Sulfate in Local Wells

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