Laserfiche WebLink
Trapper Mine, C- 1981 -010 <br />RN6; Preliminary Adequacy Review <br />21 Aug 2012 <br />4.8.5.1 Surface Water Monitoring <br />38. On Page 4 -239a of the permit, Table 4.8 -11 consists of the historic surface water monitoring schedule at <br />the site. A note at the top of the table states, "see Table 4.8 -1 la for current monitoring schedule in <br />disturbed areas ". The next page, 4 -240 another table is labeled 4.8 -11 indicates this table is the <br />operational surface water monitoring schedule. Page 4 -241a, indicates the frequency of sampling at each <br />site is indicated on Table 4.8 -11 had has been revised to be compatible with Trappers NPDES permit. <br />Please update the text and or the table heading to indicate which actual table contains the operational <br />surface water monitoring schedule. <br />4.8.5.2 Ground Water Monitoring <br />39. Page 4 -247a indicates Trapper does not plan to establish any additional groundwater monitoring wells <br />during the current permit term. Please revise this statement and update the groundwater monitoring plan <br />if necessary for the next permit term. <br />4.9.4 Topsoil Balance and Monitoring <br />40. The projected topsoil balance over the period of the current permit term is included on Table 4.9 -3 and <br />4.9 -4. Please revise these tables for the next permit term. <br />Maps: <br />41. Along with the maps listed in the above sections, the following maps will need to be updated for the next <br />permit term: M6 and M10(A and B). <br />Bond Amount <br />42. For Task 093, the volume of topsoil used for the estimate was derived from Table 1.4 -9 in the permit. <br />However, during the Phase II bond release SL12, the amount of bond was reduced to account for the <br />acreage of F -Pit contained in the release. Upon further review, the volume of material used for SL12 was <br />greater than the total volume estimate for the entire F -Pit area in Table 1.4 -9. Given this, there appears to <br />be a discrepancy in the volume estimated to spread topsoil on the remaining F -Pit area not granted Phase <br />II bond release. As indicated above, section 1.4 of the permit will need to be updated and the volume of <br />material for F Pit will need to be clarified. <br />43. For Task 101, there appears to be a discrepancy for the acreage accounted for F -Pit. During Permit <br />Renewal No. 5 (RN5), the acreage accorded to F -Pit for revegetation was 486 acres. However during the <br />PR6 it appears this acreage was reduced to 55.8 acres. It is unclear why the acres were reduced to the <br />PR6 amount. The PR6 acreage is consistent with Table 1.4 -10 in the permit. Since RN5, Trapper was <br />granted Phase III bond release on 40.1 acres of the F -Pit area. Given this, the Division used the RN5 F- <br />Pit acreage minus the SL 13 F -Pit acreage for the total area to be revegetated for F -Pit for the updated cost <br />estimate (445.9 acres). This acreage will need to be clarified. <br />The Division updated the reclamation cost estimate with updated costs. This updated estimate total is <br />$29,990,889.58. This estimate includes reclamation tasks identified in the permit and does not reflect any <br />additional costs that may be associated with the adequacy review except for item No. 43 of this letter. The current <br />liability amount is $27,880,279.69. This is a difference of $2,110,609.89 which is accounted for in the <br />differences in unit costs and the issue discussed in item No. 43 of this letter. The Division currently holds a bond <br />in the amount of $30,015,310.00. <br />Page 6 of 7 <br />