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TRAUTNERAff, <br />GEOTECHNICAL ENGINEERING, MATERIAL TESTING <br />AND ENGINEERING GEOLOGY <br />June 2, 2011 <br />John Ferguson <br />Colorado Goldfields, Inc. <br />Silverton CO 81433 <br />970-387-5254 <br />970-387-5256 (fax) <br />970-749-2279 (cell) <br />Subject: Pride of the West Mill and Clark Depository Site <br />Borehole Closure Plan <br />Howardsville, Colorado <br />Mr. Ferguson, <br />PN: 52168DR <br />This letter outlines our closure plan for the test boreholes we advanced at the requested <br />locations at the Pride of the West Mill in Howardsville, Colorado and for the new test borings <br />that we plan to drill for our geotechnical assessment for Colorado Goldfields, Inc. After drilling <br />with four and one quarter (4 1/4) inch hollow stem augers, we plan to permanently close the test <br />borings by following the Colorado Division of Water Resources Rule 16 (attached with this <br />letter). Rule 16 regulates the Standards for Plugging, Sealing and Abandoning Wells and <br />Boreholes. Note that the hollow stem augers are sized based o n the inside diameter of the <br />augers. The 4 1/4 inch augers will create an approximately eight (8) inch diameter hole. A well <br />abandonment form (Form No.GWS-09, 6/2006) will be completed as necessary to comply with <br />the State of Colorado, Office of the State Engineer. <br />According to Rule 16; "test holes... shall be plugged, sealed and abandoned pursuant to Rule <br />16.2 ... and by filling the hole(s) with drill cuttings, clean native clays, cement or high solid <br />bentonite grout to within five (5) feet of the ground surface. The top five (5) feet of the hole shall <br />be filled with materials less permeable than the surrounding soils that are adequately compacted <br />to prevent settling. " <br />We plan to utilize a grout pump to pump a Portland cement mixture with a water to cement <br />ratio of approximately 0.45 to 0.50 with between five and ten (5-10) percent bentonite mixture <br />through a tremmie tube or through hollow stem augers depending on the subsurface conditions <br />encountered during our field exploration. <br />Please contact us if you have any questions, or if we may be of additional service. <br />Respectfully, <br />TRAUTNER GEOTECH <br />f <br />J. Andrew Gleason <br />Engineering Geologist <br />Reviewed <br /> <br />David L. Trautner, P.E. <br />Principal Geotechnical Engineer <br />649 TECH CENTER DRivE SUITE A • DURANGO, CO 81301 • 970/259-5095 • FAX 970/382-2515