Industrial discharge and urban sewage are responsible for the pollution in Sutlej River.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/factory-waste-sewage-poisoning-sutlej
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/indian-express-chandigarh
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/sutlej
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-pollution
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/industrial-waste
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/jalandhar-d
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/state-pollution-control-board-spcb
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/ludhiana-d
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/sewage-pollution
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/drainage