New treatment plants at 4 lakes to quench city’s thirst

According to a recent tender floated by CMWSSB, decentralised water treatment plants with a combined capacity of 10 MLD (Million Litres per Day) would be built at the three lakes within six months. “We have also taken steps to set up an additional 6 MLD (6 lakh litre) water treatment plant at Porur lake to augment the water supply,” a CMWSSB official said.

During the 2017 drought, the water managers had drawn 4 MLD drinking water from Porur lake for the first time and built a water treatment plant near the lake. With a new plant, Porur lake would have 10 MLD treatment plant.

Apart from setting up water treatment plants and conveyance systems, the CMWSSB has proposed to draw water from abandoned quarries in Erumaiyur. “The water from Erumaiyur will be diverted to the water treatment plant in Chembarambakkam lake, from where the treated water will be supplied to the city. The bidder for 10 MLD plant will also lay the conveyance system for Erumaiyur quarries,” the official added.

Explaining the areas that are to be benefited from new lakes, the official said that the water from Rettai Eri, Perumbakkam lake and Ayanambakkam lake would be supplied to the areas around Kolathur, Sholinganallur and Mogappair respectively.

It is learnt that the CMWSSB had conducted hydrography survey at 13 lakes including Rettai Eri, Perumbakkam and Ayanambakkam lakes and six quarries, including Erumaiyur. “The water samples were tested and the results suggest that the lake water can be potable after treatment. We have already created the infrastructure to pipe 30 MLD water from several abandoned quarries from Sikkarayapuram to Chembarambakkam water treatment plant,” the official said.

Adding to the concerns, the four major lakes that supply drinking water to the metropolis have a combined storage of 13.5 per cent against the total storage capacity of 11,257 mcft. As of now, the CMWSSB is supplying 650 MLD every alternate day.