Kerala has a gap of 79.16 million litres per day in the treatment of sewage utilising sewage treatment plants (STPs) in urban areas as of June 2025.
The total sewage generated in urban areas is 305.4 million litres per day. About 129.6 million litres per day of sewage is being treated through common sewage treatment plants.
The total sewage treatment capacity through individual STPs set up in various establishments is about 96.3 million litres per day, according to a report submitted by the Kerala State Pollution Control Board before the Ministry of Jal Shakthi on August 8, 2025. Only 14 common STPs are operational in the State while there are over 2,000 individual sewage treatment plants.
The report stated that Kerala has a rural-urban continuous settlement pattern. Apartment complexes are less compared to individual households, which are having septic tank/soak pit for toilets attached to it. Sullage forms 70% of domestic wastewater and sewage is only 30%. The major quantity of sullage, which is not contaminated with faecal coliform, is disposed through soak pit and for farming in household premises.
Sewage is discharged through septic tank/soak pit, common/ individual sewage treatment plant. The mixing of sewage and sullage occurs in the case of common sewage treatment plant and individual STPs.
Over 1,100 notices under the provisions of the Water Act have been issued from the Kerala State Pollution Control Board to apartments/ hotels/houseboats/ industrial units for not complying with the norms related to liquid waste management. The inspections had revealed that the erring units had either no valid consent from the board for operating the sewage treatment plants or lacking facilities as per the environmental rules.
Published – August 19, 2025 09:27 pm IST
