Butner, N.C. — Raleigh officials and Durham residents are expressing concern about a federal bioterrorism lab that could be built in Granville County.

Butner is one of five sites being considered for the National Bio- and Agro-Defense facility, which would study animal diseases or diseases spread from animals to humans. Part of the Umstead Research Farm would be used for $450 million lab, which officials said would create 350 to 450 jobs and generate a $1.65 billion impact on the local economy.

Although Raleigh officials haven't formally taken a position for or against the lab, they outlined their concerns about the lab in a recent letter to the U.S. Department of Homeland Security.

Raleigh Mayor Charles Meeker said city leaders want to ensure that it doesn't pose a threat to the Falls Lake watershed. The headwaters of the lake, which serves as Raleigh's primary reservoir, stretch into southern Granville County near Butner.

"We don't want anything coming out of the lab, inadvertently or otherwise, that might affect our water supply," Meeker said. "It does affect the whole Triangle area, not just Butner or that surrounding area. It could affect the air or water quality throughout the area."

Nearby residents already have banded together to block the lab from coming to Butner. The federal government is expected to select the site for lab next fall.

"They're going to study the most deadly diseases on the planet," said David Krabbe, a Durham County farmer whose farm sits four miles from the proposed lab site. "What we need to do is get people to write and call public officials and say we don't need this."

Dr. Warwick Arden, dean of the College of Veterinary Medicine at North Carolina State University, said the lab poses little contamination risk to Falls Lake and surrounding landowners.

"These labs have evolved to the point where there's tremendous safety, security and scrutiny," said Arden, who is leading the effort to bring the lab to North Carolina.

The Durham City Council was expected to discuss the bio-defense lab Thursday.