Activists question lake report

CSIR-NEERI report, submitted recently to the High Court, is lacking in rigour, they contend

Environmentalists are sceptical about a report on Bengaluru lakes prepared by a government agency and fear it may result in greater ecological damage.

The National Environmental Engineering Research Institute, administered by the Council of Scientific and Industrial Research and based in Nagpur, has prepared the report on the directions of the High Court. It says 21 of Bengaluru’s lakes have water fit for drinking.

Environmental groups dispute this observation and fear it may lead to improper planning. One of the opposing voices is Leo Saldhana, coordinator, Environment Support Group (ESG). He has filed a writ petition in the High Court, drawing its attention to contentious aspects of NEERI’s recommendations.

NEERI’s approach is guided by environmental engineering, as opposed to a socio-ecological understanding, he says.

An earlier committee, headed by Justice N K Patil, was set up by the High Court in response to a petition by ESG, challenging the privatisation of the management and rehabilitation of lakes in Bengaluru in 2008. It was to help in formulating a long-term plan to conserve and manage lakes in Bengaluru by involving top officials of nine government agencies. The High Court accepted the Patil committee report on March 3, 2011. Its implementation is being monitored quarterly by the court. The CSIR-NEERI report may result in a change of priorities, environmentalists believe.

Sampling doubts

V Ramprasad, co-founder, Friends of Lakes, says the latest report by the Karnataka Pollution Control Board, covering April to December 2020, says no lake in Bengaluru has water fit for drinking.

“How did we go from having no lakes under Class A or B (see box) to having 21 lakes with water fit for drinking? Which of the two reports is then correct?” he says. The NEERI report, he says, needs to be made available to experienced scientists for peer review, as is the norm in academia and science, he says.

Nirmala Gowda, trustee, Bengaluru Environment Trust, says the report is based on ‘grab samples’.

“Grab samples are a snapshot in time and are not representative of the complete pollution profile of the lake. Taking grab samples is shoddy scientific work,” she says.

Composite samples collected at regular intervals give a better profile, but NEERI took a shortcut because of time constraints, she says.

“NEERI has not caught up with the times. Complex chemicals are at play in our everyday products which end up in sewage,” she says.

She cites the example of triclosan, present in sanitisers, soaps, plastics, lipsticks, face creams, and toothpaste.

“With incessant handwashing to prevent Covid-19, we are inevitably dumping huge amounts of toxic triclosan into the water bodies. Has NEERI tested the lake waters for triclosan or at least considered the risk? Have they tested the water bodies for the presence of the Covid-19 virus or at least considered the risk?” she says.

She also questions the recommendation to dredge and desilt some lakes. “All these pollutants settle in the sediments. By dredging up the lake bottom, we are translocating pollutants. Lake restoration is prosperity for contractors and it does very little for the lake,” she says.

Story of three lakes

Based on the measures suggested by NEERI, the High Court has directed the BBMP to initiate steps to restore three of 19 lakes in the city. These include lakes in Kamakshipalya, Arehalli and Tavarekere.

The remaining disused lakes cannot be restored, according to the report. It recommends that private and public encroachments be removed, but structures set up by the government for the sake of the public, such as bus stands and graveyards, remain.

The ESG petition fears such recommendations legitimise encroachment by public agencies.

The BBMP has other concerns. “The area left around Kamakshipalya lake is too small and implementation may not be possible,” says Mohan Krishna B T, chief engineer in the civic body’s lake department.

However, the BBMP has agreed to take up restoration of Arehalli and Tavarekere lakes.

The ESG petition says lakes can be revived “by removing accumulated silt in a manner that would result in foreshore areas being gently graded, and with the deepest desilted point being near the bund.”

This method, it suggests, would help improve biodiversity, attract waterbirds and help in cleaning the waters naturally.

Institute says

Shaikh Basha, head of the Hyderabad sector, CSIR-NEERI, says some of the contentions come from a misunderstanding of classification parameters.

“We studied the water, the pond sediment quality and other factors to rank it on a scale of 0-100 based on the water quality index. A score between 0-25 suggests that the water can be used for irrigation, and for drinking after treatment,” he says.

The team has collected samples from the surface, middle and bottom of the lake.

This method gives a total picture, he says. Basha says the study only says 21 Bengaluru lakes have drinking water, but not that they have “potable water.”

However, the distinction is flawed, say experts. The report does not specify the need for treatment, as Karnataka Pollution Control Board does in its classification.

For all practical purposes, potable water refers to water fit for drinking, they say.“All lakes are potentially potable, but none can drink from the lakes in the city as is. Such distinction has to be clarified,” says Saldanha.

Lake classification

The Karnataka Pollution Control Board classifies lakes into five categories, based on the water quality: A, B, C, D and E.

Class A: Lakes that can be drinking water sources without conventional treatment.

Class B: Lakes with water that can be used for outdoor bathing.

Class C: Lakes with water that can be used for drinking with conventional treatment, followed by disinfection.

Class D: Lakes fit for propagation of wildlife and fisheries.

Class E: Lakes that can be used for irrigation, industrial cooling and controlled waste disposal.

Environmentalists’ question

‘How did we go from having no lakes under Class A to having 21 lakes with water fit for drinking?’

How reports came into picture

A division bench headed by Chief Justice A S Oka was hearing petitions seeking directions to the BBMP to ensure effective maintenance and monitoring of the stormwater drains in 2019.

TThe High Court directed the BBMP to appoint CSIR- National Environmental Engineering Research Institute to study Bengaluru’s lakes and recommend short-term and long-term measures for their upkeep.

BBMP brought on record CSIR-NEERI’s Phase 1 report in December 2020. Its Phase 2 report, which is to follow, will delineate a plan for each lake.