Final Pebble mine EIS maintains early Corps conclusions

  • Pebble Limited Partnership spokesperson Mike Heatwole is seen overlooking the mine deposit in this 2013 file photo. (Photo/Andrew Jensen/AJOC)

U.S. Army Corps of Engineers officials describe the Pebble mine as one that would remove 99 miles of fish habitat at the mine site but poses little risk to the broader area in the project’s final environmental impact statement released July 23.

The conclusion mirrors what was written in excerpts of the preliminary final EIS leaked to the public in February.

Pebble Partnership CEO Tom Collier said both the preliminary and final documents support the company’s assertion that the mine could operate in harmony with the region’s famed salmon fisheries.

“Alaskans have demanded that Pebble, and any Alaska resource development project, meet its high standards before the project could advance. Today, we have passed a critical milestone on that journey,” Collier said in a July 24 statement.

He said the EIS process has been thorough and called criticism of the Corps’ work on the project “unfortunate,” insisting that the mine can be a source of year-round jobs in an area without many.

The final EIS is the last step in the federal review of the project before Corps officials reach a conclusion on the key record of decision for the project: whether it is an acceptable development plan based on the issues studied in the EIS process.

Pebble says it will work through state permitting over the next three years before commencing a four-year construction period for what is now planned as a 20-year mine.

Project opponents contend the Corps limited its focus to environmental impacts at the mine site and ignored potential downstream effects, particularly to fisheries, in the draft EIS. They allege the process has been rushed to fit within the timeframe of President Donald Trump’s term in office following an attempt by the Obama administration to preemptively veto the project via Environmental Protection Agency authority.

The EPA ultimately has the authority to reject the Corps’ decision on Pebble’s Clean Water Act Section 404 wetlands fill permit application, which triggered the EIS in 2018.

Corps officials responded to concerns from the commercial fishing sector that the mine would damage the perceived quality of Bristol Bay salmon and ultimately lower its market value by noting that some of the state’s other fisheries are conducted alongside resource development.

“Prices paid in Bristol Bay are nearly always lower than those paid in other Alaska salmon fisheries producing similar products, which reflects the higher transportation expense associated with Bristol Bay’s geographic location and the lack of a strong brand identity, which could boost prices,” the EIS states.

“(T)he Cook Inlet salmon fisheries exist in an active oil and gas basin and have developed headwaters of Anchorage and the Matanuska-Susitna areas. The Copper River salmon fishery occurs in a watershed with the remains of the historic Kennecott copper mine and the Trans-Alaska Pipeline System in the headwaters of portions of the fishery. Both fisheries average higher prices per point than the Bristol Bay salmon fishery.”

It concludes that there would be “no measurable change” in the numbers of salmon returning to the Nushagak and Kvichak rivers or in the long-term health of the commercial fisheries in the region.

At the mine site, approximately 99 miles of fish habitat, part of roughly 2,200 acres of permanently impacted wetlands, would be destroyed in the combined North and South Fork Koktuli drainages, which feed the Nushagak River and support all five species of Pacific salmon. However, the expected losses of wetlands at the mine site represent just six percent of the mapped wetlands in the Koktuli, according to the document.

Bristol Bay Native Corp. CEO Jason Metrokin noted the impacts of the current plan represent mining just a small portion of the copper-gold ore body and leaders of Pebble’s parent company, Vancouver-based Northern Dynasty Minerals Ltd., have long pitched additional development to investors.

“Put simply, the EIS does nothing to alleviate our concerns about the myriad risks Pebble would pose to Bristol Bay’s watershed, salmon, way of life, and economy,” Metrokin said in a statement.

Staff scientists for the Environmental Protection Agency, Interior Department and several state agencies were highly critical of apparent gaps related to wetlands, hydrology and fish habitat data in official comments on the draft EIS.

Interior scientists went as far as to suggest the Corps should rewrite the voluminous document in light of the omissions.

Corps officials said in response that the agencies’ comments would be considered alongside all others.

The final EIS states that gaps in wetlands data identified by other agencies and stakeholders in the draft EIS published in February 2019 have been filled.

Corps officials wrote in the EIS they do not believe it is necessary to analyze the likelihood that the mine’s proposed tailings dams could fail — a primary concern of mine opponents — because the Pebble Partnership is designing the dams differently than those that have failed at other mines in recent years and attracted global attention.

