Mining company to fix sulfate problem

Copper company Freeport McMoRan says it will use the most costly and probably the most effective plan to try to cure an underground water plume laden with sulfates.

The sulfate plume flows beneath parts of the Green Valley area, giving water companies a headache as they try to deliver the purest and best-tasting water to customers.

Freeport McMoRan inherited the sulfate plume problem when it acquired the Sierrita Mine west of Green Valley from Phelps Dodge.

Water activists, including operators of public water systems, have been working toward a solution to rid the water of sulfates, which can make water smell and taste like rotten eggs and can cause diarrhea.

A paper distributed at a working group Friday showed Freeport McMoRan plans to spend $81.4 million through 2058 to solve the problem.

Part of the solution will involve creating a new, 300-foot-high, water impoundment to deposit sulfate laden waters.

There’s already a 300-foot-high impoundment pond at the current mine southwest of Green Valley.

Although enthusiastic about the announcement, Freeport said it will take eight years to acquire the land and for getting the permits for the new impoundment pond.

That pond will be on the mine’s west side and out of sight in Green Valley.

A company announcement distributed Friday said the company would need to buy 8,200 acres of state land for the pond and other things.

It also said that 2,000 acres to the east of the impoundment are “to be conserved as open space and made available to the public for recreation,”

Freeport McMoRan will continue its program to use inceptor wells to monitor the plume as well as other wells to pump some sulfate-laden water for return to the mine as part of its mitigation plan.

Freeport said two state employees deserve recognition for helping develop the plan and finding laws that will permit it: Joan Card, Arizona Department of Environmental Quality’s water quality manager, and David Jacobs of the Arizona attorney general’s office.

Freeport also said a new public group to work with the mine will hold its first meeting 10 a.m., Tuesday, Jan. 6, 2009, at the Joyner-Green Valley Library.

jlamb@gvnews.com | 547-9749