Bristol Bay and The Pebble Mine Project

Kaskanak Creek

One of the first things you notice from the air is a landscape is brimming with water in every direction - such as in this view of Kaskanak Creek in the Kvichak watershed.  The vast amount of aquatic habitat and the complexity of that habitat give a hint into the reasons why these watersheds harbor such large and genetically diverse salmon communities. (U.S. Environmental Protection Agency)[1]

Bristol Bay and the Pebble Mine Project Update

By Dale Mayo, September 29, 2022

The Bristol Bay region in Southwest Alaska is vast wilderness about the size of Virginia that is made up of wetlands, tundra, forests, and rivers that flow into the bay.  Alaska Natives have lived here for thousands of years, surviving on salmon, marine animals, birds, plants, and berries. The proposed Pebble Mine project – an open pit copper and gold mine - threatens to destroy the rivers and ecosystems downstream. 

In 2022, the US Congress passed the Bipartisan Infrastructure Law. This law is a major source of initial Federal investments for the America the Beautiful Challenge, which will offer states, Tribes, territories, local groups, non-governmental organizations and others to apply for grants to advance fish and wildlife conservation, strengthen climate resilience and restoration, invest in Tribal Nations and communities, support local economies and build a better America.  The Chair of the Council on Environmental Quality recently traveled to Alaska, where she visited were the Bristol Bay region and met with various groups to discuss enforcement of fishery laws and to see the impacts of climate change, and the value of restoration and recovery efforts.  Members of Tribal Nations, communities, and industry met with her to discuss the threat of the development of the Pebble Mine and efforts to create permanent protections for the waters and wildlife of Bristol Bay.[2] 

What is the Pebble Mine?

The proposed Pebble Mine is a massive, mile-wide open-pit that could become the world’s largest gold and copper mine. The site is in an unstable seismic zone prone to frequent earthquakes and the mine would use nearly 35 billion gallons of water a year – a threat to the Nushagak and Kvichak Rivers.  It could extract over a billion tons of rock – waste rock would be stored behind a dam and then buried in the pit at the end of production (in 20 to 80 years) because it can produce acidic water runoff.[3]  The mine would also require an 84-mile transportation corridor that would further endanger pristine ecosystems in southwest Alaska. Almost half of the Bristol Bay salmon production comes from the Nushagak and Kvichak River watersheds – two of the most endangered rivers in America.[4], [5], [6], [7], [8]  

Pebble Mine location and Bristol Bay

Bristol Bay Location

Alaska's Bristol Bay watershed. The star marks the location of the proposed Pebble Mine. (U.S. Environmental Protection Agency)[9]

A 2014 report from the US Environmental Protection Agency – after years of rigorous scientific research the watershed’s importance - describes how risky even a small mine would be.  The Pebble Mine project, if built, would almost certainly contaminate Bristol Bay, Alaska, which supports all five Pacific salmon species including approximately 46% of the world’s wild sockeye salmon.[10] 

The Bristol Bay watershed provides habitat for 29 fishes, more than 190 birds, and more than 40 terrestrial mammals and rare freshwater harbor seals.  All five species of Pacific salmon (sockeye, coho, king, chum, and pink) hatch and rear in fresh water, migrate through Bristol Bay to the sea and grow to adult size, and return to spawn in freshwater systems.  The Alaska Department of Fish and Game’s Gene Conservation Laboratory has determined from genetic sampling that there are 140 distinct populations of sockeye salmon that range in southwest Alaska.  The Bristol Bay commercial fishery supports 14,000 sustainable American jobs worth $1.5 billion annually. These rivers also sustain two of the last intact, sustainable, salmon-based cultures in the world and provide clean drinking water for several thousand rural residents.[11] 

Why is the Pebble Mine bad?

Almost everyone agrees that the Pebble Mine Project is a bad idea:  Democrats and Republicans alike.[12]   

Revised 404(c) Proposed Determination

On May 26, 2022, EPA Region 10 published a Clean Water Act Section 404(c) Proposed Determination to prohibit and restrict the use of certain waters in the Bristol Bay watershed (South Fork Koktuli River, North Fork Koktuli River, and Upper Talarik Creek watersheds) as disposal sites for the discharge of dredged or fill material associated with mining the Pebble Deposit.  If finalized, EPA’s Section 404(c) determination would help protect the Bristol Bay watershed’s rivers, streams, and wetlands that support the world’s largest sockeye salmon fishery and a subsistence-based way of life that has sustained Alaska Native communities for millennia.[13]


For more than a decade, the Pebble Mine project has been at the center of controversy.  More than 4 million comments supporting the protection of Bristol Bay have been submitted by conservationists, Alaska Natives, scientists, sport anglers, commercial fishers, chefs, hunters, and photographers.  The EPA can issue permanent protections for the Bristol Bay watershed from mining.[14]  This would not be done lightly, as EPA has only used the veto used 13 times in 50 years of Clean Water Act protections (and this would be the first use in Alaska).

