2022-07-01_REVISION - M1999120 - Laserfiche WebLink

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Page 3 of 4 Ei,YHMIT G Water lnfornwtion(Rule 6A.7): DRMS agrees that groundwater issues are often complex interactions between a variety of factors;however,deviations from standard DRMS practice(such as the 2- foot trigger levels) must be based on defensible groundwater monitoring data and not speculation and/or circumstantial factors. The narrative provided also refers to wells such as"monitoring wells 9 and 10"but Figure,G-2 does not identify any wells with these names. Please provide an updated Figure G-2 that depicts all existing and proposed monitoring well locations for this site with identifiers that correspond to the data collected from them. Well construction diagrams and a summary of historical data should also be provided for existing monitoring wells. When are the new monitoring wells going to be installed?yqL—P—jz-7AR*1;�,? t This site is anticipated to,for all practical purposes;seal off approximately one mile of alluvial groundwater access to the west bank of the South Platte River. Relying on existing seasonal surface water diversions to maintain groundwater levels at current elevations is not an acceptable solution,especially as the depths of these diversions relative to the existing ground surface has not been provided. The Division will require substantial monitoring of groundwater levels along the south, west and north borders of the site and a proposal to mitigate any groundwater mounding/shadowing observed - including detailed corrective measures such as the installation of control structures such as French drains/sumps. Please provide the Division with a more specific proposal to monitor and maintain the prevailing hydraulic conditions based on historical data for the site. EXHIBIT H-Wildlife Information(Rule 6.4.8): See comment letter included from Colorado Parks and Wildlife dated April 15,2012. EXHIBIT I-Soils Information(Rule 64.9): Adequate as submitted EXHIBIT J-Vegetation Information(Rule 6A.10): Adequate as submitted EXHIBIT K-ClWmte(Rule 6A.11): Adequate as submitted EXHIBIT L-Reclamation Costs Rule 6A.12 : The bond calculation is currently under review. Please provide the perimeter distance and average depths for all cell slurry walls currently installed. You may also provide corresponding invoices for this work to substantiate actual unit costs. DRMS will also need the depth of topsoil to be replaced over the expected 132 acres that will require revegetation,and an estimate of the average push distance for that material. DRMS agrees that a phased bonding approach is appropriate for this site,however, the operator must commit to notifying DBMS IN ADVANCE of performing activities that will significantly impact the required bond for the site, such as installation of slurry walls, exposing more than 1500 feet of unreclaimed mining face, and disturbing any currently undisturbed areas of the permit. Other relevant information such as SEO approval of installed slurry walls or clay liners should also be transmitted as appropriate. EXHIBIT M-Other Permits and Li Rule 6A.13 : Adequate as submitted EXHIBIT N Source of Legal Right to Enter(Rule 6A.14): Adequate as submitted Fk„* IT O Owtter(s) of Record of Affected Land(Surface Area)and Owners of Substance to be Mined(Rule 6 151 Adequate as submitted EXHIBIT P Munkinalkles Within Two Miles(Rule 6A.16): Adequate as submitted EXMBIT O Proof of Mailing of Notkes to County Commissioners and Soil Conmrya$nn DLstrict igge 6.4.17): Adequate as submhtted EXHIBIT R Proof of FBing with County Clerk and Recorder(Rule 6.4.18): Adequate as submitted