Phelps Dodge Sierrita Mine
Monitor Well No. MH-11
Monitor well on public state land between tailings dam and Green Valley
Located approximately ¾ mile east of dam, approximately ¼ mile north of center
Sulfates and Dissolved Metals
Date |
Hardness as CaCO3 |
Calcium mg/l |
Magnesium mg/l |
Sulfate** |
Arsenic mg/l |
Molybdenum |
TDS** |
Alkalinity |
pH Units |
4/23/79 |
253 |
109 |
1226 |
2001 |
7.35 |
||||
9/14/79 |
296 |
132 |
1257 |
1953 |
7.28 |
||||
12/17/79 |
344 |
27 |
1006 |
1719 |
7.28 |
||||
4/24/80 |
334 |
72 |
1073 |
1827 |
7.32 |
||||
6/27/80 |
342 |
73 |
1098 |
1825 |
7.40 |
||||
12/19/80 |
320 |
74 |
1116 |
1888 |
7.52 |
||||
4/29/81 |
348 |
79 |
1118 |
1876 |
7.54 |
||||
9/18/81 |
415 |
33 |
1119 |
1905 |
7.38 |
||||
12/10/81 |
472 |
33 |
1122 |
1964 |
7.20 |
||||
4/28/82 |
480 |
13 |
1133 |
1971 |
6.84 |
||||
9/30/82 |
404 |
46 |
1089 |
1881 |
7.65 |
||||
9/30/97 |
438 |
98.1 |
1280 |
2240 |
-- |
||||
2/26/98 |
494 |
104 |
1440 |
2500 |
7.08 |
||||
6/30/98 |
454 |
103 |
1440 |
2570 |
6.96 |
||||
3/10/99 |
509 |
159 |
1900 |
3460 |
-- |
||||
4/05/01 |
534 |
106 |
1840 |
2790 |
7.3 |
||||
8/14/03 |
508 |
111 |
1670 |
2920 |
7.5 |
||||
12/02/03 |
517 |
112 |
1640 |
2790 |
-- |
||||
3/16/04 |
486 |
113 |
1640 |
2800 |
7.88 |
||||
MCL |
None |
None |
250 mg/ltr** |
500 mg/ltr** |
** Secondary standard set by EPA, not enforced in
Regulated Inorganic Chemicals
--not available--
Regulated Radioactive Chemicals
Date |
Gross Alpha pc/l |
Gross Beta pc/l |
Radium 226 pc/l |
Radium 228 pc/l |
Radon* 222 pc/l |
Uranium 234 pc/l |
Uranium 235 pc/l |
Uranium 238 pc/l |
Total Uranium mg/l |
8/14/03 |
5.2 ± 1.1 |
14.0 |
ND |
ND |
734 ± 79.4 |
4.0 ± 0.9 |
ND |
1.1 ± 0.5 |
0.0062 |
12/02/03 |
8.0 ± 1.3 |
24.5 ± 7.8 |
0.9 ± 0.4 |
ND |
673 ± 48.1 |
3.1 ± 0.9 |
ND |
2.1 ± 0.7 |
0.0067 |
3/16/04 |
5.8 ± 1.3 |
12.7 ± 7.0 |
ND |
ND |
618 ± 56.4 |
3.2 ± 0.7 |
ND |
2.1 ± 0.6 |
0.0059 |
MCLG** |
0 |
0 |
Ra 226 + 228 = 0 |
None |
None |
None |
None |
0 |
|
MCL*** |
15 p/Ci/ltr |
4 mrem/yr |
Ra 226 + 228 = 5 |
None |
None |
None |
None |
.03 mg/ltr |
|
* No standard set for Radon
** Maximum Contaminant Level Goal, 40 C.F.R. § 141.55.
***Maximum Contaminant Levels, 40 C.F.R. § 141.66(b) [for Ra-226+-228]; (c) [for gross alpha activity]; (d) [for beta particle and [photon radioactivity]; and (e) [for uranium].