PD: Solution in the works for local water problems

GREEN VALLEY -- As it prepares to ramp-up its mining efforts after years of diminished copper production, the Phelps Dodge Sierrita Mine continues to search for a solution to the local water problems it has caused, a mine official said this week.

Two wells in the Community Water service area have been hopelessly contaminated by sulfate and Total Dissolved Solids (TDS) levels about twice those recommended by the federal Environmental Production Agency, the result of seepage from the Sierrita Mine's tailings.

However, those recommendations are unenforceable and are meant merely as aesthetic guidelines.

Not regulated

High concentrations of sulfates and TDS in water have been known to cause diarrhea --which can, in extreme cases, lead to dehydration --in infants, the elderly, and those not acclimated to the local water supply, but the risks are not considered serious enough for federal regulation.

Instead, the EPA has listed sulfate and TDS among its Secondary Drinking Water Standards--those governing taste, odor, corrosivity, foaming, and staining properties of water.

After nearly a year of studying the issue, Mike Wood, the mine's environmental, land and water manager, said Thursday a short-term solution to the problem is still "several months away."

Speaking to the Green Valley Community Coordinating Council's Executive Board, Wood said he's found replacements for the contaminated wells, and that Phelps Dodge is in the process of transferring those to Community Water.

That takes time, however, as there are myriad county and state rules governing well transfers.

Though unwilling to give an exact timetable for the switch-out, Wood stressed it would be months before the solution is in place.

The well switch-out is merely a short-term solution to the ongoing problem, and it's expected to keep the sulfate and TDS levels down for only about two years.

A longer-term solution is still being investigated, Wood said.

Costly fix

After all is said and done, a permanent fix will likely end up costing the mine over $1 million, he said

The Sierrita complex plans to be mining at 100 percent capacity by September, he said.

GVCCC Vice-president Chet Davis requested that Wood update the council on its progress again in about six months.

thull@gvnews.com |625-5511 x22