Gold mine in Tooele County would use cyanide to get metal

Published: Monday, Feb. 18 2013 9:27 p.m. MST

Miners have pulled gold, silver, arsenic and tungsten out of the ore in southwestern Tooele County dating back to the 1860s.

Don Grayston, Deseret News archives

GOLD HILL, Tooele County  — Miners have pulled gold, silver, arsenic and tungsten out of the ore in southwestern Tooele County dating back to the 1860s.

Now, under a proposal pitched to the Bureau of Land Management, the Clifton-Gold Hill Mining District may become home to the area's first large mining operation to tap gold and silver deposits.

Seattle-based Desert Hawk Corp., wants to set up camp in the west desert and process a million tons of ore a year for two years. The entire life of the mining operation would be for six years, with another three years to reclaim the land.

Desert Hawk President Rick Havenstrite said about $12 million has been spent so far to get the project rolling, including money sunk into documentation for regulators that there won't be a problem with acid mine drainage, which is acidic water laden with iron, sulfate and other metals.

"Our system doesn't have sulfate in it — that's the beautiful thing," he said.

What's been dubbed the Kiewit Mine Project has gone through an environmental analysis by the Bureau of Land Management because part of it is on federal lands east of Iabapah and west of the salt flats. The public has a chance to weigh in on the proposal through March 14 and a similar public review of a state mining permit has already been completed.

Jim Springer, spokesman with the state Division of Oil, Gas and Mining, said no negative comments were received on the project, which involves exploratory drilling, blasting, an open-pit mine and a process to extract the gold and silver using cyanide.

While the division is a long way off in the permitting arena, the project's proposed use of what's called "cyanide heap leach pads," would be the state's only active mining operation using this extraction method.

Using cyanide

Cyanide is highly toxic and state mining regulators say the word itself alarms people. They say if it is handled properly it is safe in these types of applications.

The compound has been used in gold mining since the 1880s and continues to be used in more than 90 percent of the world's gold production today. In neighboring Nevada, there are about 30 mines that use the cyanide process to separate gold and silver from ore.

"Even though this may be slightly new to Utah, the regulatory environment is well known," Havenstrite said, adding that it is a fairly simple process.

Basically, the mounds of rock are piled on a lined pad that receive a cyanide solution through a drip application, he said.

"We mine it, crush it and sprinkle it on," he said. "Cyanide bonds to the gold and silver and carries it out. They are all in liquid form."

In its analysis of the project, the BLM notes that the cyanide would be trucked to the site from Nevada from a company with employees certified in safety procedures for handling the compound.

At the Kiewit site, a lined, 12,000-gallon tank of the material would sit inside a secondary container on top of another liner and be "triple-protected," according to the analysis. Desert Hawk plans to fence the entire project area, post warning signs and put netting over the process ponds containing the compound so bats and birds are protected.

State water quality regulators also required Desert Hawk to get a groundwater discharge permit to ensure adequate protections are in place to guard against any discharge of contaminated water.

Protection of any water resources in the area is critical, said Rob Herbert, a supervisor in the state Division of Water Quality.

"It's very important that they have lining systems properly constructed to prevent any groundwater contamination."

As part of the permit, Desert Hawk will have to drill a pair of monitoring wells in the mine project area at depth far greater than that of the mine — which is detailed to be no more than 160 feet deep. The nearest spring, the BLM analysis notes, is more than a mile away.

Mistakes of the past

On a national scale, the use of these cyanide leach pads to process gold have been a  costly environmental nightmare in Colorado, Montana and South Dakota, where hundreds of millions of dollars have been spent to clean up the legacy left by mining companies that went bankrupt.

The Environmental Protection Agency has spent more than $350 million to clean up the contamination caused by the Summitville Mine perched in the Rocky Mountains east of the Continental Divide at an elevation of 11,000 feet.

