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TRAUTHER40 01014: <br /> GEOTECHNICAL ENGINEERING,MATERIAL TESTING <br /> AND ENGINEERING GEOLOGY <br /> December 5, 2011 <br /> Mr. Steve Feam,P.E. <br /> Colorado Goldfields,Inc. <br /> PO Box 790 <br /> Silverton,Colorado 81420 <br /> PN: 52519GE <br /> Subject: Test Boring Closures and Sealing <br /> Kittimac Repository Site <br /> Silverton,Colorado <br /> Mr.Fearn, <br /> This letter provides a brief description of the method utilized to abandon and seal Test Borings KMGT <br /> One through Nine and Eleven through Fifteen. The proposed KMGT Test Boring Ten was not advanced. <br /> These test borings were advanced between July 19,2011 and August 18,2012. The test borings were <br /> sealed for abandonment immediately after the boring had been completed. We have attached Well <br /> Abandonment Reports(State of Colorado Form Number GWS-09)for each of the test borings advanced. <br /> The GPS coordinate locations of the sealed test borings may be found on the attached Well Abandonment <br /> Reports. The GPS locations were provided to us by the project surveyor. <br /> The test borings were advanced to depths ranging from approximately eighteen(18)to sixty(60)feet <br /> below the ground surface elevation adjacent to our test borings. The majority of the test boring depth <br /> caved in on itself during the removal of the auger. The remainder of the test boring was filled with an <br /> imported one and one-half(1'/2)inch minus aggregate material to a depth of ten(10)feet below the <br /> ground surface elevation. The remainder of the test boring was then sealed with a Portland cement grout <br /> slurry. We added approximately five(5)to eight(8)percent bentonite clay to the grout mix in order to <br /> facilitate achieving a good seal within the test boring. <br /> Depending on the subsurface free water elevation,the mixture was either placed directly down the <br /> boring or through a tremmie tube. We utilized a tremmie tube in locations where shallow subsurface free <br /> water was encountered. As noted in the attached abandonment reports,the quantity of Portland cement <br /> and bentonite used to seal the test borings is variable. This is due to the fact that in some test borings,due <br /> to the granular nature of the material,the upper portion of the boring became enlarged or flared due to the <br /> auger rotation. <br /> Please contact us if you have any questions or if additional information is desired. <br /> Respectfully, <br /> Jonathan P.Butler,P.E. <br /> Trautner Geotech <br /> 649 TECH CENTER DnIVE SUITE A DuFIANUU. CO 81301 970/259.5095 FAX 910/382-2515 <br />