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_ STATE OF C_O_ LORAD_ O
<br />DIVISION OF MINERALS AND GEOLOGY
<br />Depanmenl of Natural Rex>wm
<br />1713 Sherman 51., Room 215
<br />COLORADO
<br />Denver, Colorado 80203 i` i~ i~ i o v u r
<br />phone: U03) 6661567 hl I N L R A L S
<br />E.~x: uoll amt-elo6 G E O L O G Y
<br /> '~"r~ "'N"
<br />Date: July 5, 2006
<br /> eai ch..m.
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<br />To: Dcb Gonima, Carl Mount R°~~°~~'
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<br />From: Tom Schreiner Frr~t_7 ur\n..e b
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<br />RE: "2nd Adequacy Reciew Comments", Siegrist Pits/Del Camino Properties
<br />Permit ~o. M-1982-015, Class: Revision Type-Seq.::~'41-1
<br />Listed below are 2"' adcyuacy review comments on the above amendment application, based
<br />upon the Division's review of docwnents received on June 13, 20(IG and June 28, 2000. Please
<br />note that the applicant has rcsokcd Items 2, 3, 4, 7, 3, 9, lU, 12, 13, 14, 15, 1G, 17, IR, 19, 21,x:
<br />22 from T'om Schrciner's May 22, 2006 adcyuacy review memo to Dcb Gonima, Carl Mount.
<br />Items 1, 5, G, 11, & 20 from the May 22, 2flOG memo require either clarification or additional
<br />in fomtation.
<br />6.4.3 ErFIli311' C -Pre-M1ilnioe and M1tinitte Plan titan(s) of Affected 1 ands
<br />1. The Applicant states that they have submitted a revised copy of the Stormw•atcr Management
<br />Pl:mn, however the copy submitted appears to be the same version that was sent with the original
<br />application. Did the Applicant intend to send a revised stommwatcr management plan? Please
<br />clarify. Also, fn the adcyuacy comments the Division refers to Stormwatcr Management Plan
<br />maps not the 5tormw•ater Management Plan itself 14'here new maps submitted, and it so which
<br />maps should the Division refer to. If not, the Applicant will need to submit the maps requested.
<br />Please clarity.
<br />6.4.5 H:X111131"I' t: - Keclamation Plan
<br />2. 'I"he "Supplemental Geotechnical Engineering Report" prcimarcd hy'1'crracon in Amcndrncnt
<br />:lpplication submittal indlcatcs that the slurry cut-off walls should be "keyed" or "socketed"into
<br />the rclati~ cly impermeable competent'intact claystone or sandstone bedrock to reduce
<br />gmundwatcr seepage. 1 he report further states that supplemental coring and packer permcahilily
<br />testing um the area of Boring Numbers 45, 47, XE 48 indicatc<I that the upper 5 to 10 legit of the
<br />sandstone layer was moderately to severely liacturcd and that "keying" or "sockcting" into this
<br />type of sandstone hcdrock could result in excessive seepage losses, and that dee~mcr keyways for
<br />the slurry cut-oll•walls will Ilkcly he required in this area.
<br />UHice nl OH\cn of
<br />Cubrufo
<br />Amined Land Reclamuwn Active and Inactive Mines Gectl<>Rual Survey
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