The Environmental Protection Agency has ordered BNSF Railway to begin removing contaminated sediments in the upper reach of the Whitefish River by Sept. 25.

The order follows a finding that the company is responsible for the river contamination under the Oil Pollution Act, said David Romero, an on-scene coordinator from the EPA's Region 8 office in Denver. Romero said he informed BNSF of the finding in March.

The EPA has ordered BNSF to clean up the river from the company's upstream boundary all the way downstream to JP Road, to ensure the interceptor trench between the BNSF railyard and the river is functioning correctly, and to address all potential sources of petroleum products in the river.

The EPA's order is being made under the Oil Pollution Act, which covers navigable waters of the U.S., and not under federal CERCLA Superfund law.

"If there is sediment that contains enough oil to cause a sheen in the river and does appear to have impacted the environment, it needs to be removed," Romero said. "If the sheen appears after someone mucks up the sediments, it's still an issue. The driver is the sheen."

River clean-up will take place in the fall when stream flow is at its lowest and the number of recreationists is reduced.

In one scenario, metal coffer dams lined with plastic sheeting will isolate clean-up areas, which will be dewatered before excavation of contaminated sediment begins. Water will run through multi-stage filtering systems, to remove sediment and oil, before re-entering the river.

"There must be no turbidity in the river," Romero said.

Contaminated logs from historic logging and milling operations will probably be removed and hauled off to certified landfills, and both the river bottom and river banks will be restored before the coffer dams are removed.

The EPA first learned about the river contamination in August 2007 when a recreationist reported getting oil on his ankles and legs after wading in the river, Romero said. An EPA team came to Whitefish several times since then to collect samples.

By spring 2008, they learned the state had established a Superfund site at the BNSF railyard in Whitefish and began working more closely with state agencies.

"We identified the boundaries of the contamination and did a step-by-step analysis that included 'fingerprinting' the sediments," Romero explained. "We were finding Bunker C fuel oil and diesel fuel in the sediments downgradient from the railyard."

The EPA eliminated leaking underground storage tanks listed in the state's LUST database as potential sources of the contamination, Romero said. One potential underground tank held gasoline, not diesel fuel. In addition, the "tight soils' in Whitefish generally prevent the migration of underground plumes from leaking underground tanks.

The quantity of oil in the river sediments made sense in light of the historic nature of the pollution, Romero said. The Great Northern Railway made the transition to diesel-powered locomotives about 60-70 years ago, and while nobody was monitoring fuel spills back then, an unknown quantity of diesel may have run into the river before the interceptor trench was built in 1973.

"We drew a pretty fair conclusion that BNSF was the liable party," Romero said.

The EPA has described four "deliverables' that BNSF must achieve. If the company fails to meet deadlines, it could be fined or the EPA could take over the work and then bill BNSF. But Romero and his co-worker, Duc Nguyen, say they want to be reasonable and work together with BNSF and its consultant, Kennedy/Jenks.

The "deliverables' include:

¥ Conduct sampling and analysis on the river from the railroad's upstream boundary to the Second Street bridge and begin removing contaminated sediments by Sept. 25.

¥ Conduct sampling and analysis on the river from the Second Street bridge to the JP Road bridge, the most downstream location with a documented report of a sheen being observed. Assessment and identification of contamination must be completed by the end of this year, and clean-up must begin by fall 2010.

¥ Ensure the interceptor trench is functioning the way it was intended to function. BNSF has already submitted a plan, Romero said. Several test pits will be dug between the trench and the river about 5-8 feet deeper than the bottom of the trench to see if contaminated groundwater is moving beneath or around the trench.

¥ Identify and remove all potential petroleum sources within the facility boundary that could impact the river by late 2010.

"We could change the due dates," Nguyen said, "but we don't want an open-ended clean-up project. It needs to be manageable. We also want to work with BNSF and not be confrontational."