EPA officials "said on the phone, 'We have a team standing by, ready to go,'" Lindley recalled. But the technicians would have to wear elaborate protective gear.
On the other hand, sending personnel in street clothes would risk exposing them to the pathogen.
"This was the biggest decision we ever had to make," Lindley said.
When the conference call resumed, Lindley said the state would collect its own samples, without using conspicuous safety gear. "No one was willing to say, 'That's the right response, Colorado,'" Lindley recalled. "Everybody was frozen. We were on our own."
State workers discreetly gathered samples of soil, water and other items for immediate DNA analysis. No pathogen was found.
At 3 p.m., Lindley told participants in another national conference call that his agency was satisfied there was no threat. "I said: 'We are doing no more sampling. We are closing up this issue,'" Lindley recalled.
Lindley and Calonge, having staked their reputations on not believing BioWatch, were vindicated: Barack Obama gave his acceptance speech on schedule. No one turned up sick with tularemia. And, to their surprise, news of the false alarm never became public.
Officials responsible for BioWatch insist that the false alarms, which they refer to as "BioWatch actionable results," or BARs, have been beneficial.
Each incident "has provided local, state and federal government personnel an opportunity to exercise its preparedness plans and coordination activities," three senior Homeland Security BioWatch administrators told a House subcommittee in a statement in July 2008. "These real-world events have been a catalyst for collaboration."
Biologist David M. Engelthaler, who led responses to several BioWatch false positives while serving as Arizona's bioterrorism coordinator, is one of the many public health officials who see it differently.
"A Homeland Security or national security pipe dream," he said, "became our nightmare."