In this recent publication CPCB presents water quality of the Ganga for a decade spanning between 1999-2008. This will be useful for the agencies responsible for restoring and preserving water quality of Ganga and would serve as a model for conducting similar studies in other major rivers in India.
Links:
[1] http://admin.indiaenvironmentportal.org.in/reports-documents/ganga-water-quality-trend
[2] http://admin.indiaenvironmentportal.org.in/category/publisher/cpcb
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-pollution
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/river-pollution
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/ganga
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-quality
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/biological-oxygen-demand-bod
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/sewage-pollution
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/bihar
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/uttar-pradesh
[12] http://admin.indiaenvironmentportal.org.in/category/thesaurus/uttaranchal-uttarakhand
[13] http://admin.indiaenvironmentportal.org.in/category/thesaurus/west-bengal