The municipal corporation is preparing a plan to rehabilitate a nearly 50-year-old brick trunk sewer running beneath several key areas of the city, following a series of road cave-ins linked to damage to the ageing sewer. “The MC plans to reinforce the existing structure with concrete rather than replace it, with the rehabilitation cost estimated at around ₹50 crore per km,” municipal corporation commissioner Ojasvi Alankar said.
A trunk sewer is a large-diameter public sewer pipe that acts as a main artery in a wastewater collection network, gathering sewage from multiple smaller branch lines and conveying it towards a treatment plant.
“The immediate focus is a 2,100-metre stretch of the 2,850-mm-diameter sewer running from Haibowal Chowk to Ferozepur Road. The sewer passes beneath Kitchlu Nagar, Maharaj Nagar, Gurdev Nagar, Prem Nagar, Tagore Nagar and Punjab Agricultural University, besides crossing beneath DMC Road and Ferozepur Road,” the MC chief said.
According to MC officials, the brick sewer is too large and extensive to be replaced, prompting the civic body to explore structural rehabilitation. Under the proposed plan, the existing sewer would be reinforced from the sides with concrete to improve its structural strength and extend its service life.
The proposal, once prepared, will be submitted to the state government for approval. The MC estimates that the work could cost around ₹50 crore for every kilometre of sewer.
{{/usCountry}}The proposal, once prepared, will be submitted to the state government for approval. The MC estimates that the work could cost around ₹50 crore for every kilometre of sewer.
{{/usCountry}}The move comes after repeated road cave-ins over the sewer line, including a major cave-in in Kitchlu Nagar earlier this month. A section of the road collapsed after soil beneath it was eroded and entered the damaged sewer. The MC initially filled the cavity and carried out repairs, but the road caved in again two days later.
A similar cave-in was reported near Sagoo Chowk in July, also over the same sewer. The MC has attributed the damage to drilling carried out by private companies while laying optical-fibre cables, saying the work damaged the sewer wall.
The incidents have prompted the civic body to examine the condition of the ageing sewer at other locations. The MC has identified potential hotspots along around 40 km of the sewer line and ordered a safety review of the sewer at manhole portals.