Comparison of Sulfates and TDS in Monitor Wells along Impoundment and Off-Site

Sierrita Impoundment Water

Date

Hardness

as CaCO3

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mg/l

TDS

pH

Units

12/17/79

 

631

<1

1,806

 

2,856

9.2

12/02/80

 

608

5

1,842

 

2,885

9.4

11/23/81

 

601

7

1,948

 

3,011

9.3

11/02/88 

 

640 

.08 

1,720 

 

3,280 

10.9 

1989

 

655

.63

1,910

 

3,300

10.27

 

Monitor Wells along Impoundment from N to S

 

MH-3 North End of Impoundment (2/76; 520 ft)

Date

Hardness

as CaCO3

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mg/l

TDS

pH

Units

4/25/79*

 

 

 

482

 

1,000

 

4/22/80*

 

 

 

475

 

955

 

4/24/81*

 

 

 

480

 

1,000

 

4/30/82*

 

 

 

470

 

960

 

6/25/97

 

171

35.7

440

 

940

7.4

9/30/97

 

168

35.5

460

 

900

7.7

4/4/01

 

478

106

1,650

 

2,660

7.3

12/6/04

 

 

 

1,660

 

 

 

 

MH-14 North End of Impoundment (near MH-3)

Date

Hardness

 

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mc/l

TDS

pH

units

8/31/90

 

370

82

1,125

 

1,930

7.5

10/8/90

 

320

80

961

 

1,756

7.11

9/9/91

 

360

75

1,034

 

2,052

7.13

8/14/92

 

300

71.6

1,095

<.01

1,862

7.08

9/16/93

 

360

79.5

1,349

 

2,170

7.07

 

 

 

 

 

 

 

 

7/29/97

 

420

82

1,160

 

2,220

7.6

6/19/98

 

419

84.3

1,110

 

2,160

6.9

12/04/98

 

427

93.4

1,340

 

2,330

6.8

7/5/00

 

443

96.1

1,390

 

2,400

7.5

4/2/01

 

451

98.1

1,550

 

2,550

7.2

4/15/02

 

440

99.1

1,430

 

2,490

6.7

4/22/03

 

429

92.7

1,370

 

2,410

7.4

6/28/04

 

445

102

1,480

 

2,590

7.4

1/30/06

 

 

 

1,500

 

 

 

 

MH-4 One Quarter Mark—North Half of Impoundment (3/76; 550 ft)

Date

Hardness

as CaCO3

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mg/l

TDS

pH

Units

/25/97

 

427

54.7

1,260

 

2,210

7.6

9/23/97

 

600

58.8

1,650

 

2,900

7.6

4/5/01

 

 

 

2,090

 

 

 

 

MH-5 Half-Point of Impoundment (3/76; 640 ft.)

Date

Hardness

as CaCO3

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mg/l

TDS

pH

Units

4/25/79*

 

 

 

1,435

 

2,350

 

4/22/80*

 

 

 

1,440

 

2,400

 

4/24/81*

 

 

 

1,445

 

2,760

 

4/30/82*

 

 

 

1,520

 

2,860

 

6/25/97

 

470

80

1,970

 

3,140

7.4

9/30/97

 

437

75.7

1,750

 

2,890

7.7

12/12/05

 

 

 

1,900

 

 

 

 

MH-15W South of mid-point of Impoundment

Date

Hardness

 

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mc/l

TDS

pH

Units

9/27/90

 

525

107

1,800

 

2,995

7.6

7/9/91

 

480

102

1,690

 

2,856

7.08

6/4/92

 

444

105

1,792

.01

2,884

7.14

9/16/93

 

500

115

1,772

 

3,150

7.35

12/17/93

 

580

104

1,828

 

3,080

7.59

 

 

 

 

 

 

 

 

7/29/97

 

554

97.5

1,760

 

3,110

7.8

6/22/98

 

557

90

1,780

 

3,260

7.6

6/10/99

 

498

124

1,530

 

2,770

7.1

7/5/00

 

537

94

1,820

 

3,130

7.5

4/2/01

 

