Monitor Well No. MH-15W


On east side of center of Phelps Dodge tailings pond

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

                   

MCLG**

0

0

Ra-226+ -228 = 0

None

None

None

None

0

MCL***

15 pCi/l

4 mrem/yr

Ra-226+ -228 = 5

None

None

None

None

0.03 mg/l

* 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].