Pay attention to multiple government actions. https://www.federalregister.gov/documents/2022/04/20/2022-08288/national-environmental-policy-act-implementing-regulations-revisions
Opinion: Unless EPA withdraws the watershed from ANY mineral development by issuing a restrictive Final Determination, or the proponent's appeal is rejected, the law allows for the proponent to resubmit a new 404 permit application subject to NEPA review (possible new/supplemental EIS). However, if the resulting new (or current) 404 permit application were to be approved, EPA can withhold 401 Water Quality Certification though EPA would likely not allow this process to reach this point. Given Trump’s NEPA process reversal by Biden, any new EIS would include cumulative foreseeable impacts (all related and connected activities) and mining method alternatives. Trump’s change to the NEPA process was arbitrary and not based on a full understanding of public disclosure needs.
Any increase in the size of the original open pit (small mine) resulting from a new 404 permit application submittal would significantly increase environmental impacts and long-term post-closure maintenance. Hence, likely the issuance of another negative ROD.
Underground mining only while incorporating paste tailings and ARD waste rock backfilling is the only hope for this resource to be developed, albeit a non-starter if the watershed is restricted from mining by the EPA.
Economics are not a consideration during the NEPA process. It is incumbent on the proponent to evaluate mine plan economics under various mining scenario's. If the proponent’s strategy was to permit the “smaller mine” based on positive economics of mining the entire resource to circumvent the NEPA/permitting process the project is doomed on their account.
It is obvious the Biden administration is seeking to prohibit any mining in the watershed, or at least the proponent’s current proposal.