Civic agencies have been caught napping by the order of the National Green Tribunal (NGT) for immediate stoppage of the flow of untreated sewage into Bellandur lake and desilting within one month. For the past one year, they did not bother to undertake any of the preparatory measures ahead of implementing long-term solutions.
Sources said the agencies plan to seek more time to implement the order.
The Expert Committee on Rejuvenation of Bellandur Lake, chaired by additional chief secretary, Urban Development Department, in its October 2016 report had laid down a roadmap for rejuvenation, which includes short-term (six months) measures and long-term measures. “The agencies haven't begun work on any of these measures. This has rendered the latest NGT order unimplementable,” said A.N. Yellappa Reddy, member of the expert committee.
“Even basic steps like fencing the lake, clearing encroachments, de-weeding, and stopping the dumping of solid waste, construction and demolition debris are yet to be undertaken,” said Sridhar Pabbisetty, CEO, Namma Bengaluru Foundation, and a member of the expert committee.
As of today, of the 480 MLD of sewage entering the lake, only 250 MLD is being treated. BWSSB has been working on two Sewage Treatment Plants (STP) of 90 MLD capacity at Ammanikere and 60 MLD in the Koramangala-Chellaghatta Valley, which had a deadline of March 2017. However, BWSSB has sought time till July 2017.
“The work got delayed for various reasons and it will be completed by July without any further delay,” said Kemparamaiah, engineer-in-chief, BWSSB.
Once the two STPs are functional, the untreated sewage will come down to 80 MLD. It will also enable cleaning and desilting, the expert committee report had noted. The report said that desilting can be taken up when untreated sewage inlet volume is less than 100 MLD or on April 1, whichever comes first.
“Desilting the lake without stopping inlet of sewage will be an exercise in vain,” said Mr. Reddy.
Wetlands only solution
With STPs yet to become functional, a low-cost bio-mechanical wetland may be the only way to stem the flow of sewage. A combination of sit traps, meshes and water-purifying plants is being considered to improve water quality, said members of the expert committee on Thursday.
A.N. Yellappa Reddy, member of the committee, said that they had advised civic agencies to immediately start creating wetlands around the lake. “It is no replacement for STPs, but an interim measure to improve water quality,” he said.
The Karnataka Lake Conservation and Development Authority (KLCDA) had been pushing for this option, but the BDA and BWSSB did not follow through.
KLCDA is enabling wetlands in Agara Lake, which is upstream of Bellandur. Through natural and mechanical processes, raw sewage is diluted and reduced, which is giving the lake a chance to survive and heal itself.
Activists have been pushing for wetlands at the inlets to be included in the design when lakes are being rejuvenated by civic bodies.
STPs in apartments under the radar
The proverbial missing link in ensuring no untreated sewage is let into the lake is the gap in Sewage Treatment Plant (STP) infrastructure in apartment complexes around the lake.
A study by Ashoka Trust for the Environment and Ecology (ATREE) in 2015 revealed that of the 2,200 apartments that consented to install STPs, only 612 complied and the installed capacity is 109 MLD.
The expert committee on rejuvenation of Bellandur lake wants civic agencies to ensure that all apartments let only treated water to the lake and proposed live monitoring of the STPs and quality of water discharged from each apartment.
However, neither KSPCB nor BWSSB has begun enforcing norms.
