Hakai Magazine

Coastal science and societies

Aereal view of glaciers and shoreline of Kamishak Bay and Mount Douglas, Katmai National Park, Cook Inlet, Alaska
The construction of the proposed Pebble Mine in Alaska would also involve the construction of a new port in the largely untouched Kamishak Bay. Photo by Loetscher Chlaus/Alamy Stock Photo

Pebble Mine’s “Woefully Inadequate” Plan to Compensate for Destroying Salmon Habitat

A wide range of experts are critiquing the proposed Alaska mine’s lackluster environmental compensation plan.

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by Ashley Braun

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For any infrastructure project in the United States that would affect wetlands—from building roads to mining gold—the Clean Water Act requires two things: avoid or minimize damage to the aquatic environment, and, where that fails, provide what’s known as compensatory mitigation.

In the case of the proposed Pebble Mine, scientists and former regulators say the compensatory mitigation plan put forth by the Pebble Limited Partnership (PLP)—which involves projects such as improving wastewater treatment in nearby towns and cleaning debris from beaches—falls far from offsetting the damage that would be caused by the mine. They say that PLP’s plan lacks in its scientific justification.

If the construction of the Pebble Mine and its supporting infrastructure is federally approved—a decision to be made by the US Army Corps of Engineers (USACE), likely in late summer—a draft mitigation plan put together by PLP says this work would damage more than 1,214 hectares of wetlands. It would also destroy nearly 15 kilometers of salmon-supporting streams in a nearly undeveloped corner of southwest Alaska that’s home to one of the world’s largest sockeye salmon fisheries.

To make up for this, the owner of the proposed copper and gold mine has offered to shore up sewage treatment systems in three rural villages, replace culverts impeding salmon passage in remote areas, and haul away trash from the western shores of the lower Cook Inlet.

Tom Yocom, who spent two decades working on Clean Water Act permitting in the wetlands program of the US Environmental Protection Agency (EPA), says, “the mitigation that’s being offered is woefully inadequate.”

“If it had come across my desk, the permit applicant would have been told on day one: if this is the best you can do, don’t waste your money,” says Yocom.

In most places in the United States, a company would offset the destruction of wetlands by restoring or preserving either the same or a greater area of wetlands—preferably of the same type and in the same watershed. But in 2018, the EPA and USACE decided that Alaska is a special case. The agreement spells out regulatory “flexibility” for wetland mitigation in Alaska, a state where healthy habitats abound and options for restoration are less common than in the lower 48 states.

The Pebble Mine is slated to be built in a practically pristine watershed, one so packed with flourishing wetlands that the company is hard-pressed to find any needing restoration or preservation—excluding those threatened by this mine. That’s why PLP has taken this tack, turning to projects often far from the site and that don’t plug well into the usual ecological equations.

One project aims to boost water quality by improving wastewater treatment in Kokhanok, Newhalen, and Nondalton, located in the sprawling and sparsely populated Lake and Peninsula Borough.

According to borough manager Nathan Hill, because the borough is an official stakeholder in USACE’s environmental review process, it saw an opportunity to connect PLP’s need for mitigation opportunities with the region’s need for better water treatment, which environmental policy experts emphasize is regulated separately under the Clean Water Act.

“We presented the information that we had to Pebble and basically acted as a conduit,” Hill says, with the caveat that the villages could decide whether or not to accept the projects. He also notes that upgrading sewage systems, as a way of making up for destroying wetlands, wouldn’t be a first for Alaska. (Though it would only be the second.)

Gail Terzi, a retired compensatory mitigation program manager for USACE who has worked in Alaska, is sympathetic to these villages’ plight. But she echoes Yocom’s harsh assessment of PLP’s proposed mitigation plan.

“They’re not using science here. Because if they were using science, they could not permit the project,” says Terzi. “I just don’t see how they’re going to get there without cheating and ignoring all the science.”

She also slammed the 2019 USACE decision that paved the way for trading sewage treatment improvements for bulldozing wetlands. “I can’t even tell you how dangerous this is,” Terzi says.

Along with planning to fix sewage systems, PLP has also scanned a state database to find hundreds of culverts that are partially blocking salmon access to streams. Its proposed compensatory mitigation plan says the company will replace enough shoddy culverts to open up 13.5 kilometers of existing streams to the fish, though the vast majority are far from the area the mine would affect.

Finally, PLP has offered to remove marine debris, such as fishing nets, plastic bottles, and buoys, from 12 kilometers of shoreline near the site of its proposed port in Kamishak Bay. After five years, PLP would survey the beaches again to determine how much more debris had accumulated, and potentially do additional cleanups.

While marine debris removal may sound like “just going out and picking up a lot of litter … it’s a lot more than that,” says Tami Wells, who runs a small environmental consultancy. Debris cleanup has several potential benefits, she says, such as reducing microplastics in seafloor sediments, improving biodiversity and ecosystem productivity, and preventing wildlife entanglement.

Mike Heatwole, a PLP spokesperson, says the company is “confident all of the projects will improve the overall fish and aquatic environment.”

However, Wells says whether PLP’s efforts would make up for the damage caused by the mine’s construction and operation depends on the details—something the proposed mitigation plan is short on. “There’s just not enough information,” she says.

Typically, for a compensatory mitigation plan to pass muster, it has to spell out what functions those lost wetlands play in the ecosystem—the three big ones are water quality, water quantity, and habitat—and use an ecological accounting of debits and credits to show precisely how mitigation would balance each particular loss. But there’s no metric for converting acres of lost wetlands to kilometers of beach cleanup or upgraded sewage systems, and PLP’s plan hardly seems to try, says Yocom.

David Hobbie, USACE regulatory division chief in Alaska, stresses that the corps will not necessarily accept PLP’s proposed mitigation plan. He says USACE has told PLP that the plan needs improvement, but has not yet spelled out the final requirements for mitigation.

While the EPA, and select local, state, and federal agencies will offer feedback on the plan, according to USACE, the public’s last chance to weigh in on the entire mine proposal was last July, six months before the plans for these mitigation projects were released. With so many details still unknown, Yocom says, it appears that exactly how PLP plans to offset the mine’s impact will remain a black box until USACE’s final decision later this year. “That’s not how it’s supposed to work,” he says.