Dangerous levels of arsenic, cadmium, copper, chromium in the dredged sea sand dumped by TANGEDCO on Kosasthalai river: Activists

According to a statement from the environmental group which is actively highlighting the violations of TANGEDCO at Ennore Creek, sand samples collected from the “reclaimed” portion of the river contained 14.96 milligrams/kilogram (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 the 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, it said.

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, aluminium, 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.

Ironically, electricity minister V Senthilbalaji who inspected the construction site of the seawater pipeline to the Ennore SEZ power project recently said that the TANGEDCO has been using materials which was approved by the competent authority as landfill in the water bodies.

“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.

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 the removal of dumped sand and the restoration of the wetlands.