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Kensington Mine Background

The Kensington Gold Mine is a hard rock mining project proposed by Coeur d’Alene Mines Corporation of Idaho. It is located a few miles north of the City of Juneau road system (50 miles north of downtown Juneau) in the Tongass National Forest. Coeur’s proposal has been around for 15 years and been through several proposed operating plans. A final Environmental Impact Statement and Record of Decision was issued in 1997 for one of them. It would have used dry stack tailings disposal and staged its operations outside of Berners Bay. Coeur did not implement that operating plan because gold prices dropped in the late 90s. The current operating plan had a supplemental final EIS and ROD issued in late 2004. Under this plan, Coeur moved its facilities into Berners Bay and its watershed. It switched from using dry stack tailings disposal to a proposal under which it will pipe 4.5 million tons of mine waste into a lake on Tongass National Forest lands. Docks for transporting mine workers, ore, and supplies are now located within Berners Bay. This operating plan has been opposed by local and national conservation groups since its inception.

Berners Bay Facts:

The Bay is an incredibly rich estuary system that has four rivers flowing into it. Its rivers provide spawning habitat for wild Alaskan salmon. During spring runs of herring and eulachon (a small energy-rich forage fish) Berners Bay hosts whales, seals, tens of thousands of shorebirds, the second largest congregation of bald eagles in North America (up to a thousand at a time), and Steller Sea Lions, a listed threatened species under the Endangered Species Act. Research has shown that the Steller Sea Lions in particular may be dependent on the Berners Bay eulachon runs for maintaining population level viability in northern S.E. Alaska. Over 900 Steller Sea Lions have been observed feeding cooperatively in the Bay during these runs. The Bay’s uplands are also home to brown and black bears, wolves, moose, and mountain goats. It was deemed an Aquatic Resource of National Importance by the EPA during the Clinton Administration.

Berners Bay is a favorite destination for recreation, fishing, kayaking, bird watching, whale watching, air boating, and camping, and is increasingly important for commercial tourism.

Mine Facts:

Coeur proposes to mine for ten years under this operating plan and may seek to expand that time period if other ore bodies pan out.

The proposed mining operations will generate 7.5 million tons of mine waste over 10 years. Three million tons will be backfilled into the mine, and the remaining 4.5 million tons will be dumped into Lower Slate Lake. This lake is located on National Forest lands.

Coeur will build a dam 90 feet high and 500 feet long to enlarge the lake and accommodate its mine tailings. This dam will have to last forever. If it fails, the mine waste could end up in Berners Bay

In order to permit the disposal of mine waste into Lower Slate Lake, the Corps of Engineers re-defined the mine waste as “fill material.” The agency used the same Bush Administration regulation change that allowed Appalachian coal mining companies to shove overburden into stream valleys in mountain-top removal mining.

Coeur Alaska will build two docks with staging areas within Berners Bay. One in the north at Slate Creek Cove, and one in the south at Cascade Point. Cascade Point contains spawning habitat for the depressed Lynn Canal stock of pacific herring. The Slate Creek Cove facility is in close proximity to seal haul outs and eulachon spawning grounds.

Mine vessel and barge traffic will cross the Bay with fuel, ore, employees, and construction materials on a daily basis (three to five round-trips a day).

Supporting Points

Upholding the law:

More then 30 years ago Congress enacted the Clean Water Act to end the use of public rivers and waterways as dumping grounds for industrial waste. Permitting mine waste to be dumped into a lake violates the Act. Re-defining such waste as “fill material” is an effort by Bush administration agencies to circumvent the Clean Water Act.

This mine waste is not fill material. It is a pollutant. After it is discharged into the lake via a 3.5 mile pipeline, the lake’s waters will need to be treated before they can be discharged into Slate Creek and flow into Berners Bay.

For the first time since Congress passed the Clean Water Act, the Corps of Engineers has authorized a mining company to discharge chemically processed mining waste into a lake.


The agencies’ decision to allow the disposal of millions of tons of chemically processed mine waste into a pristine alpine lake sets a horrible precedent. If Coeur d’Alene Mines can do it in the heart of the Tongass, mining companies can do it in almost any lake, river, or stream throughout Alaska and in the rest of the country, even your favorite swimming hole or fishing spot.

Natural Resources:

Berners Bay is one of Southeast Alaska’s most outstanding public resources. It supports large numbers of sea lions, bald eagles, harbor seals, migrating birds, salmon, humpback whales, and herring. Up-lands support wolves, brown and black bear, moose, and mountain goat. The Bay is also culturally significant to the Auk Kwan Tlingit Tribe of Alaska Natives. It provides outstanding recreation opportunities (boating, crabbing, hunting, trapping, whale and bird watching, camping, kayaking).


Juneau, S.E. Alaska, and many other areas of the country have economies that are driven by quality of life issues. People live in Juneau because it is surrounded by wildlands. Hundreds of thousands of people visit here hoping to see those wildlands and the wildlife they support. Gold mining is legal in this country if it is done right. Coeur has had permits and an approved operating plan since 1997. That plan relied on the established and legal dry stack method of tailing disposal. Juneau could still have the jobs associated with this mining project if Coeur abandoned its plan to dispose of chemically processed mine waste into a lake.

Years of working with the agencies and the company.

The Sierra Club and the region’s other conservation groups have worked actively on the issues surrounding the Kensington mine project since the 1980s. We have used every available forum to voice our concerns. We have continually and specifically urged the agencies to uphold the law. In the end, the agencies went ahead and put corporate interests ahead of the public’s interest in ensuring compliance with long-established environmental laws. For the last few months, we have taken the extra step of talking with the mining company to see if a solution could be found. Unfortunately, a resolution could not be reached. During this time, it was Coeur’s own choice to begin construction, and the company proceeded with full knowledge of our concerns.

  • Tongass National Forest


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