Dissolved Oxygen content in Periyar nosedived after water flow was disrupted

Disrupting the flow of Periyar near Pathalam Bund for constructing the regulator led to fish kill in the area, according to officials.

The Dissolved Oxygen (DO) content in the water plummeted following putrefaction of organic matter and disruption in water flow during the past three days. The DO level has gone down to 1mg/litre though it would require at least 4mg/litre for fishes to survive. Water has been stagnant in the area as the flow was cut off, according to officials of the Kerala State Pollution Control Board.

The Irrigation Department officials in charge of the river system and responsible for maintaining the water flow in the sector could not be contacted as the offices remained closed for the past two days. A communication would be issued to the officials on Monday, said an official of the Pollution Control Board.

The reduced oxygen levels in the system will not affect the drinking water supply as the intake wells of the Kerala Water Authority are located upstream but would hit the aquatic fauna. The water quality could be improved by releasing more water and removing the barricades, he said.

The officials of the board scorched the charges that release of effluents from the industrial units caused the fish kill. No major industries were located upstream of Pathalam bund and the ones functioning there had slowed down production. No fish kill had occurred in the area during the past year and the industrial units didn’t have the capacity to store the effluents for long. Major industrial units were located downstream away from Pathalam bund, he said. The reduced DO should be blamed for the fish kill, he said.

Last week, the board launched a real-time water quality monitoring system for the river system where the water quality parameters would be displayed at the electronic display board set up at FACT junction. Water samples are collected from the upstream and downstream areas daily so that discharges from the industrial units could be monitored, he said.

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