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20 November 2015 <br />Tyler O'Donnell <br />Division of Reclamation, Mining and Safety <br />1313 Sherman Street, Room 215 <br />Denver, CO 80203 <br />by email to Tyler.ODonnell@state.co.us <br />Re: Pit 29, M-1980-183, Technical Revision No. 5 — Response to Adequacy Review <br />.RECFWED <br />NOV 2n2015 <br />DIVISION OF RECLAMATION <br />MINING AND SAFETY <br />Dear Tyler: <br />Thank you for letter dated November 19, 2015, regarding your review of Brannan's submittal of TR -05. <br />We have reviewed the questions in that letter and provide the following information in response: <br />1. Each perforation in the French drain pipe presents a circular opening 0.313 inches in diameter. Please <br />refer to the attached technical documentation provided by the vendor with regard to this product. The <br />perforated HDPE pipe has been delivered to the Pit 29 site and conforms with this specification. <br />2. The operator agrees with the Division's concern that material placed inside the geotextile fabric should <br />not migrate into the perforated pipe. Therefore, at a minimum, all granular material placed inside the <br />geotextile will be screened to a %-inch plus classification. At this time, we contemplate using %-inch <br />washed rock from Brannan's available final product at the Pit 29 site, or its equivalent. <br />As always, thank you for your attention and assistance. Please contact me at any time with comments or <br />questions. <br />Sincerely, <br />BRANNAN SAND AND GRAVE MPANY, LLC <br />Al <br />cc: Gene Riordan <br />Tom Hatton <br />encl: ADS Technical Note TN 1.01— Dual Wall HDPE Perforation Patterns <br />2500 East Brannan Way 1 Denver 1 CO 80229 1 303.534.1231 Tel 1 303.534.1236 Fax <br />www.brannani.com <br />