Laserfiche WebLink
Whetstone <br />ASSOC/ateS Technical Memorandum <br />the data are reported exactly as contained in the electronic data deliverable (EDD) from the lab" only <br />because there was no readily identifiable reason (other than normal water quality variability) for the <br />trends. Whetstone questioned the reason for the sample variability rather than the validity of the <br />samples. Because the data are considered valid, and the reason for sample variability cannot be <br />determined, the footnote about questionable sample patterns or results has been removed from the <br />revised EPP. <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 many <br />of these 33 boreholes are believed to have been drilled into the deposit from the valley floor? <br />Provide a plan to locate and map the boreholes, determine their condition, attempt to quantify the <br />chemical loading from the mine pool via these potential water conduits, and implement a program to <br />plug and abandon the holes. <br />A plugging and abandonment program was conducted in May, 2000. The Operator's mine <br />geologists and surveyors searched for all of the historical coreholes that were drilled from the valley <br />floor into the workings. These personnel had the technical expertise to locate and plug fifteen <br />boreholes, by searching from below ground and above ground. It is no longer possible to search <br />from below ground. <br />How many of the 33 remaining exploration holes may have contacted the mine workings is not <br />currently known. Because these were exploration boreholes designed to locate and delineate the ore <br />deposit, it is likely that some of them missed the target and did not encounter ore and are not <br />connected to the underground workings. It is very likely that many of the holes have collapsed in <br />the decades since they were drilled, are not be locatable. <br />A plan to map, locate, and plug any boreholes that can be found is included in Section 15 of the <br />revised EPP. There is no guarantee that any of these boreholes can be located. However, any <br />boreholes that can be located and determined to be connected with the underground workings below <br />the expected final water level will be sealed. <br />11) On page 9-26 Operator discusses the recirculation pumping from Sump I to Sump 4. Was any of <br />this water disposed on or off site? <br />No water was disposed onsite or offsite from the recirculation of sump water. <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 6,550 and 7, 000 ft <br />contours, the map shows only two contour lines where there should be four, assuming the contour <br />interval is 10 feet as stated in the legend. The resolution in this area is important in comparing the <br />elevation of the mine pool to features on ground surface. Please provide a revised set of maps with <br />correct and accurate contour resolution. <br />The maps have been revised to include the 6,560 and 6,580 ft contours which were missing from <br />previously submitted site maps in the vicinity of the Ralston Creek valley floor. The new <br />4109C.100731 6