A primary school in Peterborough, closed at the beginning of September after legionella was found in the water system, is to reopen on Monday.
Bacteria that can cause the potentially fatal Legionnaires' disease were found at Newark Hill School.
Peterborough City Council expect it to reopen after workers carried out chlorination of the system to kill the bacteria.
Tests have been completed to ensure the water system is now safe.
Headteacher Lorraine Mann said: "I am pleased to report that we have been advised it is now safe to open the school on Monday.
"I would like to thank everyone for their patience and assistance during this time."