Hikers in a park feared a chalky substance on the ground. Investigators determined it was lime that planners had used to mark a future trail.

A woman called police after her son, without telling her in advance, dropped off a pair of jeans at her house for washing. She feared white markings on the pants.

A suspicious package showed up at the downtown post office -- but turned out to be nothing more than a ripped bag of rice.

"Most of our calls were to the post office," said Durham police Master Officer R.D. Thomas. "One of them was a jar of peppers that had cracked open. That's why everyone's eyes were watering."

A year later, by Sept. 11, 2002, Durham law enforcement had responded to more than 300 calls of suspicious packages in and around the Bull City. Such fears have subsided today. But the Durham Police Department's Bio-Chemical Emergency Response Team remains ready.

"You might never use it, but it's something you definitely want to have in your toolbox," said Investigator T.K. Westcott, the sole full-time member of the unit.

Durham police formed the unit in the summer of 1999 to head off an earlier crisis -- the "Y2K problem that never came," Thomas said. Back then, the unit consisted of two officers. But when the towers of the World Trade Center came crashing down and thousands of Americans lost their lives, Durham police bolstered the unit to eight reserve officers and the full-time position Westcott fills. "That's when they gave us an office and took us off what our normal duties would have been on the streets," Thomas said. "We got 30 to 40 calls right after Sept. 11." The call volume has dropped significantly since then, Westcott said.

Nowadays, the unit typically is mobilized about once a month, leaving Westcott with time to fill out paperwork, coordinate training activities and research current affairs about domestic and foreign terrorism.

Though last week's terrorist attacks in London caught Westcott's interest, the team has not been put on special notice, he said. "It kind of opens up your eyes, but nothing has really changed over here," he said. "We're just keeping aware of what's going on and trying to keep an eye on what's going on overseas."

The team also works closely with the Durham Fire Department and the Durham County Public Health Department, Westcott said. "We couldn't function without the Fire Department. We would have no team without their support," Thomas said. "They have the water and the equipment. We're just personnel."

Durham Fire Capt. Willie Hall, who has been a member of the Durham Fire Department's hazardous materials team since 1989, said fire officials began working with the BCERT unit in earnest about a year ago. He said the main focus has been on training and building trust in one another.

"If you're going into a possible biological or chemical atmosphere, you need the support of your colleagues," Hall said. "Plus, you need to see the abilities of each other's teams and you start to develop that relationship." He said collaboration with police and the Health Department is crucial in case a suspect is found and prosecuted, Hall said.

"We've done training with the Health Department on packaging procedures so it can be taken to the state lab without causing any hazard or danger to anybody and still maintain the chain of evidence," he said.

Theresa Patrick, the Health Department's bioterrorism coordinator, said the department also is required to treat anyone exposed to a chemical or biological agent within 48 hours. Each agency plays an important role in protecting the public from possible terrorist attacks, Patrick said.

"They now overlap so much that they are trying to link public health and law enforcement to do these investigations together," she said. In April, every member of the unit attended a bioterrorism-training course in Anniston, Ala., Westcott said. The culmination of the course was suiting up in special equipment and entering a chamber filled with live chemical and biological agents.

Westcott said the purpose was to ensure each student could work effectively in pressure situations. With the unit, the Durham Police Department is able to respond to situations that were not even a blip on the radar screen before the 9/11 terrorist attacks on the WTC and Pentagon and the anthrax attacks that followed.

"Anything with a biological or chemical threat to it," he said. "But we've never found anything that was actual legitimate stuff."