Community Water Company

Water Quality Data

Wells 5, 6, 7, 8

The water quality of Well 7 and Well 8 began to deteriorate at an escalated rate after 1995. The pollution of the water source, the Santa Cruz Aquifer, had already been carefully documented in a report by a detailed report of mining operations in the Tucson Basin in 1983. [“Ground-Water Monitoring in the Tucson Copper Mining District Report and Detailed Recommendations” by the Pima Association of Governments and Upper Santa Cruz Basin Mines Task Force.] At that time, there was enthusiastic support from the GV community to do something about the situation. Unfortunately, little or nothing was done through the late 1980’s and 1990’s because in 1987 when ADEQ took over, it did not require existing mines to obtain an aquifer protection permit immediately—but gave them a waiver of 17 years to come up to ADEQ standards (ADEQ standards are "no further deterioration of the aquifer"!). This waiver ignored the fact that the above report, which was a lengthy and costly project, recommended changes in the mining system due to the high levels of pollution in the aquifer. Unfortunately, during these 17 years, the water quality has continued to deteriorate, until the TDS and sulfate levels on two of the wells, 7 and 8, has reached twice the level recommended by the EPA.

Solution: Arizona adopt the levels recommended by the EPA as law so that the pollution is curtailed before the water becomes undrinkable.

EPA Ground Water and Drinking Water Regulations

Even though Wells 5 and 6 have lower levels of TDS and Sulfate than the two wells that are located exactly in the plume, please note that at certain times the TDS and Sulfate levels of these “uncompromised wells had spikes in the data between 1995 and 1999. Note the numbers annotated in red. These dates correspond with the worse spills of sulfuric acid leaching materials on site at Phelps Dodge Sierrita mine, then Cyprus Sierrita mine. This is evidence that the leach material in large quantities can spread out past the normal plume and contaminate a larger portion of the Aquifer.

The readings from Wells 7 and 8 that have been compromised by seepage from the Phelps Dodge Sierritas Mine tailings pond. The waste from copper extraction is highly toxic. See

Community Water

Well 7

Drilled 6/82

Year

Hardness

Calcium

mg/l

Magnesium

mg/l

Sulfate

Arsenic

mg/l

TDS

Alkalinity

pH

1982

 

35

4.6

23

.01

253

185

7.9

1983

110

36

5.1

11

<.01

200

 

7.7

1985

(11.0)

68.93

4.03

--

 

263

 

7.5

1987*

     

44-49

 

240-280

   

1988

     

68

 

300

   

1989*

     

66-80

 

80-350

   

1990*

     

70-88

 

290-390

   

1991*

     

62-74

 

280-300

   

1992*

128

43

5.0

58-68

.01

289-290

140

7.6

1993*

     

56-78

 

270-303

   

11/10/1993**

     

148

 

485

   

1994*

67

170

6

54

 

270

   

1995*

373

121

16.8

61.9-80.6

.007-.013

242-305

145

 

1996*

--

--

--

71.1-284

--

172-344

   

1997**

 

--

--

98-146

--

306-448

   

1998*

--

--

--

154-284

.011

496

   

1999*

327-428

113-145

11-16

242-461

--

528-694

   

2000*

442

152

15

380-403

--

640-827

   

2001*

431

146

16

374-428

.011

734-817

   

2002*

462

157

17

436-470

.006-.009

817-856

   

2003

507

170

20

505

.007

900

   

Note 1:

* In some 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 2:

The high readings in red can be correlated with “Hazardous Material Incident” reports from Phelps-Dodge Sierrita mine.

See Hazardous Material Incident Logbook.

Community Water Company

Well 8

Drilled 7/94

Year

Hardness

Calcium

mg/l

Magnesium

mg/l

Sulfate

Arsenic

TDS

Alkalinity

pH

1994*

146

46.7-70

7.14

59.8-94

.011 - .045

286

166

 

1995*

160

59.96

4.33

138

.013 - .015

396-422

125

 

1996*

     

131-374

 

376-546

   

1997*

     

233-337

 

564-728

   

1998*

     

324-553

.012

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

Data from Wells 5 & 6 on the east side of the aquifer that have not been compromised by Phelps Dodge plume—at least, not yet—note the red letters of unusual readings that can be correlated with "Hazardous Material Incidents", that is spills of Sulfuric acid leaching solution, at Duval/Sierrita mine site! See Hazardous Material Incident Logbook.

Community Water Co.

Well 5

Drilled 12/73

Date

Hardness

mg/l

Calcium  mg/l

Magnesium mg/l

Sulfate

Arsenic mc/l

TDS

Alkalinity

ph

HCO3

4/7/80

266

87

12

148

<.01

--

178

7.7

 

3/14/83

237

77

11

132

<.01

430

170

7.9

 

6/18/85

11.1 g/gal

60

9.5

86

--

512

 

7.3

264

10/14/85

 

73.3

11.22

--

--

598

     

2/02/89

270

91

11

130

<.01

520

210

7.7

 

1990?

     

170

.005-.008

530

     

1991

No tests

     

--

       

1/14/92

241

80

10

120

<.01

450

180

7.6

 

11/1/93

 

73.3

11.22

60.7

--

294

     

1994

     

118-132

--

       

1995

364

118

16.4

120-144

.005-.008

386-557

212

7.51

 

1996

--

--

--

122-181

--

476-544

     

1997

--

--

--

101-150

--

350-663

     

1998

334

112

13

109-160

.009

432-652

     

1999

291

 97

12

121-162

--

360-594

     

2000

314

104

13

130-148

--

428-532

     

2001

226

 74

10

109-128

.009

402-494

     

2002

233

 77

10

116-126

.007-.009

418-446

     

(4/8/02)

       

(.013)

       

2003

No longer active

               

Community Water Company

Well Number 6

Drilled 1978

Year

Hardness

Calcium   mg/l

Magnesium  mg/l

Sulfate

Arsenic

TDS

Alkalinity

pH

                 

1993

     

63.6

 

222

   

1994

               

1995*

     

55.7-63.3

.007

266-304

   

1996*

     

52.7-66

 

263-326

   

3/13/96**

     

100

 

520

   

1997*

     

58-63

 

262-272

   

1/13/97**

     

73

 

572

   

1998*

     

53-66

.012

244-398

   

1999-qtr1*

152

51

6

61-98

 

236-328

   

qtr 2-4*

269

86

13

96-136

 

333-410

   

2000*

226

74

13

58.2-80

 

251-335

   

2001*

137

47

6

50.2-54.8

 

263-280

   

2002*

137

45

6

55.2-57.6

.012-.015

253-268

   

2003

149

49

6.4

53

.014

277

   

2004

144

 

6

52

281

281

 

7.17

Note 1:

* In some 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 2:

The high readings in red may be correlated with “Hazardous Material Incident” reports from Phelps-Dodge Sierrita mine.

 See Hazardous Material Incident Logbook.