CHENNAI: The Union Environment Ministry has granted an extension of three years for Tamil Nadu Generation and Distribution Corporation (Tangedco) to build and commission the Ennore SEZ thermal power station at Vayalur village in Ambattur taluk of Tiruvallur district.
An Expert Appraisal Committee of the ministry dealing with thermal power projects held a meeting on November 7 and considered Tangedco's request for extension despite several environmental concerns raised, including disposal of fly ash. The project consists of two plants with each having a capacity of 660 megawatts.
This is the second extension being granted for the project for which environment clearance (EC) was initially given in 2014 with a validity of five years, which was extended till 2021. Now, a new timeline of 2024 has been fixed.
A specific condition of the original EC states that "no waterbody shall be disturbed" during construction. However, Tangedco has already drastically altered the water flow in tidal water bodies within Kosasthalaiyar river's backwaters, alleges Pooja Kumar of the Coastal Resource Centre.
Tangedco officials submitted before the EAC that work is progressing well to commission the project by 2022-23. The EAC was informed that 45 percent of civil work is over and 55 per cent of the total cost of Rs 9,799 crore has been spent so far.
Due to disruption caused by cyclones and the COVID-19 lockdown, commissioning of the project has been delayed. "It is estimated that extension of validity of EC for three more years is essential to complete the project works including provision of Flue-gas desulfurization (FGD) for compliance with latest environmental norms. The unit-1 and unit-2 are expected to be commissioned by May 2022 and August 2022 including completion of FGD," an official said, adding that the tender for installation of FGD was in the process.
Also, Tangedco will be using the ash dyke of North Chennai Thermal Power Station (NCTPS) for the new project for bottom ash disposal. It has to augment the capacity by raising 6 m under technical guidance of IIT Madras after which the carrying capacity of ash dyke will increase to around 78.30 lakh cubic metres.
While granting fresh extension, the EAC made it clear that the ash pond (about 353 acres) shall have all adequate environmental and safety measures such as high density polyethylene (HDPE) liner, high concentration slurry disposal system, ash water recycling system and minimum distance of 500 m from water bodies.
"The safety and structural stability of the ash pond is to be ascertained once in three years by a reputed agency, which has expertise in the field of geo-technical aspects, to avoid breaching as Ennore creek is less than 1 km from the ash pond," the committee said.
However, environmentalists have expressed concerns saying as per law, power plants should make 100 percent utilisation of fly ash generated. "Considering Tangedco's track record at NCTPS, that looks impossible. The existing dyke capacity is being enhanced to dispose of more fly ash. An expert committee of the National Green Tribunal notes that this expansion indicates a plan to dispose of more flyash than it utilises. NCTPS' ash utilisation stands at less than 78 percent," Pooja said.