More than $110 million has been spent by the federal agency at the Gilt Edge Mine in South Dakota, where the governor sought emergency action to keep the mining company from abandoning its costly water treatment program when its parent company went bankrupt. The state and federal government later sued to obtain some compensation, reaching a $30 million settlement in 2012.

Matthew Allen, an EPA spokesman, said both Superfund sites will demand cleanup for years to come.

In Montana, companies that owned the Zortman-Landusky Mine were sued by the state and federal government asserting they were illegally discharging mine waste water into the water of the Little Rocky Mountains. 

Problems at other open pit cyanide leach-style mines led to a voter ban of the practice in Montana in 1998. The law was challenged but left intact when the U.S. Supreme Court refused to take up the issue in 2006.

Although the Montana Legislature passed a measure that would have allowed the practice to resume, Gov. Brian Schweitzer vetoed it in 2011.

Many of these environmental catastrophes played out in the late 1980s and in the 1990s, before federal mining regulations underwent an overhaul.

Doug Siple, a mining engineer with the Nevada BLM offices, said that state has not had any major issues with mines that use the cyanide process.

"Today's standards are very, very stringent," Siple said. "There is lot of regulatory oversight with federal and state agencies."

Cyanide and Utah

Kelly Payne, the environmental manager at Kennecott Utah Copper, said agencies were heavily criticized because of what played out at Summitville and in Montana and South Dakota, where communities had drinking supplies contaminated or nearly contaminated.

"We've been doing this for a number of years, the industry has, but I think it took a bit for the regulations to catch up, in terms of what the required protections are, and making sure mining companies are providing the right amount of assurance in bonding."

Kennecott, in fact, was the last mining operation to use the cyanide process in Utah.

Payne said the practice began in 1989 and was discontinued in 2007 at Barney's Canyon.

The water is continuing to circulate through the heaps of rock to rinse out the solution, Payne said, and eventually it will all be drained.

Over the years, there were five other mining operations in Utah that used the heap leach method of processing ore for gold or silver. Springer said none of them remain active and there were no major issues with any contamination of water or failed reclamation of the land.

One, the Drum Mine in Millard County, eventually closed because it could not meet its requirement to reline its process ponds, according to Herbert.

"They never did get the permits they needed to get back in operation."

Havenstrite said the issue comes down to location. He said it is problematic to situate an operation high in the mountains where snowfall and precipitation can be excessive and the mines are close to pristine water sources.

"The people who get in trouble with these heap leaches, they're like a big bath tub and at an elevation like Summitville, you can be constantly accumulating precipitation that you need to get rid of."

In Utah's arid west desert where the Kiewit Mine Project would be located, Havenstrite said the annual average precipitation is 11 inches.

"With these operations, you have to start with the worry about whether you are going to contaminate the waterways. Whatever groundwater is here is deep. We're not near a waterway — no mountain stream or pristine lake."

The mine's process pond will have an operating capacity of 100,000 gallons, but will be built to have enough additional capacity to withstand 100-year 48-hour precipitation events.

Its actual containment capacity would be 6.2 million gallons, which Havenstrite said emphasizes the prudence of "having huge safety factors. We want to make sure we never lose the (water) solution."

Herbert, too, said a lot has changed over the years. The division was just getting its groundwater rules finalized for the first time when the new Drum Mine operators came knocking for permits and could not meet the requirements to get up and running.

"We were just getting going with our rules," he said. "Since then, technology has improved dramatically for liner systems for protection in these type of facilities."

Payne said a Government Accountability audit was highly critical of lax regulatory oversight related to the use of cyanide heap leach pads in mining operations. The criticism helped propel tightening of mining rules about a dozen years ago. A subsequent Congressional inquiry in 2011 revealed that since the rules were put in play, there have been no high profile mine closures that have left government agencies stuck paying cleanup costs, Payne said.

"The regulators are a lot smarter about this," Payne said, "by forming a system they feel would prevent the creation of future Summitvilles and Gilt Edges. Those have been the rallying cries."

E-mail: amyjoi@desnews.com, Twitter: amyjoi16

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