Sulfate Data from Other Local Wells

Although the figures are much lower, a gradual increase in sulfate is creeping into wells at other water companies, including Las Quintas Serenas, which is owned by the mining company—and does not bother to test for sulfate. Remember, it's a secondary standard, so they don't have to do so. (Or if they do they don't have to report it.) Note that the well that does have the increasing sulfate is closer to the Twin Buttes mine tailings pond.

Twin Buttes mine is in line to get an up-dated Aquifer Protection Permit by 2006, even though it has been closed, except for a small part, since 1985. It did qualify for a APP permit in 1988 for its operations at that time, but its expansions since then have to be permitted also.

Las Quintas Serranas Water Co.

Sahaurita

Well

No.

Date

Hardness

Calcium mg/l

Magnesium mg/l

Sulfate

Arsenic mc/l

TDS

pH

                 

4*

1/15/91

     

86.7

 

345

 
                 

5

1/15/91

     

118

 

410

 
 

9/24/93

233

   

163

 

415

7.5

 

9/30/96

426

   

342

 

686

7.1

                 

6

9/24/93

111

   

29.8

 

245

                 

7

7/13/98

102

   

38

 

214

7.3

                 

*closed?

               

MCL 

 

 None

None 

None 

250 mg/ltr **

 .05 mg/ltr

 500 mg/ltr**

 

Green Valley Water Company

Well No. 1

Drilled 1978

Date

Hardness

Calcium mg/l

Magnesium mg/l

Sulfate

mg/l

Arsenic mc/l

TDS

mg/l

Alkalinity

pH

9/26/77

 

38

5

23

 

190

   

11/2/82

 

37.5

5.3

16

 

203

   
                 

1994

166

52

8.7

113

.05

350

186

8.12

1999

     

53

       

2001

130

44

6

         

2002

 

50

     

269

171

7.58

2003

     

39.8

.015

260

   

Well No. 2

Drilled 1978

Date

Hardness

mg/l

Calcium mg/l

Magnesium mg/l

Sulfate
mg/l

Arsenic mc/l

TDS
mg/l

Alkalinity

pH

9/15/77

 

41

6

23

 

273

 

8.1

                 

1994

233

75.6

11.1

109

.007

412

190

8.08

1999

     

114

       

2001

196

62

10.0

         

2002

 

65

     

340

189

7.52

2003

     

94.3

.013

394