2008-01-14_HYDROLOGY - M1977215

• Permit No: M1977215
• IBM Index Class Name: HYDROLOGY
• Doc Date: 1/14/2008
• Doc Name: Water quality monitoring in Windy Gulch
• From: Water Management Consultants
• To: Homestake Mining Co. of California
• Email Name: RCO
• Media Type: D
• Archive: No

Mr. Alan Cox
November 30, 2007 Page 2
Table la
2007 Windy Gulch Water Quality-Lower Weir

Parameter (mg/1)
Agricultural
Standard Average
at Lower
Weir 1

3/19/2007

3/30/2007 Lower Weir

4/17/2007 5/15/2007

5/30/2007

6/12/2007
Aluminum total (mg/1) None 0.36 0.2 <0.03 0.37 0.47 0.34 0.11
Arsenic dissolved (mg/1) 0.0145 0.0114 0.0178 0.0204 0.0206 0.0143
Arsenic total (mg/1) 0.10 0.038 0.0144 0.0113 0.0193 0.0255 0.0253 0.0193
Cadmium dissolved (mg/1) 0.009 0.009 <0.005 0.008 <0.005 0.006
Cadmium total.(mg/I) 0.010 0.017 0.01 0.009 <0.005 <0.005 0.005 0.008
Copper dissolved (mg/1) 0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Copper total (mg/1) 0.20 0.01 <0.01 0.01 <0.01 0.01 <0.01 <0.01
Iron dissolved (mg/1) 0.06 <0.02 0.08 0.09 0.08 <0.02
Iron total (mg/1) None 0.48 0.14 0.03 0.24 0.38 0.4 0.11
Manganese dissolved (mg/1) 0.036 <0.005 <0.005 0.036 0.02 <0.005
Manganese total (mg/l) 0.20 0.144 0.03 0.009 <0.005 0.037 0.02 <0.005
Mercury dissolved (mg/1) <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <0.0002
Mercury total (mg/1) None <0.0002 <0.0002 <0.0002 0.0002 <0.0002 <0.0002 <0.0002
Zinc dissolved (mg/1) 1.99 2.19 t.25 0.73 0.94 1.74
Zinc total (mg/l) 2.0 3.85 2.08 2.17 1.28 0.84 1.03 1.7
pH (units) None 6.6 7.12 6.72 7.22 7.07 7.59 7.18
Conductivity (umhos/cm) None 37] 272 358 183 110 160 247
TDS (mg/1) None 278 190 240 140 110 130 190
TSS (mg/1) None 5 <5 <5 <5 <5 <5 <5
Sulfate (m None 159 80 120 60 30 50 90
(1) Average from 16 samples taken since 1998 prior to final reclamation activities
Table lb
2007 Windy Gulch Water Quality-Upper Weir

Parameter
Agricultural
Staudard
Average at
Lower Weir (1)

3/19/2007

3/30/2007 Upper Weir

4/17/2007 5/15/2007

5/30/2007

6/12/2007
Aluminum total (mg/1) None 0.36 0.7 1.16 1.74 0.44 0.59 0.54
Arsenic dissolved (mg/1) 0.0022 0'.002 0.0019 0.0024 0.0022 0.0028
Arsenic total (mg/1) 0.10 0.038 0.0022 0.0028 0.0022 0.0024 0.0025 0.0028
Cadmium dissolved (mg/1) <0.005 <0.005 <0.005 <0.005 <0.005 <0.005
Cadmium total (mg/1) 0.010 0.017 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005
Copper dissolved (mg/1) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Copper total (mg/1) 0.20 0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Iron dissolved (mg/1) 0.25 0.3 0.2 0.09 0.09 0.11
Iron total (mg/1) None 0.48 0.58 0.86 1.05 0.37 0.41 0.41
Manganese dissolved (mg/1) 0.07 0.045 0.019 0.013 0.024 0.035
Manganese total (mg/1) 0.20 0.144 0.088 0.054 0.031 0.016 0.033 0.042
Mercury dissolved (mg/1) <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 0.0002
Mercury total (mg/1) None <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <0.0002 <0.0002
Zinc dissolved (mg/1) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Zinc total (mg/I) 2.0 3.85 0.01 <0.01 <0.01 <0.01 <0.01 <0.01
pH (units) None 6.6 7.42 7.41 7.02 7.13 7.04 7.48
Conductivity (umhos/cm) None 371 56 111 73 52 63 72
TDS(mg/l) None 278 50 100 80 ~ 70 80 80
TSS (mg/1) None 5 6 <5 <g <5 <5 <5
Sulfate (m 1 None 159 <10 <10 <10 <10 <10 <10
(I) Average from 16 samples taken since 1998 prior to final reclamation activities