As part of its efforts to reduce pollution in the city’s waterways, the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) has intensified its drive against unauthorised dumping of sewage on open lands and in waterbodies.

The CMWSSB recently seized two vehicles for illegally decanting sewage into the storm-water drain network in Adayalampattu and on R.K. Shanmugam Salai in K.K. Nagar. According to the CMWSSB, the sewage lorries were seized by the Area XI and Area X officials during night inspections. The seized vehicles were parked at the Nolambur sewage pumping station and K.K. Nagar water distribution station. Action is being initiated against the operators along with the police.

Officials said one of the vehicles was a water lorry, which was operated under a previous contract with the CMWSSB. The water agency has initiated action against vehicles that were found releasing sewage into waterways such as the Buckingham canal, the Cooum, and the Virugambakkam-Arumbakkam Canal.

“We plan to step up vigilance in peripheral areas to prevent unauthorised release of sewage into storm-water drains and waterways. The CMWSSB has already deployed squads and installed surveillance cameras at vulnerable points in Areas 3, 7, 11, 14, and 15,” an official said. Residents of Nolambur and Mogappair said vigilance should be increased along waterways, particularly during night time.

Balaji Srinivasan, resident of Mogappair West, said the storm-water drain network along the service lane of Chennai Bypass Road continued to carry sewage. “This is a recurring issue despite repeated complaints being raised with the authorities. The CMWSSB must increase surveillance and GPS tracking of lorries,” he added.

The CMWSSB said it had written to the local bodies in added areas and district administration to step up vigilance and have also requested the residents’ welfare associations to inform them about instances of sewage being let out into storm-water drains.

The Septage Management Regulations and Operative Guidelines has mandated that only registered operators are allowed to remove sewage from the septic tanks in houses and commercial establishments. The CMWSSB has issued licences, which have a validity of two years, to nearly 509 sewage lorries. It also tracks the GPS equipment installed in registered lorries.

Officials said on an average, nearly 1,537 trips were being operated daily to decant sewage collected from the fringes of the city to 13 points spread across the city, including Nesapakkam and Perungudi. A decanting fee of ₹150 is collected per trip, and the licence is provided for a fee of ₹2,000 as per the septage management guidelines.