A boil advisory has been issued for all City of Centralia water customers. The advisory is scheduled to be in effect until noon Thursday. The advisory is city-wide. It is due to a water valve leak at the north water tower today that has caused the potential for water pressure to potentially drop to a level that could allow backflow and contamination of the city’s water supply. Residents are encouraged to boil water vigorously for three minutes prior to use. Residents with questions are encouraged to call Centralia City Hall at 573-682-2139.