The City's Water Department will put a boil advisory in effect for two reasons.
The first and most typical reason is if a water main break occurs and there is potential contamination in the area of the break. In this case, the advisory is a precaution and will be in effect for three days in predetermined areas. Once a water main break has been repaired the City is required to take water samples from the area of the break and have them tested for contaminants. These tests take 48 hours. Once the results prove negative for any contaminant, the City will lift the advisory. If a contaminant is detected the City will extend the advisory. New samples will be tested until the contaminant has been removed from the system.
The second, and most rare, reason an advisory would be issued is if a contaminant is detected during the routine testing the City performs on the entire water system. If this is the case, the City will issue a boil advisory for the entire system until the source of the contaminant is determined and until it is proven that the contaminant has been removed from the system.