Why India Needs Coal and Ash Pond Design Standards ASAP
A worker transports coal in a basket in an industrial area in Mumbai on May 31, 2017. Fly ash is a product of burning coal. Photo: Reuters / Shailesh Andrade / File photo
- India produces nearly three times as much coal ash as municipal waste every year.
- Coal ash is stored in poorly designed and poorly designed facilities that often fail catastrophically, especially during monsoons.
- Coal ponds across India are not subject to any regulations, technical standards and guidelines. It is a major political failure.
Indian coal-fired power plants generate an average of 226 million metric tonnes of toxic ash each year from the combustion of coal. This figure is expected to reach 600 million tonnes by 2032.
While environmental standards strive to use 100% ash rather than disposing of it, tens of millions of tonnes go unused each year. And the new coal ash produced each year adds to the 1.6 billion tonnes of unused ‘heirloom’ ash already piled up in large unplanned coal ash dumps or dykes across India – enough to fill a thousand by Taj Mahals.
The Ministry of Environment, Forestry and Climate Change estimates that the ash dumps occupy nearly 40,000 hectares of land – an area almost as large as Chennai. These landfills can reach tens of meters high and are prone to leaks and breaches, posing serious threats to the environment and public safety.
From 2010 to 2020 alone, 76 “incidents” of coal ash ponds, including catastrophic breaches, were reported across India. Most notable of these was the Reliance Sasan Power disaster in April 2020, which left six people dead, significantly damaged property and polluted water and soil in Singrauli, Madhya Pradesh.
Unfortunately, there are no standards governing the design and maintenance of these toxic waste landfills – and the results are far too predictable. Many poorly constructed ash dikes broke, inundating the surrounding landscape and often burying villages with millions of tons of ash sludge. Many more disasters are sure to follow as millions of additional tons of coal ash accumulate.
Given these realities, dealing with coal ash in India is an overlooked crisis that requires immediate government attention. Like municipal solid waste, the management of coal ash suffers from poor law enforcement, which allows this problem to escalate. Worse yet, the coal ash crisis is magnified by the fact that nearly three times as much coal ash is generated in India than municipal waste.
However, there are several lessons that can be learned from India’s experience with solid waste management in policy making on coal ash management. Most important of these is the urgent need for scientific and technical standards to guide disposal and other facilities.
The Delhi-based Forest and Environment Legal Initiative (LIFE )1 examined three major ash basin failures – the Essar Mahan and Sasan incidents in Singrauli and the Vedanta Jharsuguda factory in Odisha – and concluded that foundation slippage was probably the main cause. That is, the structures of the ash ponds are greatly compromised by weak foundations, which are often built using residual coal ash, and by the frequent increase in the height of the embankments in an uninformed manner. planned.
Many ash basins that have suffered breaches were also originally built without first having studied the foundations in depth. The resulting flaws in the final design are exacerbated by heavy rains during monsoons, which soften poorly designed foundation materials. Note here that many of these failures are associated with pond structures built over the past 10 years – a time when plant operators had access to improved design and construction methods, including those commonly applied in other countries.
Additionally, an aerial assessment of 10 coal ash disposal facilities identified various issues related to their location, land use, and engineering standards. For example, many ash ponds covered large areas that would otherwise have been used for agriculture. Many facilities also had large dams (over 5 m high) located nearby, themselves close to bodies of water or populated areas. More importantly, many of these facilities were huge and contained large amounts of sewage mixed with ash – a combination that greatly increases the risk of dam failure and endangers people and farmland.
Perhaps the most important conclusion of the LIFE analysis is that many ash dykes – the structures that form the perimeters of ash ponds – are built using coal ash. When used in this way, coal ash is subject to liquefaction, a process in which the soil and / or coal ash is fluidized by a sudden increase in fluid pressure. The causes of several ash basin accidents reported across India can be attributed to this phenomenon.
According to NITI Aayog estimates, India will depend to a large extent on coal power – 42 to 50% of the energy mix – for decades to come. This “ambition” undermines our climate goals – and will also perpetuate the country’s coal ash crisis. India’s economic position on the continued use of coal is questionable, but its lack of political action on the management, design and construction of ash ponds puts it at odds with its ethical obligation under the article 21 of the Constitution (protection of life and personal liberty).
Coal ponds across India are not subject to any regulations, technical standards and guidelines. This is a major political failure which requires an urgent solution. The 1995 Tailings Dam Design Standards, published by the Indian Bureau of Mines, are a good starting point for developing new and updated standards.
Considering the severity of the coal ash crisis in India, regulating coal ash ponds with clear and enforceable requirements and timelines for implementation is the obvious first step.
Dharmesh Shah is Senior Technical Advisor to the Delhi-based Forest and Environment Advocates Initiative (LIFE).