Purana Qila lake revival being done as per IIT-Roorkee suggestions: NBCC tells NGT

State-owned construction firm NBCC (India) Monday told the National Green Tribunal that development work of the iconic Purana Qila lake here was being done as per the suggestions of the IIT-Roorkee and rainwater harvesting structures were being built for ground water recharge.

The NBCC, which submitted a 38-page report in pursuance to NGT's order, said that drawings for development works at Purana Qila lake were approved by the Archaeological Survey of India (ASI) and it was directed to seek expert advice from a reputed institute such as IIT for laying of the ethylene propylene diene terpolymer (EPDM) membrane in the lake and send the same to ASI.

"Accordingly, a detailed study report was sought by NBCC from IIT Roorkee on proposal to lay impermeable membrane beneath the Purana Qila lake. It is stated that Dr Bhanu Prakash Vellanki from the Deaprtment of Civil Engineering, IIT Roorkee submitted a report on the same which was duly forwarded by NBCC to ASI," it said.

The NBCC told the tribunal that IIT Roorkee report states that the benefits of maintaining a perennial source of surface water of good quality over an area of approximately seven acres outweigh minor concerns on ground water recharge and rain water harvesting structures can be built within the area.

"The report states that synthetic liners such as EPDM membrane have been extensively used in the west for creation of artificial ponds for aesthetic purposes, canal lining, swimming pool lining etc and there are no reported cases of water contamination," it said.

The NBCC also informed the green panel that no chlorination is being used in the lake water and the eutrophication of the water body was being done through "ABR technology".

A bench headed by NGT Chairperson Justice Adarsh Kumar Goel said it would go through the report and posted the matter for hearing on September 28.

The tribunal had earlier directed the NBCC to submit a report on the question whether plastic lining should be removed or whether alternative options for lake revival should be preferred. It was also asked to respond on the plea against chlorination of the water body.

The direction came on a plea filed by city-resident R K Gupta who contended that NBCC and the Archaeological Survey of India (ASI) have put a plastic sheet on the bed of the lake, preventing groundwater recharge by both treated recycled water and rainwater.

The plea said that the method of concretisation and laying down of the sheets will lead to damage to the lake.

"The ASI and NBCC should have noted that the Old Fort lake in its old form was unlined adding considerably to the groundwater recharge round the year in the area declared as critical by the Central Ground Water Board.

"By their act the two agencies have eliminated recharge through the bed of the lake causing grave environmental damage. The project as conceived and being implemented has adverse impacts on the environment, contrary to the ecosystem of the lakes," the bench said.

The petitioner has sought directions to restore the lake to its natural condition by removing impermeable plastic lining and explore alternative revival techniques for the water body.

The NGT had earlier slammed the ASI over the poor condition of the lake and summoned its senior official to explain why it had not been cleaned despite its direction.