Impact of Sequential Backfilling of Basalt Stone Quarry by Fly Ash for Restoration: On Ground Water Quality - A Case Study

Ash disposal in general is a huge problem for Coal Based Thermal Power Plant. Thermal power plant has to dispose fly ash generated during power generated in enviro friendly manner. There is another environmental and safety problem with the basalt stone quarries used as minor mineral for construction and infrastructural activities from restoration point of view due to non availability of backfilling material to restore the pit during mining. Hence to overcome these two issues a solution to backfill basalt stone quarry with fly ash is proposed. But major threat involved during prolonged backfilling of Ash in Basalt Stone Quarries from ground water point of view are i) between the water and fly ash at the bottom of fly ash filled void/quarries results in leaching of heavy metals into ground water system ii) The infiltration of rain water falling on fly ash filled mine void is confined only to the top 1 m or even less, and as such there will be reduction in recharging of ground water in the area. A study is carried out to conclude whether between the water and fly ash at the bottom of fly ash filled void/quarries results in leaching of heavy metals into ground water system A stone quarry admeasuring 4.2 ha at Pimpalgaon Singru in Warora Tahsil of Chandrapur district is selected. Four ground water samples around the basalt stone quarry and one ground water sample within stone quarry lease hole area are collected analyzed before start of fly ash backfilling and at a interval of six months for eighteen months during backfilling of void by fly ash. It is concluded that no leaching of heavy metals in to ground water quality found due to backfilling of mine pit void by fly ash. The study reveals that fly ash generated from Coal Based Thermal Power Plant can be dumped into the basalt stone quarry as a backfilling material to restore the void and hence fly ash disposal can be addressed in enviro friendly manner.