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• -32- <br />water interceptor ditch should be provided at the toe of the spoil, near the <br />spoil - bedrock interface. This interceptor ditch should be provided with <br />sufficient slope that will provide for drainage to low spots where water <br />collected can be removed. We recommend that the ditch be:lined with shotcrete <br />to reduce the likelihood of water infiltrating joints especially if a cut is <br />made in the rock below the spoil for leveling of the pit floor. <br />We recommend a surface water diversion ditch should be provided upslope <br />of the crest of the spoil slope. We believe that this ditch should be con- <br />structed near the point where the spoil surface has been topsoiled and vege- <br />tated. We suggest that the diversion ditch be designed to adequately convey <br />at least a 10 -year frequency event. <br />• LIMITATIONS <br />The analyses and recommendations presented in this report were based <br />upon conditions exposed in the bandoned 8050 pit, exploratory test pits, <br />the results of laboratory testing performed by our firm for this investiga- <br />tion and previous investigations we have made within the mines. Considering <br />the complexity of construction, it is recommended that construction of the <br />entry cut slope as well as regrading of the spoil face be periodically observed <br />by a representative of our office. Variation in the conditions exposed by the <br />cut may result in some adjustment in our recommendations. <br />