Pebble Mine: Unprecedented Waste Water and Perpetual Pollution

The Army Corps of Engineers has just released the Draft Environmental Impact Statement (DEIS) for the proposed Pebble Mine.  Northern Dynasty is proposing a “smaller” mine plan, but don’t be fooled. They intend to expand if they receive a permit, and even the “smaller” plan is staggering in size.

The DEIS estimates that it will generate an average of 6.8 billion gallons per year of waste water during operations and 11.8 billion gallons per year during phase one of closure, requiring capture and treatment. The waste water will contain metals and other pollution harmful to fish and public health.

The proposed Pebble Mine will generate a pit lake that contains more contaminated water (estimated 61 billion gallons) than the Berkeley Pit (estimated 50 billion gallons) – one of the largest Superfund sites in the nation.

This is unprecedented.  We can find no other U.S. hardrock mining operations that capture and treat such a large volume of contaminated mine water (see the comparison here).

Pebble’s proposed water treatment system is highly complex and untested, and it will likely need to operate in perpetuity.

It’s important to consider the track record of big open-pit copper mines when considering the potential for lasting harm.  In a 2012 review of operating U.S. copper mines that account for 89% of U.S. copper production, 92% failed to capture and treat mine waste water, resulting in significant water quality impacts.

That’s right.  The industry has failed – across the board – to show that it can effectively capture and treat waste water at these big copper mines. Yet, none of these mines come close to generating the vast amount of contaminated mine water that Pebble will generate.

This type of track record is unacceptable when you consider Bristol Bay’s value as the world’s largest and most valuable wild salmon fishery.