <br />2007 were back in line with historic variations. The saturated zone under the dumps remains <br />thin and similar to previous years. Homestake will continue to evaluate the cause and possible <br />effects of the seasonal spikes in the water levels in some piezometers, and observe surface <br />features of the dumps. However, there continues to be no indication of instability in either of the <br />waste rock dump. <br />Table 1: Pitch Project - Depth to Water in Waste Rock Dump Piezometers [teet telow ground surtace at couar (bgsl] <br />DATE 10630 10600 10525 10440 10370 10360 10300 TC10375 <br />Collar Elev. 10631.5 10603.8 11053.6 10440.0 10380.52 10373.4 10299.5 10373.0 <br /> <br />1/9/2007 <br />203.1 <br />252.9 <br />229.1 <br />190.8 <br />228.5 <br />190.8 _ <br />171.9 <br />2112/2007 203.1 253.0 229.3 190.8 230.6 190.9 172.8 <br />3/9/2007 203.2 253.0 229.4 190.8 231.7 191.0 173.0 <br />4/4/2007 202.0 252.4 227.7 190.6 221.8 188.2 171.4 <br />5/21/2007 202.0 243.6 220.3 ° 219.9 181.0 167,9 <br />6/18/2007 202.1 247.6 221.6 220.4 185.4 169.2 <br />7/20/2007 202.0 249.8 224.3 220.8 186.2 169.9 <br />8/17/2007 202.0 252.1 225.8 ° 221.6 188.7 170.4 <br />9/28/2007 202.0 252.7 226.7 ° 221.8 189.5 170.6 <br />10/18/2007 202.0 252.7 228.2 ° 223.6 190.0 170.8 <br />t 1 N 312007 202.0 252.2 228.6 224.3 190.3 170.8 <br />12/11/2007 202.0 252.3 229.2 226.0 189.9 171.1 <br />Avera a de th 202.3 251.2 229.1 190.7 224.3 188.5 170.8 <br />2007Maximum <br />Differential <br />1.1 9.4 <br />9.1 <br />0.2 11.8 <br />10.0 <br />5.1 <br />Homestake Pitch Reclamation Project Page 3 <br />2007 Annual Geotechnical Report December 14, 2007 <br />M•1977-004HR 2007ReportText .Final <br />