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Bristol Bay

About EPA's Proposal to Protect the Bristol Bay Watershed

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

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Region 10’s proposal to protect the Bristol Bay watershed outlines restrictions that would protect waters that support salmon in and near the Pebble deposit area. The geographic restrictions of this proposal cover only the mining claims surrounding the Pebble deposit. No other lands or developments are subject to these restrictions.

EPA Region 10 has initially concluded that mining the Pebble deposit would affect the South Fork Koktuli River, North Fork Koktuli River, and Upper Talarik Creek watersheds. The proposed restrictions are outlined in a document called the Proposed Determination.

These restrictions are based on the construction and routine operation of a 0.25 billion ton mine at the Pebble deposit. The 0.25 size mine was the smallest of the three mine scenarios EPA analyzed in the Bristol Bay Assessment and is significantly smaller than mines contemplated by Northern Dynasty Minerals.

The EPA proposes to restrict the discharge of dredged or fill material related to mining the Pebble deposit that would result in any or all of the following:

  • Loss of streams: The loss of five or more miles of streams with documented salmon occurrence (Coho, Chinook, sockeye, chum, pink); or the loss of 19 or more miles of streams where salmon are not currently documented, but that are tributaries of streams with documented salmon occurrence
  • Loss of wetlands, lakes, and ponds: The loss of 1,100 or more acres of wetlands, lakes, and ponds that connect with streams with documented salmon occurrence or tributaries of those streams
  • Streamflow alterations: Streamflow alterations greater than 20 percent of daily flow in nine or more linear miles of streams with documented
    salmon occurrence

According to EPA records, losses of the nature and magnitude listed on the previous page would be unprecedented for the Clean Water Act Section 404 regulatory program in the Bristol Bay region, as well as the rest of Alaska and the nation.

Degradation of these aquatic resources is likely be even more pronounced, given the extensive cumulative impacts expected with successive stages of mine expansion.

If these restrictions are finalized, proposals to mine the Pebble deposit that have impacts below each of these restrictions would proceed to the Section 404 permitting process with the U.S. Army Corps of Engineers.

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Why EPA Region 10 Initiated this Action

In 2010, several Bristol Bay Alaska Native tribes, fishers, and other stakeholders requested that EPA take action to protect the Bristol Bay watershed and salmon resources from development of the proposed Pebble Mine using its authority under Clean Water Act Section 404(c).

EPA Region 10 is proposing this action because the Clean Water Act requires the agency to protect the nation’s waters, including the protection of fisheries. The Bristol Bay watershed is an area of exceptional ecological value with salmon fisheries unrivaled anywhere in North America. Development of a mine at the Pebble deposit would result in one of the largest open pit copper mines in the world and would threaten this valuable resource. Simply put, this is a uniquely large mine in a uniquely important place.

The region’s streams, wetlands, lakes and ponds provide intact habitat that support all five species of Pacific salmon found in North America: coho, Chinook, sockeye, chum, and pink. The salmon populations are critical to the health of the entire ecosystem, which is home to more than 20 fish species, 190 bird species, and more than 40 terrestrial mammal species, including bears, moose, and caribou.

Bristol Bay supports commercial, subsistence, and recreational fisheries that are worth hundreds of millions in economic yield each year and create thousands of jobs. Bristol Bay’s fishery resources have supported a subsistence-based way of life for Alaska Natives for over 4,000 years.

After careful consideration of available science in the recently completed multi-year Bristol Bay Watershed Assessment and other available information, including extensive materials provided by the Pebble Limited Partnership, EPA Region 10 decided to proceed under its Clean Water Act Section 404(c) regulations to protect Bristol Bay resources from the adverse environmental effects of mining the Pebble deposit in southwest Alaska.

EPA has received over 850,000 requests from citizens, tribes, Alaska Native corporations, commercial and sport fishers, jewelry companies, seafood processors, restaurant owners, chefs, conservation organizations, members of the faith community, sport recreation business owners, elected officials and others asking EPA to take action to protect Bristol Bay.

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How Mining the Pebble Deposit Would Affect the Bristol Bay Watershed

Based on information provided by Northern Dynasty Minerals to investors and the U.S. Securities and Exchange Commission, mining the Pebble deposit is likely to result in:

  • A mine pit nearly as deep as the Grand Canyon. EPA estimates the mine would require excavation of the largest open pit ever constructed in North America and would cover nearly seven square miles at a maximum depth of over 3/4 of a mile. The maximum depth of the Grand Canyon is about one mile.
  • Mine waste that would fill a large football stadium up to 3,900 times if the largest mine were built. This includes mine tailings and waste rock.
  • Massive mine tailings impoundments that would cover approximately 19 square miles and waste rock piles that would cover nearly nine square miles in an area with productive streams and wetlands.
  • A mining operation that would cover an area larger than Manhattan. This includes all three mine components the EPA considered (mine pit, tailings impoundments, and waste rock piles).

The construction of a mine would also require other infrastructure, such as a major transportation corridor, pipelines, a power-generating station, wastewater treatment plants, housing and support services for workers and administrative offices.

Although preliminary plans could change, any mining of the Pebble deposit would require similar components. The EPA’s analysis included a mine size smaller than what Northern Dynasty Minerals has articulated to investors.

Even this smaller mine size would have significant, unacceptable impacts on salmon spawning and rearing areas.

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Next Steps

Tribal Coordination
EPA Region 10 invited engagement with Alaska Native tribes and corporations. The Bristol Bay region is home to 31 Alaska Native Villages. Residents of the area depend on salmon both as a major food resource and for their economic livelihood. Nearly every household in the Nushagak and Kvichak watersheds uses salmon resources.

Public Comment Period
Public comments were accepted from July 21 until September 19, 2014.

Withdraw or Recommend
EPA Region 10 expected to either withdraw the Proposed Determination or prepare a Recommended Determination no later than February 4, 2015, following consideration of comments and the administrative record. Due to the large number of public comments received, EPA extended the 30-day decision period Exitspecified in Clean Water Act Section 404(c).

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