Adyar River Pollution Report

Faecal Coliform Levels

• Excessive Contamination: Faecal coliform levels in the Adyar River were found to be more than 10 times the prescribed safe limit according to a report by the Tamil Nadu Pollution Control Board (TNPCB). 
• Measurements: Water samples collected showed levels of 1026 MPN/100 ml, significantly above the permissible limit of 100 MPN/100 ml. MPN (Most Probable Number) is a method to estimate microorganism concentration. 

Additional Water Quality Indicators

• Low Oxygen Levels: Inspections showed dissolved oxygen levels under 2 parts per million, below the threshold needed to sustain aquatic life. 
• Organic Contamination: Biological Oxygen Demand was 133 mg/l and Chemical Oxygen Demand was 136 mg/l, indicating severe pollution. 
• Nutrient Overload: Total Nitrogen was noted at 57.74 mg/l, exceeding the standard of 23.697 mg/l. 

Causes and Effects

• Cause of Fish Kills: High contamination levels were linked to fish deaths observed in the Adyar eco-park in June 2024. 
• Source of Pollution: Unchecked discharge of untreated domestic sewage from residential areas was identified as the primary source of contamination. No industrial discharge was noted as a contributing factor. 

Recommendations and Response

• Immediate Actions: TNPCB recommended that the Greater Chennai Corporation explore the installation of a sewage treatment plant to prevent further contamination.