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EPA: Hart Senate cleanup nearly complete

From Kate Snow
CNN Washington Bureau

WASHINGTON (CNN) -- The massive anthrax cleanup of the Hart Senate Office Building was nearing completion Tuesday and the building could be open as soon as next week, according to the Environmental Protection Agency's on-scene coordinator.

Over the weekend chlorine dioxide gas was pumped through a portion of the heating and air conditioning system in the corner of the building that houses the office of Senate Majority Leader Tom Daschle, D-South Dakota, where an anthrax-laced letter was opened in October.

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The EPA's Richard Rupert said the weekend effort was tedious, but appeared to have worked.

"We've met all the criteria necessary to get a good kill. We had to have around 75 percent humidity [in the building], the concentration of the gas and the temperature. We got all three," Rupert said.

Based on experimental data and what the experts found when they used the same treatment on Daschle's office suite, Rupert said, "it's our best guess at this point in time that we've been successful."

He cautioned it was impossible to know at this point whether all anthrax spores in the ventilation system were gone.

"We're a long way from saying we killed any spores. It's impossible to know until we get our data," Rupert said.

About 400 Band-Aid-sized test strips were removed from inside the ventilation ducts Monday night.

The strips contain a bacteria similar to anthrax. If tests on the strips are negative, then the anthrax likely is gone. It will take about five to seven days to produce test results on the strips.

Workers also will use cloths to swipe environmental samples from the system for testing.

Rupert and his team were optimistic they would not find many, if any, traces of anthrax.

Positive final results on the ventilation system would then clear the way for the Hart building to be reopened.