Chhattisgarh's five river stretches have been put under “Priority Class V” of pollution parameters of Central Pollution Control Board (CPCB).
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/c%E2%80%99garhs-five-river-stretches-are-polluted-min
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/pioneer-raipur
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/chhattisgarh
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/river-pollution
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/central-pollution-control-board-cpcb
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/central-water-commission-cwc
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-quality
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-pollution