There are many reasons a state drinking water agency would require a water system to tell customers not to drink the tap water. Loss of distribution system pressure creating a backflow condition, for whatever cause, is just one such reason, as happened in Somerset, Mass. Click here for a local news article reporting the ban.
Even if no one eventually becomes ill as in this case, a ban on tap water presents a significant inconvenience and many challenges to a community. It is no fun at all….and something water systems should work hard to avoid. Click here for the article reporting lifting of the ban.