A joint committee headed by the Dakshina Kannada Deputy Commissioner that was constituted by the National Green Tribunal (NGT) to inquire into the fish kill in the Phalguni (Gurupura) reported by The Hindu on April 26, 2022, has said that the Mangaluru City Corporation has to take immediate action to prevent flow of domestic sewage and solid waste through storm-water drains into the river course.
The NGT Principal Bench took up a suo motu case after the news report on April 29 and constituted the joint committee to inquire into the issue.
The committee, however, said that fish kill in creeks upstream the Phalguni near Kenjaru Gutthu Mane in Kenjar and surrounding areas was an isolated and small incident, possibly by organic/ sewage load dumped in the particular location leading to oxygen stress during the summer.
It further said that no traces of industrial effluent was observed in the storm-water drain where the fish kill occurred. Though the dissolved oxygen (DO) level in these creeks was about 0.9 mg/l, the level at the point where the drain joins the river was about 4 mg/l, indicating that the fish kill was due to inadequate tidal flushing in creeks and the drain resulting in reduced DO levels.
No fish kill occurred in the main river course while its water quality met Central Pollution Control Board-designated best use standard of Class-C, except for Biochemical Oxygen Demand (5-7 mg/l), the report said.
Baikampady
The committee said that major water intensive industries in the Baikampady Industrial Area have provided in-house effluent treatment plants (ETP) and some have Zero Liquid Discharge, while a few smaller ones are yet to have ETPs.
Sullage was discharged into storm-water drains from godowns, commercial establishments and labour quarters, as the area does not have proper underground drainage system. There is no proper collection of solid waste either in the area.
Domestic sewage
Plenty of domestic sewage joins the river through storm-water drains that are filled with solid waste near ELF Gas Plant, Kulur Church, Dambel, Skate City, Boloor and Kudroli, the committee said.
Post-construction of the Maravoor Vented Dam, the river does not get minimum flow of fresh water during the summer leading to build-up of organic load and fish kill.
Solutions
The city corporation and the Karnataka Industrial Area Development Board have to provide underground drainage and solid waste management facilities at Baikampady Industrial Area and areas around Baggundi Lake. The city corporation has to prevent the entry of domestic sewage through storm-water drains and dumping of sewage by cesspool operators. Bajpe Town Panchayat and Jokatte Gram Panchayat should provide underground drainage and sewage treatment facilities in their limits.
The Minor Irrigation Department has to conduct a comprehensive survey to identify and remove encroachment on river banks, while the Zilla Panchayat should ensure adequate fresh water flows into the river from Maravoor dam.
