Officials of the Batavia school district said Thursday levels of the bacteria are too low to be dangerous, the Chicago Tribune reported.
Tests conducted Thursday found the bacteria on bathroom faucets at two elementary schools and on a shower head in a high school locker room, Superintendent Jack Barshinger said.
The affected areas were closed and school officials consulted with county and state health departments, he added.
State health officials said "there wasn't any immediate danger," Barshinger said.
He said the water in the schools is safe to drink because the disease can only be contracted when it is airborne.
The areas will be cleaned during the three-day weekend.
No student, or anyone in the county, has reported symptoms of Legionnaire's disease, but officials became concerned after three people died from it last summer at a Chicago hotel.
The bacteria thrive in areas with warm water and can cause a severe form of pneumonia.