If you are heading towards Perungudi, chances are you can feel a stark difference in the odour in the air. The unwelcome scent of pungent air is all thanks to the Perungudi dump yard.
“But people residing in Perungudi are used to the smell,” says P Sajeevan, a resident of the area.
Air, water and land are being polluted due to the presence of the dump yard.
The Greater Chennai Corporation has been dumping waste in the 200-acre dump yard in Perungudi for around three to four decades.
Perungudi dump yard harms extend beyond just the odour.
The dump yard on one side of the Ramsar-tagged Pallikaranai marshland, where leaches toxins and other chemicals into it, harming the natural ecosystem. Human health is also deteriorating around the dump yard.
Health issues are common among people living near the dump yard
“Chest congestion due to garbage burning and the methane smell from the dump yard is very common among people living near the area,” says Sajeevan.
“People also suffer due to breathlessness and other respiratory disorders,” says A Francis, president of the Federation of Thoraipakkam Welfare Associations, about the impact on health due to air pollution. His house is 600 metres away from the dump yard.
Last year, a major fire broke out in the Perungudi dump yard. Not only residents of Perungudi but people in Velachery, Adambakkam and Besant Nagar were also exposed to the smoke from the fire. Experts cite that the wet waste being dumped in the dump yard has led to the generation of methane gas. Methane can catch fire due to its highly flammable nature.
Not just air, but water is also being contaminated in and around the marshland. “You go more and more towards the marshland, you will see the groundwater turning more and more brownish,” says Sajeevan.
“Long-term exposure to the water has been causing skin diseases and hair fall among people,” adds Francis. “The leachate from the garbage goes into the land and then into the water table, polluting the groundwater. Some families of four spend Rs. 20,000 per month to buy fresh water from private contractors in Perungudi,” he continues.
Perungudi dump yard’s environmental impact
A researcher with the state government, who wished to remain anonymous, talks about how the Perungudi dump yard is affecting the marshland.
“The marshland’s fresh waterbodies help dragonflies and tadpoles to thrive. These species eat mosquitoes, keeping the mosquito menace at bay. However, with the freshwater being contaminated, the dragonflies and tadpoles are unable to thrive, leading to an increase in the mosquito population,” says the researcher.
The native fish population is also dwindling, thanks to the low oxygen concentration in the contaminated waterbodies. Moreover, the civic body has introduced mosquitofish (gambusia) which feed on mosquito larvae. But it is an invasive species, which takes up all the resources for survival, dominating the native species.
“There are 110 native fish species in the marshland. But there are five invasive species fishes. They do not allow other species to thrive,” explains Jayshree Vencatesan, Managing Trustee of Care Earth Trust.
However, the bird population in the marshland has not been impacted much, due to the availability of food in the garbage dumped.
“Even though the population will not be influenced much immediately, they will be negatively impacted down the lane,” adds the researcher.
The waterbody near the dump yard turned pink last year due to the presence of algal bloom and other bacteria, which could have been facilitated by the leachate from municipal organic wastes and heavy metal pollution.
The contamination of the waterbody was so high that even the migratory birds that usually visit the spot were absent.
The researcher shares an indicator to note the contamination in the marshland. “Ditchjewel dragonflies are an invasive species that thrive in areas with polluted waterbodies. The presence of this insect shows that the waters are contaminated.”
Not only garbage leachate spoils the ecosystem, but even illegal sewage inflows which join the Pallikaranai marshland also pollute the area, killing the ecosystem slowly.
“Pallikaranai does not have a buffer, due to the dense human habitation around it. A hypothesis is, this marshland is going to be an ecological relict (a previously bigger ecosystem which has now been reduced) in another ten years,” remarks Jayshree.
Mitigatory measures to reduce the impact of the Perungudi dump yard
GCC has been biomining the Perungudi dump yard since 2022 for Rs. 150 crores, aiming to complete it by March 2024.
“But this process is a very long process and may not work overnight to the extent we want to work,” says Jayshree. To holistically reclaim the land, she recommends breaking its integrity and biomining the parcels in nuggets, then waiting for a year. Then, the government must come up with a restoration plan.
“Simply putting across a plan for eco-park may not be completely holistic,” says Jayshree. “The focus must be on restoring the hydrology of the marshland and not on greening, at the moment.”
To treat the leachate before entering the marshland, IIT Madras developed a pilot system along with GCC in 2021. But little headway has been made on this key project.
“We are awaiting funds to run the plant,” says Indumathi Nambi, a professor in the Civil Engineering Department of IIT. “The system consists of a series of eco-friendly treatment techniques, where organic coagulants are used to remove suspended solids. Electrochemical-based technology is used for organics and heavy metals. Then, constructed wetlands are used for the treatment,” explains Indumathi about the process of the treatment system.
Rs. 150 crores are being spent for biomining the Perungudi dump yard and Rs. 50 crores have been allotted to set up an eco-park in the reclaimed land. However, treating the leachate before it enters the Pallikaranai marshland is equally important to prevent the ecosystem from further deterioration.
A multi-pronged approach that looks beyond biomining becomes necessary to mitigate and possibly reverse the harms caused by the Perungudi dump yard over the past few decades.