KOCHI: Dead fish, pungent smell and a discoloured Periyar greeted the residents along the banks of the river at Manjumal and Pathalam on Saturday. The trouble in Periyar seems to be compounding. The municipality is investigating while the PCB plans strictures.
“The colour of the water had turned black and an unidentifiable smell was wafting in from the river. At first, we thought someone might have dumped septic waste into the river. But, further investigations had us doubting the earlier explanation,” said Shiny Antony, chairperson, Health Standing Committee, Aluva Municipality.
According to her, the water is emitting a rotten egg smell. “We are also investigating whether the discolouration and smell are due to the effluent being dumped into the river by the factories along the banks,” she added.
However, the PCB is very critical about the situation. “This is not a new situation. Periyar has been bearing the brunt of pollution for the past many years. The recent issue has been inspected by the PCB chairman and he has decided to take strict action,” said P B Sreelakshmi, engineer, PCB. According to her, an action plan to save Periyar had been submitted by the PCB three years ago.
“But municipality has done nothing to implement it. If the action plan had been implemented, then the present situation could have been avoided,” she said. According to her, the discolouration of Periyar is due to the algae bloom. “You can see that discolouration is black in some places, milky white and green in others. This actually presents the life-cycle of algae. The algae grows, blooms and then dies. The dying plants decompose turning the water black and also emit a foul smell,” she said.
“The chemicals released by the decaying algae reduce the dissolved oxygen content and kill the fish. This might be the reason for the fish deaths,” she said. The boom in algae growth is due to the high concentration of nutrients in the river water, she added. “Another factor behind the discolouration is zero movement of its water. The water is basically stagnant and today the river looks like a large lake,” she said.