Every year Indian thermal power plants (TPPs) spew out 100 million tonnes of flyash, a grey outpour soon expected to reach 175 million tonnes. According to current estimates nearly one lakh hectares (ha) of land in India is taken up by ash ponds. Bad news for the environment. For, most of the flyash is disposed off in ash ponds, from where it contaminates both surface water and groundwater. As if that isn’t bad enough, exposure to flyash has been linked to diseases such as silicoses, fibrosis of the lungs, cancer and bronchitis.

Flyash is a byproduct of coal combustion. TPPs powered by this fossil fuel are the mainstay of India’s power sector. In 2002, out of a total of 1,04,917.50 megawatts (MW) of electri