File picture of the Mahanadi

Bhubaneswar, July 21: Four rivers of Odisha have figured among the most polluted in the country in a recent report of the Central Pollution Control Board.

The Brahmani, Kathajodi, Kuakhai and the Mahanadi river have been found to be carrying great amount of pollutants in certain stretches.

While the Kathajodi and Mahanadi rivers are badly polluted downstream of Cuttack city, the Brahmani has been found to be carrying a large amount of municipal waste near Panposh and Rourkela. Kuakhai is polluted along its stretch in Bhubaneswar.

Sources in the State Pollution Control Board (SPCB) said length of the polluted stretches measures between 2km and 3km and the untreated sewage released into the rivers is mainly to blame for the pollution. The research also took an account of the biological oxygen demand (BOD) in all the 150 stretches, which were being monitored in the country. BOD is a measure of the quantity of oxygen used by micro-organisms in the oxidation of organic matter.

While three river stretches excluding Kathajodi recorded a BOD between 3mg to 6mg per litre, the latter recorded a BOD level of 6.4mg per litre, which suggests that the situation is alarming in Kathajodi. Sources in the SPCB said the water pollution increases with the rise in the level of the BOD. Senior environmental scientist of SPCB B.N. Bhol said the BOD of all the stretches was on lower side as compared to some of the other stretches in the country.

“Though the BOD level is on lower side, but the situation is alarming. The water cannot be used for bathing and other useful purpose. The situation is likely to be alarming till sewage plants are being set up to treat the domestic and municipal sewage before discharging to the rivers,” said Bhol.

The Central Pollution Control Board has been entrusted with the job of monitoring the water quality in the country under the National Water Quality Monitoring Programme. The water quality data is analysed and monitoring locations exceeding the water quality criteria are identified as polluted zones. In Odisha, water quality is examined in 75 locations of the state.

Member secretary of the SPCB Siddhant Das said that out of the 36 parameters of water quality, the rivers of Odisha, including Brahmani, Kathjodi, Kuakhai and Mahanadi, matches 34 parameters. “Sometimes two parameters such as the BOD and presence of coliform organism exceed the prescribed limit, which takes place in the down streams of residential areas. Absence of sewage treatment plants is responsible for this,” said Das.

He also said the State Pollution Control Board had asked the municipal authorities to set up a sewage treatment plant.