Pebble Mine Timeline and EPA Actions To Protect Bristol Bay


Cominco discovered Pebble West


Canadian company Northern Dynasty Minerals (NDM) acquired rights to Pebble Mine


NDM discovered Pebble East


South African company Anglo American and NDM formed Pebble Limited Partnership (PLP)


Nine Bristol Bay Tribes, commercial fishermen, and sportsmen requested the EPA conduct a Section 404c Environmental Assessment study under the Clean Water Act.


Developers released preliminary assessment and environmental data

EPA began a 3-year assessment of Bristol Bay watershed


Anglo American left the project


EPA published Environmental Assessment. Issued Proposed Determination under 404(c) of the Clean Water Act for the use of the Pebble Deposit Area in Southwest Alaska as a disposal site associated with mining of the deposit. 

PLP sued the EPA and the process to add protections for Bristol Bay and its fisheries was halted.

“Bristol Bay Forever” ballot passed, which required Alaska’s legislature to approve a large-scale mine in Bristol Bay.


State of Alaska Department of Natural Resources issued PLP permit renewal; required $2 million reclamation bond.


EAP and PLP settled: Pebble dropped suits and EPA halted 404(c) action.


After hearing from stakeholders and the people of Alaska, EPA reversed again:  suspended the process to withdraw proposed restrictions on mining.


US Army Corps of Engineers issued a Draft Environmental Impact Statement and reviewed the Pebble Mine Permit Application.


EPA withdrew its 2014 Proposed Determination issued under section 404(c).


Army Corps of Engineers released it final Environmental Impact Statement and denied the project a permit for its discharge plan.


Alaska District Court allowed EPA to move forward with next steps in the Bristol Bay Clean Water Act Section 404(c) process for the Pebble Deposit in Southwest Alaska.


EPA Region 10 published a Clean Water Act Section 404(c) Proposed Determination to prohibit and restrict the use of certain waters in the Bristol Bay watershed (South Fork Koktuli River, North Fork Koktuli River, and Upper Talarik Creek watersheds) as disposal sites for the discharge of dredged or fill material associated with mining the Pebble Deposit. After extending the time for public comment, received more than 500,000 comments.

Currently awaiting EPA decision.


The EPA’s move to ban mining the Pebble deposit in the Bristol Bay watershed brought up questions about whether the proposed Clean Water Act veto could stop all mining in the region. The veto, however, is limited to certain headwaters (two watersheds) within a 309 square mile area around the 2020 Pebble Mine plan – a move that would stop the mine from permanently damaging 99 miles of stream habitat and more than 2,000 acres of wetlands. Other mine claims within that restricted area will not be affected by the restriction - only mining the Pebble deposit, and only if dredging and filling of wetlands and streams associated with mining would have similar or greater effects to any one of the “adverse effects” EPA identified the 2020 mine plan would cause.[15] 

Sockeye Salmon in Bristol Bay

Sockeye salmon in the Bristol Bay watershed (US EPA)[16]

Salmon from a wild, sustainable source

The Bristol Bay helps to provide a sustainable source of wild caught Alaska salmon.  Eating high-quality, sustainably sourced seafood is not only good our customers, but also for earth.  We hope that Bristol Bay will be protected and that the world’s sockeye salmon supply will not be cut in half by the likely disaster that Pebble Mine would bring.



[3]   Cornwall, W. (2020). Critics blast U.S. study finding huge Alaskan mine poses little environmental risk. Science, July 24, 2020.


[5] Daley, Jason. These Are America’s ten most endangered rivers. Smithsonian Magazine. April 11, 2018.

[6] Main, Douglas. The risky plan to haul minerals from a mine in the Alaskan wilderness. National Geographic. January 14, 2020.

[7] Developers say Pebble Mine won’t hurt Alaska's Bristol Bay. The facts say otherwise. World Wildlife Fund. April 30, 2020

[8] Alaska’s Bristol Bay & The Pebble Mine. Earthjustice. October 9, 2019.

[9] also see

[10] U.S. Environmental Protection Agency (2014) An Assessment of Potential Mining Impacts on Salmon Ecosystems of Bristol Bay, Alaska (Report No. EPA 910-R-14-001ES). Region 10, Seattle, WA.

[11] American Rivers. Protect Bristol Bay’s Rivers.




[15]   Holzman, J. and Wittenberg, A. (2022). EPA’s Pebble ‘veto’ won’t stop all mining in Alaska’s Bristol Bay. E&E News_Greenwire. May 27, 2022.



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