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Environmental Protection Plan, Schwartzwalder Mine 1-2 <br />Dewatering of the spiral decline ceased in September 1998, when the pumps were shut off at the bottom of <br />the decline (approximately 2,200 feet), and the lower workings of the mine were allowed to refill to the 19 <br />Level. Mining operations continued until May 2000, when the pumps were shut off on the 19 Level and 7 <br />Level, and the mine was allowed to flood. <br />(b) Mine Layout <br />The mine was accessed through the Steve Level, which occurs at approximately 6,602 feet elevation in <br />North American Datum [NAD] 27 coordinates or 6,550 feet elevation in mine coordinates . Two portals <br />exist on the Steve Level, which provided for normal mine access (the Steve Portal) and emergency egress <br />(the Pierce Adit). <br />Several older workings were developed above the Steve Level. The Charlie and Minnesota levels, which <br />are 119 and 226 feet above the Steve Level, respectively, intercept the CV glory hole and represent the bulk <br />of the upper workings (Figure 1-1). Additionally, the Upper Level and LBJ Level daylight on the hillside. <br />The elevations of the upper levels are given in Table 1-1. <br />Table 1-1. Elevations of Upper Levels at the Schwartzwalder Mine <br /> MINE NAD27 <br />LEVEL ELEVATION ELEVATION <br />Upper ............................. .............................6, 895.............................. .........................._6,947.._......._....... <br />LBJ <br />.. . ....................... 6,835 <br />......................... . . . . . . . ........................ . ........................... 6,887 <br /> <br />. . . <br />.............................................................. _ ......... <br />................ <br />Minnesota <br />.............._................... 6,776 <br />..................................................................................... 6,828 <br />............................................................................ <br />CV 6,739 <br />... <br />..... 6,791 <br /> <br />.................................... <br />. ....................................... <br />....._.._...._. ................_........................... <br />Charlie ................ . <br />........................................................ ................... <br />............................_6,669............................. .........................._6,721....................... <br />Steve 6,550 6,602 <br />Below the Steve Level, the levels are identified according to their depth (in hundreds of feet). The most <br />extensive workings are on the 19 Level, with significant development on the 7, 9, and 15 through 17 levels. <br />The total mine depth is 2,222 feet from the Steve Level portal to the bottom of the spiral decline <br />The mine was ventilated through the Main and Jeffrey Shafts. The Main vent shaft extends from ground <br />surface at the top of the hillside (elevation 7,294 ft, NAD 27) to the 7 Level. The Jeffrey vent shaft extends <br />from ground surface near the Charlie level to the 11 Level. Areas that were not actively worked were <br />typically bulkheaded during operations, to minimize radon gas exposure. <br />During operations, the Schwartzwalder Mine was kept dry by pumping water from the lower levels of the <br />mine. Water was collected on the 19 Level, pumped to the 7 level, and then pumped to the surface where it <br />was treated and discharged to Ralston Creek. The water treatment plant also processed water from four <br />sumps in the alluvium and fill. Combined pumping from the sumps averaged approximately 100 gpm. <br />• <br />4109C.090807 Whetstone Associates