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A=COM <br /> Technical Memorandum—3 Dam Reslope Project <br /> October 5, 2017 <br /> Page 5 <br /> June 27, 2017 <br /> Regrading/trimming of the downstream slope of the original 3 Dam was in progress using two <br /> Caterpillar D8T dozers, one with GPS elevation control on the blade. The dozer without GPS was <br /> rough-cutting to about 1 foot above finished grade, and the dozer with GPS was doing final trimming. <br /> The typical cut was about 1 to 2 feet at the toe and 8 feet at the crest. The exposed material at the <br /> base of the cut was mostly yellowish-tan, fine to coarse, silty sand tailings, with little fine gravel and <br /> trace medium to coarse gravel-sized pieces and occasional cobble-sized rock fragments. There <br /> were also occasional pockets of reddish-brown or light grey, clayey silt tailings (possible slimes) of <br /> generally medium stiff to stiff consistency. <br /> Placement/compaction of the excess fill in the 3 Dam stepback area continued, using a third D8T <br /> dozer(spreading the tailings in lifts and performing track compaction using the weight of the <br /> machine). <br /> The operators left intact zones of several feet of tailings around piezometers that exist in the slope. <br /> That material will be trimmed to grade once the standpipes to the instruments are lowered. <br /> Approximately 550 If of the downstream slope of 3Dam remains to be regraded. <br /> Afia— <br /> 'a <br /> i-8 <br /> L ' <br /> •`\ � 1 a, ¢ 1����i a, •� ..t.:. ��- ., `�� „�. ,�yam, "- ,�,, <br /> t i p ✓`� <br /> - <br /> 4-a;- 'r y � t, ''y�) - 'SIT ✓ a # c�e , a 'i►. <br /> d ` <br /> Photo 5—View of instrument on regraded slope (to be lowered). Looking north on June 27. <br />