Milltown sediment heads for Opportunity Ponds

Front-end loaders: carry contaminated sediment to railcars at the Milltown Reservoir Superfund Site on Tuesday prior to the first train full of the sediments leaving for Opportunity Ponds. Over the next two years, 2.2 million cubic yards of the sediments will be excavated

By PERRY BACKUS of the Missoulian

MILLTOWN – The first load of the 2.2 million cubic yards of contaminated sediments to be excavated from the Milltown Reservoir Superfund Site rolled away Tuesday afternoon.

In 28 brand-spanking-new shiny black railcars, nearly 3,000 tons of the arsenic- and copper-laden material headed southeast to its new home at Opportunity Ponds near Anaconda.
The trainload marked another milestone in the cleanup of Milltown Reservoir.

“It’s a big day for us,” said Matt Fein, Envirocon’s senior project engineer.

Over the next two years, an estimated 30,000 railcar loads of sediment will follow the same route to the expansive Atlantic Richfield Co.’s Opportunity Ponds mine waste repository.

“There will be one train a day with between 45 and 55 cars running seven days a week, with the exception of a few holidays,” said Fein. “Each car will carry just a little over 100 tons of material.”

Since January, Envirocon has stockpiled about 450,000 cubic yards of sediment excavated from the huge bypass channel that will reroute the Clark Fork River sometime this winter. It’s enough to keep the trains running for about six months.

On Tuesday, large loaders were busy scooping up the jet black soil from the towering 20-foot tall windrows stacked neatly on the delta just upstream from Milltown Dam into the waiting railcars.

The plan calls for spreading the material about 2 feet deep over hundreds of acres at the Opportunity Ponds – where it will act as a cap for toxic mine wastes stored at the site. The soils at the facility are so contaminated with heavy metals that weeds won’t even sprout.
While contaminated with its own toxic brew, the Milltown sediment is rich in organic material.

“Stuff will definitely grow in it,” Fein said. “We had weeds growing all over our stockpiles.”

Envirocon crews will spread the material over the site. Atlantic Richfield employees will then add whatever soil amendments might be needed before applying grass seed.

Dust has been a problem for people living near the Opportunity Ponds for years.

While some people are opposed to bringing even more toxic soil to the site, Fein said using the sediment to cap a portion of the area should help with the dust problem.

“Even as hot as it was all summer long here, we never had a problem with dust out here,” he said. “It’s just the nature of this material. It doesn’t blow away. I think this is going to be a big help to those people.”

It will take about 800 days to move the 2.2 million cubic yards of sediment above Milltown Dam to the Opportunity Ponds.

If you put the railcars needed to move that much material end to end, they’d stretch 350 miles. Stack them on top of each other and they’d soar 50 miles into the sky, Fein said.
The trainloads filled with sediment will pull out of Milltown each day sometime after the normal shift ends around 5 p.m.

“It’s going to take us the better part of a day to load,” Fein said. “The trains will probably leave near the end of the shift sometime around 5 p.m. It will be well after school is out.”

Montana Rail Link officials have been meeting with schoolchildren at the Bonner School in an effort to educate them about rail safety. The company is using a rail spur just behind the school and has fenced off that area to keep kids out.

A new path has also been built from the school to Piltzville to help keep children away from the railway activity.

The empty train should arrive in the area well before 6 a.m., Fein said.

“There shouldn’t be that much more in the way of rail traffic,” he said. “MRL has done a good job of putting up the fence and providing safety training at school.”

The loaders topping off railcars wasn’t the only activity occurring at the cleanup site Tuesday.

Crews were busy reinforcing several bridges that span the Blackfoot River just upstream of the river. The bridge work needs to be completed before Envirocon can begin removing Milltown Dam sometime later this winter.

The Montana Department of Transportation is expected to start constructing the temporary bridge that will carry traffic during the construction of a new Highway 200 Bridge in the next two to three weeks.

Workers are also lining the bypass channel with rock-filled cages called “Reno mattresses.”
“It’s very hard work,” Fein said. “An excavator puts the rocks in the baskets and then workers have to smooth them out by hand. It’s a young man’s job.”

Audio Slideshow: Milltown Sediments