Ulsoor Lake STP to be ready in six months

Sewage will be treated before being let into the lake area

A sewage treatment plant is being constructed at Ulsoor lake, in Bengaluru.

The centrally-located Ulsoor Lake, which rose to infamy after turning into a graveyard for fish last year despite being known as one of the better maintained lakes in the city, is finally getting a sewage treatment plant. The plant, work for which is already under way promises to treat sewage water being let into the lake.

Construction has begun and officials of the Bangalore Water Supply and Sewerage Board (BWSSB) said the STP, coming up on a 30x30 m area, will be completed in six months. The Karnataka State Pollution Control Board (KSPCB) is also pitching in for the plant. “At present, the sewage being let in is let out into a restricted area near the lake. The STP being built has a capacity of one lakh litres. Once functional, sewage water will be treated in the plant before being let into the lake area,” said M.P. Adarsh, civil engineer, BWSSB.

Last year’s fish kill episode had exposed the dumping of solid and wet waste in that part of the lake. The inflow of untreated sewage from surrounding areas was listed as one of the reasons for repeated fish kills as ammonia levels in the water increased and oxygen levels decreased.

The story is a similar one for other city lakes too. An Indian Institute of Science (IISc.) study, conducted by T.V. Ramachandra and a team from the Centre for Ecological Sciences, studied the fish kill in Ulsoor Lake and two other lakes.

Researchers explained how broken down nutrients from bio-degradable solid waste dumped into the lake increase the concentration of ammonia and other nutrients in water.

Tushar Girinath, chairman, BWSSB, said more STPs will be installed in other lakes in the coming months.

These include Hennur and Hulimavu lakes. “Around eight decentralised STPs will be installed close to the lakes,” he said.