With water downstream Malavoor vented dam in Gurupura (Phalguni) river turning blackish again on Saturday, the Karnataka State Pollution Control Board (KSPCB) is scrambling to identify the source of contamination.
G. Srinikethan, Professor in Chemical Engineering Department, National Institute of Technology (NITK), Surathkal, told The Hindu that prima facie the contamination appears to be because of faecal coliform. Prof. Srinikethan is assisting KSPCB in finding out reasons for the contamination.
He said untreated sewage let out to the river over a period of time must have contaminated the water downstream the vented dam, which becomes stagnant during summer, as fresh water does not flow down due to closure of dam gates. Only a hydrography test, which has to be got done by the government, could reveal the exact cause, Prof. Srinikethan said. The influence of industrial waste too cannot be ruled out, he said.
KSPCB Environment Officer Rajashekar Puranik, who was near the dam with Prof. Srinikethan, said the oxygen level in the water downstream the dam was less than 0.5 mgd. Oxygen level should be at least 3.5 mgd for aqua fauna, he said. The Board is inspecting each and every industry in Baikampady Industrial Area to find out discharge of effluents; but so far no such discharges were found, he said.
Mr. Puranik said every stakeholder, including the Mangaluru City Corporation (MCC), should work in unison to contain the pollution. Flow of untreated sewage into the river, which is in vogue at several places, including Boloor and Kudroli, should be stopped, he said.
Pungent smell
When The Hindu visited Malavoor dam site on Saturday, not only was the water turning blackish, but there was also a pungent smell emanating out of it. The smell appeared to be that of a chemical.
KSPCB, last week, got some chemical sprayed into the blackish water to neutralise pollution after water had turned greenish. However, it became blackish again on Friday and Saturday.
