Sewage killing lakes, city needs a ‘drain brain’

Bengaluru’s lakes, among the most polluted in the world, are only getting worse. Recent data from the Karnataka Pollution Control Board shows that water quality remains very poor, while the state government and BBMP received a rap from the National Green Tribunal for making no progress on lake rejuvenation. The trouble is that the storm water drains, which empty into the lakes, carry sewage. Also, as the BBMP has failed to appoint marshals to keep watch, garbage is dumped in the lakes, making the situation even worse, reports Aksheev Thakur

On November 1, the National Green Tribunal put the Karnataka government and the BBMP on the dock for failing to improve the condition of Bellandur and Varthur lakes, two of the city's most toxic spots. The  NGT even demanded with civil imprisonment should not be ordered against the officials concerned, for failing to comply with the court's earlier orders.

The BBMP had been given the task of implementing measures to rejuvenate both these lakes but as is evident, nothing has happened on ground. Reports say that the condition of the lakes has deteriorated over the last year, despite the NGT and Bangalore Development Authority suggesting that a panel be constituted to deal with the matter.

Other lakes have fared no better. Not a single lake or tank within the city or rural limits has met the satisfactory Water Quality Index (WQI) over the last several months. Data released by the Karnataka State Pollution Control Board shows that not a single water body in  Bengaluru shows satisfactory water quality. Since April, the lakes have remained in the D and E categories.

Entry of sewage through Storm Water Drains
The entry of sewage into the lakes is one of the major reasons behind worsening water quality. Sewage flows through Storm Water Drains (which, strictly speaking, should not be the case) and as these connect with the lakes, directly into the already-ailing waterbodies. Local sewage treatment plants are the answer to this but there are none.

"If a lake is 15 acres, then two acres should be wetlands. The BBMP took up 75 lakes for rejuvenation but has only completed work on around 20," says Jagadish Reddy, lake warden at Varthur Lake. "Since we don't have the space to put up Sewage Treatment Plants for every lake, micro STPs are an alternative. We need local treatment plants," he says.

Officials in the BBMP are of the opinion that the STP should be decentralised and, passing the buck as always, say BWSSB should ensure that sewage doesn't enter the storm water drain. "We need to have a responsible sewage mechanism," says a BBMP official. "The only reason behind the bad WQI is the non-separation of SWDs from sewage drains. Since SWDs are linked directly to the lakes, the sewage discharges into the water bodies. When there is heavy rain, we do divert the sewage from the lakes," he adds.

No lake marshals
On August 14, the BBMP's finance department approved funds for the deployment of marshals at Varthur Lake. However BBMP sent a letter to BDA, asking them to take care of the lake, citing a shortage of funds. "Garbage is dumped into the lake, enabled by illegal Bangladeshi settlements around the area. We still await CCTV cameras and streetlights around the lake. Moreover, the fencing of the lake has also not been completed," he said.