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Environmental Protection Plan, Schwartzwalder Mine 7-3
<br />• Dewatering of the spiral decline ceased in September 1998, when the pumps at the 22 Leve14 were shut off
<br />and the lower workings of the mine were allowed to refill to the 19 Level. Mining operations continued
<br />until May 2000, when the pumps were shut off on the 19 and 7 Levels, and the mine was allowed to flood.
<br />Refilling rates are discussed in Section 8(b)(iii).4. The portals of the Steve and Pierce adits were
<br />bulkheaded in December, 2007, followed by contact grouting in January 2008 (MES, 2008).
<br />Water in the flooded underground workings is a strongly-buffered calcium-magnesium-sodium-sulfate
<br />water with near neutral pH (median value = 7.17), high concentrations of total dissolved solids (about 3,000
<br />mg/L), and elevated concentrations of sulfate, antimony, arsenic, iron, manganese, molybdenum, thallium,
<br />uranium and radium 226. Water quality in the flooded mine is described in detail in Section 9(b)(iv) of this
<br />EPP. However, because flow rates from the mine are extremely low, as described in detail in Section
<br />8(b)(iii), total mass loading from the underground workings is small.
<br />Issues related to the flooded mine workings include water chemistry in the mine, flow rates from the mine,
<br />potential interaction with water in Ralston Creek, and potential pathways in low-permeability bedrock
<br />including potential conduits or barriers to groundwater flow such as faults (including the East Rogers Fault,
<br />West Rogers Fault, and Illinois Fault) and lithologic units (including the garnet-biotite-horneblende gneiss,
<br />mica schist, and garnet-biotite gneiss and quartzite rock of the Schwartz Trend). These topics are discussed
<br />in Sections 8(e)(ii)and 14(b).
<br />Table 7-2. Schwartzwalder Mine Void Volumes
<br />•
<br />
<br />Level From
<br />ft To
<br />ft Volume
<br />ft3 Cumulative
<br />Volume ft'
<br />Above Steve 6,602 6,949 2,568,698 21,861,745
<br />200 6,479 6,601 609,236 19,293,047
<br />300 6,352 6,478 669,047 18,683,811
<br />400 6,245 6,351 498,698 18,014,764
<br />500 6,118 6,244 756,206 17,516,066
<br />600 5,993 6,117 985,274 16,759,860
<br />700 5,861 5,992 2,360,088 15,774,586
<br />800 5,764 5,860 256,162 13,414,498
<br />900 5,660 5,763 2,284,199 13,158,336
<br />1000 5,556 5,659 1,013,990 10,874,137
<br />1100 5,453 5,555 784,829 9,860,147
<br />1200 5,351 5,452 458,321 9,075,318
<br />1300 5,246 5,350 621,218 8,616,997
<br />1400 5,140 5,245 125,914 7,995,779
<br />1500 5,033 5,139 1,273,234 7,869,865
<br />1600 4,929 5,032 1,174,644 6,596,631
<br />1700 4,823 4,928 1,061,254 5,421,987
<br />1800 4,718 4,822 213,873 4,360,733
<br />1900 4,598 4,717 3,438,490 4,146,860
<br />2000 4,485 4,597 216,185 708,370
<br />2100 4,380 4,484 492,185 492,185
<br />Rule 6.4.20(1) requires that the EPP describe how the Operator will protect all areas that have the potential
<br />to be affected by designated chemicals, toxic or acid-forming materials or acid mine drainage. Section 15
<br />of the EPP describes the mitigation options proposed for the constituents of concern (uranium and
<br />molybdenum) in groundwater at the site.
<br />• a Approximately 2,200 feet below the Steve Level
<br />4109C.100731 Whetstone Associates
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