Kokua Line: Why did tap water have yellow tinge?

Question: On Tuesday, neighbors reported a yellow tinge in their cold water. The Board of Water Supply’s explanation was that a fire hydrant was damaged at the corner of Dole and McCully streets. We live on Makiki Street. What is the interaction between a damaged fire hydrant and the potable water system? Does this happen every time a fire hydrant is damaged? Is the water quality still acceptable when this happens?