County firefighters returned to UCSB’s station Friday after a three-week absence.

The UCSB Fire Dept. evacuated its firefighters from the Public Safety Building – which also houses the campus police department and communications services – after employees from several agencies complained of health problems. At the time, UCSB’s Environmental Health & Safety (EHS) said the illnesses were caused by soil and mineral deposits in the building’s air ducts but said it would carry out new tests to search for asbestos, lead and mold contaminants. Those tests, released by EHS on Friday, turned up no further contaminants, biosafety officer Bruce Hanley said.

Additional tests by EHS determined there is inert asbestos and other construction materials in some parts of the building, Hanley said, but that as long as it is undisturbed it poses no risk to the building’s occupants.

The sediment in the building’s vents, which are located underground, was deposited by fluctuating groundwater, Hanley said. Facilities management shut off the building’s ventilation system in November. The system remains shut off while the university designs and installs a new one.

Fire Capt. Wes Herman, who has returned to the building after being temporarily posted at the station on Storke Road, said he was glad to being going back and that the tests were reviewed by the county’s Public Health Dept.

“We’re real happy to be going back,” Herman said. “The tests looked like they were very thorough.”