Groundwater near Perungudi landfill has 37 times higher TDS
As per the recently conducted groundwater quality analysis of TNPCB, dissolved solids in one of the borewells near the dumpsite were found to be a whopping 18,762 mg per litre.
Perungudi dump yard
CHENNAI: Even as the Greater Chennai Corporation (GCC) is going ahead with measures to create an eco-park and ponds on the Perungudi dumping yard land after the completion of the bio-mining process, an analysis conducted by the Tamil Nadu Pollution Control Board (TNPCB) has revealed that total dissolved solids (TDS) in groundwater near the dumping yard is 37 times higher than the prescribed standard.
As per the recently conducted groundwater quality analysis of TNPCB, dissolved solids in one of the borewells near the dumpsite were found to be a whopping 18,762 mg per litre. The Indian Standard (IS) 10500:2012 – a set of guidelines for drinking water quality and safety in India – prescribes only 500 mg per litre of water.
During the analysis, the pollution control board collected samples from two borewells near the Perungudi dumpsite and parameters were compared with the drinking water standards as prescribed in Solid Waste Management Rules, 2016.
Dissolved solids refer to any minerals, salts, metals, cations or anions dissolved in water. Dissolved solids would also comprise inorganic salts like calcium, magnesium, potassium, sodium, bicarbonates, chlorides, and sulfates and some small amounts of organic matter that are dissolved in water.
Apart from the dissolved solids, chloride content in the sample was very high with 6,248 mg per litre as against the prescribed standard of 250 mg per litre. Levels of copper and lead were also higher than the prescribed levels. The analysis showed 0.81 mg per litre of copper and 0.58 mg per litre of lead. As per the standard, 0.05 mg per litre is the normal for both metals.
Meanwhile, samples collected from another borewell near the dumpsite also showed higher TDS content with 996 mg per litre. However other parameters were within the prescribed limits.
The residents' association around the dumping yard are demanding that the GCC drop the eco-park and other waste processing projects in the Perungudi dumpsite. Pointing out that years of garbage dumping have degraded the groundwater and Pallikaranai marshland, the residents urged the civic body to remove legacy waste from below the ground level too. Even though the bio-mining process is nearing completion in Perungudi, legacy waste is present up to 4 to 5 feet below the ground level.
Samples collected by the residents a few months ago too had revealed that the water is unsuitable for drinking purposes. The tested water had 5.5 mg per litre of ammoniacal nitrogen against the acceptable limit of 0.5 mg per litre. Albuminoid nitrogen was found at 2.8 mg per litre against an acceptable limit of 0.5 mg per litre. Moreover, total dissolved solids (TDS) were found to be at 1,040 mg per litre.
Parameters of groundwater collected near Kodungaiyur dumpsite were within the prescribed levels except nickel. The sample had 0.102 mg per litre of nickel. Dissolved solids were at 388 mg per litre. An analysis of ambient air quality around Perungudi and Kodungaiyur showed PM10 exceeding at one location each.
GCC to bio-mine below ground level:
On the other hand, the Greater Chennai Corporation has decided to carry out bio-mining of legacy waste present below the ground level.
A senior civic official said that a consultant will be appointed to quantify the legacy waste below the ground level. "Eco-park and other waste processing projects will be commenced only after completion of bio-mining below the ground level," he added.
Following the opposition from the residents against the eco-park project, the civic body has decided to revise the detailed project report.
