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immediately adjacent on the west side of I-25 is a lined reservoir and is field proof that the <br /> materials in the vicinity are adequate to construct a reservoir liner. <br /> Groundwater Impacts <br /> The proposed mining operation will be done as a dewatered pit with pumping used to lower the <br /> groundwater table in the immediate vicinity of the pit. The operator will ring the entire property <br /> in the second phase and remove a 200-foot wide strip of gravel down to bedrock. As the material <br /> is removed, reclamation will follow with the construction of the reservoir liner proceeding <br /> immediately behind. This construction sequence will minimize the amount of time that <br /> dewatering will be necessary. Once Phase 2 is completed, then the mining operation can work on <br /> the interior proceeding from north to south. The mining can be done in the dry since the alluvial <br /> aquifer will be blocked from the pit by the liner. This also gives the operator a significant time <br /> period to determine the effectiveness of the lining method. The liner will be in operation for at <br /> least 8 years before the mining operation has been completed. <br /> There will be no impacts on the groundwater table on the east side of the river. The Poudre <br /> River will serve as a hydraulic barrier to any dewatering operations during the first phase. <br /> It is unknown how many of the identified wells are still in operation today. Some of the wells <br /> are large capacity irrigation wells with the majority of the wells being small capacity wells. It is <br /> unknown if any of the wells are used for other than agricutural purposes, however, given the poor <br /> water quality in the area, it is unlikely that water from this aquifer serves as a potable supply. <br /> The Operator proposes to monitor the groundwater table as follows: <br /> 1. A monitoring grid will be located around the property. A total of 6 monitoring points <br /> will be established with baseline data collected prior to the start of mining. The baseline <br /> information will consist of at least three sets of water table measurements being made <br /> before mining begins. The measurements will attempt to collect data during different <br /> times of the year to allow for fluctuations that normally occur such as deep water <br /> percolation from irrigation, etc. <br /> 2. The Operator will monitor the water table depth on a monthly basis for the life of the <br /> mine. The water table data shall be supplied to the Division of Minerals and Geology <br /> with the annual report. <br /> The proposed construction of a lined reservoir in this location may also create a barrier to the <br /> flow of groundwater in this reach of the valley fill aquifer. The lining of Wellington Downs <br /> reservoir effectively removed approximately 25% of the cross sectional area of the aquifer. (see <br /> Figure G-1) This has resulted in a noticeable rise in the lake levels of unlined pits that lie <br /> immediately to the north of Wellington Downs. The rise has been estimated at between 1 to 2 <br /> feet. This rise has stabilized and appears to have allowed the aquifer to reach a new equilibrium. <br /> This has not resulted in any known adverse impacts to adjacent properties. However, the <br /> construction of this reservoir would effectively remove approximately 50%of the aquifer cross <br /> section. Based on the evidence that previous lining operations have created a rise in groundwater, <br />