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Corey Heaps <br />CAM Colorado LLC <br />June 21, 2011 Page 36 <br />permit may be necessary. One option would be to line the ponds but this is not discussed <br />and there are no plans presented for pond liners. Given the fact that pond bottom <br />elevations are very close to the groundwater table, the Division is requesting that the plan <br />designs and discussion for each of the ponds be reviewed and revised accordingly. <br />Please elaborate on whether or not groundwater is likely to be encountered at each pond <br />location and provide appropriate mitigation plans. Otherwise show that the appropriate <br />permits have been obtained for exposing groundwater from the Division of Water <br />Resources. If CAM intends to discharge through the pond bottoms, please contact the <br />Water Quality Control Division to determine if a CDPS Permit is required. <br />CAM : The projected groundwater elevation as shown on Figure 2 in the AVF Report <br />(Exhibit 14) at the location of ponds 1 and 2 is approximately 4455'. The elevation <br />bottom of pond 1 is 4463' and pond 2 is 4460' and therefore groundwater is not likely to <br />be exposed. In addition, the concern about the sediment pond discharging to the <br />groundwater is unlikely. Please see discussion presented on page 2.05 -51. <br />Division Response: Response accepted. <br />53. Sediment Ponds #1, #2, #3, and #5 appear to be incised, based on the details shown on <br />Maps 13 and 14. No embankments are proposed to be constructed for these four ponds, <br />and dewatering will occur as needed by pumping to Reed Wash. <br />Sediment Pond 94, however, is located immediately adjacent to Reed Wash and has been <br />designed with an emergency spillway. Details of Pond #4 are provided on Map 14. The <br />spillway elevation appears to coincide approximately with the existing ground surface. It <br />appears that an embankment is proposed along the outermost edge of the pond (Section I- <br />I'), in order to provide sufficient freeboard above the spillway. It is unclear, from this <br />drawing, what is the intended vertical limit (depth below ground surface) of embankment <br />construction. The fine - grained in -situ soils may be unsuitable material to effectively <br />form the lower reaches of the impounding structure. <br />The Division has determined that a detailed design plan for this structure (Sediment Pond <br />#4) is required, as described in Rule 2.05.3(4)(a)(ii)(A) and (B), to ensure compliance <br />with the safety factor requirements of Rule 4.05.6 and Rule 4.05.9. <br />CAM : Sediment pond 4 no longer exists. Design for ponds 1 and 2 are shown on Map - <br />13. Ponds 1 and 2 are entirely in cut, no embankment will be constructed for either pond. <br />Division Response: Response accepted. <br />54. The Division has a general concern regarding the sediment pond designs and their <br />location. The long ponds immediately adjacent to the railroad track embankment could <br />cause stability problems over time due to saturation of the embankment fill. Does the <br />