Chennai Corporation to address direct leachate discharge from Perungudi dumpyard into Pallikaranai marshland

The Hindu

21-04-2025

The Pallikaranai marshland may see reduced contamination if the Greater Chennai Corporation (GCC) goes ahead with its plan to engage experts from Anna University to address the issue of direct, untreated leachate discharge at the Perungudi dumpyard.
The Hindu had recently published a news report, which said the leachate released from piles of fresh garbage has been flowing into the freshwater marshland, without undergoing treatment or processing.
GCC Commissioner J. Kumaragurubaran said while a leachate management unit is in place at Kodungaiyur, similar facilities are not available at Perungudi.
The private firms handling biomining at Kodungaiyur dumpyard, where biomining began recently, have partnered with the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) to establish a tertiary treatment reverse osmosis (TTRO) plant and a sewage treatment plant (STP). These have not yet been established at Perungudi, he said.
'Just concrete structures, retention walls, or barricades would not be scientific solutions. Therefore, experts from Anna University will be consulted for long-term solutions to manage the leachate, including methods for handling discharge depth, in-situ treatment, or transferring it off-site,' he added.
Leachate from legacy waste
The ₹350.64-crore biomining project to process legacy waste at Perungudi, spread across over 34 lakh cubic metres, is underway and being taken up in three sections. The project was sanctioned under the Swachh Bharat Mission.
Due to delays and inadequate work by one of the two firms involved in the biomining process, the issue was taken up for arbitration in the Madras High Court and was only recently resolved, according to the GCC.
Regional Deputy Commissioner (South) M.P. Amith, who inspected the dumpyard on Thursday (April 17, 2025), noted that the initial contract with both concessionaires, i.e. private firms, mandated the implementation of a leachate treatment plant. However, the current status of this clause and its implementation needs to be reviewed, as arbitration was involved with one of the two concessionaires.
Another senior GCC official said: 'The other firm that completed the biomining project in three packages had set up a leachate treatment plant at the the Perungudi dumpyard. The treated leachate from this plant was used as biofuel. The GCC has requested technical details from the company regarding the amount of leachate treated, the processes involved, conversion to biofuel etc.'
The reclaimed land at Perungudi now covers over 90 acres. 'We had announced the setting up of two windrow plants, which will have leachate collecting and processing tanks with a capacity of 4,500 MLD each,' the official said. A windrow composting plant is a facility where organic waste is decomposed in long, narrow piles called windrows, which are regularly turned over for aeration.
'Further, an STP from CMWSSB is located on Corporation Road near Radial Road in Perungudi, where further treatment can be done and the final product can be reused for vermicomposting. These plans are set to be presented for approval in the upcoming Council meeting, and then for administrative sanction from the State,' he stated.
Notably, in the Micro Composting Centres (MCCs), water is collected in underground storage units via silt catch-pit-like structures and is reused for vermicomposting after treatment, he added.