The Pebble copper and gold project has a new PEA, providing new cost and price estimates and detailing a new infrastructure plan.

The Pebble deposit is located at the headwaters of the Bristol Bay watershed in southwest Alaska. Its developers have called it the “world’s largest undeveloped” resource of copper, gold, molybdenum, silver and rhenium – but development of a mine at the Pebble deposit has been the subject of debate for nearly two decades. 

The protracted dispute over the development of a mine at Pebble is on environmental grounds. Bristol Bay boasts wild salmon runs, where fish migrate back to freshwater from the ocean and dissolved metals, and in particular copper, can be dangerous for salmon. The debate has seen national attention with President Joe Biden stating that Bristol Bay’s headwaters were “no place for a mine” when on the campaign trail. 

In January 2023, the US Environmental Protection Agency issued a “Final Determination” under its Clean Water Act Section 404(c) authority to limit the use of certain waters in the Bristol Bay watershed as disposal sites for certain discharges of dredged or fill material associated with development of a mine at the Pebble deposit in January 2023.  In the 50-year history of the Clean Water Act, the EPA has used its Section 404(c) authority sparingly, with the Pebble decision being the third time in 30 years, and only the fourteenth time in the history of the Clean Water Act.

It is in this context that the PEA has been published and Northen Dynasty Minerals note that it was prepared to accomplish several objectives. It provides cost and price estimates to reflect current economic volatility, includes an infrastructure plan that uses the “southern route” for project access as defined in the original permitting application for the project, and updates the status of the Environmental Protection Agency (EPA) Final Determination and United States Army Corps of Engineers (“USACE”) Record of Decision Appeal processes.

The 2023 PEA assumes that project developers will ultimately be able to obtain the required Federal government and State of Alaska permits to enable development but does not account for any additional capital or operational costs that may be necessary to obtain the required permits, should adjustments to the operating or environmental mitigation plans be required.

The project would be capable of processing 1.3Bnt of mineralized material over 20 years of mining at a low strip ratio of 0.12:1, with an average annual mine operating cost of US$14.17/t. Average metal production is forecast to be 145ktpy copper, 6,800tpy molybdenum, 10tpy of rhenium in addition to 1.8Mozpy of silver and 368kozpy of gold.

It is perhaps the highest profile example of permitting issues in the USA at present, at a time when many are lobbying government for a streamlined permitting progress to make it more viable to source the critical materials required for energy transition domestically.