New Delhi: A high-speed water pipeline burst at the Kopili hydropower plant in Assam’s Dima Hasao district last week not only led to massive flooding at the power station but three employees of the North Eastern Electric Power Corporation Limited (NEEPCO) present at the site, along with a casual worker have also been missing since.
The flooding also caused an abrupt stop to the plant’s functioning, while triggering panic in neighbouring areas.
According to news reports, top NEEPCO officials said rescue operations have been underway since October 7 to locate the missing persons, who are believed to have been inside the power station at the time of the disaster. The operation is being conducted by a joint team of the National Disaster Response Force (NDRF) and the State Disaster Response Force (SDRF), but has not met with any success yet. Officials said loose earth that filled up the basement of the two-storey power station has come in the way of the rescue operation.
The three missing employees of the public sector unit have been identified as Prem Lal Balmiki, Robert Baite and Joy Singh Timung. The name of the casual worker is not yet known.
Early on October 7, the pipeline ferrying water from the reservoir at the speed of 12,000 litres per second to the power station in Umrangso area of the district ruptured, throwing up water hundreds of feet into the air with a deafening sound. The gushing water engulfed the power station in no time, thus trapping employees stationed inside it.
The Kopili hydropower plant is the first by the public sector unit set up in Assam, in 1976 and commissioned in 1984. It produces 275 megawatts of electricity, out of which 150 MW is allotted to the state. The unit has two concrete components – the 30-metre Kopili dam over Umrang river, a tributary of river Kopili, at Umrangso, and the 66-metre Khandong dam on Kopili itself.
While the Khangdong dam produces 50 MW of electricity, the one on Umrang river generates 200 MW of power. The Kopili’s water is first used by the Khangdong dam and thereafter, the tailwater is stored at the Umrangso reservoir. The water then passes through a 5,475-metre tunnel to the Kopili dam on Umrang River to produce 200 MW of electricity. The disaster occurred when the water was passing from the Umrangso reservoir to the Kopili dam.
Stage 2 of the Khangdom dam was developed in 2004 to produce an additional 25 MW of power.
While the state government has instituted an inquiry into the disaster – preceded by chief minister Sarbananda Sonowal meeting NEEPCO officials – Vijay Kumar Gupta, the public sector unit’s director, held rat-hole mining in neighbouring Meghalaya responsible. He said mining has turned the Kopili water acidic, thus affecting most of the dam’s machinery and pipes.
A report in The Telegraph quoted Gupta as saying, “The acidic water led to the corrosion of metals and other materials in the reservoir that failed to sustain the water pressure, resulting in the pipeline bursting. The capacity of the reservoir is 6,000 crore litres. The pH level of the water is very high and it cannot be brought to normal even after the use of lime.”
He also said that NEEPCO had apprised not only the Ministry of Power in New Delhi but also the chief secretaries of both Assam and Meghalaya of an impending disaster due to increase in acidity of the river water since 2009.
“We held a seminar on Pollution of Kopili Water and its Probable Effects on the Power Project in 2011 in Guwahati. We kept the governments informed of the warnings issued at the seminar. However, no action has been taken. Now it will take six to seven months for restoration and production of power,” Gupta told the newspaper.
A report in The Hindu said that the pipeline which ruptured on October 7 was changed a year ago and raised questions about the quality of work.