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<br />Lyster Pit Page 3 of 5 <br />Moffat County, Colorado July 3, 2008 <br />Ditch in this area. A review of the NRCS soils data agrees with this observation. Since <br />loam soils tend to be poorly to moderately draining, this will in turn help keep the ditch from <br />leaking substantially into the pit. <br />Nearby Wells <br />Figure 1 also shows the location of permitted wells, per the State Engineer's records. Of <br />all the permitted wells, only two have filed completion reports. These are well I.D. 8 and <br />11. Both of these wells are extremely deep, being 1170 and 760 feet deep, respectively. <br />Based on completion reports, the alluvial gravels are no more than 30 feet deep. Thus, <br />any gravel pit, which only intersects the surface alluvial groundwater, will not materially <br />impact a well that derives its source of water from an aquifer in the bedrock formation. <br />Mining activity will occur within the surficial, alluvial gravels and clays. To the extent that <br />adjacent wells pump water from deeper aquifers, no material impact is expected, do to the <br />source(s) of water being separate. <br />The cone of depression caused by the pit will vary depending on the transmissivity of <br />materials adjacent to the pit. Based on borehole logs of the pit, it appears there may be a <br />significant quantity of fines in the gravels. Based on similar observations of pits in the <br />Yampa Valley, it is our belief that the drawdown curve for the pit will not extend more than <br />several hundred feet from the edges of the pit. An exception to this may occur if gravels <br />are fairly clean, and the water table is unhindered by fines. <br />2) Rule 3.1.6(1) discusses the need to address the hydrologic balance of the site, and how it <br />will be monitored. <br />The site should have monitoring wells installed along the upgradient sides of the proposed <br />pit. Given that the Deep Cut Ditch is south of the pit, two wells between the Deep Cut <br />Ditch and the pit should be adequate to monitor the alluvial groundwater table adjacent to <br />the ditch. One well should ideally be located with 10 to 30 feet of the ditch, between the <br />ditch and the pit. Similarly, two wells on the east side should be adequate to provide <br />monitoring of possible drawdown of the alluvial aquifer towards the East. <br />Water from dewatering operations will utimately rejoin the Yampa river. The two <br />exceptions to this are moisture in the gravels and evaporative losses. A well permit has <br />already been issued for the pit which accounts for these losses. This addresses the legal <br />requirement to address the open pit, which is also considered a well for water rights <br />purposes. <br />An accounting sheet (spreadsheet) will need to be developed to match the actual <br />operation. There are two discharges that will need to be accounted for: <br />a. Pumped discharges will need to have flow meters, or estimates of flows made. If <br />flows are estimated, this can be done by measuring flow into a container or pond <br />of known volume, and averaging flows over time. <br />Ah, <br />WATER RESOURCE CONSULTANTS, LLC