Coliform levels high along Kalamassery stretch of Periyar and Kadambrayar near Brahmapuram

Water samples collected from monitoring points along the Kalamassery stretch of the Periyar and the Kadambrayar near Brahmapuram recorded higher levels of faecal contamination from January to November 2025.

The average total coliform levels were above the maximum limits prescribed under the criteria for bathing by the Central Pollution Control Board, according to results compiled by the Kerala State Pollution Control Board as part of the National Water Quality Monitoring Programme of polluted river stretches in Ernakulam. The maximum permissible limit of total coliform in bathing water, as prescribed by the Central Pollution Control Board (CPCB), is less than 2,500 MPN per 100 ml.

In February 2025, the total coliform count was 5,400 MPN/100 ml on the Brahmapuram stretch of the Kadambrayar. The total coliform count on the Manakkakadavu stretch of the Kadambrayar was 2,700 MPN/100 ml. The situation had worsened in March 2025 after tests revealed higher levels of faecal coliform along the Brahmapuram stretch. It was 20,000 MPN per 100 ml. The faecal streptococci level had also exceeded the permissible limit on multiple occasions on the same stretch. It was recorded at 1,200 MPN per 100 ml, against the maximum of 500 MPN per 100 ml prescribed by the Central Pollution Control Board.

In July 2025, the total coliform level was 2,600 MPN/100 ml. The total coliform level in August 2025 was 7000 MPN/100 ml at Brahmapuram.

The total coliform count, indicating faecal contamination, was 3,900/100 ml along the Kalamassery stretch of the Periyar in March 2025. In April and May 2025, the corresponding figures along the Kalamassery stretch were 5,800 MPN/100 ml and 2,800 MPN/100 ml respectively.

The Department of Environment had earlier said that pollution in the Kadambrayar was caused by discharge of domestic effluents from townships and households through drains and creeks leading to the waterbody. In its report submitted to the National Green Tribunal in March 2025, it had said that leachate discharge, if any, from the Brahmapuram plant and flow restrictions caused by the growth of water hyacinths had further worsened the pollution.