The Wetland Authority of Delhi has informed the National Green Tribunal (NGT) that it has identified six drains contributing to the pollution in Najafgarh Lake, adding that the Municipal Corporation of Delhi (MCD) has now begun to desilt these drains.
The authority, which submitted a report on the status of an environment management plan (EMP) prepared for the rejuvenation of the lake, has also said it has identified the need to construct 14 decentralised sewage treatment plants DSTP) around the lake — three of which will be built in the “core zone” of the lake.
In September 2021, the Delhi government prepared an EMP listing the short, medium and long-term measures the state would take to revive as well as protect the lake, after directions from NGT. The latest report, submitted on December 21, 2023, detailed the status of the action taken by the government since the January 2022 NGT order asking for the EMP to be executed.
SWA said the 14 DSTPs will take care of the sewage generated in the vicinity of the lake at present and have been planned keeping in mind the estimated increase in the quantum of sewage in the next 15 years.
“Delhi Jal Board has submitted they are installing 14 decentralized STPs, including three in the core area of the lake. DJB has been asked to submit details on their plans to reuse the treated water from these DSTPs,” the report said.
The core zone of the lake is below the contour level of 209 metres. The report added that the Municipal Corporation of Delhi had carried out a detailed gap analysis over the past year, including drains contributing to the flow and the overall pollution of the lake. “The MCD has identified six drains. All the six drains are being monitored and being desilted periodically,” it added.
The other short-term measures part of the EMP include the commissioning of a species inventory of birds around the lake, along with a hydrological assessment of its water level. SWA said it initiated both these processes, with a bathymetric survey carried out for “critically silted” areas, while the forest department completed a preliminary bird survey.
“Regular monitoring of the bird population will be done by the Salim Ali Centre for Ornithology and Natural History (SACON) in Coimbatore,” it added.
Environmental activists, meanwhile, said that a large chunk of the sewage and effluents were reaching the lake from Haryana. “This makes coordination with the neighbouring state equally important. Delhi’s efforts alone cannot help. Haryana too has to help and until these DSTPs come up, the government needs to ensure no further encroachments come up in the vicinity of the lake,” said activist Diwan Singh.