Montana Fish, Wildlife & Parks is poised to tell the public not to eat any rainbow trout caught in the Clark Fork River below the Smurfit Stone mill site. But more sampling is needed to know how much farther the advisory should apply.

After finally grinding through data received in September from the U.S. Environmental Protection Agency, Trevor Selch, Fish, Wildlife & Parks fisheries pollution biologist, is pretty certain further limits need to be placed on rainbow trout in the fish consumption advisory for the Clark Fork River.

“This has kind of been a delayed presentation. But dioxins are a different beast, and so is getting all the data synthesized so we could analyze it. It’s not as simple to interpret as some other contaminants as we look at,” Selch told the Frenchtown Smurfit Stone Community Advisory Group on Thursday night. “I still have to talk to a few superiors, but we hope to get an announcement out pretty soon. But, I don’t see any of these numbers changing, so this is probably what it’s going to be.”

The current consumption advisory FWP issued in 2013 told people to avoid eating pike caught in the Clark Fork River below Missoula and to limit rainbow trout to four meals a month. But, based upon the toxins found in fish tissue from sampling efforts in 2018 and 2019, the advisory should now tell people to avoid all rainbow trout and pike from the river from the confluence with the Bitterroot River to the confluence with the Flathead River.

The new advisory doesn’t have to be issued right away, because Montana doesn’t allow anglers to keep any trout until the fishing season opens again in the spring. So no one should be eating any fish from the river in the meantime.

Selch said his results had a few surprised but confirmed what biologists noted a few months ago looking at the raw data: rainbow trout caught near St. Regis, the farthest sample site downstream from Smurfit Stone, had the highest contamination of any samples along the river. Also, the toxins in the trout were linked to those produced by the pulp mill.

Selch would have expected to see such high concentrations in larger predatory fish such as pike or bull trout, because toxins accumulate when such fish eat a lot of smaller fish. But he was surprised to see such high concentrations in all size classes of rainbow trout near St. Regis.

Upstream from the Smurfit Stone site, near East Missoula, both rainbow trout and pike samples had some contamination, such that people should limit the number of trout meals to one a month. The explanation is probably that East Missoula is still close enough to Frenchtown that contaminated fish are moving upstream from the mill site.

Selch had to sample even farther upstream in the Blackfoot River near Greenough to find fish that are minimally contaminated.

He also expected to find minimal contamination a similar distance upstream on the Bitterroot River, but that’s not what was found near Lolo. The data shows that people should not eat more than one or two large rainbow trout a month or three to four smaller Northern pike. Pike longer than 26 inches should not be eaten.

“The Bitterroot fish were supposed to show the background (levels),” Selch said. “There is a state Superfund site (near Darby) with dioxins, but there hasn’t been any evidence of that contributing to the river. But there’s definitely concentrations there that we weren’t expecting to see.”

Several side channels and oxbows crisscrossed the floodplain between large stands of cottonwood trees on the north side of the river. Now it is largely denuded and carved into wastewater ponds. (Missoula County file photo)
Several side channels and oxbows crisscrossed the floodplain between large stands of cottonwood trees on the north side of the river. Now it is largely denuded and carved into wastewater ponds. (Missoula County file photo)

The fish tissues were assessed for dioxins, furans and dioxin-like PCB’s that are produced during the manufacture of paper and cardboard. The Darby site is another pulp mill owned by International Paper, one of the Smurfit Stone potentially responsible parties, but it isn’t near any stream so it’s probably not contributing to river contamination. But now, more information is needed.

Because fish contamination levels are so high near St. Regis, David Schmetterling, FWP Fisheries Research Coordinator, is concerned about how much farther the contamination might extend downstream.

Plus, biologists sampled only two fish that people would likely eat, pike and rainbow trout. But the toxins are probably affecting other species that wildlife eat, such as mountain whitefish or bull trout.

Bull trout can’t be sampled because they are a threatened species, but Mary Price, Confederated Salish and Kootenai Tribes Legal Department scientist, asked if other fish could be a good surrogate for bull trout, especially for when the EPA does the ecological assessment. She also wondered how the contamination affects wildlife that eat fish, such as raptors or otters.

Schmetterling said pike might be a surrogate, but not much is known how any fish population reacts to dioxins and PCB’s except that reproduction is reduced. To answer all these questions, he said more sampling is necessary.

“We weren’t able to complete the sampling we intended in 2019, so we’d want to finish that. But also cover a larger spatial extent, going downstream farther, going upstream farther,” Schmetterling said. “We’ve only done preliminary sampling. This is what we’d hoped to do in 2014, after what we’d learned from 2013. I thought by 2021, we’d have a much greater understanding of what’s going on.”

But EPA project manager Allie Archer said the EPA wasn’t planning on any additional sampling .

“When we work with everyone to identify potential data gaps to the remedial investigation, we could (sample) at that time or during the feasibility study. But there’s no plan to sample now to complete what we need for Superfund,” Archer said. “I don’t want to say that there’ll never be any more samples – we’re still working through that full characterization over the next year to put together our report. But to finalize our risk assessments, we won’t be collecting any more data.

Archer’s answer means if any sampling is done, it’s at least a year or two out, which could extend the process, already going on 10 years, even further.

Schmetterling told the Missoula Current he had hoped that EPA sampling could be more continuous, so they could learn about the extent of contamination faster.

The EPA is focused only on the Smurfit Stone site to decide what cleanup work to be done, and now they’ve collected enough information for that. But there’s potentially a larger effect on the Clark Fork River beyond the mill site that would need to be part of the remediation, Schmetterling said.

FWP could sample below St. Regis on its own, Schmetterling said, but the EPA has already shown a reluctance to accept data from samples it doesn’t gather itself. The EPA almost didn’t use the 2018 data from sampling that was primarily FWP’s responsibility.

“The reason we want the EPA involved is so they can use (the data), that they accept it and they have buy-in with it. It’s not like we’re trying to foist off responsibility or work,” Schmetterling said. “We have been showing these contaminants are on the landscape, and we don’t know they’re from the site. But there’s enough information to warrant further investigation. We’ve just done preliminary work.”

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