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5 April 2012 <br />Mr. Ron Roberts <br />Construction Manager <br />Cripple Creek & Victor Gold Mining Company <br />P.O. Box 191 <br />100 North 3rd Street <br />Victor, Colorado 80860 <br />RE: SPECIFICATION CHANGE #1 - OVERBURDEN FILL TESTING FREQUENCY <br />CRIPPLE CREEK & VICTOR GOLD MINING COMPANY, CRESSON PROJECT <br />Dear Ron: <br />AMEC Environment & Infrastructure, Inc. (AMEC) proposes a modification to the Construction <br />Specifications for the Mill Pad with regard to frequency of Construction Quality Assurance (CQA) testing of <br />the Overburden Fill materials. AMEC's Kimberly Morrison and Jay Janney -Moore phoned Tim Cazier on <br />the 23rd of March regarding this request to modify the Overburden Fill CQA testing frequency, and has <br />prepared this letter as a follow up to that discussion. <br />The current specification (Section 1400.1 — Earthworks Construction Quality Assurance (CQA) Plan) <br />specifies that a suite of testwork consisting of standard Proctor compaction (ASTM D698), particle size <br />(ASTM C117, C136, D1140), and Atterberg limits (ASTM D4318) be performed at a frequency of one <br />sample per 50,000 cubic yards of material placed. It is important to note that "Overburden Fill" is the same <br />as "Structural Fill" per the current specification. Though this frequency of testwork was considered <br />appropriate for Phase 5 construction of the existing Cresson Valley Leach Facility (VLF), the total placed <br />volume was a fraction of the current volume being placed (i.e., 320,000 c.y. for Phase 5 vs. 7,400,000 c.y. <br />for the Mill Pad). Further, haul trucks are being used to place the Overburden Fill, providing approximately <br />50,000 c.y. of material placement on a daily basis. <br />AMEC proposes to reduce the CQA testing frequency to one test per 200,000 c.y. of Overburden Fill <br />material placed. This frequency would result in one to two suites of testwork on a weekly basis at the <br />current placement frequency. AMEC representatives provide continuous monitoring of Overburden Fill <br />placement. <br />1125G_ SpecificationChange _OverburdenFill_Ap2012 doc <br />AMEC Earth & Environmental, Inc. <br />Colorado Center Tower II <br />2000 S. Colorado Blvd, Suite 2 -1000 <br />Denver, CO 80222 <br />Tel 303 - 433 -0262 <br />Fax 303 - 433.0362 <br />www.amec.com <br />ame0 <br />Project 74201125H0 <br />