The National Green Tribunal (NGT)-monitored rejuvenation process for the infamous Bellandur and Varthur lakes in Bengaluru has faced fresh opposition. The Bangalore Environment Trust (BET), a noted pro-environmental NGO in the city, has questioned the merit and practicality of desilting the lakes by spending crores of rupees, without stopping sewage entering the lake at first. 

In a detailed letter submitted to the government and relevant authorities, Yellapa Reddy, a former IFS officer and Chairman of BET, has raised concerns over how the government will extract and use 20 million tonnes of silt, which may be toxic. The letter has been signed by many experts in lake rejuvenation and environmental governance, including Harini Nagendra, Professor of Sustainability at the Azim Premji University.

Incidentally, this move by BET has made another section of activists unhappy as they feel all the work done over the last year, as per the current plan, will be undone if it is delayed and if the desilting work is not finished by the monsoon.

One-time cleaning plan

Bellandur lake is the largest lake in Bengaluru, and receives water from three upstream lakes. Bellandur lake flows into Varthur lake, then to Dakshina Pinakini river as part of the connected tank systems of Bengaluru. Pinakini continues to flow towards Tamil Nadu.

As part of the lake rejuvenation, the Bengaluru Development Authority (BDA), the custodian of the lake, has emptied or de-watered the lake, as advised by the NGT-appointed panel.

Additional temporary channels have been created to directly divert the water entering the Bellandur lake to Varthur lake. 

Meanwhile, tenders for desilting the Bellandur lake have also been floated. Desilting is expected to be completed before the onset of monsoon. Once the desilting process is complete, treated sewage will be let into the lake once again. 

However, according to NGT’s plan, this will be a one-time clean-up process. By September, another sewage treatment plant is set to be ready to ensure only treated water enters the lake. Once Bellandur lake is cleaned, Varthur lake will be de-watered and desilted.  

Once the clean-up of lakes is complete, clean water will flow into the river, the NGT argues.

Are we translocating pollution?

BET has questioned NGT’s rejuvenation plan, calling it ‘translocation of pollution’. Rejuvenation of one waterbody “should not spell a death knell to other water bodies”, it said.  

“If the objective is pollution abatement, then diversion work is in contradiction to that objective, as it allows the toxic wastewater to travel long distances and thus increase the pollution load of the water bodies downstream,” the BET said in its letter. 

According to the NGO, the activity is, in fact, in contravention to Section 24 in The Water (Prevention and Control of Pollution) Act, 1974. This section prohibits a person from knowingly causing or permitting any poisonous, noxious or polluting matter — per standards laid down by the State Board — to enter, directly or indirectly, into any stream or well or sewer or on land. 

“According to our Constitution, people downstream of Bellandur Tank also have the right to a clean and healthy environment. Bellandur Tank wastewater has already been diverted to Varthur Lake. Varthur Lake diversion is in the works. We request the government to pause, validate the approach via an Environmental Impact Assessment (EIA) and make the necessary course correction,” BET said. 

The BET also highlighted the thumb rule to prevent pollution — stop pollution at source. “Any enforcement programme to prevent pollution is a continuous activity and is cheaper than clean-up later,” the letter read

Speaking to TNM, Sharatchandra Lele, a lake expert who was part of the panel of Bellandur lake in the past, said that desilting is a hazardous, extensive and a resource-intensive process and it is fruitless if sewage keeps entering the lake. 

“Desilting should be an option only after all pollution sources have been eliminated. In some cases, it may not be required at all, because once clean water starts flowing in, pollutants might get gradually washed away on its own,” added Lele, who is a signatory of the letter.

The BET further argued that to desilt the Bellandur lake at a rate of 1000 tonnes per day will take a total of 53 years, and 20 years to desilt Varthur lakebed. 

NGT team confident about plan

Experts on the NGT-appointed panel, on the other hand, believe that the current rejuvenation plan will prove effective. 

According to TV Ramachandra, a veteran scientist at the Indian Institute of Science (IISc) who is part of the rejuvenation process, the Pollution Control Board and IISc have collected samples and sent for testing to prevent possible toxicity of the lake. “Based on the results, a plan will be drawn to scientifically deal with different types of silt. Besides, authorities have been asked to remain vigilant to stop effluents from flowing into the lake,” he insisted.

Regarding the concerns of pollution downstream, he pointed out that the polluted water has been flowing for the last 30 years. “If the decontamination is carried out at least now, clean water will flow, the water holding capacity of the lake will improve and subsequently, the water table in the area will be rejuvenated. The same model was followed for redeveloping the Jakkur lake. It has been 10 years now and it is still full of life,” he told TNM.

‘NGT-monitored plan backed by scientific study’

In a joint statement, citizen groups — Whitefield Rising, Varthur/Bellandur lake citizen volunteers — opposed the move by the BET. They said Environmental Impact Assessment should be done for Orange and Red categories of industry.

They pointed out that the current plan is backed up by scientific data of over 22 years, including a bathymetric study (of underwater depth of lake and ocean floors) of lakes by IISc and supported by Defence Personnel. “The Bellandur/Varthur rejuvenation is eco-friendly. This is being closely monitored by the National Green Tribunal and vigilant resident citizens around the lakes,” they said.

“These lakes have accumulated silt for over 50 years. Desilting is the need of the hour as waterborne diseases continue to affect the health of the residents living around the lake. We also believe the government agencies will dispose of the silt as per the applicable environmental laws and the norms set by the central and state Pollution Control Board.”