Negligence narrative unfolds as Kopili hydropower plant pipeline burst kills four

Joy Sing Tisso had started working in the Kopili Hydro Electric Project (HEP), in Assam in 1986. He was only 23 years old then.

The 59-year-old had given his all to the HEP, the maiden venture of North Eastern Electric Power Corporation when it came into existence in 1976. 

Straddling the border of Assam and Meghalaya, the plant is located in Umrangso, a small industrial town in the hilly Dima Hasao district of Assam. 

The twin project comprises two concrete dams (Khandong and Umrong) and two corresponding reservoirs, one on the Kopili and the other on the Umrong stream, a tributary of the rain-fed, interstate Kopili. There are two separate water conductor systems and three powerhouses.

The first unit of the plant was commissioned in 1984, two years before Tisso joined the project. An additional unit under stage two was commissioned in July, 2004, making the total power generation 275 MW.

After 36 years of service as a mechanical operator, Tisso was just three months away from retirement. Surrounded by the fervour of the Durga puja, the veteran staffer was counting his days to retirement, when disaster struck in the wee hours of October 7, 2019.

A penstock (pipe) carrying water from the dam to the main power station burst, leading to massive flooding. 

Water gushed into the power station trapping three NEEPCO staff Robert John Ngamlai (39), Prempal Valmiki (54), a contractual worker, K Raju (23) and Tisso, inside.

Almost a fortnight later on October 21, a rescue team led by the National Disaster Response Force (NDRF), managed to find the dead bodies of Ngamlai and Tisso. The bodies of Valmiki and Raju were recovered subsequently.

Joy Sing Tisso is survived by his wife, son Albertson and three daughters. Up until Tisso’s body was recovered, Albertson was camping at the spot of the disaster.

“My father had given his all for this organisation (NEEPCO). During our childhood, we would seldom see him as he would always be busy at the site,” a shaken Albertson told Mongabay-India.

A NEEPCO spokesman said that the penstock had burst around 4.30 am on October 7 and the isolating valve meant to stop the water flow also failed to do the job. The pipe which carries water at a speed of 12,000 litres per second inundated most of the complex. 

Eyewitnesses said that the force of the water was so strong that it created a water fountain that went up to several hundred feet into the sky. 

Albertson says that his father had a close shave in the past when the rebel group Black Widow opened fire inside the premises of Kopili powerhouse in Umrangso. In the incident, which took place in January, 2008, two security guards and three civilians were killed. 

“My father was on duty that night,” Albertson recalled.

But years before his life was cruelly snuffed out, Tisso was aware of an impending danger-the damaged penstock, which has triggered a political blame game.

Albertson squarely blames the power corporation’s negligence for his father’s death. He says that his father had apprised him about the impending threat from the ruptured penstock.

“I used to visit my father at the site regularly. He had told me that the penstock (pipe) was due for a change. He also told me that until it is not changed, there is a possibility of an accident at the site. I will say that this disaster happened only because of the negligence of authorities,” Albertson stressed.

Acid alarm and blame game

But the power corporation blames Meghalaya’s notorious illegal rat-hole mines for the damage to the penstock.

According to NEEPCO Chairman and Managing Director Vinod Kumar Singh said that the hydroelectric project suffered some serious damage from the acidic water coming from the rat-hole mines in the neighbouring state of Meghalaya.

The primitive method of rat hole mining (also called box cutting) entails clearing ground vegetation and then digging pits vertically into the ground ranging till one hits the coal seam. Then tunnels are dug in from the sides for extraction of coal, which is brought into a pit by using a conical basket or a wheelbarrow.

The rivers and streams of the Jaintia hills are the “greatest victims” of mining, according to experts.

The culprit is the spike in acidity of rivers and streams, when water washes along the sulfur-rich coal (a phenomenon called acid mine drainage or AMD) that degrades water quality and thins biodiversity in the water bodies of the mining area. Kopili river basin is bound by the Jaintia hills in the west.

