Even after 55 years of Independence, India does not have legal standards that would help to clearly define clean and potable water.
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/no-legal-standards-define-clean-water
[2] http://admin.indiaenvironmentportal.org.in/category/journal/wastelands-news
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/drinking-water
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-quality
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/cse
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rural-water-supply
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india