Oct 192012
 

I recently returned from a Donlin Gold sponsored tour of the Golden Sunlight mine just a few miles outside of a small ranching town in Montana called Whitehall.  The operating mine is about 50 miles west of Bozeman, which is about 90 miles to the north of Yellowstone National Park.  The mine is presently owned by Barrick and has been in operation for over 30 years and is a typical open-pit truck and shovel operation – similar to what Donlin Gold would be.

From all indications the mine appears to be situated in a location that couldn’t be better.  For starters, the climate is relatively dry, with average precipitation about 10 inches a year.  It’s also not far from a major highway – Highway 90 that connects Bozeman with Butte and Missoula to the west and Billings to the east; you can see a good portion of the mine from the highway (see photo below).  Logistically, the proximately to infrastructure such as a power grid and highway make operations like this relatively easy compared to one in remote Alaska that has virtually none.

Looking from the highway at the waste rock storage area

Secondly, most locals who reside in the area are very glad the mine is where it is – in part because it employs a good many local residents, over 200 in the town of a little over 1,100 people.  Not only does the mine provide direct employment, it also requires the services of about 70 contractors (who hire many others) who carry out much of the work.

Upon arrival at the Bozeman airport Kurt Parkan with Donlin Gold and Bill Bieber with Barrick were there to greet us and shuttle us to our hotel.  Bill pointed out that the Golden Sunlight mine was the first mine he ever worked at – he grew up in Whitehall and still has family there.

After the long flight and a short’s night rest the group travelled the following day to Whitehall and observed one of the monthly meetings of the group called the Community Transition Advisory Committee, or CTAC for short.  This group is comprised of local community members, e.g., representatives of the chamber of commerce; county commissions; Fish Wildlife and Parks which is similar to ADF&G; the local college; the local development corporation; the school district; bank; several local landowners and various mine managers.  The intent is to have a representative cross section of the community.

One of the members, a county extension agent, came to Bethel several years ago to speak about the ongoing mine operations at an AVCP Convention while another used to live in St. Marys.

The group was established about ten years ago with the purpose of regularly communicating the happenings of the mine to local residents; in other words an information conduit.  It was originally started when it appeared that the mine life would be coming to an end and the community leaders feared that the mine would be typical of many boom and bust resource extraction projects like are common in the western part of the lower 48.  They wanted as smooth a transition as possible to offset the large economic void left when the mine does eventually cease operations.

During the meeting it was noted that Barrick has done a lot for the community and that one of their guiding principles is sustainable development….even after the closure of the mine; the goal here being to build economic and social capacity throughout the region.  Several times during the meeting it was noted that safety in all aspects of the operation is one of Barrick’s highest priorities, and that they have worked to transfer that ethic throughout the community via safety fairs and other means.

Several of the local residents expressed a sincere trust between the community members and the managers of the mine.  It seems that the mine’s personnel and the local residents have a very good working relationship.  Not only are those 200+ residents employed by the mine, but a good portion of the managers are thoroughly involved in civic activities.

The second day of our trip was the actual tour of the mine facilities.  We first sat through a safety briefing and then a presentation about the workings of the mine.  During the mine’s life around 3.2 million ounces of gold has been recovered from 64 million tons of ore that have been blasted, trucked and processed in one way or another.  To date about 2,300 acres of land have been disturbed, much of which has already been reclaimed (we did see some wildlife; i.e., deer in and around the reclaimed areas).

If you look closely in the center of the picture you'll see a mule deer - there were three others on the other side of the road we were traveling on.

During the presentation our group asked many good questions, specifically about the similarities and differences between what we were about to see and the proposed Donlin mine.  Most obvious to us was the difference in climate, Montana’s being very dry compared to the Kuskokwim – especially after the past three excessively wet summers!

All operating mines use water, and usually vast quantities of it to process the gold – especially the milling process.

One of the many leaching vats

Both mines are, or will be, what’s called zero discharge meaning that no surface or ground water within the mine’s working perimeter is allowed to enter any streams downstream of the mine itself during the mine’s operation.

Consequently, mining operations have to deal with what’s called a water budget or water balance, and that can be tricky because it’s all contingent on weather conditions…which at best are unpredictable.

A Golden Sunlight representative said that their 10 inches of annual precipitation actually works to their advantage because lots of water flowing through, and around, acid generating ore is problematic. If there was more water then they could handle say from a tremendous amount of snow in a given year, or an exceptionally rainy summer, the probability of acid mine drainage getting into the downstream waters would greatly increase.

