The state started new work this week to prevent toxic metals in century-old mine waste from seeping into the Upper Clark Fork River.
On a warm August morning, representatives of Montana Fish, Wildlife and Parks, the state’s Natural Resource Damage Program, and the nonprofit Clark Fork Coalition and I set out on a bright green raft for a float just south of Deer Lodge.
We’re on a scouting trip, to find where some of the most pressing work on the largest complex of Superfund sites in the country is about to begin. The decades-long cleanup of the area’s industrial past sprawls from Butte to Missoula.
Not long after we push off, the crew spots something potentially ominous: a dead sculpin, floating on the surface of the water.
Nathan Cook, fisheries biologist at FWP, says there’s no way to know what killed this particular fish. But last fall, a lot of trout turned up dead on this stretch of river. Cook floated through to assess the damage.
“We counted 32 dead fish,” Cook says. “I’m sure that was only a small fraction of actually the number of fish that were affected."
He says all that death was likely a result of a combination of factors. At the time water was low, and temperatures were high — which means stressed out fish.
But Cook suspects another ingredient was the nail in the aquatic coffin, and that’s what we came here to see.
Alex Leone, restoration specialist with the Clark Fork Coalition, spots what’s called a “slicken” through the brush on the side of the river. Slickens are wedges of the otherwise vibrant floodplain that are totally barren due to the high concentrations of heavy metals deposited there.
We eddy out and step ashore to take a look.
“When you’re on the river, and you’re floating through this reach, unless you got out you wouldn’t even know this is here,” Leone says.
The ground is bare and brown, except for a spot where it looks like someone spilled a bucket of paint all over the place. Beau Downing, the Upper Clark Fork Restoration Project Manager at the state’s Natural Resource Damage Program within the Montana Department of Justice, looks closer at the ground.
“Imagine the Statue of Liberty, that really greenish-blue oxidized copper look. And imagine if you just scraped her off and threw it onto the floodplain of the river,” Downing says. "That's really what it looks like."
He says that dried-out Statue of Liberty puddle kills a lot of things.
Huge floods over a century ago blasted through the Upper Clark Fork, and deposited mine waste here all along the floodplain. Among other contaminants, the slickens are laden with copper and zinc, which devastate marine life; and arsenic and lead, which can have major human health impacts. These metals, dried out by the summer sun, give the soil here this hue of psychedelic blue.
When storms come, a toxic slurry gurgles past eroded berms built in the 80s, and the metal-laden water flows right into the Clark Fork. These leaky slickens, all three researchers think, are the key ingredient to that fish kill last year, and also a cause of slower, but pervasive ongoing damage to the ecosystem as a whole. So this is what they’re trying to fix.
Blue flagging waves at the places the work is about to begin.
“We're gonna come in behind the berm and the contractor is going to basically dig a six-inch deep trench and pull that material back,” Downing says.
Then, they’ll put down biodegradable fabric made of coconut husk, and stake in straw bales. The new barriers will keep that sludge of toxic rainwater from running into the river, and the straw and fabric should filter most of the nasty stuff out of anything that does make it through.
“The idea is to keep these metal-laden waters from making it directly to the river,” Downing says.
We hit the river again.
This $30,000 straw-bale berm project started Monday, and is meant to be a short-term measure to stave off more fish kills and contamination from the half-dozen most high risk slickens.
“They’re gonna buy us a year and half until DEQ can actually get in here and actually remove the contaminants and remove the banks and the point bars and things,” Downing says.
He describes the timeline of all the work that’s gone on here.
A court settlement between the Atlantic Richfield Company and the State of Montana allocated about $100 million to clean up 47 miles of the Upper Clark Fork. That work officially began in 2012, and the state has completed several phases of cleanup. But the work turned out to be much larger in scope and more expensive than anyone originally thought. So there was a major pause in the efforts.
The CFC’s Alex Leone says it’s taking a lot longer than expected.
“The initial cleanup on the Upper Clark Fork was anticipated by the EPA to take 12 years. And we’re looking at 20-plus, easily now.”
As we float down the river, we pass slicken after slicken. A report published earlier this month identified 109 that pose a risk to the Clark Fork.
But as we round every bend, FWP’s Nathan Cook keeps his eyes glued to the water. Every now and then, we see a fish rise. He says fish numbers here have bottomed out the last couple years. But that’s not the whole story.
“This place is just teeming with life. There’s waterfowl, we just saw a muskrat, there’s songbirds. It’s just incredible how resilient this ecosystem can be.”