Packaged drinking water may not always be your safest bet, going by a random survey conducted by the Food and Drug Administration (FDA).
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/53-packaged-drinking-water-samples-maharashtra-fail-fda-test
[2] http://admin.indiaenvironmentportal.org.in/category/author/umesh-isalkar
[3] http://admin.indiaenvironmentportal.org.in/category/newspaper/times-india-pune-0
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/maharashtra
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/drinking-water
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/bottled-water-case
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/pune-d
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-quality
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/bureau-indian-standards-bis-0
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/food-safety-and-standards-authority-india-fssai
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/health-effects
[12] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-pollution