The National Green Tribunal has directed the TNPCB to take action against agencies, including the MTC and SETC for polluting the river.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/another-cooum-crackdown
[2] http://admin.indiaenvironmentportal.org.in/category/author/vivek-narayanan
[3] http://admin.indiaenvironmentportal.org.in/category/newspaper/hindu-chennai
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/tamil-nadu
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/river-pollution
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/thiruvallur-d
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/drainage
[8] http://admin.indiaenvironmentportal.org.in/thesaurus/national-green-tribunal-ngt
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/state-pollution-control-board-spcb-0
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/common-effluent-treatment-plant-cetp
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-pollution