“We spoke to the governments of Assam and Meghalaya many times on this without avail,” said Vinod Kumar Singh, claiming that NEEPCO had followed every protocol and there was no negligence on their part.

There are two parts to the Kopili HEP layout. The 66-metre-high dam on the Kopili river is known as Khandong dam. It intercepts the flow in the Kopili river and retains the water in the Kopili reservoir. This reservoir feeds the Khandong power station (2 x 25MW) and Kopili Stage­-II Power Station (25 MW).

The second one, the 30-metre-high Umrong dam is across the Umrong stream, creating the Umrong reservoir and linked to the Kopili power station. The water from Umrong reservoir is taken through a 5.5 km long tunnel to the Kopili power station to generate 200 MW (4 X 50 MW) of power. The water is finally discharged into the Kopili river.

A NEEPCO document ‘Acidity in reservoir water and its effects on Kopili hydroelectric plant’ describes the acidity in the Umrong reservoir as “unprecedented” and “extraordinary”.  Acidity in the water of the Umrong reservoir was detected in December, 2006. The pH value was found to be 4.8. Tests revealed low pH in Kopili reservoir too. The corrosive action of acidic water led to an increase in the number of breakdowns, the document said.

Singh, while addressing media persons said that they had cautioned the states and the Centre that such an accident might take place as the acidic water had led to the corrosion of metals. 

Ratanlal Langthasa, who served as the Security Administrative Officer in the Kopili Power Plant till 2010, however, pointed the finger at the plant authorities for the fiasco. 

“They (NEEPCO) are saying that the equipment got rusty because of the acidic water coming from Meghalaya. If they knew this all along, then what were they doing? Why didn’t they take preventive measures? For preventive measures, they should have carried out regular mock drills, which as per my information didn’t happen in the last few years,” Langthasa said.

Himanshu Thakkar, Co-ordinator, South Asia Network on Dams, Rivers, and People (SANDRP) questioned as to why the project authorities continued to operate the damaged penstock.

Thakkar pointed out that the Kopili powerhouse underwent “premature” renovation and modernisation (R and M), completed in 2015-16 at a cost of over Rs 132.5 crores. Quoting a presentation made by NEEPCO official that states the penstock was categorised one of the components “most affected” from acidic water, Thakkar said the penstock failure was one of the remaining issues after R and M.

“Among the parts that were affected and not replaced and modernised include the penstock. Why did they continue with such damaged penstock which they themselves say was damaged and needed repair,” Thakkar said.

Meanwhile, the Congress in Assam, which is in Opposition, held the incumbent Bharatiya Janata Party-led central government responsible for not releasing Rs. 200 crore for maintenance which was approved by the Congress-led UPA government in 2014. 

Senior Spokesman of the Assam Pradesh Congress Committee, Durga Das Boro said the lifeline of the pipeline expired in 2014 and a major repair was due in 2014. “Since the BJP-led NDA government did not release the money, the repair could not be carried out.”

Delayed rescue and lost warnings 

Meanwhile, junior engineer Robert John Ngamlai’s death has cast a pall of gloom in his native Umrangso. 39-years-old Robert, who was also a good musician was quite popular among the town’s youth. 

Unmarried Robert was the oldest among eight siblings. His younger brother Charles said that the NEEPCO authorities didn’t inform the family about the accident. 

“They didn’t have the basic courtesy to inform us about the rescue,” said an anguished Charles who was also the site since the day of the disaster till Robert’s body was recovered.

Charles also raised some critical questions regarding the incident. “Pipelines might get ruptured. But why was there no mechanism in place to stop the water? Also, was there any alarm to warn the people working below about such an accident? And if there was an alarm, then why it didn’t reach the victims? Had they got the warning, it would have taken them less than five minutes to come out,” he said.

Prempal Valmiki, who had settled in Umrangso, hailed from Badaun, Uttar Pradesh. He had been working in this plant for three decades. His three sons, Biren, Umesh and Manoj were also on the site since October 7. Sources said that K Raju is a resident of Pithapuram near Vishakapatnam in Andhra Pradesh. His body will be handed over to his family after autopsy.

