NEEPCOChairman & Managing Director VK Singh on Tuesday said that the publicsector enterprise has lost around Rs. 600 crore due to the burst at the Kopilidam.

Addressing the media in Delhi, Singh added acidic water due to coal mining has resulted in the pipeline bursting.

"Theacidic water led to the corrosion of metals and other materials in thereservoir that failed to sustain the water pressure, resulting in the pipelinebursting," said Singh.

He further mentioned that NEEPCO had informed not only the Ministry of Power but also the chief secretaries of both Assam and Meghalaya of an impending disaster due to the increase in acidity of the river water since 2006.

Till Tuesday evening, the operation to rescue four NEEPCO officials trapped in the basement of a two-storey pump house of the hydel project in Umrangsu under Dima Hasao district could not start as the water pressure in the pipeline is yet to recede.