When is a boil-water advisory issued?

Unfortunately, tap water is sometimes not clean enough for direct use. This may be the result of a malfunction, leakage or maintenance work. For example, when we are working on a water main, there is a small chance that a contamination could enter the pipe. If this happens, we will issue a boil-water advisory. Sometimes, we issue a boil-water advisory as a precaution. This happens when we cannot be certain that the tap water is completely safe.