Visitors to the BNSF Railway refueling depot last week were surprised to learn that the railroad had found an inch-thick sheen of petroleum products on top of the Rathdrum Prairie aquifer.
The layer of fuel and oil was said to be about 15 feet in diameter, and was the result of last year’s depot spill, said Barry Rosenberg of the Kootenai Environmental Alliance, who attended the tour.
Rosenberg issued a press release Thursday taking issue with the fact that neither BNSF nor the Idaho Department of Environmental Quality made an announcement about the July discovery.
“DEQ and BN always seem to be downplaying these issues,” he said. “There needs to be better public notification process.”
But DEQ’s Marc Kalbaugh said that the find wasn’t unexpected, so it wasn’t considered a new development.
“It appears that this is part of the old release, obviously, and appears isolated to this particular area,” he said, adding that the well where the sheen was found was the same well that detected contamination after the spill was discovered in December. “The bottom line is, it’s not new information.”
The thick sheen doesn’t appear to be moving downward, but nonetheless the state has asked BNSF to install more down-gradient monitoring wells.
Up to 1,800 gallons of fuel and motor oil are believed to have leaked into the ground beneath the depot last fall after it opened. Some of the contamination is in the soil, and some managed to make its way to the aquifer, which provides drinking water for more than 400,000 people in Idaho and Washington.
A BNSF spokesman said the recent sheen was caused by gravity pulling the petroleum product down to the aquifer.
“We’re continuing to work with the state on the cleanup plan,” said spokesman Gus Melonas. Current efforts to clean up the year-old spill include placing absorbent pads between the ground and the water in the aquifer and using a vacuum system to suck the petroleum vapors out of the soil.
About 200 cubic yards of contaminated soil and between 800 and 1,000 gallons of petroleum products have been removed to date, Melonas said. Removing the rest will take months, at a minimum.
“We have that area surrounded by ground water monitoring wells, so we would have known if it had gone anywhere,” Kalbaugh said.
Officials downstream are trying to keep an eye on the contamination, said Jani Gilbert, spokeswoman for the Washington Department of Natural Resources.
A newly formed Aquifer Protection Council meets monthly to review aquifer-related issues and consider steps to further protect the region’s largest drinking water source.
The council met this week, Gilbert said. “They were curious as to why we hadn’t heard about it (the sheen). We were kind of taken by surprise when the first thing happened, and we were surprised again.”