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STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Natural Resources <br />1313 Sherman St., Room 215 <br />Denver, Colorado 80203 <br />Phone: (303) 86b3567 <br />FAX: 1303) 832-0106 <br />November 3, 2005 <br />Dave B. Mehan, PWS <br />Gary D. Wltt, PG <br />Wright Water Engineers, Inc. <br />2490 West 26th Ave., Suite 100A <br />Denver, CO 80211 <br />RE: Heit Sand & Gravel Mine, Technical Revisiou No. 2 -Adequacy Review <br />Perulit No. M-2003-016, Class: Revisiou Type-Seq.: TR-2 <br />Dear Sirs: <br />COLORADO <br />DIVISION O F <br />MIN SRALS <br />GEOLOGY <br />0.EC LANATION•NINING <br />SAf FTT•SO FNCF <br />Bill Owens <br />Governor <br />Russell George <br />Executive Director <br />Ronald W. Cattany <br />pivision Director <br />Natu21 Resource Trustee <br />Listed below aze adequacy review comments on the operator's (S W Chambers, LLC) request for <br />a technical revision to permit M-2003-016, Heit Sand & Gravel Mine. Please respond with two <br />(2) copies of your written response on or before November 16, 2005. As you have stated in your <br />October 19, 2005 submittal, the purpose of the revision request is to provide 16 months worth of <br />groundwater monitoring data, and to provide a specific groundwater level "trigger" and <br />information on measures which will be used in the event of adverse impacts to groundwater from <br />the operation. <br />1. On page 2, the applicant states "A potential impact to groundwater will have occurred when <br />post-mining groundwater monitoring data ..." Please clarify what is meant by "post-mining" <br />groundwater data. Generally speaking, the Division typically recognizes the following time <br />periods for a sand and gravel mining operation, a) pre-mining, b) mining or operational phase, c) <br />reclamation phase, d) final reclamation or time when all reclamation tasks have been completed. <br />Please respond. <br />2. On page 3, the applicant states "Possible Impacts ... the modeling showed that the magnitude <br />of effects due to the Heit Pit will be relatively small (2-feet of mounding and 3 feet of shadow <br />effect): ' Please clarify the lateral extent of the mounding and shadowing effects and identify any <br />structures within either lateral extent that may be potentially effected, ie: basements, septic tanks, <br />groundwater wells, cottonwood trees. Please respond. <br />3.On page 4, the applicant states " If the proposed trigger is reached, the following action will <br />take place ... Completion of an investigation to assess the cause(s) of the reduced groundwater <br />levels (this will be completed within 30 days)." Along with this action, the Division will require <br />that the operator submit a final report listing the findings of the investigation in form of a new <br />Technical Revision to the permit, within 30 days of an exceedance. Please respond. <br />Office of Office of Colorado <br />Mined Land REClamation Active and Inactive Mines Geological Survey <br />