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 � 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 � 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 � 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