New Study Reveals High Pollution Levels in This Montana River

Missoula, MT (KGVO-AM News) - Montana Fish Wildlife and Parks has released results from an ongoing water quality study on the Clark Fork River stating that “pollution is more prevalent that initially thought”, and that fish consumption should be avoided.

Similar pollution studies resulted in a fish consumption advisory in 2020.  The area where fish consumption should be avoided is currently the Clark Fork River from the Bitterroot River to the Flathead River.  The more recent water quality data collected in 2023 is from an expanded area on the Clark Fork, from the headwaters to the Idaho border.  Fish tissue analysis is not complete, so an updated consumption advisory is not available yet.

I spoke with FWP Fisheries Pollution Biologist Trevor Selch on Tuesday about the results of the water quality studies.

“This study stemmed from working with EPA (the Environmental Protection Agency) in 2018 and 2019, collecting fish for them to service their ecological and human health risk assessments,” began Selch. “Coming out of that data collection with those fish was that we ended up issuing an ‘avoid all fish consumption’ (recommendation) on the Clark Fork from the confluence with the Bitterroot River to the confluence with the Flathead River.”

The Recommendation is to Avoid Fish Consumption in Certain Areas on the River

Selch further defined the parameters of the study of the Clark Fork from the confluence with the Bitterroot River to the Flathead.

“These are an estimated concentration that we detected, but they are well below any human health concern from a drinking water perspective,” he said. “However, what we're looking at in the fish and again the data from the fish is still getting qualified, the concentrations bio accumulate into the fish tissues and that's where they become a human health concern.”

Selch described the area of concern to Montana Fish, Wildlife and Parks.

“In Missoula, folks are familiar with the wastewater treatment plant there on the Clark Fork, and then Maclay Flats is where the where the Bitterroot River comes in there,” he said. “So it's downstream of where the wastewater treatment facility is that the Bitterroot kind of comes in connection with the Clark Fork. So that's on the downstream end of town, and there is where that advisory starts, from the confluence with the Bitterroot River all the way down to the confluence with the Flathead, and that's based on guidance we issued in 2020.”

FWP wants Montanans to be Aware of the Possible Danger

Selch said the effort is already underway to get this information out to residents and recreationists in western Montana, so that all can be better informed of the risks involved in consuming fish in those waters.

“With this study, we've already had a couple of public presentations,” he said. “I've been presenting information so far to the Frenchtown Community Advisory Group, and we just issued a press release yesterday (Monday) on the topic to let folks know. We've actually already based on that 2020 guidance, and many of our fishing access sites have signs recommending people to avoid consumption at all of those access points. That's the outreach we've had thus far. And, as new data comes in, we actually have a lot of events planned to get this information out to folks.”

READ MORE: Wood-products pollution found at numerous Clark Fork locations

Consumption of Fish out of the Clark Fork is Not Recommended

Montana Fish, Wildlife and Parks wants all those enjoying the rivers in the area to be aware that consumption of fish in the targeted areas is allowed, but not recommended at this time.

Partners in the study include Missoula Public Health, the Confederated Salish and Kootenai Tribes, Trout Unlimited, the Clark Fork Coalition, and the Montana Department of Justice Natural Resource Damage Program.