Nemont
Well-known member
IT, EG, and all of the other leftist President Bush haters.
I thought the EPA wasn't going to anything to clean up any superfund sites? You may need to contact both the EPA and the Chicago Tribune that they are spreading lies about this.
I thought the EPA wasn't going to anything to clean up any superfund sites? You may need to contact both the EPA and the Chicago Tribune that they are spreading lies about this.
Montana river cleanup a tricky prospect
By Maurice Possley Tribune staff reporter
About 200 years ago, when Meriwether Lewis and William Clark passed near here on their historic journey of discovery, the Clark Fork and Blackfoot Rivers came together in a confluence of pristine waters.
A century later, another William Clark, this man a U.S. senator and copper baron, constructed a dam in what was then known as Riverside--now Milltown--just below this confluence to harvest electricity from these rivers.
Five months after it went into operation, the dam was in ruins. A great flood, estimated to be flowing at 48,000 cubic feet per second, scoured the Clark Fork for more than 100 miles upstream. That torrent, along with later, lesser floods, brought with them 6 million cubic yards of sediment containing thousands of tons of hazardous metals--arsenic, copper and cadmium, to name a few--and dumped it right behind the dam.
Now, if all goes as expected and the weather cooperates, workers this fall will begin taking the first physical steps toward removing the dam and restoring the Blackfoot--the river so romantically described by Norman Maclean in his book "A River Runs Through It"--and the Clark Fork to their original free-flowing state.
The monumental project, expected to last several years, is complicated because all the sediment is part of the largest Superfund site in the U.S., stretching from the headwaters of the Clark Fork in Butte to the Milltown dam.
It is also expensive. The current projected price tag for removing the dam and sediment is about $106 million. And it is an ambitious--some would say tricky--project calling for removing 2.6 million cubic yards of the sediment, leaving the rest in place above the water line, and removing a 500-foot-wide dam without sending a torrent of the fish-killing contamination downstream.
Environmental Protection Agency (news - web sites) officials who oversee the Superfund program have estimated the cleanup and restoration of the Blackfoot from Butte to the dam will reach nearly $1 billion. The bill is being paid primarily by Atlantic Richfield Co., which purchased Anaconda Mining Co. in 1977--just before arsenic was discovered in Milltown's drinking water, triggering more than 20 years of debate over how to clean it up.
While the project will be executed with the muscle and grit of workers and giant machines, it involves a synchronized plan that relies largely on keeping to a schedule that as a computer printout covers nearly all of Matthew Fein's desk in nearby Missoula.
Intricate project
Fein is a senior project director at Envirocon Inc., the environmental remediation company contracted to remove the dam and the contaminated sediment. As he leaned over his desk on a recent morning, studying the schedule, he said, "This is going to be a symphony that we have to conduct here."
One might compare this project to a giant game of pick-up sticks, where removing the wrong stick at the wrong time could render the game pointless. A wrong move could loosen large amounts of sediment downstream on the Clark Fork with disastrous consequences for one of the more popular fisheries in western Montana.
It already has happened once, not that long ago.
In 1996 a giant ice dam broke free on the Blackfoot and came rushing toward the dam. Fearing the dam would be damaged if the ice struck it, officials used torches to cut open gates to lower the reservoir, but the rapid release and scour by the ice sucked up tons of copper-laden sediment and sent it downstream in a fish-killing plume.
The following year, fish surveys showed drops of more than 50 percent in the number of catchable rainbow and brown trout and a decrease of more than 70 percent in the numbers of juvenile trout of both species.
Water to be lowered
For that reason, the first step in the project--lowering the water level in the reservoir by 10 feet--will be gradual and monitored carefully to ensure a minimum amount of contaminated sediment is washed out.
Most of the contamination is in a V-shaped area of nearly 90 acres, in depths of 15 to 25 feet, directly behind the dam. Fein said lowering the water level would allow a significant amount of the sediment to dry out--so that it can be removed quickly and safely.
The next step in Fein's symphony would begin next spring, when Envirocon is to begin building roads into the contaminated site and driving supports for a bridge that will be built over a channel that is to be dug to redirect the Clark Fork.
Digging the 100-foot-wide, 3,500-foot-long bypass channel will require removing 750,000 cubic yards--each cubic yard weighs 1.3 tons, according to Fein--of sediment and piling it nearby for later removal. The channel will be 17 feet deep in the center and berms will be installed to keep the river in place as it is directed around the contaminated area, Fein said.
Because the entrance to the canal will be much higher than the end of the canal, a "drop structure" will be constructed that will slow down the redirected Clark Fork--thus preventing it from coming too quickly toward the dam and scouring out the new channel. At the same time, the bridge over the bypass canal will be constructed.
The bridge is for a rail line, Fein said. "We have to get that sediment out of there somehow, so we are going to take it out in rail cars."
He explained that an abandoned rail spur will be rebuilt and lead directly to the V-shaped area. "It will have to accommodate 60 rail cars at a time," he said. "We are going to lay a mile of track."
River to be redirected
The next step involves redirecting the Clark Fork into the bypass channel--a feat to be accomplished by dumping clean fill and rocks into the river and opening the channel so that the water ultimately turns into it, leaving the old river channel high and dry.
Fein explained that the reservoir would then be drawn down another 10 feet, bringing the reunited Blackfoot and Clark Fork that much closer to the level--just 10 feet of difference--on the opposite side of the dam.
He said some contaminated sediment may wash out during these operations, but said it would be minimal and the work is to be done during the time of year when it will be least harmful to aquatic life.
"It's like surgery," he said. "You're going to have a little blood on the table, but in the end, you're going to be better off."
A temporary dam then will be constructed perpendicular to and directly behind the dam that will split the reservoir in half and direct all of the flowing water through the dam's powerhouse intake tunnels. This will allow Envirocon to remove contaminated sediment behind the temporary dam while the water continues to flow.
When that sediment is removed--Fein said engineers are still studying the best method for that removal--the left side of the dam can be knocked down, which, when completed, will allow for removal of the temporary dam so the water can be redirected from the powerhouse to a fully opened gap.
At that point, the powerhouse and what's left of the dam can be removed. Meanwhile, back on the main site, the digging up and removal of the V-shaped area will have begun, Fein said.
"The hard part of this project is setting it up, "Fein said. "Then it's just an earth-moving job."
Still, it will be a significant one.
"We will be filling 60 rail cars a day and hauling them 90 miles north where it will be unloaded at Opportunity Ponds," he said. "We will be hauling loads out of there seven days a week for two years."
Already a huge site of mine wastes, the ponds in the town of Opportunity will be capped with the contaminated sediment. "There is organic material in this," Fein said. "It will grow things and it will be used to cap over the . . . ponds."
When the last of the sediment has been removed and the powerhouse knocked down, the tracks will be pulled out, the bridge over the bypass channel taken out, and yet a new channel for the Clark Fork will be dug in a wavy pattern directly through the excavated area.
Once more, the river will be redirected into a new channel. Then, the bypass channel will be covered and leveled off.
The dam will be gone and the two rivers will flow freely. And if all goes on schedule, sometime in the next five years, Montanans and tourists alike will be able to fish, swim and enjoy the Blackfoot and Clark Fork much as the rivers were when Lewis and Clark passed through.
"The EPA has estimated that this plan will allow the aquifer to become drinkable in 4 to 10 years," Fein said. "Without it, the estimates range from 200 to 2,000 years. This is going to make a real difference."