While the accident occurred on October 7 at the 29 Kilo area of Umrangso, rescue operations could start only after October 12 as rescuers had to wait for the water to recede. 

As the NEEPCO authorities failed to stop the flow of water, a team working in the Bhakra Nangal project in Himachal Pradesh was called. They along with experts from NHPC finally managed to close the intake gate of the tunnel stopping the flow of water from the reservoir.

When asked why it took so much time to find the victims, Sanjeev Kumar Sinha, Assistant Commandant, 1st Battalion, NDRF told Mongabay India: “We reached here on the evening of October 10 and made it to the site on the morning of October 11. As the water was coming through at that time, there was no scope of carrying out any rescue operation. Only after the water was diverted, we could start our operation.”

Apart from 45 people from NDRF and State Disaster Response Force (SDRF), around 90 labourers employed by NEEPCO also joined the rescue operation. 

As much as 50 feet of debris had to be cleared manually and it took a lot of time to clear the mud and sludge, Sinha said.

“We didn’t have any idea about where these four people would be. We knew that they were trapped inside but we didn’t have any location or CCTV footage. Three floors of the power station are underground. They were found on the lowest floor,” he said.

Elwin Teron, who has been working as a mechanical cleaner for NEEPCO in the Kopili HEP since a year-and-half, played a pivotal role in the recovery of the dead bodies.

Riki Phukan, District Project Officer, Assam State Disaster Management Authority (ASDMA) acknowledged Teron’s contribution, saying: “The powerplant is not like a normal building. There are tunnels inside rooms through which heavy machinery is moved. Our rescuers were obviously not familiar with the way things are inside the building. So, we needed someone from NEEPCO who knows his way around here. Teron, who is very well versed in the building layout volunteered. He was given swimsuits, oxygen masks, and lights. He guided our team on the floor and helped them locate the bodies.”

Phukan, when asked about the safety measures put in place at the plant, said, “NEEPCO authorities said that they had fluorescent lights on the stairs. They didn’t have a siren because its sound would be overshadowed by the sound of turbines. When water entered the plant, all the battery banks submerged. All these happened within seconds.”

He said that a letter has been sent to NEEPCO asking whether mock drills were held on the plant site.

Regarding probable measures to prevent such accidents in the future, he said ASDMA will write to the state government told conduct safety audits involving concerned departments in industries, especially power plants.

More disasters waiting to happen?

Following his loss, Albertson Tisso has demanded a CBI investigation into the matter even as the Assam government has decided to carry out an inquiry on the matter. 

A high-powered committee headed by the Hill Areas, Mines, and Minerals Minister Sum Ronghang and constituted by Assam Chief Minister Sarbananda Sonowal in the wake of the disaster recently visited the accident site. They have said that the disaster “could have been avoided”, and the “negligence on the part of the NEEPCO authority is apparently visible”.

NEEPCO sources said that it will take six to 12 months to study whether the plant will be viable again. As per sources, the disaster affected 800 metre of the project area and 90 percent of the machinery. NEEPCO stands to lose approx Rs 600 crore from the disaster.

Apart from Kopili, NEEPCO has four other hydroelectric plants in the northeast region- Ranganadi Hydro Electric Plant in Arunachal Pradesh, Doyang Hydro Electric Plant in Nagaland, Pare Hydro Electric Plant in Arunachal Pradesh and Tuirial Hydro Electric Plant in Mizoram. Right now, work is going on in the 600 MW Kameng Hydro Electric Plant in Arunachal Pradesh, which has hit hurdles due to leakage from damaged penstock.

SANDRP, in a submission to the Expert Appraisal Committee in September 2013, had raised a number of issues about the Kopili HEP while the EAC was considering clearance for the lower Kopili HEP, including the issue of corrosion of the parts of the Kopili HEP and issue of safety.

“The lower Kopili HEP also faces a similar risk,” added Thakkar.