EPA’s Final Determination 12/2022? https://www.federalregister.gov/documents/2022/05/26/2022-10976/proposed-determination-to-prohibit-and-restrict-the-use-of-certain-waters-within-defined-areas-as
"Construction and routine operation of the mine proposed in the 2020 Mine Plan would result in discharge of dredged or fill material into waters of the United States, including streams, wetlands, lakes, and ponds overlying the Pebble deposit and within adjacent watersheds. The direct and certain secondary effects of such discharges would result in the total loss of aquatic habitats important to anadromous fishes. These losses are the result of the construction and routine operation of the various components of the mine site, including the open pit, bulk tailings storage facility, pyritic tailings storage facility, power plant, water management ponds, water treatment plants, milling/processing facilities, and supporting infrastructure. According to the FEIS and ROD, discharges of dredged or fill material to construct and operate the mine site proposed in the 2020 Mine Plan would result in the total loss of approximately 99.7 miles (160.5 km) of stream habitat, representing approximately 8.5 miles (13.7 km) of streams with documented anadromous fish occurrence and 91.2 miles (146.8 km) of additional stream habitat. Such discharges of dredged or fill material would also result in the total loss of approximately 2,113 acres (8.6 km2 ) of wetlands and other waters at the mine site.
Additional secondary effects of the proposed discharges of dredged or fill material at the mine site would degrade anadromous fishery areas downstream of the mine site. Specifically, the stream, wetland, and other aquatic resource losses from the footprint of the 2020 Mine Plan would reverberate downstream, depriving downstream anadromous fish habitats of nutrients, groundwater inputs, and other ecological subsidies from lost upstream aquatic resources. Further, streamflow alterations from water capture, withdrawal, storage, treatment, or release at the mine site are another secondary effect of the discharge of dredged or fill material associated with the construction and routine operation of the 2020 Mine Plan. Such streamflow alterations would adversely impact at least 29 miles (46.7 km) of anadromous fish streams downstream of the mine site due to greater than 20 percent changes in average monthly streamflows. These streamflow alterations would result in major changes in ecosystem structure and function and would reduce both the extent and quality of anadromous fish habitat downstream of the mine. All instances of complete loss of aquatic habitat and most impairment to fish habitat function would be permanent.
EPA Region 10 believes that the discharge of dredged or fill material associated with mining the Pebble deposit within the mine site footprint for the 2020 Mine Plan could result in unacceptable adverse effects on anadromous fishery areas in the SFK and NFK watersheds due to losses of documented anadromous fish habitat and degradation of downstream anadromous fish habitat."