Radioactive Chemicals in Monitoring Wells along Impoundment and Off-Site
Monitor Wells along Impoundment from N to S
MH-14 North End of Impoundment
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 |
4/06/98 |
23 ± 2 |
17 ± 14 |
0.17 ± 0.13 |
0.0 ± 0.9 |
0.0022 |
||||
9/25/09 |
20 ± 4 |
||||||||
4/10/00 |
10 ± 12 |
11 ± 8.1 |
0.017 |
||||||
7/05/00 |
27 ± 11 |
1.4 ± 8 |
0.0181 |
||||||
10/09/00 |
31 ± 13 |
34 ± 8.9 |
0.0206 |
||||||
4/02/01 |
29 ± 13 |
28 ± 12 |
0.0202 |
||||||
2/15/02 |
29.1 ± 12 |
16.9 ± 8.6 |
12.3 ± 2.2 |
.11 ± 0.79 |
9.59 ± 2.2 |
0.0197 |
|||
4/15/02 |
21.4 ± 10 |
17.2 ± 8.8 |
ND |
0.6 ± 0.7 |
9.2 ± 2.0 |
<0.31 |
7.55 ± 2.1 |
0.0204 |
|
9/13/02 |
40.4 ± |
23.9 ± |
13.9 |
<0.67 |
7.2 ± |
0.0238 |
|||
4/22/03 |
29.8 ± |
24.2 ± |
13 |
<.41 |
7.5 ± |
0.023 |
|||
8/11/03 |
27 ± 11 |
16 ± 15 |
ND |
ND |
666 ± 56.9 |
13.5 ± 1.8 |
0.6 ± 1.4 |
8.3 ± 1.4 |
0.0286 |
11/17/03 |
27 ± 11 |
16 ± 15 |
ND |
ND |
982 ± 70.0 |
13.0 ± 1.5 |
0.3 ± 0.2 |
8.2 ± 1.2 |
0.0331 |
3/11/04 |
27 ± 11 |
16 ± 15 |
ND |
ND |
1,150±84.9 |
14.7 ± 1.9 |
0.6 ±0.4 |
10.1 ± 1.5 |
0.0306 |
MH-15W South of
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 |
2/26/98 |
64 ± 9 |
18 ± 24 |
0.2 ± 0.4 |
0.2 ± 1.1 |
0.061 |
||||
6/22/98 |
60 ± 5 |
11 ± 24 |
0.069 |
||||||
9/28/98 |
68 ± 8 |
22 ± 25 |
.006 ± 0.1 |
0.065 |
|||||
12/04/98 |
72 ± 20 |
25 ± 26 |
0.061 |
||||||
3/09/99 |
53 ± 17 |
20 ± 11 |
0.0483 |
||||||
4/15/99 |
43 ± 9.8 |
25 ± 6 |
0.0243 |
||||||
6/10/99 |
29 ± 14 |
23 ± 11 |
0.0508 |
||||||
10/11/99 |
52 ± 25 |
8.6 ± 12 |
0.06 |
||||||
4/11/00 |
60 ± 20 |
16 ± 13 |
0.0535 |
||||||
7/5/00 |
66 ± 22 |
8.9 ± 12 |
0.0561 |
||||||
10/9/00 |
55 ± 18 |
99 ±12 |
0.72 |
||||||
4/02/01 |
130 ± 70 |
88 ± 61 |
0.0444 |
||||||
2/19/02 |
61.2 ± 20 |
24.8 ± 10 |
31.2 |
1.05 ± 0.96 |
20.8 ± 2.8 |
0.0532 |
|||
4/15/02 |
34 ± 15 |
25.2 ± 13 |
0.17 ± 0.2 |
0.76 ± 0.7 |
28.1 ± 3.4 |
1.58 ± 1.1 |
17.3 ± 2.8 |
0.0541 |
|
9/13/02 |
51.6 |
27.9 |
24.3 |
0.32 |
17.4 |
0.0492 |
|||
11/14/02 |
25.7 |
35.4 |
23.9 |
0.26 |
18.1 |
0.0455 |
|||
1/24/03 |
20.2 |
18.2 |
23.3 |
1.25 |
16.1 |
0.0474 |
|||
4/22/03 |
73.5 |
50.1 |
27 |
0.6 |
21.5 |
0.0478 |
|||
8/11/03 |
54.5 ± 2.4 |
37.1 ± 2.7 |
ND |
ND |
671 ± 66.6 |
26.3 ± 2.3 |
1.0 ± 0.4 |
16.8 ± 1.8 |
0.0565 |
11/27/03 |
55.2 ± 2.6 |
55.3 ± 8.2 |
ND |
ND |
760 ± 68.0 |
24.8 ± 2.0 |
0.6 ± 0.3 |
17.7 ± 1.7 |
0.0708 |
3/11/04 |
55.3 ± 3.7 |
9.3 ± 7.6 |
ND |
ND |
780 ± 79.0 |
27.8 ± 2.6 |
0.6 ± 0.4 |
19.3 ± 2.2 |
0.0602 |
MH-16W South Quarter of Impoundment
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 |
2/26/98 |
13 ± 4 |
24 ± 20 |
0.0 ± 0.3 |
0.0 ± 1.1 |
0.0077 |
||||
6/22/98 |
14 ± 3 |
27 ± 19 |
0.0088 |
