The State Pollution Control Board has initiated action against local bodies and industrial units found polluting the Periyar River, based on the water quality levels at select monitoring stations.
The Ernakulam Regional Office of the board has asked the Kalamassery Municipality to clean up the Thoombunkal thodu based on the finding that industrial discharge and indiscriminate waste disposal had led to the depletion of oxygen levels at Puthalamkadavu, one of the monitoring stations identified by the board.
Besides Puthalamkadavu, the board takes samples from Vettukadavu, Pathalam bridge and the Kerala Water Authority's pumping station at Aluva.
Investigations by the board found that the dissolved oxygen concentration was very low at Puthalamkadavu compared to the other stations. The level was below four, the tolerable level specified for the stretch on various occasions. Testing of samples and enquiries by board officials revealed that heavy organic load being carried to the river through the Thoombunkal thodu was the main reason for depletion of oxygen level.
M. S. Mythili, the chief environmental engineer of the board in Ernakulam, said that industrial discharge from Kalamassery industrial estate and from Kalamassery dumping yard, the decay of the algae booms in the upstream side and indiscriminate waste disposal in to the stream at the NAD area also contributed to the decrease in levels of dissolved oxygen content.
The board issued directions to stop the discharge of untreated effluent in to the river from a food industry at Kalamassery. Ms. Mythili said that the Kalamassery municipality was also asked to stop the discharge from the dumping yard. De-sludging and de-weeding of the canal can solve the problem of depletion of dissolved oxygen to a great extent. With the help of temporary bunding arrangements, the leachate flow from the dumping yard has been regulated considerably, she said.
Tests showed that the average biochemical oxygen demand at the Aluva drinking water station in October was 0.2 mg/l against the limiting value of 3mg/l. The maximum value of total coliform observed was 3100 count/100m against the prescribed maximum total coliform bacteria organism count of 5000 per 100 ml.
The Hindu has been publishing the water quality data provided by the board daily in public interest.