487

96.3

1,840

 

3,080

7.3

4/15/02

 

560

93.5

1,850

 

3,170

7.3

4/22/03

 

549

82.2

1,750

 

3,110

7.6

6/28/04

 

544

87.9

1,790

 

3,140

7.38

1/27/06

 

 

 

1,750

 

 

 

 

 

MH-6 Quarter Mark—South Half of Impoundment (3/76; 960 ft)

Date

Hardness

as CaCO3

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mg/l

TDS

pH

Units

6/26/97

 

569

98.3

1,920

 

3,020

7.5

9/30/97

 

557

93.6

1,510

 

2,790

7.8

12/09/05

 

 

 

1,720

 

 

 

 

 

MH-16W South Quarter of Impoundment

Date

Hardness

as CaCO3

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mg/l

TDS

pH

Units

9/27/90

 

78

17

173

 

495

7.6

10/8/90

 

57

16

124

 

517

7.49

7/9/91

 

80

11

120

 

570

7.28

8/14/92

 

42.6

10.4

48.4

<.01

293

7.5

9/6/93

 

56.4

14.4

47.8

 

334

7.68

*Note

huge

jump in

levels

in

four

years!

 

7/29/97

 

566

135

1,550

 

2,760

7.7

6/22/98

 

524

101

1,620

 

2,830

7.4

3/8/99

 

539

111

1,750

 

2,950

7.2

7/5/00

 

559

113

1,810

 

3,010

7.6

4/2/01

 

551

113

1,980

 

3,030

7.0

4/15/02

 

553

116

1,900

 

3,170

7.0

4/22/03

 

555

106

1,680

 

3,090

7.4

3/11/04

 

524

113

1,910

 

3,170

7.8

1/30/06

 

 

 

1,180

 

 

 

 

MH-9 South End of Impoundment (7/76; 1,400 ft)

Date

Hardness

as CaCO3

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mg/l

TDS

pH

Units

 

 

 

 

 

 

 

 

6/26/97

 

163

39.7

400

 

930

7.7

9/30/97

 

314

51.6

770

 

1,280

7.8

12/06/05

 

 

 

420

 

 

 

 

Monitor Wells between Green Valley and Impoundment/N to S

 

MH-12  (2/77; 800 ft)

Located approximately ľ mile east of dam, approximately in line with north end of dam

Date

Hardness

as CaCO3

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mg/l

TDS

pH

Units

4/24/79

 

94

19

251

 

660

7.18

7/12/79

 

193

44

572

 

1,023

8.19

12/17/79

 

85

17

143

 

550

7.32

4/23/80

 

84

45

288

 

722

7.85

10/20/80

 

89

18

178

 

563

7.73

12/19/80

 

83

17

214

 

625

7.90

4/29/81

 

193

42

559

 

1,068

7.93

9/18/81

 

130

2

223

 

752

7.53

12/10/81

 

130

0

236

 

660

7.39

4/28/82

 

139

4

263

 

690

7.20

9/30/82

 

104

36

266

 

680

7.78

 

 

 

 

 

 

 

 

9/25/97

 

285

58.6

860

 

1,640

--

2/26/98

 

310

60.7

860

 

1,590

7.23

6/30/98

 

334

61.7

880

 

1,760

6.93

4/04/01

 

321

65.9

980

 

1,720

7.3

12/2/03

 

342

67.3

1,050

 

1,860

 

3/15/04

 

336

69.7

1,040

 

1,900

 

4/20/06

 

 

 

1,090

 

 

 

 

 

MH-11 (2/77; 820 ft)

Located approximately ľ mile east of dam, at quarter point, north side of dam

Date

Hardness

as CaCO3

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mg/l

TDS

pH

Units

4/23/79*

 

 

 

1,220

 

1,940

 

4/22/80*

 

 

 

1,080

 

1,800

 

4/24/81*

 

 

 

1,100

 

1,760

 

4/30/82*

 

 

 

1,140

 

1,920

 

4/23/79

 

253

109

1,226

 

2,001

7.35

9/14/79

 

