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_~LI"-'- ~=~"I- _~S1L_1.1.. .L~..~'l.rv . ~ i H . to tn•~_1 .~ttr.W .vim _ r.. b1 III'I'II"I"""I' Mountain States Engineering Associates, P.C. - - _. _ _. ~~ 999 Consultants fn Civil Engineering & Land Surveying September 13, 1994 _Reclamation Resources, inc. c/o Mr. Ron Thompson, Ssq. 160U Stout Street, Suite 1300 Deiivert CO. 80202-3132 Re: Alma Placer Mine Dear Mr. Thompson, In response to your request to suggest improvement that could be made to the settlement pond earth dam in area ~A" of the Alma Placer Mine, we have come to the following con lusion: 7. The existing earth dam (berm) is adequate to provide the required volume of detention. 2. Said earth dam is actually constructed from a m xture of top soil, sand, and a blend of Band and gravel. This material is well compacted, and although not impervious, it is o sufficient thickness and density to be able to adequate resist serious leakage. i 3. The pond itself, although originally lined with lastic, is at this time also lined with a very thick and dense 1 yer of fine silt. This lining was naturally created from the silt deposited from khe water effluent generated by the minin operation. Inasmuch as the pond is dry, at the present t me, enabled us to test the thickness of the silt liner in se eral places. We are satisfied that the thickness exceeds 3 fe t in the middle of the pond and progressively less toward the edges. It is our recommendation that before the pond is placed n use again, some of this silt material should be placed along the above-described earth dam all the way to the very top of the dam. That way, even the one foot free board would be pro ected with an impervious liner in case that it should ever be eeded. 4. As a last measure, we recommend that you install at least 4 Pizzo tubes, evenly spaced along the length of t e dam. The tubes should go down to a point at least 3 feet belo the lowest point of the pond, and preferably several feet be and that if possible. The pizzo tube should be 4-inch, class 80, PVC pipe, with several perforations throughout the lengt o£ the tube. •Observation of the water level and recording these 165 South Union Boulevard, Suite 318, Lakewood, Colorado 80228 (303) 987.390