Laserfiche WebLink
EPP Adequacy Review No. 2 4 19 March 2010 <br />Schwartzwalder Mine . File No. M-1977-300 <br />alluvium are directly linked to drinking water to sources. The Operator must design mitigation <br />strategies with the drinking water standards as the target. <br />9) Operator states in footnote 15 on pg 9-4 "....uranium concentrations in excess of the ground <br />water standard reported by the lab for upgradient monitoring well MW00 are questionable...." <br />Please elaborate on why the data are questionable. <br />10) Operator states on pg 9-4 "Potential conduits from the flooded mine workings to the alluvium <br />included historical exploration boreholes that were drilled into the deposit from the valley floor." <br />Applicant later states on pg 9-5 that 33 exploration boreholes remain unaccounted for. How <br />many of these 33 boreholes are believed to have been drilled into the deposit from the valley <br />floor? Provide a plan to locate and map the boreholes, determine their condition, attempt to <br />quantify the chemical loading from the mine pool via these potential water conduits, and <br />implement a program to plug and abandon the holes. <br />11) On page 9-26 Operator discusses the recirculation pumping from Sump 1 to Sump 4. Was any of <br />this water disposed on or off site? <br />12) The contour resolution of the base map, on which monitoring wells and other sample locations <br />are plotted, contains an error. In the immediate area of the mine, between the 6550 and 7000 ft <br />contours, the map shows only two contour lines where there should be four, assuming the <br />contour interval is 10 feet as stated in the legend. The resolution in this area is important in <br />comparing the elevation of the mine pool to features on ground surface. Please provide a revised <br />set of maps with correct and accurate contour resolution. <br />SECTION 11. SURFACE WATER QUALITY DATA <br />13) Based on surface water quality data from stations SW-A001 and SW-BPL, the uranium <br />concentration in Ralston Creek increases about two orders of magnitude between the two <br />stations. Knowledge of the concentrations along this reach is important to understanding the <br />system, yet the five surface water sampling stations between these two sites have been <br />discontinued from the monitoring program. The monitoring plan must initially include all of the <br />surface water sampling stations SW-BDIS, SW-PL, SW-OS, SW-BOS, and SW-GS. <br />14) Pursuant to comments provided by CDPHE Water Quality Control Division in their memo of 10 <br />May 2010, please ensure that the appropriate and current water quality standards are referenced <br />and apply to the entire stream segment of Ralston Creek. <br />SECTION 12. WATER QUALITY MONITORING PLAN <br />15) DRMS supports the proposed locations of future surface and ground water quality monitoring, <br />and requires additional surface water monitoring sites as discussed in item 13 above. With <br />respect to analytes, the plan must include field temperature along with pH and conductivity for