296

132

1,257

 

1,953

7.28

12/17/79

 

344

27

1,006

 

1,719

7.28

4/24/80

 

334

72

1,073

 

1,827

7.32

6/27/80

 

342

73

1,098

 

1,825

7.40

12/19/80

 

320

74

1,116

 

1,888

7.52

4/29/81

 

348

79

1,118

 

1,876

7.54

9/18/81

 

415

33

1,119

 

1,905

7.38

12/10/81

 

472

33

1,122

 

1,964

7.20

4/28/82

 

480

13

1,133

 

1,971

6.84

9/30/82

 

404

46

1,089

 

1,881

7.65

 

 

 

 

 

 

 

 

9/30/97

 

438

98.1

1,280

 

2,240

--

2/26/98

 

494

104

1,440

 

2,500

7.08

6/30/98

 

454

103

1,440

 

2,570

6.96

3/10/99

 

509

159

1,900

 

3,460

--

4/05/01

 

534

106

1,840

 

2,790

7.3

8/14/03

 

508

111

1,670

 

2,920

 

12/2/03

 

517

112

1,540

 

2,790

 

3/16/04

 

489

106

1,640

 

2,800

7.2

1/24/06

 

 

 

1,570

 

 

 

 

MH-13 (2/77; 1,425 ft)

Located approximately ľ mile east of dam, aligned with the center of dam

Date

Hardness

as CaCO3

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mg/l

TDS

pH

Units

4/25/79*

 

 

 

720

 

1,320

 

4/22/80*

 

 

 

690

 

1,225

 

4/24/81*

 

 

 

980

 

1,590

 

4/30/82*

 

 

 

950

 

1,560

 

4/24/79

 

220

59

721

 

1,314

7.32

7/12/79

 

311

89

1,047

 

1,659

7.58

9/19/79

 

152

32

442

 

900

7.24

12/21/79

 

236

51

650

 

1,250

7.46

4/28/80

 

240

37

663

 

1,247

6.57

12/31/80

 

319

66

1,064

 

1,805

7.50

4/29/81

 

324

62

994

 

1,661

7.59

9/16/81

 

386

15

960

 

1,652

7.40

12/10/81

 

420

3

1,006

 

1,743

7.34

5/25/82

 

388

7

934

 

1,750

7.22

8/26/82

 

252

54

711

 

1,513

8.03

9/30/82

 

356

55

1,070

 

2,000

7.85

 

 

 

 

 

 

 

 

4/04/01

 

508

92.8

1,690

 

2,650

7.0

8/14/03

 

557

91.8

1,650

 

2,940

7.33

12/02/03

 

514

93.4

1,610

 

2,750

 

3/11/04

 

505

98.1

1,620

 

2,740

7.20

4/29/06

 

 

 

1,750

 

 

 

 

*Approximations read from graphs in “Mines Task Report”, 1983

 

Community Water Well #8

 

CWC 8 – Due West of MH-3, MH-14 and MH-12

Year

Hardness

Calcium

mg/l

Magnesium

mg/l

Sulfate

Arsenic

TDS

pH

1994*

146

46.7-70

7.14

59.8-94

 

286

 

1995*

160

59.96

4.33

138

.

396-422

 

1996*

 

 

 

131-374

 

376-546

 

1997*

 

 

 

233-337

 

564-728

 

1998*

 

 

 

324-553

.

603-873

 

1999*

381-502

131-170

13-19

316-578

 

636-884

 

4/12/99**

 

 

 

820

 

1280

 

2000*

521

179

18

390-456

 

704-880

 

2001*

488

164

19

428-479

 

780-896

 

2002*

488

166

18

475-487

.007 - .015

776-922

 

2003

565

190

22

547

.011

956

 

2004

587

 

22

502

.010

952

7.18

 

* In this year, more than one test was performed, therefore, the high and low values on all tests are given.

** On this test date, there were unusual readings, so they were separated out.

Note: The high readings in red appear to correlate with “Hazardous Material Incident” reports from Phelps-Dodge Sierrita mine.

 

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