Fly ash utilisation and scientific disposal at thermal power plants has increasingly come under the scrutiny of the National Green Tribunal. The NGT, in its most recent July 14, 2020 order, suggested remedial action against thermal power stations in Singrauli and Sonbhadra districts of Madhya Pradesh and Uttar Pradesh against violation of environmental norms, which led to the pollution of Rihand Reservoir.
The NGT order was about the ash dyke breach at Essar Mahan MP Ltd in Singrauli and National Thermal Power Corp Ltd (NTPC) Vindhyachal plant in Sonbhadra, which took place on August 7, 2019 and October 6, 2019 respectively.
The tribunal directed NTPC Vindhyachal to pay an interim compensation of Rs 10 crore for breach of its fly ash dyke into the Rihand Reservoir.
Nine major thermal power stations operate out of Singrauli and Sonebhadra, with a total installed power generation capacity of around 21,270 megawatt (MW). More than half of this capacity (11,180 MW) is relatively new and was added in the last 10 years. More capacity addition caused tremendous amounts of coal consumption and subsequently, fly ash generation in the region.
At least four incidences of ash dyke breach have happened within a year.
In its November 5, 2019 order, the NGT directed NTPC and Essar power to initiate steps to restore their respective ash dykes by December 31, 2019. The Tribunal also directed the Central Pollution Control Board (CPCB) to have an action plan prepared by the power plants for de-silting of the reservoir and improvement of dykes.
However, the issue was stayed by the Supreme Court and recovery of compensation deferred.
The two power plants had said they took corrective action. An on-spot inspection by the oversight committee set up NGT, however, revealed the veracity of corrective actions; with regard to NTPC, the committee found that a large portion of ash dyke had been breached with the result huge quantity of fly ash had spread all over the land and travelled up to the Rihand reservoir in Uttar Pradesh.
Fly ash is a solid waste generated by the combustion of coal. Indian coal has higher percentage of ash (30-45 per cent) as compared to other countries.
The NGT directions
The bench in its recent order stated:
Prima facie, the interim environmental compensation demanded by the Madhya Pradesh Pollution Control Board (MPPCB) at Rs 10 crore cannot be said to be excessive. The said amount ought to be deposited. Plant should have an RCC wall to strengthen the ash dyke.
The NGT had asked the two thermal power plants to explore the possibility of developing fly ash mount like it was developed by NTPC, Dadri, said the order.
The order added:
Neither any interest has been shown in this regard nor any step taken to develop the fly ash mount. In the face of status stated above, we direct NTPC-Vindhyachal to be very sincere and implement the directions given by the committee and by the NGT in a shorter time. Committee directs the MPPCB to assess the environment compensation finally within one month. Plant is also directed to give the status report time to time, preferably within 15 days each time.
Similarly, during the Uttar Pradesh Rajya Vidyut Utpadan Nigam, Anpara, visit, the committee found that flow of water coming from plant along with fly ash was filling up Rihand reservoir. The committee observed plant deliberately concealed facts. The NGT stated:
Act of pollution amounts to violation of various laws and polluter is liable to be punished. The only way to stop the flow is to close operation of the unit and their unit is liable to be closed until they make arrangements and ensure that no water with ashes may go to the Rihand reservoir.
It added that the power plants were “liable for the environment compensation as well as cost of desilting of the ashes from the reservoir on the principle of polluter pay”.
It directed the Uttar Pradesh Pollution Control Board to assess environmental compensation and “take all stringent actions under the provision provided in the various Acts”.
On the issue of de-silting and restoration of Rihand Reservoir, court directed CPCB guidelines on ash disposal in mounds and backfilling of ash in abandoned mines should be followed. Since, it is difficult to verify the quantity of fly ash released by different power plant in Rihand reservoir, the CPCB suggested the total ash slurry volume generated by each plant on the periphery of Rihand reservoir be considered as the basis of sharing of the cost of the study to assess sediment volume at various places in the reservoir.
The NGT also made the following observations, critical for fly ash utilisation from all thermal power plants (TPP) in India:
Improper storage of fly ash results in air pollution and water pollution affecting the environment. To address this, MoEF&CC issued the first fly ash notification on September 14, 1999, which has subsequently been amended in 2003, 2009 and 2016 to achieve 100 per cent fly ash utilisation in a prescribed manner.