Hundreds of mines around world at risk of catastrophic waste dam failure


Center for Science in Public Participation, Earthworks, Nunamta Aulukestai press release

Date of publication: 
4 February 2015

Communities, enviros call upon EPA, UN, to create independent expert panel to assess threats posed by tailings dams in existing & proposed mines in U.S. and globally

Washington, D.C., Dillingham, AK — In response to the findings of an investigation of the Mount Polley tailings dam failure in British Columbia, Canada, a coalition of environmental and community groups today called upon the U.S. Environmental Protection Agency (EPA) and the United Nations Environmental Programme (UNEP) to investigate threats posed by similar mine waste dams in the U.S. and around the world, and to reassess existing mine proposals.

“The most important finding of the Mount Polley investigation is that catastrophic mine waste dam failures can and will happen anywhere, unless we apply the lessons of Mount Polley and act to prevent them,” said Dr. David Chambers, president of the Center for Science in Public Participation. He continued, “Preventing these failures is critical to protecting the public from environmental and financial impacts, since there is no financial surety for catastrophic tailings dam accidents.”

“The panel has made it clear that these catastrophes will continue to happen, even at modern mines. Business as usual simply isn’t acceptable,” said Jennifer Krill, Executive Director of Earthworks. “To protect clean water, communities and the environment, we need independent investigations of similar mine waste dams, and to act on the recommendations of the panel for major changes in the way tailings dams are designed, permitted, and operated.”

The panel’s investigation into the Mount Polley dam failure, which released roughly 24.4 million cubic meters of mine waste into the Fraser River watershed last year, concluded that the dam design was at fault, and predicted that an estimated 2 additional tailings dam failures could occur every 10 years in British Columbia if business continues as usual.

There are 839 tailings dams in the United States and approximately 3,500 around the world, according the U.S Army Corps of Engineers and the United Nations, respectively. Mining companies worldwide use Knight-Piésold, the engineering firm that designed and built the tailings dam that failed at Mount Polley — including at the proposed Pebble copper-gold mine in Alaska and the Yanacocha gold mine in Peru.

Large tailings dams built to contain mining waste, among the largest structures in the world, must stand in perpetuity. Yet there is no federal agency in the U.S., nor global entity, responsible for oversight of tailings dam safety. The few tailings dam safety and construction requirements that exist were developed from those intended for water retention dams, not for mine tailings dams.

“Imagine our concern when we realized that the same company that designed the faulty Mount Polley mine tailings dam designed the proposed Pebble tailings dam,” said Kimberly Williams of Nunamta Aulukestai, an association of Alaska Native Tribes and corporations. She continued, “No other community should have to experience the disastrous tailings spill that BC First Nation’s did.”

Mount Polley is an open pit copper/gold mine that covers more than 18,000 hectares in south-central B.C. The tailings pond was breached on August 4, releasing approximately 25 million cubic meters of mine tailings. The spill extended roughly 5 miles down Hazeltine Creek into Quesnel Lake. On August 18, 2014, an independent review panel of three geotechnical experts was established to investigate into and report on the breach of the tailings dam. On January 30, 2015, the independent review panel delivered its final report and recommendations “Independent Expert Engineering Investigation and Review Mount Polley Tailings Storage Facility Breach” to the British Columbia Minister of Energy and Mines, the Williams Lake Indian Band and the Soda Creek Indian Band.


The Mount Polley panel report can be viewed here:


Dave Chambers, PhD, Center for Science in Public Participation, 406-585-9854, dchambers [at] csp2 [dot] org Bonnie Gestring, Northwest Organizer, Earthworks, 406-549-7351, bgestring [at] earthworksaction [dot] org Kimberly Williams, Nunamta Aulukestai, 907-843-0875, nunamtaexdir [at] gmail [dot] com

Earthworks is dedicated to protecting communities and the environment from the adverse impacts of mineral and energy development while seeking sustainable solutions.
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