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t • <br />R. G. OTTO & ASSOCIATES <br />.; <br />.; <br />typically saturated within a few feet of its surface, and the <br />saturated zone in the alluvium is hydraulically conaeated to the <br />stream, the relative proportions of percolation flow which eater <br />the ground water or become surface runoff are really only of <br />academic interest. Both components will become contributors to <br />the flow in Ralston Creek. <br />McDermid (1983) estimated the infiltration capacity at the pile <br />surface and the vertical permeability of the waste rock using <br />field measurements. An oil drum was sunk into the pile, sealed at <br />the sides and pumped full of water. The rate of water inflow <br /> <br />f necessary to reach an equilibrium level in the drum wa+s noted as <br /> was the time for the drum to drain following the cessa•Gion of <br />pumping. Infiltration values ranging from 193 to 857 inches per <br />hour and a vertical permeability of about 6 inches an Hour were <br />obtained. One would not expect, on the basis of these estimates, <br />to find any puddles on the top of the pile or see any appreciable <br />surface runoff from the side-slopes of the pile, even cinder the <br />extreme conditions of a summer storm. This is in accord with my <br />observations for the five years (1979-1984) that I havca been <br />sampling Ralston Creek is the vicinity of the waste roc;k pile. I <br />have, however, noted that small quantities of water occasionally <br />appear to exit the base of the pile and collect in the adjacent <br />road during the spring, snow-melt period. Concurrent !snow-melt <br />!':`r~ and runoff on the road and along the peripheries of then waste rock <br />VV;;,,;;yy pile make it difficult to ascertain actual sources of runoff. <br />