In major cities in the US like the ones you name, it would be very unusual to doubt the safety of standard municipal tap water.  In my home city, this is based upon my own reading of the annual water quality reports they put out.  I filter a lot of my own drinking water for taste reasons, but it&#x27;s un-necessary and I do not hesitate to drink from taps anywhere.<p>With the recent worries about BPA and other components of plastics, it&#x27;s unclear if bottled water from plastic is safer than tap at the 99.9th percentile of paranoia.  I don&#x27;t know about exotic risks from bottled water in glass (radioactive Evian from Chernobyl?), but I assume they are there also.<p>Nonetheless, in my circle of friends, I do know people who drink bottled water because they think it&#x27;s more pure.  I also know people who don&#x27;t use microwave ovens because of harmful radio waves, and others who do not use plastic containers or plastic-lined metal cans because of hormone disruptors in plastics.  I think they&#x27;re nuts, and they compensate by thinking I&#x27;m naive and complacent.