2007-11-07_HYDROLOGY - M1977300

• Permit No: M1977300
• IBM Index Class Name: HYDROLOGY
• Doc Date: 11/7/2007
• Doc Name: Hydrologic evaluation of mine closure & reclamation
• From: Whetstone Associates
• To: Cotter Corpoartion
• Media Type: D
• Archive: No

Schwartzwalder Mine -Hydrologic Evaluation of Mine Closure and Reclamation 119
7.5 Shallow Bedrock Water Quality
Two monitoring wells were installed in the shallow bedrock on the hillside above the mine, MW 10 and
MW1l (Section 4.1.1). Both wells are located far above the mine (Figure 5), in bedrock undisturbed by
mining, and represent background bedrock water quality. MW10 could not be sampled, due to poor
completion. MW 11 was sampled ten times between February 1999 and July 2001. Results indicate that
groundwater in the shallow bedrock is calcium-bicarbonate19 type water with low to moderate dissolved
solids and near-neutral to slightly basic pH (Table 32). Dissolved uranium averaged 0.29 mg/L with a
median value of 0.033 mg/L. Molybdenum was below detection.
Table 32. Water Quality in Shallow Bedrock
MWII MWiI MWII MWil MWII MWiI MIN MAX MEAN MEDIAN COUNT ND
2/17/99 3125/99 4/21/99 5/25/99 1/2/01 1/2/01 ND
pH 8.2 7.4 7.9 7.3 7.3 8.2 7.70 7.65 4 0 0%
Conductivity 259 234 348 197 197 348 259.5 246.5 4 0 0%
Total diss. solids 199 164 340 121 121 340 206.0 181.5 4 0 0%
Total susp.solids 35.1 120 50.7 64.7 35.1 120 67.625 57.7 4 0 0%
Carbonate <l0. 10 IO 5 5 I 1 100%
Bicarbonate 51 51 51 51.0 51 1 0 0%
Alkalinity, Diss. 69 100 69 100 84.5 84.5 2 0 0%
Alkalinity, total 110 69 51 51 110 76.7 69 3 0 0%
Nitrate Nitrogen 0.4 <0.1 l <0.1 l 0.48 0.4 3 I 33%
Ammonia, total 0 0 <l. 0 <1. 0.167 0 3 3 100%
Calcium, diss. 5.5 5.5 5.5 5.5 5.5 l 0 0%
Magnesium, diss. 3.8 3.8 3.8 3.8 3.8 1 0 0%
Sodium, diss. 14 14 14 14.0 14 1 0 0%
Potassium, diss. 0.4 0.4 0.4 0.40 0.4 I 0 0%
Sulfate 36 37 88 50 36 88 52.8 43.5 4 0 0%
Fluoride, total 0.2 0.2 0.2 0.200 0.2 l 0 0%
Chloride 5 5 5 5 5 5 5.0 5 4 0 0%
Aluminum, diss. 0.4 <0.4 <0.4 0.400 0.4 1 0 0%
Antimony, diss. <0.003 <0.001 <0.001 <0.003 0.001 0.001 2 2 100
Arsenic, diss. <0.003 <0.003 <0.003 0.0015 0.0015 I I 100%
Barium, diss. <0.02 <0.02 <0.02 O.OIO 0.01 l I 100%
Beryllium, diss. <0.002 <0.002 <0.002 0.001 0.001 1 1 100%
Cadmium, diss. <0.0002 <0.0002 <0.0002 0.0001 0.0001 1 I 100%
Chromium, diss. <0.005 <0.005 <0.005 0.0025 0.0025 I 1 100%
Copper 0.005 0.005 0.005 0.005 0.005 1 0 0%
Iron, diss. 0.2 <0.2 <0.2 0.200 0.2 I 0 0%
Lead, diss. <0.002 <0.002 <0.002 0.0010 0.001 1 1 100
Manganese, diss. <0.01 <0.01 0.01 0.005 0.005 1 1 100%
Merc ,diss. <0.0002 <0.0002 <0.0002 O.000I 0.0001 I I 100%
Molybdenum, diss <0.01 <0.005 <0.005 <0.01 0.004 0.00375 2 2 100%
Nickel, diss. <0.04 <0.04 <0.04 0.020 0.02 1 I 100%
Selenium, diss. <0.005 <0.005 <0.005 0.003 0.0025 1 1 100%
Silver, diss. <0.0002 <0.0002 <0.0002 0.0001 0.0001 1 l 100%
Thallium, diss. <0.001 <0.001 <0.001 <0.001 0.0005 0.0005 2 2 100%
Vanadium, diss. <0.01 <0.01 <0.01 0.005 0.005 1 1 100%
Radium-226, diss. l.8 1.8 1.8 1.80 1.8 l 0 0%
Radium-226, susp. I 1 1 1 1 l 0 0%
Uranium, susp. 0.004 0.004 0.004 0.004 0.004 1 0 0%
Uranium, total 0.0017 0.0017 0.0017 0.0017 0.0017 l 0 0%
2/17/99 3/25/99 4/21/99 5/25/99 1/2/01 1/2/01
Uranium, diss. 0.019 0.0625 0.047 2.63 0.008
2/5/0 l 3/5/01 5/3 l /01 6/20/01 7/25/01
0.007 0.057 0.0013 0.0101 0.055 0.0013 2.63 0.290 0.033 l0 0 0%
Notes: All results in mg/L except conductivity (µmhos/cm) and pH (standard units).
Mean and median statistic calculated using one half the detection limit (l/2 D.L.)
19 At pH less than 8, bicazbonate can be calculated from total alkalinity using the relationship HC03 = T.AIk/0.8202 (Hem, 1985).
4109B.071116 Whetstone Associates •