The Union Environment Ministry has allowed the state-owned power generator NPTC for one more year to continue to dispose of fly ash generated from its Talcher plant in Odisha in a mine void.
It was in 2013 that NTPC was given permission to backfill fly ash in mine void on a pilot basis subject to various studies on its impact. Later, it was extended for one more year till March 2016.
NTPC and the National Environmental Engineering Research Institute (NEERI) were asked to conduct additional studies on the impact of backfilling of fly ash in mine voids.
"The Expert Appraisal Committee (Thermal Power) discussed the proposal twice in the last two months. In view of the clarification provided by the company, the ministry gave permission to continue the said disposal of fly ash on a temporary basis for further one year," a senior government official said.
NTPC has been allowed to backfill fly ash generated from its Talcher plant located in Odisha in a mine void of south Bolonda open cast mine (OPC) of Mahanadi Coalfields Ltd.
However, NTPC has been directed to submit a report studying the impact of disposal of fly ash in abandoned mines in the next six months, the official added.
NEERI has been asked to monitor and review regularly the continuing study to ensure objective analysis of impact, which will form the basis for grant of further permission.
Besides, NTPC has been asked to conduct additional studies to trace radioactive for heavy metals. The final report of the study should comprise particle size distribution of fly ash, mine pit water samples analysis data for various periods, trace metal analysis and data from piezometric well, among others.
"Based on data generated and its analysis, the study should clearly establish whether or not the ash backfilling in mine voids can be permitted further or not. If yes, then what are the precautions and what regular monitoring has to be done?" the official asked.
NTPC has been asked to conduct studies prescribed during 2013 and 2015, apart from the existing one.
Fly ash is being used an an alternative material to backfill mine void due to regulatory curbs on use of river sand and gravel for this purpose.
