Community Water Company Now Receiving

 Water from Phelps Dodge Sierrita Wells

Effective June 1, Phelps Dodge Sierrita, Inc. and Community Water Co.  signed an agreement that provides water for the Green Valley area from three wells owned by the Sierrita mine.

The Sierrita wells are unaffected by a sulfate plume in the area and will temporarily replace water from two Community Water wells that have shown elevated levels of sulfates.

This water from the Sierrita wells is now flowing. It means that customers of Community Water will have adequate water through the hot summer months and beyond.

The affected Community Water wells are not being used. Community Water’s use of the Sierrita wells is a temporary solution.  The parties are continuing to work cooperatively to identify a long-term solution.

“Our attention remains focused on determining the most effective long-term way to control the plume and to assure clean, unaffected water for the Green Valley area,” said John Brack, general manager of Sierrita.

What are sulfates, and what more is being done?

Sulfates are a kind of salt and do not pose a health risk, but they can affect the taste of the water and, at high concentrations, can for some people create a mild, short-term laxative effect.

Sulfates apparently reached the groundwater from the tailing impoundment at the Sierrita mine. (Tailing is the rock, dirt and other material left over after copper and molybdenum is removed from ore.)

Interceptor wells were placed along the toe of the tailing impoundment in the 1970s. With wells beyond that area now being affected, Sierrita is studying to what degree the plume may or may not continue to spread in the future, and whether additional interceptor wells or other actions are required.

“We need to make sure a proposed solution is effective for the long term,” Brack said.

The Phelps Dodge Sierrita mine employs about 800 people and produces copper and molybdenum for world markets.

Community Water Co. is the largest water utility in the Green Valley area, serving about 20,000 people.

For further information: Ken Vaughn, Phelps Dodge Corp., 602-366-8318