“Modeling of a catastrophic, very low-probability tailings release was requested by commenters, but deemed inappropriate based on the applicant’s permeable flow-through design for the tailings storage facility (TSF) main embankment, compared with historical water-inundated TSFs that have been subject to large-scale failures,” the EIS states.

Corps officials have also said in media briefings that a detailed review of the tailings dams would be done by the state under the Department of Natural Resources Dam Safety Program.

DNR officials wrote in March comments on the preliminary final EIS that a full breach of a large and well-designed and operated tailings dam is very unlikely, but asserted that Pebble’s mine waste storage plan high-level and key aspects of it could be impractical.

According to the comments, Dam Safety officials believe the Corps’ use of a subject risk analysis process in the preliminary final EIS to study tailings and water management pond dam failure scenarios was “based on a marginally developed, conceptual design, and the exclusion of other risks including the other relatively large, water management dams, does no represent a thorough assessment of risk from potential failure modes and potential impacts.”

The pre-final EIS comments from DNR’s Dam Safety Unit also state that Pebble’s plan to move pyritic, or potentially acid-generating, mine tailings from a temporary storage facility into the pit at mine closure “does not appear to be reasonable, practicable or safe” because filling the pit would preclude accessing other parts of the deposit.

Additionally, the tailings are likely to consolidate over years in a storage pond, making them more difficult and costly to extract, according to the Dam Safety Unit comments.

The EIS highlights Pebble’s plan to drain and thicken the bulk tailings — which has caused critics and regulators to question whether the company can constantly treat the large volume of water — as a design element likely to limit the downstream flow of tailings in the event of a spill. However, Corps officials also acknowledge in the document that the ground waste rock may not settle as expected and it could only be confirmed if the tailings system was working as intended after about two years of operation.

Additionally, the corridor identified as the least environmentally damaging route for a road to a port on west Cook Inlet needed to supply the mine remains viable despite the fact that some of the Alaska Native corporations that own land in the corridor are some of Pebble’s staunchest opponents, according to the EIS.

In late May, Corps officials announced they had identified a road route along the north shore of Iliamna Lake to a port on the west side Cook Inlet as the least environmentally damaging practicable alternative, or LEDPA, for the expansive mining plan in its environmental impact statement review. Until that point, Pebble had long promoted its plan for a year-round, ice-breaking ferry across the lake to shuttle supplies and metal concentrates to and from the mine site to the north of the lake.

Alaska Native village corporation Pedro Bay Corp. owns much of the land along Iliamna’s northeastern corner and along with regional Bristol Bay Native Corp. — which holds the subsurface rights to Pedro Bay Corp. property — has opposed to the project for years and insists Corps officials are discounting the fact that Pebble does not have access to the area.

Army Corps Alaska District Regulatory Chief David Hobbie said in a July 20 call with reporters before the release that Pebble officials maintain they believe they can gain access to the area so the agency considers the route viable.

The EIS states the Corps has determined that “even though some alternatives may not be available to the applicant at this time, the alternatives remain reasonable under (National Environmental Policy Act) guidelines and are retained in the EIS.”

Economic review unlikely

Opposition groups and some technical observers of Pebble’s complex plan question the economics of it, particularly given the scaled-back, 20-year mine, and have pointed to the lack of an independent economic assessment as justification for the skepticism, but Collier said in an interview that that one is unlikely to come at this point.

That’s because Northern Dynasty Minerals is past the stage of seeking the retail or institutional investors that would find a public economic assessment of the project valuable, Collier said. At this point, the junior mining firm is focused on attracting a large partner to help fund development.

“A major mining company isn’t going to give two wits about a PEA (preliminary economic assessment),” he said, adding any interested company would conduct its own evaluation and it would be costly for Pebble to hire the required independent analysts.

Northern Dynasty ended the first quarter with $7.2 million Canadian in cash, according to its latest quarterly report.

Canadian finance law prohibits the company from disclosing its internal projections, he said.

Collier told the Journal in the spring of 2018 — shortly after Pebble filed its permit application — that Pebble would likely publish a PEA by the following winter.

Opponents have urged the Corps to demand economic information from Pebble so it can be better known which of the development options are truly viable.

Project managers for the Corps have said they would like to have the estimates but they are not required for the EIS.

Editor's note: This story was updated for the Aug. 2 edition of the Journal that went to press July 29.

Elwood Brehmer can be reached at [email protected].

Updated: 
07/29/2020 - 9:17am