Kerala Water Authority (KWA) has initiated a survey for laying a 27-km sewage pipeline across several wards in the city, including Kadavanthra, Girinagar, and Panampilly Nagar, as part of its sewerage treatment project. It has also initiated steps to retender other components of the project, including a 5-MLD sewage treatment plant (STP) and a 17-km sewage pipeline.
Amid growing sanitation concerns in Kochi and limited sewerage coverage, compounded by the dumping of solid waste into canals and drains, the KWA’s three-component sewerage project is gathering pace.
As part of the project, a topographical and social survey to collect ground elevation and sewage generation data from potential consumer points has begun, a KWA source said. The project has been proposed under AMRUT 2.0.
At present, Kochi’s sewerage system meets only 5% of the total demand, which is insufficient to cater to the projected population by 2055, the source said.
“Around 80% of the drinking water consumed is generated as sewage. At present, sewage from houses, apartments, and commercial establishments is discharged into nearby canals. This pollutes the canals and triggers algae growth and the anaerobic decomposition of organic matter. As a result, the canals turn blackish and highly contaminated, leading to environmental pollution. It is a major public health concern,” the source said.
The project has been designed for a 30-year period, taking into account the expected sewage load up to 2056.
Nearly 1,400 manholes, one lifting station, and one collection well are part of the project. The collection well will be located on KWA land at Cheruparambath. The project is estimated to cost ₹185 crore and is expected to be completed within two years.
Sewage treatment technology
The STP will comprise several units employing primary, secondary, and tertiary treatment of sewage, the source said.
“Mechanical screening and the removal of oil, grease, and grit will take place in the primary treatment unit, while the secondary treatment unit will handle the biological and chemical treatment of sewage. The biological reactor employs aerobic decomposition of organic matter using microorganisms and aeration. The moving bed biofilm reactor (MBBR) technology has been adopted as it is compact, robust, and widely used,” the source added.
The chemical treatment process includes coagulation-assisted sedimentation. The tertiary treatment will comprise sand filtration, activated carbon filtration, ultrafiltration, and disinfection. Separate sludge removal units have also been provided. The design and detailed project report (DPR) have been prepared by the KWA’s in-house team.
Published – July 12, 2026 09:51 pm IST
