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Ralston Quarry Slope Stability <br /> Zone 1 — Relocated Tailings Stockpile In this area, displaced material — primarily <br /> tailings — removed from the slope to northeast were stockpiled. The stockpile was <br /> constructed on Asphalt Paving Company property that, we understand, now has been <br /> incorporated into the ground permitted for mining. <br /> The stockpile extends over an area about 360 feet by 420 feet and is up to <br /> approximately 25 feet in thickness. The stockpile margin slopes descending to the north <br /> and to the west were graded at an angle of about 3 : 1 (horizontal : vertical) or slightly <br /> flatter as shown in the photographs below. <br /> Scrapers were used to construct the stockpile, bringing material from the slope. An <br /> average penetration resistance value (sampler blow count, N) of 14 was obtained from <br /> the test holes advanced into the stockpile (Test Holes 10 and 11) indicating that the fill <br /> materials comprising the stockpile were reasonably well compacted. <br /> Stockpile <br /> ,q w. <br /> sue# <br /> Stockpile of Relocated Tailings, seen from the northeast Northern Slope of Stockpile of Relocated Tailings <br /> Stability analyses of the stockpile slope (Section E — F) on the Google Earth® image on <br /> the following page indicated a minimum, Morgenstern-Price factor of safety against <br /> failure of about 2.4, as shown on the SlopeVV® output below, even with the groundwater <br /> at the base of the tailings stockpile which we consider unlikely. <br /> Job No. 18-3046 GROUND Engineering Consultants, Inc. Page 10 <br />