How to stop fishkill

After thousands of fish suddenly die at Ulsoor lake, can Bengaluru clean up its act and look into proper maintenance of the water bodies?

KARNATAKA - BENGALURU - 07/03/2016 : Large number of fish were found dead and floating in the morning and being washed ashore later in the day, at Ulsoor Lake, in Bengaluru on March 07, 2016. Photo K Murali Kumar.

From taking criminal action against those illegally letting sewage into Storm Water Drains to having the army’s speed boats ‘stir’ up the water daily, government departments got into a huddle to figure out why >thousands of fish died suddenly at Ulsoor lake.

On Tuesday, officials of the Karnataka State Pollution Control Board (KSPCB), Bangalore Water Supply and Sewerage Board (BWSSB), Bruhat Bangalore Mahanagara Palike (BBMP), Fisheries Department and members of the Madras Engineer Group – which helps maintain the lake – chalked out a list of directions to ensure fish kill does not happen again.

MEG, for instance, were told by the KSPCB to run their speed boats for an hour to increase oxygen in the water. “The engine stirs up the water and acts like aeration of the lake. We have suggested that they do this once in the morning and evening,” said Lakshman, Chairman, KSPCB.

Sewage inflow Officials blamed leakage from an inlet that passes close to MEG Centre – which brings in untreated sewage from Tannery Road, Frazer Town, Pottery Town – for the decrease in oxygen levels in the lake, which choked thousands of fish.

The silt trap, which is intended to capture sludge, is instead filled with garbage and has led to overflow of sewage. “We have started a survey of all properties illegally letting sewage into the drains. Once this is complete, criminal action can be taken,” said Krishnappa S., Engineer-In-Chief, BWSSB.

Minimum depth

Among the reasons discussed could be lowering the lake’s bed and increasing the temperature of the water. “A minimum of 2.2 metres (around 6 feet) depth of water is required for healthy marine life. This is not the case now. We have proposed construction of a 3 MLD Sewage Treatment Plant to ensure treated water is let into the lake,” said Mr. Krishnappa, adding that BBMP is yet to identify land for an STP.

Abattoir dumps sewage Is waste from a slaughter house among the reasons for Ulsoor lake becoming a ticking time bomb for the fish?

Activists have alleged that abattoirs in the area let out waste water directly into storm water drains that lead to the water body.

Kiran Kulkarni, who was involved in a clean up of Ulsoor lake in 2009, said, “The Tannery Road abattoir, for instance, has an Effluent Treatment Plant that is not working. Entrails and waste from thousands of animals eventually flow into Ulsoor lake,” he said, adding that the waste contains blood, droppings, fat and intestinal contents.

While Karnataka State Pollution Control Board (KSPCB) admitted that the ETP at the abattoir is a concern – and several notices had been sent, including just a week prior – it did not conclusively say that this led to the death of the fish.

“There are multiple factors that may have led to sewage inflow, or other reasons that led to the death of the fish. However, we have asked the BBMP to rectify this immediately,” said Lakshman, Chairman, KSPCB.

A BBMP official said while the British-era abattoir is struggling to handle the amount of animals being slaughtered – nearly 200 large animals and around 800 small animals – he dismissed suggestions that this led to the fish kill. “The ETP cannot handle the waste being produced, but even if blood is let into the drain, it clots immediately. It will not cause harm to the lake,” he said.

Issue to be discussed The possibility of similar incidents in many other lakes is expected to come up at a meeting scheduled on Wednesday between residents, activists and Karnataka State Pollution Control Board (KSPCB) officials.

The meeting will start at 2.30 p.m. at the KSPCB office on Church Street. The theme is “Programmes implemented by NGOs and Residents Welfare Associations in the field of lake rejuvenation and maintenance, their future plans in the said field and the expectation from the Karnataka State Pollution Control Board in this regard.”