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Ms. Cynthia Pazker July 13, 2001 Page 6 a potentially significant impact could be felt within a short period of time by the wetlands adjacent to WCR 28, across from the proposed mine operations. This impact, a decline in existing groundwater level conditions, could result in adverse impacts to the wetlands. The Theis analysis indicates that significant groundwater level declines may begin almost immediately with the initiation of mine dewatering, and that the decline may increase over the 20 year dewatering period to significant levels -possibly as much as 50 feet. This could result in a major decrease in groundwater contribution to wetlands water supply. The wetlands aze, to some degree, reliant upon water originating from the Last Chance Ditch. A potentially significant impact to the domestic well on your property. Although this well is decreed, it is located beyond the 600 foot radius considered by the State Engineer in its evaluation. The impact could result in the need to drill a deeper well for continued reliable water supply, as this well is relatively shallow, (around 14 feet). The Theis analysis indicates that the dewatering activities could cause the groundwater level to decline to levels below the total well depth. An impact could occur at the irrigation well, which is also decreed, but located beyond the 600 foot radius considered by the State Engineer. Although it is farther from the proposed dewatering operations, the resulting cone of depression is likely to result in a decline in groundwater level at that location. This could cause increased pumping costs and diminished production capability of the well. There may be an impact on the spring and pond it supplies. If the spring is supplied from the shallow alluvial aquifer, any drawdown of the groundwater level in that area could have a very serious impact, including a decrease or complete cessation of flow on a permanent or seasonal basis. There may, however, be other hydrogeological factors involved with the spring and related pond which make the impact of mining operations difficult to evaluate without fittther study and analysis. Because the hydrogeology of the spring is not known to us, a final conclusion regazding the impact of the proposed mining/dewatering operations on the flow of the spring requires further study. We do not know whether the pond is presently in hydraulic contact with the groundwater surface. A decline in the groundwater table under the pond may result in increased losses to groundwater and an increased water supply requirement for maintenance of the existing surface water conditions. Hydrosphere Resource Consultants, 1002 Walnut Suite 200, Boulder, CO 80301