CHENNAI: With the ecologically-sensitive Ennore Creek remaining in a state of neglect due to continuing industrial pollution, National Green Tribunal (NGT) has constituted a new committee with a mandate to prepare a blueprint for restoration of the creek within the next three months after conducting necessary inspections and studies. The committee will comprise members from Central Pollution Control Board (CPCB), IIT- Madras and Tamil Nadu Pollution Control Board (TNPCB). Its primary focus will be on illegal fly ash dumping allegedly by North Chennai Thermal Power Station (NCTPS).
While disposing of a batch of petitions, the green bench, comprising Judical Member K Ramakrishnan and Expert Member Nagin Nanda, said: “Committee shall inspect the unit and ascertain the present status of the unit (NCTPS) in respect of fly ash disposal, the damage caused to the environment, to the area in question and its surrounding, cost of restitution and assess the damage caused to the environment on account of illegal act committed by the above unit.”
The tribunal had passed several orders in the past directing Tamil Nadu Generation and Distribution Corporation Limited (TANGEDCO) to remove the fly ash dumped in the water bodies at Ennore by its units and restore the place; but none of those directions had been complied with.An independent assessment conducted by another NGT-appointed expert committee, which submitted its report on December 14, 2017, using 1965 declassified aerial imagery acquired from United States space agency NASA reveals that Ennore Creek and Kosasthalaiyar river basin have been subjected to intense exploitation to an extent that today the critical ecosystem is on the verge of extinction.
Besides, highlighting serious irregularities in managing the fly ash situation by NCTPS, the committee found that samples taken from the water bodies at Ennore contained elevated levels of several toxic metals like mercury, lead and cadmium. The report said fly ash spill was noticeable to an extent of 344.39 hectares and the likely extent of fly ash in rivers, canals and water bodies is 309 hectares. The report said flyash pollution has injected poison (toxins) into every bit of environment in Ennore be it air, water and soil making the place inhospitable for local communities, who are dependent on the creek for living for ages.
The tribunal has directed the new committee to take 2017 expert committee’s report as reference point to carry out the investigation and “the expense of conducting the study has to be met by polluting unit, the power plant in this case and they shall also give all logistic support to the members of the panel in conducting the inspection and preparation of the report. The CPCB may direct the project proponent to deposit probable expense which they anticipate for conducting the inspection and submit the report,” NGT order said.
IIT-Madras professor Balaji Narasimhan, one of the expert committee members, said the 2017 assessment was conducted in a limited area as the scope of NGT order was restricted to fly ash contamination caused by NCTPS. The committee, in its report, said fly ash ponds off three power plants - NCTPS and now closed Ennore Thermal Power Station and Vallur Power Plant - are located in and near the creek.
“Only a comprehensive study of entire Kosasthalaiyar river basin will reveal the actual damage caused. It would be humongous. There is also Kamarajar Port, which is constantly in news for illegal dumping of dredged soil and reclamation of wetland”. The committee had intended to map the affected area using aerial drones to get a more accurate picture of the extent and intensity of the contaminated area. However, it could not be carried out due to want of clearance from Directorate- General of Civil Aviation.
Effect on hydrology
The fly ash dyke with western bunds that rise six metres above prevailing contours block the eastward flow of rainwater from the hinterland into the creek, resulting in flooding of settlements at Seppakam, Mouthambedu. The stretch from northern tip of NCTPS fly ash dyke to the southern tip of NTECL and ETPS ash pond is a contiguous dam obstructing water flows, the impact on surface water hydrology has to be seen in a cumulative context. This hinterland has now perpetually become water logged.
The design drawing seems to indicate that there are future plans to raise the bund height in three additional stages of five metres each to an ultimate height of 21 metres from the present height of six meters. This would mean that NCTPS is preparing themselves for more fly ash generation and less fly ash utilisation which is an unsustainable model.
The tail-end of Kosasthalaiyar river is home to several kinds of habitat – tidal mud flats, mangroves, salt marshes, deep and perennial tidal water bodies typical of coastal wetlands. The Coastal Zone Management Plan of the region describes the area between Sattankuppam and Madras Metropolitan Area boundary as ecologically sensitive due to the presence of salt marshes and mudflats. Plants are the best indicators of the habitat. The habitat is a typical saline marsh or mangrove vegetation as evidenced by the presence of sedges, mangrove and its associated species. This habitat should be treated as a critical ecosystem.