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• ~ - vnti~-t ~1t cof l Minor Revision 86-3 GEOTECHNICAL SITE INVESTIGATION - LITTLE MIDDLE CREEK CYCC is requesting a minor revision in order to complete geotechnical site investigations as proposed for excess spoil fill sites, and as required in Ch1LRD's preliminary adequacy letter of the Little Middle Creek Permit Revision. This revision should be under section 776.11 page 776-1 of permit C-81-071. The geotechnical investigation requires drilling in representative locations of the proposed excess spoil placement areas to substantiate the assumptions made in the slope stability analyses. As shov+n on the attached figure, five borings are planned. All drilling and reclamation activities are consistent with CYCC's exploration permit for the area. Access to the drill sites will be along existing exploration roads where possible. If existing roads are disturbed by the proposed activities, they will be bladed and returned to a condition equal to or better than their • condition prior to the proposed activities. New or additional roads will be constructed only when necessary. At conclusion of the proposed activities all new roads will be reclaimed. All roads v+ill have water bars if necessary to prevent excessive erosion. All drill sites will be located next to existing roads, where possible. If necessary, a bulldozer will be used to construct a level bench for the drill. In those cases v+here level bench construction is nece<_sary, for reclamation purposes, topsoil will be removed from the drill site leveling location, stored and replaced during road reclamation. Until redistribution, the topsoil v+ill be stock-piled and protected from erosion. Borings 1, 2, 3, and 5 will include both soil angering/sampling and 20 feet of rock coring. Boring 4 is located in spoils; it v+ill extend through the spoils to the pit floor approximately 60 feet below the surface. Once bedrock is encountered, 20 feet of core will be obtained. If ground water is encountered it will be measured. Plastic standpipe will be installed in the holes for that purpose. Upon completion of the proposed drilling program, cuttings will be placed in each drill hole and each hole will be plunged six (6) feet from the top with a plastic plug and filled with dirt. If necessary, drill holes will be cemented. Excessive cuttings will be spread evenly over the surrounding surface prior to re-topsoiling. All drill sites will be leveled after • completion of the proposed program to their approximate original contour. Topsoil v+ill be replaced, and the surface will be scarified, if necessary. After the topsoil has been replaced, the affected areas will be broadcast seeded at a seeding rate of 24 pounds per acre using CYCC's rangeland seed mix. 776 - 1(a) 9/4/86