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999 ----.-- ......,. W1~TER MANAGEMEN'T' - ~'ONSUL'I'ANTS ~ 4~ - ~t ErdTEEF1TH ST SUITE 370 Mr. Louis F. Swift ~ ~Y'"iS ~ . ~ `~ ,, ~ ,~ criooc eozoz usa 6101 S. County Road #7 ~ - ~ ~ ` - Fort Collins, Colorado 80525 1 -~.i.tr , ~~_,E r~u3, r; ;one ~u~Tr ~ Y' September 14, 1999 C7 f /~ t l Dear Louis: 05 ~~,rU-5 s ~ Swift Ponds, Timnath Connell Pit Application, File #M-99-0§8~ Following your request and our meeting on the 14th of August, I have reviewed all of the available information that you have provided pertaining to the above permit application. Between the 19th of August and the 7th of September, [have met with Mr. Dave Jones from Tuttle Applegate, Inc., the consultants for Connell Resources Inc., on four occasions to discuss the proposed mining operation and resolve potential issuesthat may adversely affect the Swift Ponds. The mining plan calls for the excavation of a pit approximately 2,400 by 2,600 feet in plan and approximately ] 6 feet in depth. The inside of the pit will be lined with a compacted clay and overburden berm that will act, for all practical purposes, as an impervious barrier to groundwater flow into the pit. This lining however will also prevent the flow of groundwater to the south and west from areas outside of the pit. It is understood that the mining operation will be continuous for a period of up to 12 years. The primary concern is the potential effect that the mining operations will have upon the natural groundwater flow to the south and the consequential effect upon both water levels and quality within the Swift Ponds. This concern requires evaluation at two different time scenarios, namely: 1) during mining operations and 2) post-mining conditions. These two time scenarios are addressed separately as follows. 1. During Mining Operations We understand that, at the commencement of operations, two dewatering/recharge ponds will be constructed on the southern boundary of the proposed mine with a total east-west length of approximately 1,600 feet. These ponds will be excavated to bedrock and the north side of the ponds will be lined with the compacted clay lining while the south side will remain open. On the north and west sides of the permit area, groundwater collection trenches will be excavated to a depth of approximately 6 feet to convey water from the north side to the recharge ponds. Prior to conveying water to the recharge ponds, all groundwater will pass through a siltation pond which should be constructed upstream of the ponds on the west side of the operations. These trenches will have temporary culverts and gates installed to control the flow of water to the recharge ponds, and to divert groundwater flows to the Cache La Poudre river should mounding start to occur on the north side