BWSSB drops project to develop natural treatment of sewage in Arkavathy, Bellandur

The projects aimed to utilise aquatic plants and enzymes to cleanse Bengaluru’s sewage.  

It will probably be back to brick and mortar of sewage treatment plants (STPs), as the Bangalore Water Supply and Sewerage Board (BWSSB) has dropped two ambitious projects to utilise natural systems of aquatic plants and enzymes to cleanse the city’s sewage.

Among the first projects aimed for was the cleaning of the immense quantities of sewage pouring into the Tippagondanahalli reservoir, whose 135 million litres of water could provide Bengaluru with an alternative water source. Since 2012, pumping of water has been stopped as the water was deemed too contaminated for the purification systems — a result of Bengaluru’s urbanisation push into the northern outskirts. However, a ₹9.8-crore Natural Biological System (NBS) was planned at the confluence of Madavara Nalla with the Arkavathy River Valley, funded by the Karnataka State Pollution Control Board.

Tenders were floated thrice, and only in the final attempt in 2017 did a company qualify for the project. “We even issued a letter of expression, but the company did not come forward to sign the agreement. They believed they could not deliver on the price quoted,” said a senior BWSSB official.

In its place, the officials have now started surveying land for the creation of an effluent treatment plant to treat sewage. This proposal is expected to cost more and will take significantly more time to implement, said officials.

According to project documents, the NBS system was to come up on 2.4 km of the drain, including 1.6 km of wetlands. It was to treat 12 MLD of sewage during the dry season. At least nine types of plants would line the banks and drain bed to purify the water.

Meanwhile, officials also reported that a bio-remediation project, using a combination of enzymes and aquatic plants, was planned on 6 km of storm-water drains leading to Bellandur. The hope when tenders were called last year was that this would dilute the sewage and cleanse the lake until STPs were constructed. “But, the committee overseeing Bellandur lake rejuvenation has termed this infeasible. While the project has been withheld, we expect the Central Pollution Control Board to give us a letter that would allow the project to be formally dropped,” said an official.

While both projects have not been vetted or reviewed by independent researchers, Sharachchandra Lele of Ashoka Trust for Research in Ecology and the Environment said the dismissal of new technologies shows a lack of institutional backing or long-term thinking in the board. “There is little spending on research and development, and little expertise within the BWSSB. Experiments should continue in smaller scales to find new technologies. There should be a much more consultative, adaptive policy,” he said.

This article is closed for comments.
Please Email the Editor

Printable version | May 16, 2021 10:17:12 AM |

Next Story