Officials seek to educate public of mining practices

KYLE VON BOSE

February 29, 2008 at 8:56AM AKST

Fears pertaining to the proposed Pebble mine are real.

However, as state and federal officials push forward with an informational campaign to educate the public about mining, mine permitting and environmental accountability, many of the misunderstandings that drive the fears are being brought to light.

While scientific information regarding modern-day mining is beginning to reach the public, many people’97including anti-Pebble groups’97do not believe that the Pebble Partnership can safely develop the proposed mine.

They further doubt that state and federal agencies have the proper measures in place to protect Bristol Bay and the environment.

Art Hackney, spokesman for the Renewable Resources Coalition, said the No. 1 fear over the proposed project is the potential pollution of waterways. One way that mines can pollute is through water runoff, which can carry toxic metals and chemicals away from mine sites.

Hackney said that because of the sheer size of the proposed Pebble mine, there is an extreme likelihood that harmful substances will leech into the surrounding waterways.

"You’re going to have a poisonous soup; you’re going to have heavy metals; you’re going to have acids; you’re going to have diesel fuel; you’re going to have lubricating fluids," Hackney said. "And it’s a gold mine, so there will be cyanide."

Hackney said mining engineers have told him the Pebble mine cannot be built without toxic discharge. For Hackney, it all comes down to good science. He said that an over-abundance of groundwater and rainfall make a clean Pebble Mine an impossibility.

"The footprint that they are dealing with, conservatively, is going to be 6,000 acres," Hackney said. "In a normal year, you have an average of 34 inches of rain a year or 6 billion gallons of runoff. In a year of extraordinary rainfall it will be impossible to control water runoff."

Anglo American’s head of safety, health and environment, John Groom, said that excesses of water in a mining region, whether from rainfall or snowmelt, can be diverted or discharged, unaffected by the mining operations.

He said water that is affected by mining operations can be collected, treated and processed so that it is essentially potable and (meet) environmental quality.

Modern mining practices routinely require sampling surrounding waterways, underground wells and surface water, Groom said.

"In copper mines in Canada, one of the water-monitoring devices was actually a trout tank," Groom said. "We would take a constant flow of water out of a stream, pass it through a tank with trout in it and watch the trout."

Groom said trout are an extremely sensitive biomarker and gave the operation a high degree of confidence about the surrounding water quality.

Tailings dams

The Renewable Resources Coalition’s Website compares the proposed Pebble mine’s tailings dam to the Hoover Dam. However, a tailings dam and a dam that holds back water in a river are two entirely different structures.

"People talk about toxic tidal waves or have these notions of the Hoover Dam sitting in the middle of Bristol Bay," said Sean Mcgee, spokesman for the Pebble Partnership. "I think they are creating perceptions and fears that are not based on fact."

Tailings dams aren’t exactly enormous containers of toxic sludge. Modern tailings dams are similar in structure to a pool, and hold waste rock and mine tailings.

The water in a tailings dam is used to prevent the tailings from oxidizing. Waste rock is earth that is not processed because it is either unmineralized or sub-ore-grade material removed to get to ore.

Tailings are what’s left after ore has been ground and as much of the economic value as can reasonably be extracted is removed.

Tom Crafford, mining coordinator for the Alaska Department of Natural Resources, describes mine tails not as toxic waste but more of a mixture of demineralized dirt and rock.

However, tailings can contain harmful components depending on the saturation of metals in the rock.

Crafford said leaking mine waste is a concern, because in most metallic mines, metals occur in combination with sulfur in the form of sulfide minerals.

If sulfide minerals are exposed to the surface or near-surface environment, they mix with oxygen, water and bacteria’97a process called weathering. When tailings weather, they dissolve and release sulfur and metals into the surrounding environment.

If sulfur combines with oxygen and water, it creates sulfuric acid. If this is allowed to happen, acidic condition accelerates weathering and increase the rate of the entire process.

Even Anglo American’s Groom thinks it would be rash for an engineer to say a leak is impossible.

"What can be done, however, is to design the whole tailing dam, with failsafe options," Groom said.

The first line of defense is close monitoring. The next step is a set of engineering solutions to the "what if" questions.

"You design it with a backup," Groom said "That, together with the appropriate managing and monitoring plans, provides a very high level of confidence."

He said that in terms of public perception, the most common problem with tailings dams is water seepage.

"It’s highly, highly unlikely these days with good monitoring to have anything more dramatic than that," Groom said.

Controlling seepage is done through monitoring water catchments, which prevent contaminated water from reaching sensitive environments.

