July 25: A three-storey-tall lump of solidified fly ash today lay submerged in the depths of the Hooghly, threatening to defile its waters and defying the frantic efforts of a team of divers to disintegrate it with a jackhammer.
The site of the frenetic activity to drill the cement-like block was so deep under water that not a ripple was visible near the surface off Budge Budge, where a Bangladeshi cargo ship ferrying fly ash from CESC’s Kolaghat and Budge Budge plants sank at sundown yesterday.
The rush to break up the mass — formed after water worked overnight on 750 tonnes of fly ash — was fuelled by fears that it could contain arsenic, which is toxic and could be potentially damaging to fish and underwater plants. The lump and the ship together are now as high as 35 feet.
“With the current, the fly ash will spread like a concrete layer across the riverbed and destroy aquatic plants. What they should try to do is extract the fly ash and load it on another barge to lessen damage,” environment expert Sudipto Bhattacharya said.
He said it was all very well to try to carve up the mass, but the broken bits would have to be scooped out immediately. Else the damage to the aquatic ecosystem would be immeasurable.
“If the fly ash contains arsenic, there is a risk that it will eventually move into the water and into fish,” added Tapas Chakrabarti, a scientist at the National Environmental Engineering Research Institute in Nagpur.
Another scare was that the submerged Khulna-bound ship was blocking the flow of water and leading to a pile-up of silt on the riverbed, Bhattacharya said.
“This would make the riverbed rise along this stretch, which in turn would lead to the water overflowing the banks and eroding them. The more time they take to salvage the ship, the worse would be its effect.”
The entire process could take three to four weeks, said A. Ghosh, in charge of shipping company Tirupati Vancom’s salvage operations.
“Fly ash is cement-like in nature and has solidified after coming in contact with water. We are using an underwater jackhammer to crack the fly ash and unload it into the river to help the ship re-surface,” he said.
A diver involved with the operations said it was not possible to set up a crane on the riverfront and tug the ship out.
“Once we unload the cargo, we will attach iron chains at both ends and tug it out in a horizontal direction and simultaneously pump out the water trapped inside,” he said.
But with each passing day, things would get tougher, he warned. “Nearly 4 inches of silting has taken place since yesterday on the surface of the barge.”
Environmental scientists in Delhi said the fate of the lump could also be determined by the force of the water and the chemistry of the sediment. A fast current could quickly flush it downstream, while a weak flow or a depression on the riverbed could “trap” it.
In case the fly ash remained stuck in the riverbed, periodic surveillance of the fish would have to begin within weeks and be continued for at least three years, Nagpur scientist Chakrabarti said.
Anger simmered in the Indira Ghat area in Budge Budge, some 20 km from Calcutta, with local residents Naushad Sheikh and Manoj Bag demanding that CESC and Tirupati Vancom’s Rajiv Agarwal stop “polluting” the river further.
“Waste water combined with fly ash that flows out of the power plant has already polluted the water. Extra care should also be taken during the loading of fly ash,” Sheikh said.
Tirupati Vancom, one of three companies that exports fly ash to Bangladesh, ferries 1,100 tonnes daily. About 2,400 tonnes are produced at the CESC plant.
A Bengal environment department official said a team had visited the spot and asked Calcutta Port Trust to furnish a report.
“There are allegations that the ship was over 17 years old. If this is true, we would like to know how it entered Indian waters. Indian law does not allow entry of ships over 15 years old,” he said.
Environment secretary M.L. Meena has ordered the state pollution control board to undertake a probe and sampling of waters to gauge the extent of damage.
With inputs from G.S. Mudur and Jayanta Basu