Effect of pond ash on ground water quality: a case study

The potential problems and their consequences due to fly ash disposal have been well studied around the world. Ash pond is a common available disposal facility for thermal power plants. The pond ash is subjected to weathering and the ions present in ash migrate to the soil and subsequently to the ground water over a period of time. A study has been carried out at Vijayawada Thermal Power Station (VTPS), Andhra Pradesh, India, to monitor the ground water quality in order to determine the potential impact of ash ponds. It has been found that ground water quality is deteriorated due to the presence of fly ash ions (macro and micro such as Fe, Ca, Mg etc.) which were leached out from the ash up to some extent. The contamination is likely to increase in the case of toxic and other ions with the passage of time. The presence of vegetative cover and plant growth on the down stream slope and fly ash ponds which are covered by soil may effectively control the leaching of ions.