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Response to CN-01 Third Adequacy Issues - June 6, 2011 <br />Adequacy Issue #18 <br />Previously, the Division had requested clarification on a 700 foot long pipeline proposed to <br />transport dewatered tailings to the underground disposal location. The Applicant's response <br />contradicted itself sufficiently to confuse what is intended. <br />• The Applicant's response indicated the 700 foot long pipeline was no longer <br />proposed. Mill tailings would be dewatered at the mill facility located at the May <br />Day 1 bench (at surface). The dual lined slurry pipeline and recycled water return <br />pipeline would be less than 50 feet long. <br />• The Applicant's response indicated the mill tailings would be pumped, in slurry <br />form, to the approved disposal location. Mill tailings would be dewatered at the <br />approved disposal location and the recycled water returned by pipeline to the <br />flotation cells. The proposed disposal location was shown on Figure D-la. <br />• Figure D-1 a was not included in the April 18 submittal. Rather, the April 18 <br />submittal provided Figure D-1B, which showed the proposed underground <br />location for tailings disposal. The text of Figure D-1B is not legible, but the <br />general location for tailings disposal is sufficiently shown to be readily identified <br />on other mine maps which were not submitted by the Applicant. <br />• By comparing Figure D-1B to other mine maps the Division determined the <br />proposed underground location for tailings disposal is approximately 2,100 feet <br />underground. <br />Therefore, the Applicant's response indicated tailings would be dewatered at an underground <br />location and not at surface, as stated by the Applicant. Additionally, the dual lined slurry <br />pipeline and recycle water return pipeline would be approximately 2,100 feet long rather than the <br />50 foot long pipelines stated by the Applicant. <br />The mill facility and the associated pipelines and tailings disposal location(s) are Environmental <br />Protection Facilities and subject to the most rigorous environmental protection regulations. <br />Pursuant to Rule 6.4.21(10)(a), the Division had previously requested design specifications <br />certified by a licensed professional engineer for all Environmental Protection Facilities intended <br />to hold, convey, contain, or transport designated chemicals, including process solutions and mill <br />tailings containing designated chemicals. The Division clarified the certified designs must <br />address the redundant containment measures required under Rule 6.4.21(7)(e). (DRMS <br />preliminary adequacy letter, dated March 15, 2011, adequacy item number 39) <br />Rather than submitting the required certified designs the Applicant's response was cursory and <br />sufficiently contradictory to confuse what is intended. The Applicant's response to the adequacy <br />issue is not acceptable. Please answer the Division's adequacy questions in a clear and concise <br />manner. Please clarify what is intended. <br />Revised <br />6/6/2011 <br />17 <br />