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Sixth Adequacy Letter, Amended CN -01 <br />May Day Idaho Mine Complex, M- 1981 -185 <br />The Applicant submitted design specification for several of the Zircon units identified as <br />Environmental Protection Facilities. The specifications are provided on CLC drawings <br />C6.10 and C6.11, and on Figure D -1 of Attachment D -2. On Figure D -1 of Attachment D- <br />2, the capacity of the secondary containment structure is claimed to be 2,350 gallons. <br />Measurements taken from Figure D -1 of Attachment D -2 do not support the stated <br />capacity. Measurements taken from Figure D-1. of Attachment D -2 indicate the capacity <br />of the secondary containment structure is approximately 1,720 gallons. Please clarify <br />how the Applicant determined the containment capacity. Please support the <br />clarification with drawings of smaller scale and greater detail, as necessary for the <br />Division to verify the containment capacity. <br />The Applicant did not provide the specifications required by Rules 6.4.21(10) and <br />6.4.21(7), for the mill facility, tailings dewatering location, pipelines for transport of <br />tailings and recycled process fluids, storage tanks for recycled process fluids, process <br />fluids disposal locations, and the tailings disposal locations. <br />The Applicant has requested to resolve the issue of design specifications for all <br />Environmental Protection Facilities through a follow -up Technical Revision and /or <br />Amendment process subsequent to the conditional approval of CN -01. <br />10. In a correspondence dated September 16, 2011, the Water Quality Control Division <br />(WQCD) of the Colorado Department of Public Health and Environment verified the <br />mine drainage from the Idaho No. 1 Adit did not comply with the receiving stream <br />standards for total recoverable arsenic. According to the application, the mine drainage <br />from the Idaho No. 1 Adit is the water source for the Augmentation Pond. Therefore, <br />the Augmentation Pond is an Environmental Protection Facility and subject to the <br />requirements of Rules 6.4.21(10), (7) and (13). Please delete any and all statements <br />from the application alleging the proposed operation is exempt from the requirements <br />of Rule 6.4.21(13). Please address the requirements of Rules 6.4.21(10), (7) and (13) for <br />the Augmentation Pond. <br />11. Pursuant to paragraph (3)(b) of the Joint Stipulation, approved and signed by the Mined <br />Land Reclamation Board on July 28, 2010, ground and surface water quality data <br />required under Rules 6.4.20(9) and (11) shall be collected subsequent to permit <br />issuance. The parties agreed that mining may not commence until the Applicant <br />submits appropriate and adequate hydrologic information to the Division and the <br />Division approves the information as a permit modification. Paragraph (3)(b) of the <br />Joint Stipulation clarifies that limited mining activities, which will not affect surface or <br />ground water quality, may occur subject to the Division's approval. <br />NOTE: Subsequent to the signing of the Joint Stipulation and prior to the filing of CN -01, <br />the Rules were updated and the reference to Rule 6.4.20(9) and (11) in the Joint <br />Stipulation now refer to Rules 6.4.21(9) and (11). <br />7 <br />