Faecal contamination high in Marina, unsafe for plunge: Study

It is summer, and thousands of city residents are already heading to the beach to ‘cool off’ and get respite from the blistering heat. However, a study by NCCR confirms what Chenniiates have long suspected – that water in city beaches has a high level of microbial contamination (from sewage inflow), with Marina topping the list with the highest prevalence of Faecal coliforms (FC).



Chennai: 

National Centre for Coastal Research (NCCR) – formerly known as the Integrated Coastal and Marine Area Management Project Directorate (ICMAM PD) – assessed the distribution of bacterial load in the city’s five recreational beaches, by analysing 192 samples. The study revealed that total heterotrophic bacteria (THB) was ubiquitous to all beaches. Faecal coliforms (FC), the indicators of faecal pollution, were dominated, exceeding the standard limits (100 cfu/ml) in all beaches. In fact, during the dry season (March to September), the faecal coliform levels increased manifold.

The study stated that Marina beach had the highest level of microbial contamination, followed by Elliots Beach, Thiruvanmiyur, Ennore and Kovalam. The investigation suggested that the city’s rivers – Cooum and Adyar – are responsible for this pathogenic contamination and variability in water quality. The sewage, which contains nitrate and phosphate, trigger algal bloom. 

Pravakar Mishra, a scientist, said that the NCCR was studying the sea off Marina and has been monitoring the water quality in different beaches in the city. “In many other countries, there are programmes to monitor public beaches for pollution, but we don’t have such an initiative here. Our research revealed that Marina is the most polluted and more than 30,000 visit it. The pollution is caused by the rivers, as untreated sewage is released into them because most of the treatment plants are not functional. Marina is worst-affected because it is trapped between Cooum on one side and Adyar on the other,” the scientist explained.

A water quality app and shoreline maps for coastal zone applications will be released on April 20 by M Rajeevan, Secretary to Government of India, Ministry of Earth Sciences, in the presence of MV Ramanamurthy, Director of NCCR and it will be formally unveiled on the same day, to provide scientific and technical support to the coastal states to conserve their coastline for sustainable development. 

Last year, city-based NGO Arappor Iyakkam’s audited 27 pumping stations, out of which 10 were discharging untreated sewage into waterbodies, while in the five sewage treatment plants (STPs), sewage was inadequately treated. “There is no doubt that sewage is being let into the waterbodies without treatment. At Kodungaiyur and Nesapakkam STPs, the aerators and clarifiers were not working. We recently released a video where in RK Nagar, sewage from 19 pumping stations was directed to the relay station, which was releasing it untreated into the Buckingham canal. Officials don’t have an idea of the quantity of sewage generated and treated daily. Chennai Metro Water Supply and Sewage Board (CMWSB) needs to have a plan to deal with the situation,” said Jayaram Venkatesan, Convenor of Arappor.

BAD BEACHES

• Marina beach topped in microbial contamination (due to presence of faecal coliform) followed by Elliot, Thiruvanmiyur, Ennore and Kovalam.
• Pollution is due to sewage inflow directly into the Adyar and Cooum rivers.
• The faecal coliforms exceeded normal standards of 100 CFU/ml in all beaches.