Mike Cirian keeps track of a lot of numbers.

As the remedial project manager in Libby for the U.S. Environmental Protection Agency for the past nine years, he has overseen the cleanup of asbestos-contaminated homes, schools, public areas and commercial properties left in the wake of decades of toxic exposure from the former W.R. Grace & Co. vermiculite mine near Libby.

Since 2000, about 1.2 million tons of asbestos-laden soil have been removed and replaced with clean soil in a Superfund site so big it is broken into eight “operable units.”

Cleanup costs have topped $400 million.

More than 2,060 properties have been cleaned. Roughly 7,200 properties have been investigated for potential contamination, including 650 during this calendar year.

Over the last two years the EPA has made a concerted effort to determine what’s left to clean in the Libby footprint, Cirian said. A $250 million settlement from Grace has been covering both the cost of inspections and cleanup.

The EPA determined there were about 8,000 properties within the cleanup project’s National Priorities List boundary, and that includes 1,600 properties in the neighboring community of Troy.

Most of the indoor inspections have been done, Cirian said.

“We did the worst [sites] first,” he said. “Now most of the properties have about the same amount of contamination.”

Throughout the cleanup, properties with greater than 1 percent asbestos contamination triggered an automatic removal, and those with less 1 percent went into a pending category. A change made this year, though, narrowed the contamination level for mandatory cleanup.

Now anything greater than a trace detection goes to removal, Cirian said.

About 600 properties still need to be probed and about 400 sites are owned by property owners who have refused cleanup.

Many of those who declined to have their properties cleaned want to wait until a federal toxicity report is issued along with a record of decision outlining a cleanup strategy for the area in which they live.

“Of the 400, I think at least half of them may change their mind,” Cirian said, adding that number also includes those who have been contacted by EPA but have not responded.

The big question weighing on most Libby residents’ minds is how toxic the asbestos is, and whether properties already cleaned will have to be cleaned again once the toxicity values area known.

The long-awaited toxicity report will provide a baseline for safe containment levels, allowing the EPA to determine how much contaminated material must be removed and how much can safely be left behind.

Contractors working for the EPA have cleaned about 150 to 160 properties per year. As the cleanup has moved from Libby’s core to its fringe areas, the cleanup sites generally have gotten larger, Cirian said.

“It may be five acres rather than a half-acre lot,” he said.

Because the most contaminated sites were cleaned first, fewer properties are being tagged for cleanup now. In past years, 20 to 30 percent of the sites inspected went to cleanup; now it’s less than 10 percent, Cirian said.

Of the eight operable units within the Superfund site, only the first two — the former export and screening plant sites that were part of the mine operation — have had a record of decision issued and cleanup completed.

Operable unit 3, the vermiculite mine site, is being studied and no record of decision has been issued.

Operable units 4 through 8 will be handled with a combined record of decision that also is still pending, Cirian said. Unit 4 is the Libby community, unit 5 is the former Stimson Lumber campus, unit 6 is the railroad corridor, unit 7 is Troy and unit 8 includes the highway corridors in the Libby area.

The EPA forged ahead with cleanup on a removal basis while the toxicity report has been underway and “we’re waiting for the science,” Cirian said.

“Once the ROD (record of decision) is issued, then it becomes remedial because we know what the final cleanup numbers are. We’ll let the science guide what we do out here,” Cirian said.

With about 300 to 500 properties left to clean, the EPA will remain in Libby for another three to five years.

“That’s if everyone says yes [to cleanup] and all the stars align,” he said.

Once the settlement money from Grace is gone — probably sometime next year — remaining cleanup costs will become part of the EPA’s budget, Cirian added.

Features editor Lynnette Hintze may be reached at 758-4421 or by email at lhintze@dailyinterlake.com.