If seepage does occur, wells can be drilled to remove tainted water and either put it back into the dam, or process it and release it as clean water.

As for earthquakes, Groom said that’s an area Anglo American has considerable experience in. It operates several mines and tailings facilities in Chile, an area of frequent seismic activity.

"It’s an issue where there are safe engineering solutions," Groom said. "It is an important consideration, but with modern construction techniques, it’s not something that has caused a problem, even in some particularly highly seismic areas."

Despite advances in science, there are still claims that modern mining techniques are not reliable enough for Bristol Bay.>

Hackney points to Red Dog mine, within Alaska’s Northwest Arctic Borough, as an example of predictable problems.

"Red Dog had 18 years of acid over-runs and enormous fines," Hackney said. "They are listed on the EPA’s Website as the No. 1 polluter in America,"

Hackney said that while people have complained about pollution at Red Dog in the past, by and large, most people today are happy because of the large amounts of money being made and shared all around the state.

"But Bristol Bay is different; if you dropped Red Dog down of top of Bristol Bay, it would be a catastrophe," Hackney said.

Red Dog comparisons

Crafford hears references to the Red Dog mine from people in relation to the Pebble Project almost every time he gives his presentation.

"Red Dog is often brought up, and you hear these stories about how the EPA says that Red Dog is the largest polluter in the U.S., and that there are all the hundreds if not thousands of water-quality violations," Crafford said.

"I always say, ‘There is nothing simple about Red Dog,’ and not only that, but Red Dog is such a poor example to use about mining," he said.

Red Dog mine went into operation 19 years ago. Crawford said that if there was a spectrum of mines based on how much metal is in the ground, Red Dog would tip the scale.

"There is so much bloody metal in the ground at Red Dog, it is virtually unparalleled," Crafford said. "So many of the issues at Red Dog are simply not applicable to any other mines."

Crafford said the reason Red Dog gets confused as the country’s largest polluter is because of the EPA’s Toxic Release Inventory. The EPA classifies all mine waste, including waste rock and tailings, as toxic release.

Operators are required to report any of the metal that is in that waste rock excavated and stored on the site. The metal is reported as release even though it is safely stored onsite and not actually released into the environment as pollution.

Red Dog has so much metal in the ground that its waste rock and tailings contain several (high) percentages, putting the Toxic Release Inventory through the roof.

"The average grade of lead and zinc at Red Dog is like 22 percent in the mine," Crafford said. In contrast, he said the Pebble Project is predicted to be on the order of 1 percent to maybe 1.5 percent copper equivalent.

"The saturation of metal at the Pebble Project is a whole lot less, which makes for less metal in the waste rock and the tailings," Crafford said.

Mine reclamation

Before a mining operation is issued a permit to extract minerals, a comprehensive reclamation plan must be approved and permitted.

Mine reclamation consists of stabilizing tailing dams physically and chemically, removing buildings and roads, and resculpting and capping waste rock piles. What’s left is a smoothed-over landscape that can take on a number of purposes.

At the Fort Knox gold mine outside Fairbanks, a functioning wetland was constructed on a portion of the reclamation. At the Red Dog mine, Arctic grayling were transplanted into a pond on reclaimed land, resulting in a self-sustained population.

"I know of metal mines which have cattle and sheep happily grazing on top of it," said John Groom. "There is a long track record of the safe construction, operation and closure of mine tailings."

The Usibelli Coal Mine in Healy is being reclaimed now, with aerial seeding and summer crews of local college students transplanting about 25,000 native shrubs and trees each year.

The most important part of reclaiming a mine site involves attempting to predict what rock in the ground will do as time passes.

Crafford said that one of the ways this is done is with humidity cell tests. The tests take crushed rock from the ore body or from the waste rock and place it in vertical cylinders. He said samples of all the relative rock types are collected from a realistic distribution throughout the ore body.

Water is then percolated down through the cylinders. The decanted water is collected and analyzed.

"You are analyzing how that material weathers over time," Crafford said. "It is a means of accelerating the weathering process.’

Geochemists who conduct these types of tests look at the water quality coming out of those humidity cells over a long period of time to predict how water will move through.

Because of its large size, reclaiming the Pebble Project would be a long and arduous undertaking.

At a mining presentation at the Alaska Wilderness Recreation and Tourism Association’s Ecotourism Conference on Feb. 20 in Anchorage, Ed Fogel, director of the Department of Natural Resources Office of Project Management, said that when it comes to mine closure, the reality is that mining company’s obligations to a reclaimed mine site could conceivably go on forever.

Kyle von Bose can be reached at (907) 348-2438 or toll free at (800) 770-9830, ext. 438.