20-07-2025
Coliform scare in Chennai waterbodies as corporation shies away from collecting fine
CHENNAI: The city corporation has now revised the fines for illegal sewage connections to the city's storm water drains, which eventually make their way into the major waterbodies. However, it remains to be seen if the fines would be enforced, as despite a 2017 amendment of the Chennai City Municipal Corporation Act, 1919 allowing for fines from Rs 5,000 (residential) to Rs 2 lakh (commercial), the corporation officials told TNIE they have not collected any fine yet.
Setting the alarm bells ringing, a recent test on the water sample drawn from a stormwater drain in Thirumangalam showed faecal coliform levels were five times higher than the permissible limit prescribed by the TNPCB. The test was conducted by civil contractor R Rama Rao.
According to the private laboratory report dated July 2, the sample contained 490 MPN/100ml of faecal coliform, higher than the TNPCB's permissible limit of 100 MPN/100ml.
In addition to microbial contamination, the chemical parameters revealed the Chemical Oxygen Demand (COD) was measured at 490 mg/l, almost 10 times the acceptable limit of 50 mg/l, indicating a high level of organic pollutants that can severely reduce oxygen levels in water and endanger aquatic life. The Biochemical Oxygen Demand (BOD) was found to be 185 mg/l, far exceeding the prescribed limit of 10 mg/l. Other test results including Total Suspended Solids (TSS) was at 120 mg/l, against the standard of 30 mg/l, and a total hardness level of 340 mg/l, further indicating poor water quality. The sample also emitted disagreeable odour and showed a high colour intensity of 90 Hazen units, which measures the 'yellowishness' of water.
