EPA to change removal criteria

Bolstered by the completed release of background soil studies, the Environmental Protection Agency has formalized a decision process for the removal of contaminated soils in Libby.

EPA Toxicologist Dr. David Berry explained to Lincoln County Commissioners recently background soil studies in Libby and Troy have established a baseline of Libby Amphibole Asbestos to be 500,000 asbestos fibers per gram of soil.

“The average concentration of Libby Amphibole Asbestos on background is about 500,000 structures per gram of soil,” Dr. Berry said. “That sounds like a lot of fibers, but that equates to approximately 2/100ths of 1 percent.”

One gram of soil is a size equivalent to about the size of a sugar cube.

The new criteria for cleanups would include properties that consist of 0.2 (two-tenths) of 1 percent. That area would also be non-detect for vermiculite.

Areas that include less than 0.2 percent Libby Amphibole Asbestos — a trace — but do include visible vermiculite would be cleaned if 25 percent of that property area includes vermiculite and a trace of LA.

Mike Cirian, the EPA onsite remedial project manager, said the change reflects a better understanding of what the baseline numbers represent.

“We’re changing our removal processes,” Cirian said. “Our removal activities are going back to a way we used to do it. The reason we’re going back is the results of our background study and our activity-based sampling. Those activities are getting us closer to what our final remedy needs to be.”

Still, there are those who are not convinced.

“It’s all junk science,” said former Libby resident Michelle Hartley. “Until we have a third-party objective review by real scientists, it’s all junk science.”

Berry’s studies established baseline levels of asbestos soil for Libby, Troy borrow sources in Libby and Eureka and a comparative exposure study in Eureka, Helena and Whitefish.

“We collected background samples from 21 areas in and around Libby and 11 in and round the Troy area,” Berry said. “All of these areas that we sampled had to be below a contour line of 2,450 (feet elevation) sea level. That contour represents the lake level for the historic glacial Lake Kootenai. It was present over this area 16,000 years ago.”

Berry explained that glaciers covered much of the area, including Vermiculite Mountain, where W.R. Grace mined vermiculite much of which carried asbestos. As the glaciers scoured the mountain, deposits containing asbestos were deposited in the ancient glacial Lake Kootenai. As asbestos fibers are lighter than soil, they were carried farther than many of the other deposits by lake water, ultimately being deposited up to 11,000 years ago as the ancient lake gradually receded. What was left behind, were deposits of soil containing asbestos fibers.

“So, it was grinding off material and depositing it into what we would call the Rainy Creek delta,” Berry said. “As the lake would go up and down, that delta would erode and bring material into the lake bottoms. And the fibers are lighter than the soil, so a lot of times those things would float. So, the whole process would cause the material that was eroded by the glacier to be spread out all over this lake. When the glaciers receded, lake bottom sediments remained containing asbestos fibers.”

What remained ultimately became the Kootenai River Valley. The asbestos deposits then have established the background level to measure for standards.

“This tells us what was occurring naturally in this area,” Cirian said. “What it does is establish criteria for removals. It tells us what numbers we need to clean up to. This establishes where background is at and where do we stop our digging based on the glacial history and getting it to within a risk management level. It establishes background.”

Cirian said previously the EPA was trying to remove any trace. Now, there is a baseline figure.

“Basically, we’re not removing materials we don’t need to anymore,” Cirian said. “I don’t want to say we were removing things before that weren’t necessary, but we were trying to be protective based on what we knew at that time.”

With a baseline number for the valley, Cirian said elevated levels beyond the background levels can be attributed to distribution through the mining process and by residents used as fill.

“There is no indicaton that Libby Amphibole is more toxic than other amphiboles,” Cirian said with the support of Berry. “It’s just that it was mined here; it was processed here; it was shipped from here. At the time, there was not the kind of limitations that there are today, so it was released into the air. It was driven down the road so it was released into the air. People could pick it up in the back of a truck and fill in a yard.  So, people here were dealing in multiple concentrations and multiple exposure pathways. All of those things combined made Libby what it was.”

Cirian said some people are confused about the dangers of asbestos vs. vermiculite.

“This is not commercial asbestos,” Cirian said. “This is not something that was a material for different things and then combined with the vermiculite. The vermiculite is not the contaminate concern. The Libby Amphibole fibers are.”

Cirian said Berry’s studies inch the EPA toward criteria that will one day move the process closer toward a risk assessment.

“Where it comes more into play is acreages, fields, yards, where there wasn’t a lot of human activity,” Cirian said. “And it really helps us with a landowner with a huge hay field, for instance. You go out and cleanup around the house where there was human activity. This tells us there was some in naturally occurring soils. That kind of helps us so we don’t have to say we need to clean this up, his hay field. This is good news. This also tells us that we just don’t have to get the vermiculite because it’s there. We now know we don’t have to remove Libby Amphibole unless its 0.2 percent or higher.”

Jeff Camplin, of Camplin Environmental Services in Rosemont, Ill., said there still needs to be more data.

“They are working toward an exit strategy,” Camplin said. “They are searching for a standard. Libby Amphibole is an airborne substance. I don’t know what measuring soil will do to determine airborne effects.”

Berry’s studies also included samples taken from Eureka, Whitefish and Helena.

“In those samplings outside the Libby Valley in Helena, Eureka and Whitefish, we actually found amphibole asbestos that’s naturally occurring there in the soils, but they’re not Libby Amphibole,” Berry said.

Cirian said amphibole fibers are common throughout the country.

“It’s interesting to note that in Helena and Whitefish, those amphibole fibers were actually higher in air concentrations than they are in Libby, even though they’re a different kind of amphibole,” Cirian said.

Berry defined those asbestos fibers in Helena and Whitefish as tremolite and actinolite, not Libby Amphibole. A trait of Libby Amphibole Asbestos is concentrations of potassium and sodium, unique to the Rainy Creek Vermiculite Mountain deposit because of its alkaline origin.  

“These studies were conducted using new methodology that is from 100 to 1,000 times more sensitive than conventional methods that have been used to measure for asbestos in soils and solid media,” Berry said. “With these studies we can see asbestos levels concentrations in soil that we have not been able to before.”

Cirian was asked whether residents can feel better about living in Libby.

“I can’t tell you that,” Cirian said. “All I can tell you is we have to do some cleanups here in Libby based on what we now know about background levels. All we know is we found fibers in other places. I can tell you this: We have made it cleaner in Libby, Montana. I live here. I raised my family here.”

Berry said the problem stems from excessive exposure.

“Essentially, it was a question of exposure or an exposure level,” Berry said. “And there were many exposure pathways that the residents and the miners of Libby were exposed to. So, it’s the level of exposure that people were subjected to that made the disease state so high.”

Cirian said the EPA knew asbestos was out there, so that was the initial attack plan.

“The exposure to people here was so high while the mine was open,” Cirian said. “The mine didn’t shut down until 1990. It was all over Libby. That’s why we clean up little islands here in the sea of Libby. Well, they brought something in. It’s not all airborne deposits.”