Chennai: Residents of Pallavaram near Putheri lake woke up on Friday morning to find foam creeping near their homes, sparking renewed concerns over pollution, especially after the Tamil Nadu Pollution Control Board (TNPCB) declared the lake's water safe following a similar incident in Nov last year.
Spread over 10.45 acres, Putheri lake is a vital waterbody, channelling overflow from Periya Eri to the Pallikaranai marshland through Keelkattalai lake and recharging groundwater in the area. Putheri lake, under the Tambaram corporation, on the southern side of Radial Road, was renovated. But, the part of the lake on the northern side remains filled with water hyacinth.
Tambaram corporation officials say despite their warnings, chemical discharge and garbage dumping continue from nearby commercial establishments. "Whenever we get complaints, we clean the lake," said corporation commissioner S Balachander.
In Nov 2023, TNPCB said there were no "industrial pollutant discharge" in the lake as the biochemical oxygen demand (BOD), chemical oxygen demand (COD), and dissolved oxygen (DO) levels in the lake stood within limits at 12mg/L, 56mg/L, and 5.6mg/L respectively. Residents feel the report does not reflect the reality on the ground. "We've been assured before that the lake is safe. So why is there foam? We need a solution that stops this problem at the source," said Vanessa J, a resident of Erikkarai Road.
The corporation says it will clear the northern side of the water hyacinth by the month's end. "The lake's southern side has been cleaned as part of monsoon preparations. Now, we have started cleaning the Perungalathur lake too," he said. Plans are underway to deepen the lake next year to improve water quality.
As one of the few remaining natural reservoirs in this fast-growing area, residents worry that unless stricter pollution control measures are enforced, Putheri lake's ability to sustain the community's water needs could be at risk. Civic activist David Manohar said, "We go through this every monsoon. The corporation needs to plug sewage pipelines to end this cycle."