New Delhi:The Ganga water at the Triveni Sangam in Prayagraj, where lakhs of people are taking a holy dip every day during the ongoing Maha Kumbh, is currently unsafe for bathing as it exceeds the prescribed limit for biological oxygen demand (BOD), a key parameter to determine water quality, according to government data.
BOD refers to the amount of oxygen required by aerobic microorganisms to break down organic material in a water body. A higher BOD level indicates more organic content in the water. River water is considered fit for bathing if the BOD level is less than 3 milligrams per litre.
Government data shows that the river water at Sangam is currently exceeding this limit. The BOD level at Sangam was 5.09 milligrams per litre at 5 am on February 16. It was recorded at 4.6 milligrams per litre at 5 pm on February 18 and 5.29 milligrams per litre at 8 am on February 19 (Wednesday).
According to Central Pollution Control Board (CPCB) data, the BOD level at Sangam was 3.94 milligrams per litre on January 13 when the Maha Kumbh started. It improved to 2.28 milligrams per litre on Makar Sankranti (January 14) and further dropped to 1 milligram per litre on January 15. However, it rose to 4.08 milligrams per litre on January 24 and was recorded at 3.26 milligrams per litre on Mauni Amavasya (January 29).
In a report submitted to the National Green Tribunal on February 3, the CPCB said the river water quality did not meet bathing standards during monitoring on January 12-13 at most locations in Prayagraj, Uttar Pradesh. "However, after that, organic pollution (in terms of BOD) started to decrease due to freshwater intrusion at upstream locations. After January 13, 2025, river water quality (is) conforming (to) the bathing criteria w.r.t. BOD except (at) Lord Curzon bridge on river Ganga on January 19, 2025," the CPCB report read.