Worse quality than tap water? You've obviously had less 'boil water advisories' than I have. I actually used bottled water for the example because it is easy

Worse quality than tap water? You've obviously had less 'boil water advisories' than I have. I actually used bottled water for the example because it is easy to visualize and synonymous with potable water. I was recently on an island with 'tap water' which had poisonous levels of arsenic, so tap water seemed like a bad example.