National Bio and Agro-Defense Facility on Denison Avenue.

Completion of the National Bio and Agro-Defense Facility will be delayed by at least two and a half months because of the coronavirus pandemic.

Officials are stopping construction work on the National Bio and Agro-Defense Facility after a worker tested positive for COVID-19, they announced Wednesday.

NBAF program manager Timothy Barr said the Department of Homeland Security Science and Technology Directorate learned that an employee with McCarthy Mortenson Joint Venture, the construction contractor for NBAF, had tested positive. The contractor stopped construction Tuesday to investigate and determine what areas, tools and materials might need additional cleaning and disinfection.

There is no estimate yet on when the site might reopen for construction, but officials do not anticipate an extended shutdown. Since the worker is not from the county, that person is not included in the local case count, public information officer Vivienne Uccello said.

Officials did not give the person’s age, gender or county of residence.

Other COVID-19-related disruptions on the construction supply and labor chain have pushed back the project’s planned commission date, originally set for May 2021, by at least two and a half months, project officials announced in April.

However, the project is still expected to come in under its $1.25 billion cost estimate.