Laserfiche WebLink
<br />(3) years prior to completion of the reservoir. Please comment. <br />l9. Please clarify whether improvements to the South Platte River channel or emergency <br />overtlow structures are a necessari part of [he minins and reclamation plan. ie: to help maintain <br />slope stability and/or to help achieve [he designated post-minin=land use(s). If yes, then please <br />provide a description of these improvements, a [imetable for when they will be consructed, an <br />estimate of the installation cost, and representative cross sections or engineering designs. <br />20. Throuzhout the permit application, the applicant has referenced a number of terms relating to <br />the South Platte River :`'low flow channel", "existing high banks", "floodplain", and "tloodwav' <br />aria. Given the close proximity of the South Plaae River to the proposed operation, the Division <br />requests that you clarify or define the terms mentioned above. A representative cross sec[ion of <br />the river channel depicting the four (4) terms mentioned above will be useful. Also, submitting <br />a copy of the Hydraulic Analysis of the South Platte River as required for the Adams County and <br />urban Drainage & Flood Control District flood permi[s may answer this question. Please <br />respond. <br />2l. The applicant states on page ~ of Exhibit G -Water Information "There will be no impacts on <br />the Groundwater table on the east side of the river. The operator proposes to install a slurry wall <br />around the perimeter of the property prior to beginning de~vatering operations. The slurry wall <br />will prevent any drawdown on the sroundwa[er table outside of the properly. The slurry wall <br />may create some mounding of groundwater en the upgradient side. ivlounding will not adversely <br />impact groundwater wells." First, it appears that the applicant meant to say that there will be no <br />impacts on the groundwater table on the west side of the property, since the slurry wall will be <br />installed on the west side of the South Platte River. Second, as shown on Figure G-1 Well <br />Location Map and Exhibit C-? ivlining Plan Map, there are numerous wells and several or more <br />buildings in close proximity to the affected land on the west side of the South Platte River. <br />Therefore, the Division requests that you quantify the lateral and vertical extent of the <br />"mounding' and/or "shadowing" effects that may occur within the regional groundwater table as <br />a result of the completed slurry wall. Will there be any flooding of basements and/or drawdown <br />of neighboring wells? Please respond. <br />22. The applicant states on page 5 of Exhibit G -Water Information "The proposed operation <br />will have temporary impacts on both surface and groundwater in the local area. The minins and <br />reclamation plan is designed to minimize the extent of these impacts. The operator has proposed <br />mitigation to address these impacts." In order to verify these statements and in conformanca.with <br />Rule 6.4.7(2)(b), the Division requests that the applicant further characterize the aquifer to be <br />affected during mining and reclamation and include the following information :average depth to <br />groundwater, hydraulic gradient and/or flow direction, and expected seepage velocity or flow <br />ra[e. Please respond. <br />6.4.3 EIHIBIT H - ~ViLDLIFE INFORMATION <br />23. The Division agrees with the four (4) recommendations of ivir. Dave ``Veber of the Colorado <br />