A small section of riverbank along the Swan River in Bigfork will be the site of an environmental cleanup this winter as PacifiCorp removes soil contaminated with Polychlorinated biphenyl, also know as PCBs.
The chemicals came from the nearby PacifiCorp Bigfork Hydroelectric Project facility and transformers that were once used there. Company spokesperson David Eskelsen said the chemicals were used as coolant for transformers, a practice that has since ceased. He added that cleanup projects like this are not unusual and the chemicals pose no immediate threat to the public. However, the chemicals are known to harm fish if they get into the water.
“We’ve run across this on a number of occasions,” he said. “There are a number of issues created by the processes and materials that we used decades ago that we now know are problems.”
According to Montana Fish, Wildlife and Parks, some fish in Flathead Lake, as with many rivers and lakes, are contaminated with PCBs. Leo Rosenthal, a fisheries biologist for FWP, said it is unknown if the contaminated soil along the Swan River has affected the water.
“Anytime we have PCB-contaminated soil, cleaning it up is a good idea to eliminate this risk of contaminating the fish,” he said.
Montana Department of Environmental Quality project officer Chris Cote said the hydroelectric project site was first inspected in 2000 and had soil within the transformer yard removed in 2003. A subsequent inspection in 2009 found that some of the PCBs had leeched into the soil along the riverbank. Cote said a roughly 20-foot-long section of riverbank is affected.
According to Eskelsen, the power facility isn’t a dam but rather a “run-of-the-river” project and uses water depending on its seasonal flow and does not have a large reservoir of water behind it. Built in 1902, the site can produce about four megawatts of power, although it is not always in use. PacifiCorp at one time provided western Montana with electricity but Eskelsen said the service area was sold around 2000. Even so, the company retained the Bigfork facility and it still produces power that is fed into the grid.
“Most of these (older projects) are still valuable and we still have multiple small plants like that still in use,” Eskelsen said.
Cote said PacifiCorp has volunteered to clean up the site as part of the Voluntary Cleanup and Redevelopment Program run by state of Montana. To remove the contaminated soil, a contractor will bring in an excavator and vacuum truck. Cote said once the sediment is removed, it will be disposed at a designated site. Officials expect the cleanup to take less than a week and should begin sometime in February.