Nearly three years after various schemes were devised to restore the Cooum, Chennai Metrowater has begun carrying out preliminary works to construct modular sewage treatment plants along the river.
This is part of the ambitious Integrated Cooum River Eco-restoration Project that aims to clean the polluted river. Four modular sewage treatment plants (STPs) of smaller capacity have been planned in different parts of the city to intercept raw sewage released into the river and treat it.
In its 72-km journey to the sea, the river traverses nearly 18 km in city limits. While core parts of the city are covered by a sewage network, raw sewage often gets discharged into the waterway either due to illegal sewage outlets or capacity constraints.
Officials said preliminary work has been started to construct a plant with a capacity to treat 10 million litres of sewage a day (mld). This facility with the largest treatment capacity among the four plants would come up at Langs Garden Road, Pudupet. Work is yet to begin on the other three plants as their design had to be revised and soil tests had to be conducted due to change in location, according to sources in Metrowater.
The other plants of 0.6 mld, 1.2 mld and 1 mld capacity will come up along the river near College Road, near Choolaimedu railway bridge and near Chennai Bypass Road, Maduravoyal. These projects, taken up at a cost of nearly ₹36 crore, would be finished in two years, officials added.
The water agency has identified 178 sewage outfalls in the urban stretch of the Cooum river. As an effort to treat and divert sewage to the existing network, Metrowater has initiated work to lay a pipeline along the river to intercept the raw sewage draining into the waterway. In areas that have modular STPs, it will be treated and let into the river.
Several of these projects chalked out years ago now are finally taking shape. Encroachment removal, resistance from residents on alignment of pipeline, poor response to the tenders and issues with the contractors were cited as reasons for the delay.
The Water Resources Department has removed 7,000 encroachments out of the 12,000 structures identified between Koyambedu and the Cooum river’s mouth. Work in places like NSK Nagar, Mehta Nagar and South Cooum Road are awaiting clearing of encroachments, sources said.
