Ignoring a National Green Tribunal (NGT) order banning the use of dredged sea sand to reclaim waterbodies, TANGEDCO has blocked the Kosasthalai River’s backwaters using dredged sea sand with dangerous levels of arsenic, cadmium, copper and chromium. Sand samples collected from the reclaimed portion of the river contained 14.96 mg/kg of Arsenic, more than two times the Interim Sediment Quality Guideline (ISQG) for aquatic sediment of 7.24 mg/kg, 15.23 mg/kg of cadmium, more than 20 times ISQG, 23.54 mg/kg of copper which is 1.25 times ISQG and 106.1 mg/kg of chromium, which is more than twice safe levels in aquatic sediments. The ISQGs are safe threshold levels of chemicals for protection of aquatic life, and represent levels above which toxic effects on aquatic life may occur. The samples were taken on 14 July, 2021 and were analysed at the US Environmental Protection Agency-approved Chester LabNet. A January 2020 report submitted to the NGT by a joint committee of Central Pollution Control Board and Tamil Nadu Pollution Control Board found that sea sand dredged and dumped in the Ennore Creek by Kamarajar Port contained very high concentrations of magnesium, aluminum, potassium, chromium, lead and calcium, and high concentrations of other toxic metals like copper, nickel and zinc. The levels of these metals found in the samples taken from TANGEDCO’s dumpsite inside the river are far higher than even the very high concentrations reported by the joint committee.
Movement of sand is a strictly regulated activity. However, given the prevalent lawlessness in the Ennore-Kattupalli area, sea sand is routinely transported from the ports to various places without license from the revenue authorities. This matter has been brought to the notice of the revenue authorities. On 19 July, 2021, fishers from Kattukuppam occupied the site of the illegal encroachment in Kosasthalai River by the coal conveyor corridor for TANGEDCO’s Ennore SEZ project. A 3-member citizen panel has written on this matter to the Chief Minister and Chief Justice of Madras High Court echoing the demands of the fishers. They have called for an immediate halt to any further dumping, and recommended removal of dumped sand and restoration of the wetlands. “Fish is an inexpensive source of protein for the poor. Dumping contaminated sand in this section of the river is like poisoning their food. This is the place where we catch the fish that we sell in the market”, said R.L. Srinivasan, a fisherman from Kattukuppam.
Contamination of river due to industrial pollution, coal ash leakage and dumping of toxic material such as contaminated sand dredged from the harbour basin has degraded the river water quality and harmed fish population. Health of Ennore fishers is severely impacted due to contamination of river and fish. Exposure to contaminated water while fishing has chronic skin diseases among fishers. Consumption of contaminated seafood may also lead to health impacts. With a public health infrastructure that is not sensitive to the special needs of this pollution-impacted community, health issues due to industrial pollution go untreated. Fisherfolk have demanded that all further encroachment of the river bed should be stopped, and the river should be restored to good health.