EPA completes 404(c) process with a final determination to protect Bristol Bay

The U.S. Environmental Protection Agency has determined that certain activities associated with development of the proposed Pebble mine “will have unacceptable adverse effects on certain salmon fishery areas in the Bristol Bay watershed.” As a result, the EPA issued a Final Determination, the last step in a long process to use its authority under the Clean Water Act 404(c) to establish protections near the Pebble deposit.

Alaska Native communities and others first asked EPA to use its 404(c) authority to protect Bristol Bay in 2010. The agency has only used this authority 13 times in the past.

According to the Final Determination, these are the specific prohibitions/restrictions:

  • Prohibits the specification of certain waters of the United States in the SFK and NFK watersheds as disposal sites for the discharge of dredged or fill material for the construction and routine operation of the 2020 Mine Plan. This includes future proposals to construct and operate a mine to develop the Pebble deposit with discharges of dredged or fill material into waters of the United States anywhere at the mine site that would result in the same or greater levels of aquatic resource loss or streamflow changes as the 2020 Mine Plan.
  • Restricts the use for specification of certain waters of the United States in the SFK, NFK, and UTC watersheds as disposal sites for the discharge of dredged or fill material associated with future proposals to construct and operate a mine to develop the Pebble deposit with discharges of dredged or fill material into waters of the United States that would result in adverse effects similar or greater in nature and magnitude to the adverse effects of the 2020 Mine Plan.

In other regulatory activity related to Pebble mine permitting, the U.S. Army Corps of Engineers denied the project a key 404 permit in 2020. An appeal of that decision still under review.

The EPA’s Final Determination is expected to result in litigation from developers and the State of Alaska.

Map of restricted and prohibited areas from the Executive Summary of:
USEPA (U.S. Environmental Protection Agency). 2023. Final Determination of the U.S Environmental Protection Agency Pursuant to Section 404(C) of the Clean Water Act, Pebble Deposit Area, Southwest Alaska. Office of Water, Washington DC.

Read more:

Fact Sheet on the Final Determination (2 pp)

Executive Summary (27 pp)

Full text of the Final Determination (435 pp)

Read the EPA’s response to comments on the May 2022 Proposed Determination (966 pp)