Last fall, a hunter in Whitefish Lake’s Mackinaw Bay stepped into the water and yanked his boot out of the lakebed’s muck. When he looked down, the water glimmered with an unmistakable petroleum-tinted sheen.
The hunter contacted the Whitefish Lake Institute, which conducted soil and water tests. Hydrocarbons indicating diesel were detected.
Lab results showed that the contaminant level in the water was 16 times higher than the maximum level suitable for drinking water, and contamination in the soil was eight-and-a-half times higher, according to Whitefish Lake Institute Director Mike Koopal.
As far as Koopal and city officials know, there’s only one reasonable explanation: The diesel is leftover from a 1989 incident in which a Burlington Northern Santa Fe Railway freight train derailed and dumped 25,000 gallons of fuel into Mackinaw Bay on the lake’s west shore.
It’s the only recent oil sheen sighting stemming from the 1989 derailment that Koopal is aware of, and it comes on the heels of the 2007 sheen discovery in the Whitefish River. That discovery prompted the cleanup effort currently taking place on the river.
“For this to be manifesting 20 years later,” Koopal said, “we suspect that there’s still a large parent source of contaminated soil.”
He added: “We don’t think the concentration levels are in the acute zone for aquatic or plant life, but it’s a chronic situation that’s detrimental to the aquatic life.”
Koopal points out that measuring the contamination levels in terms relative to drinking water is simply a useful way to communicate the information, not a suggestion that anybody’s drinking water has been compromised.
“Obviously people aren’t out there drinking it, but there’s no other way to communicate it to the public,” he said.
At a June 21 meeting, the Whitefish City Council voted to send a letter to the Environmental Protection Agency. The letter has been drafted and, as of last week, was awaiting the signature of Mayor Mike Jenson.
It reads, in part, that the city would like to “pursue having the area of Whitefish Lake where the diesel spill occurred in 1989 (Mackinaw Bay) designated for remedial clean-up under the Oil Pollution Act, much as the Whitefish River is being cleaned-up. Please consider this letter as such a request.”
Koopal took David Romero, an on-scene coordinator with EPA’s Region 8, out to Mackinaw Bay in the winter. Romero is in charge of the ongoing Whitefish River cleanup. Because of wintery conditions, Koopal said he and Romero weren’t able to see much.
But EPA sent a contractor in the spring who took soil samples and conducted tests. Last Wednesday, Koopal said he hadn’t yet seen EPA’s lab results.
In early June, Whitefish officials held an update work session with Koopal where he discussed the oil sheen. Shortly afterward, City Manager Chuck Stearns sent an e-mail to BNSF and received a response the next day. BNSF quickly dispatched an environmental consultant who accompanied Stearns and Koopal on a site visit June 18.
They stirred up sediment near the shore and saw nothing. But, taking into account the higher water levels than during the fall and spring tests, they moved to deeper water. Stirred sediment then produced a rainbow-colored sheen.
“It’s significant enough to let people know about it and see what can be done,” Stearns said. “It seems like it’s trapped down in the sediment as opposed to being a regular occurrence.”
After the derailment in 1989, the Montana Department of Environmental Quality oversaw a cleanup effort and then closed its file on the case, Koopal said. If the hunter hadn’t been in the lake during low water, Koopal said the lingering diesel might not have ever been discovered.
“I think it’s a good lesson with the Gulf spill,” Koopal said. “Petroleum products persist in the environment longer than people suspect. They’re volatile compounds and they evaporate, but when they’re in the soil it’s a different story.”