Three Baltimore government buildings reopened on Monday after undergoing mitigation efforts for Legionella bacteria in the water system, the mayor’s office announced.

On Friday, City Hall and the Abel Wolman building, both located on Holliday Street, shuttered early due to precautionary testing showing elevated levels of Legionella bacteria in the water. On Monday, the mayor’s office reiterated that the closures were caused by the nature of the mitigation efforts, which included cleaning, flushing and chlorination treatments, and not any public health or safety concern.

Legionella is a type of bacteria that naturally exists in bodies of water and moist soil that can become problematic if it enters water systems and grows. By ingesting tiny droplets of Legionella-contaminated water, it’s possible to get sick, but not likely. Those who do become ill after Legionella exposure may develop flu-like symptoms.

The city also conducted testing on the Benton Building on East Fayette Street, and those results will be available on Jan. 5, the mayor’s office announced on Friday. The building also closed early on Friday to undergo mitigation efforts, which included flushing and chlorination treatments.

Water systems at other city-owned buildings in Baltimore have also previously been impacted by Legionella bacteria. The Baltimore City District Court on East Fayette Street, the Clarence M. Mitchell Jr. Courthouse, the Elijah E. Cummings Courthouse, both on Calvert Street, the State Center office complex on West Preston Street and district court buildings on Wabash and Patapsco avenues all previously tested positive for the bacteria.

At one point, they each had to close down for at least a day to undergo mitigation efforts. The mayor’s office said Monday the city will continue to conduct precautionary testing on city-owned buildings as needed.