At present, DJB tankers provide water in Delhi slums.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/govt-mulls-%E2%80%98pay-and-use%E2%80%99-water-atms-slums
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/indian-express-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/slums
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-supply
[5] http://admin.indiaenvironmentportal.org.in/thesaurus/grid-0
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/solar-energy
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/renewable-energy
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi-jal-board-djb
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-demand