||||||
9/28/98 |
16 ± 4 |
19 ± 22 |
0.0 ± 0.1 |
1.1 ± 0.6 |
0.0084 |
||||
12/04/98 |
15 ± 5 |
12 ± 19 |
0.0086 |
||||||
3/08/99 |
17 ± 11 |
41 ±11 |
0.005 |
||||||
6/10/99 |
130 ± 38 |
51 ± 21 |
0.339 |
||||||
10/11/99 |
0 ± 19 |
10 ± 9.5 |
0.01 |
||||||
1/12/00 |
11 ± 14 |
21 ± 13 |
0.0057 |
||||||
4/11/00 |
0 ± 9.6 |
14 ± 15 |
0.0061 |
||||||
7/05/00 |
13 ± 12 |
9.2 ± 10 |
0.0055 |
||||||
10/09/00 |
40 ± 22 |
39 ± 14 |
0.006 |
||||||
4/02/01 |
22 ± 13 |
35 ± 14 |
0.0048 |
||||||
4/02/01 |
6.8 ± 6.8 |
24 ± 11 |
0.0049 |
||||||
4/15/02 |
5.4 ± 5.4 |
26 ± 11 |
0.15 ± 0.2 |
0.64 ± 0.7 |
2.07 ± 1.0 |
<0.65 |
1.31 ± 1.2 |
0.0053 |
|
9/13/02 |
13.3 |
26.9 |
4.32 |
<0.43 |
2.38 |
0.005 |
|||
11/14/02 |
6.3 |
27 |
5.01 |
<0.29 |
3.44 |
0.0048 |
|||
1/23/03 |
4.5 |
11.5 |
5.72 |
0.51 |
3.43 |
0.0056 |
|||
4/22/03 |
33 |
27 |
6.81 |
0.61 |
4.54 |
0.0049 |
|||
8/11/03 |
5.0 ± 0.6 |
35.5 ±2.7 |
ND |
ND |
978 ± 81.8 |
4.1 ± 1.0 |
ND |
1.3 ± 0.6 |
0.0063 |
11/17/03 |
7.4 ± 1.0 |
16.4 ± 8.2 |
ND |
ND |
1,170±7.3 |
3.2 ± 0.7 |
ND |
1.5 ± 0.5 |
0.0066 |
3/11/04 |
5.0 ± 1.0 |
24.7 ± 7.6 |
ND |
ND |
911 ± 81.2 |
3.3 ± 0.9 |
ND |
1.9 ± 0.6 |
0.0057 |
MCL** |
15 pCi/l |
4 mrem/yr |
Ra-226 + |
Ra-228 = 5 |
None |
None |
None |
None |
0.03mg/l |
Monitor Wells between
MH 12 - (2/77; 800 ft)
Located approximately ¾ mile east of dam, approximately in line with north end of dam
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 |
12/2/03 |
5.3 ± 1.6 |
19.7 ± 4.7 |
0.5 ± 0.4 |
ND |
535 ± 45.9 |
2.7 ± 0.9 |
0.2 ± 0.2 |
0.9 ± 0.5 |
0.0045 |
3/15/04 |
4.9 ± 1.8 |
24.4 ± 4.2 |
0.5 ± 0.3 |
ND |
2.9 ± 0.7 |
ND |
ND |
1.0 ± 0.4 |
0.0042 |
MH-11 (2/77; 820 ft)
Located approximately ¾ mile east of dam, at quarter point, north side of dam
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 |
12/2/03 |
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 |
MH-13 (2/77; 1,425 ft)
Located approximately ¾ mile east of dam, aligned with the center of dam
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 |
10.8 ± 1.6 |
23.7 ± 2.6 |
ND |
ND |
ND |
6.4 ± 1.1 |
0.4 ± 0.3 |
2.4 ± 0.7 |
0.0099 |
12/2/03 |
13.0 ± 2.5 |
37.5 ± 7.8 |
0.5 ± 0.3 |
ND |
ND |
8.0 ± 1.2 |
0.3 ± 0.2 |
2.6 ± 0.7 |
0.0098 |
3/11/04 |
9.5 ± 3.1 |
13.3 ± 7.0 |
ND |
ND |
ND |
6.8 ± 1.2 |
ND |
2.8 ± 0.8 |
0.0082 |
MCL** |
15 pCi/l |
4 mrem/yr |
Ra-226 + |
Ra-228 = 5 |
None |
None |
None |
None |
0.03mg/l |
* No standard set for Radon, even though it is on the World Health Organization’s list for lung cancer.
** 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].
Well #8 Date Gross Alpha Radium 226
02/01/96 3.8 0.5
04/23/96 4.0 0.5
07/11/96 5.9 0.6
12/09/96 5.4 1.2
01/30/01 6.6 0.4
04/04/01 6.9 0.4