2010-08-02_REVISION - M1977300 ‎(27)‎

• Permit No: M1977300
• IBM Index Class Name: REVISION
• Doc Date: 8/2/2010
• Doc Name: New Amend.- EPP- Groundwater Quality
• From: Cotter Corp.
• To: DRMS
• Type & Sequence: AM2
• Media Type: D
• Archive: No

Environmental Protection Plan, Schwartzwalder Mine 9-5
2,200 feet. Either the boreholes act as "one-way valves" or groundwater flow along these pathways was so
low as to be unrecognizable.
Table 9-2. Mixing Calculation to Determine Maximum Contribution of Mine Water to
Alluvial Water Quality
•
•
Sample Results - Alluvial Well MW-9 Mixing Calculation
Avg Final Conc.in Ratio of flow
Parameter 12/29/04 6/23/05 9/6/07 3/25/08 10/29/08 Initial Conc. Increase mine from mine water
Conc. water to cause increase
pH (std units) 7.26 7.41
Total dissolved solids (mg/L) 352 334 366 356 494 350.7 494 143.3 3,290 4.9%
Bicarbonate (mg/L as HC03) 120 115 153 131 148 129.3 148 18.7 471 5.5%
Alkalinity, total (mg CaC03/L) 98 94 126 107 121
Calcium, dissolved (m 59.8 56.4 73.5 89.4 58.1 89.4 31.3 428 8.5%
Calcium, total (mg/L) 64.7
Magnesium, dissolved (mg/L) 20.3 19 25.3 30.6 19.65 30.6 10.95 256 4.6%
Sodium, dissolved (mg/L) 17.9 13.5 15.1 18.9 23.7 15.5 23.7 8.2 256
Potassium, dissolved (mg/L) 3.1 4 3.4 4.2
Sulfate m 132 131 112 151 183 125 183 58 2,050 3.0%
Chloride (mg/L) 26 15 27 31 43 22.67 43 20.3 21 -1220.0%
Aluminum, dissolved (mg/L) <0.2 <0.2 <0.2 <0.2 <0.1
Aluminum, total (mg/L) <0.1 <0.1 <0.2 <0.2 <0.2
Antimony, dissolved (mg/L) <0.001 <0.001 <0.001 <0.001 <0.05
Antimony, total (m <0.05 <0.05 <0.001 <0.001
Arsenic, total (mg/L) <0.001 <0.001 <0.1 <0.1 <0.1
Copper, dissolved (mg/L) <0.005 <0.005 <0.005 <0.005 <0.01
Copper, total (mg/L) <0.005 <0.01 <0.005 <0.005 <0.005
Iron, dissolved (mg/L) <0.03 <0.03 0.09 <0.03 <0.03
Iron, total (m ) 0.03 <0.03 0.08 <0.03 <0.03
Lead, total (mg/L) <0.05 <0.05 <0.005 <0.005 <0.005
Manganese, diss. (mg/L) <0.01 <0.01 <0.01 <0.01 <0.01
Manganese, total (mg/L) <0.01 <0.01 <0.01 <0.01 <0.01
Mercury, total (mg/L) <0.0001 <0.001 <0.0001 <0.0001 <0.001
Molybdenum, diss. (m 0.053 0.052 0.046 0.04 <0.1 0.05 0.031 0.0 1.45 -1.4%
Silver, total (mg/L) <0.01 <0.01 <0.001 <0.001 <0.001
Thallium, dissolved (mg/L) <0.001 <0.001 <0.001 <0.001 <0.1
Thallium, total (mg/L) <0.05 <0.1 <0.001 <0.001
Zinc, total m 0.008 <0.01 0.006 0.006 0.008
Uranium, dissolved (mg/L) 0.593 0.43 0.601 0.481 0.849 0.541 0.849 0.308 41 0.8%
Uranium, total (mg/L) 0.635
Radium-226, dis. (Ci/L) 0.8 0.2 0.4 0.15 0.05 0.05 1 _j
The waste rock dumps do not appear to affect water quality in the alluvium, based on two decades of
monitoring results. However, recent water quality results indicate that water quality in alluvial well MW-0
may be affected by other sources in the alluvium. Uranium concentrations in MWO peaked at 0.98 mg/L in
2003 during surface reclamation operations, and have declined to their present levels of about 0.3 mg/L.
No consistent trend of increasing uranium concentrations has been observed in the well, and radium
concentrations are currently at the lowest concentrations observed in 10 years of monitoring.
4109C.100731
Whetstone Associates