According to Bill Bieber, even though our region averages over twice as much precipitation a year, the needs for water at Donlin are such that they will still have to capture every possible drop they can (Crooked Creek averages 15.5” of precipitation a year).  All mines, in order to minimize their water consumption, recycle as much as they can again and again and again.

But such an operation like Donlin will prevent a certain amount of water from entering the streams below (e.g., snowmelt in the spring and rain runoff during the summer).  And it goes without saying, but fish do need a certain amount of water to survive; the less water the less productive the system will be.  It will be interesting to watch just how low Crooked Creek gets in the coming years if the mine goes into production – especially low water years.

Another difference noted was the amount of land that will be disturbed.  It’s uncertain how large Donlin will eventually be, but there is the potential for it to be mind-boggling.  In all sincerity, some mining officials believe from analyzing the exploration data that it could be the world’s largest!  So everything we saw in Montana would be amplified several times, which to be honest, is a little disconcerting.

The height of the tailings dams at both Fort Knox in Fairbanks and in Montana were impressive, but Donlin’s will be that much bigger and holding that much more potentially acid generating material behind them…magnitudes more.  During the tour one geologic plus was noted, and that is that there tends to be a fair amount of naturally occurring carbonate minerals up behind Crooked Creek that could lessen the potential for acid drainage problems by neutralizing much of the acid.

With any mining project, it’s dealing with the tailings that is the most significant environmental challenge.  One thing I learned about tailings impoundments is that they’re designed to hold mostly sand sized processed ore and relatively little water compared to a normal dam; knowing that did allay some of my fears.  Why they don’t hold much water is that, as already mentioned, most of the water going into a tailings impoundment is constantly being recycled back up to be used in the milling process.

Golden Sunlight's tailings impoundment - note the relatively little water in the background

Although these dams are designed to withstand the probable maximum precipitation and large earthquake events, it was noted that the biggest causes of dam failure are overtopping by water and seismic activity – in that order.  So unfortunately, there are no real assurances that there won’t be any problems since nature and its concomitant weather are factors.

In the following pictures you’ll see the plastic liner that will be used to potentially prevent acid mine drainage from seeping through – or out – of the tailings impoundment.  It’s 80-mil thick (a little thicker than a quarter) and will be placed over the entire bottom and sides of the impoundment with pieces spliced together to make it one gigantic impermeable layer.  Unfortunately, liners aren’t forever, so no one knows for sure just how effective they’ll be hundreds of years from now.

 

A portion of the liner being placed on the side of the tailings impoundment

If liners do fail, which has happened, it’s usually from improper installation or mechanical damage; i.e., a piece of machinery puncturing it.

It is highly unlikely that no acid mine drainage will seep from such an impoundment; so smaller backup impoundments are built to gather the seepage and pump it back up into the main impoundment.  At the Golden Sunlight mine there are three such catchments.

Acid seepage from Golden Sunlight's tailings impoundment

 

A backup catchment pond pumping water back up to the main impoundment facility

Upon completion of the Donlin project, it’s expected that the tailings facility contents will stabilize and eventually look and function very much like a meadow.  To make that happen they’ll recontour the surface and cover it with three or more feet of topsoil and then plant native vegetation.  It’s also expected that, over time, the concern for any toxic seepage from the tailings impoundment will diminish.

One thing that is forever, however, will be the need to monitor the water leaving the pit once it fills up…which could take 50 or more years.  Here’s a few pictures looking into the Golden Sunlight pit, which as noted will be much smaller than the one planned for Donlin.

Looking across toward the top of the pit

 

Looking half way down the pit at a truck carrying blasted ore to the processing mill

And looking at the bottom of the pit. Note the water and acid mine drainage seeping from the pit walls. This is indicative of why the water will have to be monitored for its quality for perpetuity...which is forever.

Similar to the Fort Knox mine in Fairbanks, there was little concern for mercury being emitted at the Golden Sunlight mine, but that’s not the case at Donlin.  Since there was little to no concern at either site, very little discussion ensued – so we’ll leave that topic for a later discussion, however.

The official permitting process for the Donlin Gold project will soon begin now that Donlin Gold has formally submitted their application to the Department of Natural Resources.  Now’s the time to pay attention to what exactly is proposed and express your concerns during the public involvement process.

As time goes on we’ll keep you posted on this site as to what’s happening during that process.

 

Dave Cannon

Environmental Director

 

 

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