In the absence of a mechanism to construct and operate robust dams to contain fly ash slurry stored in ponds in thermal power plants, lives and the environment of populations living in close proximity to these mega projects stand at risk. The risk has been further heightened after the Central government opened up the coal sector in June for commercial mining by private players, which indirectly paves the way for generation of more fly ash.
Most of the coal mined in the 41 blocks which have been put up for auction is expected to be consumed by domestic thermal power plants, resulting in the generation of huge quantities of fly ash. With most thermal power plants already failing to meet deadlines to put accumulated fly ash to alternate use, ponds with dams constructed and operated with no expertise whatsoever are brimming with toxic slurry.
Fly ash is the toxic waste product generated in thermal power plants after the burning of coal. It is stored in huge ponds, at times in volumes exceeding millions of gallons, in the form of slurry.
“We have no mechanism or set rules to ensure fly ash dams are designed, constructed and operated keeping in mind the safety of lives and environment. The Central Electricity Authority which operates thermal power plants has no expertise in the construction of dams. The pollution control boards, whether at the state-level or at the Central-level, have no expertise in dams either. Agencies constructing dams and dykes for fly ash ponds tend to cut costs, thereby resulting in frequent accidents by way of breaches,” said Himanshu Thakkar of the South Asia Network on Dams, Rivers and People, an informal network of individuals and organisations working in the water sector.
In April this year, a fly ash dam breach in the Sasan Ultra Mega Power Project in Singrauli, Madhya Pradesh, resulted in the deaths of six persons as toxic slurry flooded into habituated villages. The slurry polluted hundreds of acres of fertile agricultural land. The toxic slurry further overflowed into the nearby Rihand Reservoir which is the source of potable water for millions of people.
Last year, in August, a dam breach had occurred in another thermal power project in Singrauli: the one belonging to Essar. The slurry had damaged houses and flooded agricultural fields. In September, the fly ash dam of Bokaro Thermal Power Plant, which belongs to Damodar Valley Corporation, had breached flooding agricultural fields and polluting the Damodar River. Similarly, the fly ash dam of a thermal plant belonging to National Thermal Power Corporation in Singrauli had also breached in October last year resulting in loss of agricultural crops and domestic cattle.
In most cases, power plants are levied a penalty by the state governments following a dam breach. But hardly any measures are taken to mitigate the long-term impact caused by the toxic slurry to farm lands and also to underground water sources through seepage.
“Generally, construction of fly ash dams is carried out as per the convenience of the operators so that the slurry overflows to nearby rivers during monsoons. At other times, there occur breaches which could be due to faulty construction, plain negligence or even sabotage. The Central Water Commission is the only agency in the country with expert knowledge in dam construction. But it has no role in thermal power plants,” added Thakkar.
The Congress-led United Progressive Alliance (UPA) Central government had put in place a set of rules upon thermal power plants to put fly ash to alternate uses so that possible hazards, by way of storing the toxic waste in slurry form in overfilled ponds, are mitigated. The Union Ministry of Environment and Forests (MoEF), as it was called back then, had issued a notification in November 2009 giving thermal power plants a five-year stage-wise time period for 100% disposal of fly ash. New plants were allowed a maximum time limit of four years for complete utilisation of fly ash from the date of their commissioning.
Rules also do exist for thermal power plants for putting fly ash to alternate uses including brick-manufacturing, cement manufacturing, laying of roads and reclamation of open pit mines. These rules further stipulate that these activities are to be compulsory carried out, through ancillary industries, within a certain geographical radius of each thermal power plant.
However, the Central Electricity Authority’s latest report (Report on Fly Ash Generation at Coal/Lignite based Thermal Power Stations and its Utilization in the Country) found that only 78% fly ash generated by 194 thermal power plants in between April and September last year was diverted for alternate use. While 129.09 tons of fly ash was generated during the six-month period, only 100.94 million tons were diverted for alternate use. The remainder was invariably added to the overflowing slurry in fly ash ponds.
Most ancillary industries and development works had ground to a halt in between April and June due to the nationwide COVID-19 lockdown announced by the Bharatiya Janata Party-led National Democratic Alliance (NDA) government. Thermal power plants were not able to divert fly ash for alternate use, thereby adding to further pressure on fly ash dams, even though demand for electricity and consequent use of coal, had plummeted considerably during this period.
Two steps undertaken by the Central government recently are expected, albeit indirectly, to increase further the generation of fly ash in thermal power plants, while no agency has yet been entrusted to oversee construction and operation of dams of ponds meant to store the toxic waste.
One, the UPA government had in January 2014 issued a notification upon thermal power plants to switch over completely to the use of coal with a maximum of 34% ash content. This was to reduce fly ash generation. The deadline had been set at June 2016, varying for different power plants on the basis of their distance from coal mines. On May 21 this year, the NDA government reversed this rule allowing thermal plants to use coal of any quality without putting any restriction whatsoever on the ash content.
Coal mined in India is generally considered to be of low-grade globally because of its high ash content which is often more than 40%. Owing to the earlier rule barring usage of coal having ash content above 34%, thermal power plants had been importing good quality coal for the purpose of blending in order to minimise ash generation.
Two, as the scope for exports seem distant with the world gradually shifting away from fossil-fuel based power, most of the low-grade coal with high ash content extracted by private players, who win the bids for the 41 blocks, will invariably find its way into indigenous thermal plants. This will eventually lead to generation of more quantities of fly ash with a concurrent increase in the threat of hazards.
Experts, in fact, foresee a greater demand in India for domestically produced low-grade coal over the next few years which is to be led by the power discoms, especially after the central government announced a package of Rs 90,000 crore to revamp the sector.
“Once the discoms are in good health, they will begin purchasing more power thereby pushing up the plant load factor. If the plant load factor increases by 15 per cent, from the level of 55 per cent which is the current figure, we will see an additional demand of 150 million tons of coal. At present, India has a stranded capacity of 40,000 MW because numerous plants are non-operational owing to a variety of factors. An additional demand of 200 million tons of coal will arise as and when these plants begin operations. Besides, indigenous thermal power plants must also be looking forward to substitute annual imports of 120 million tons of coal with the mineral that will be produced in the country,” said Partha Sarathi Bhattacharya, former chairman of the public sector Coal India Limited.
Ayaskant Das is a journalist and author.