A Central Pollution Control Board (CPCB) report tabled before the National Green Tribunal (NGT) has verified that the water quality of the Ganga during the just-concluded Maha Kumbh at Prayagraj was at par with the bathing standards.
However, the report also pointed out significant fluctuations in water quality data, noting variations in samples collected from the same locations on different days and from different locations on the same day.
Dated February 28 and published on the NGT’s website on March 7, the report states:
"As per statistical analysis, the water quality during Maha Kumbh 2025 at monitoring locations along the Ganga and Yamuna in Prayagraj was found to be fit for bathing under Primary Water Quality Criteria."
Water Monitoring & Observations:
The CPCB had conducted water quality monitoring at twice a week frequency from January 12, major bathing days on, at five locations along Ganga and at two locations along Yamuna. The results suggested that variations in water quality resulted from multiple influencing factors like,
Sewage drains pouring into the rivers
Inflow of tributaries
Changes in weather
Owing to such disparities, CPCB highlighted the requirement for statistical scrutiny in order to make a better appraisal.
The report also found:
Fecal coliform (FC) concentrations had a median value of 1,400 MPN/100 ml, which was far below the limit of 2,500 MPN/100 ml
Dissolved Oxygen (DO) was measured at 8.7 mg/L, which was above the minimum requirement of 5 mg/L
Biochemical Oxygen Demand (BOD) stood at 2.56 mg/L, within the acceptable limit of 3 mg/L
Contradictory Observations:
Interestingly, only a few days ago, CPCB had reported to the NGT that water at various points in Prayagraj during the Maha Kumbh was not meeting primary bathing quality criteria on account of high fecal coliform levels.
There were apprehensions about discharge of untreated sewage into the Ganga and Yamuna, and in response to which Uttar Pradesh authorities filed an affidavit detailing measures to preserve water quality.
The affidavit read:
"To prepare for Maha Kumbh 2025, proper stock of chemicals like chlorine, FeCl3, poly, lime, and defoamer will be kept in all sewage treatment plants (STPs). More manpower will also be used, keeping in mind the population growth during the festival."
Understanding Data Variability:
The report emphasizes that data variability of water quality is caused by a number of natural and anthropogenic factors, such as:
Flow rate & currents of the river
Depth and time of sample collection
Upstream human activities
Against this backdrop of variables, CPCB explained that a single reading from a sample does not directly reflect the water quality of the entire river length but rather an indication of the situation at that particular point in time and place.
As against this fluctuation, a step-by-step statistical analysis was conducted from January 12 to February 22 in ten major mass-bathing centers, with a total of 20 rounds of monitoring.
The results reaffirmed that median values of important indicators of water quality were within limit, assuring pilgrims of the safety of Ganga water for bathing at Maha Kumbh 2025.
(Input from various sources)
(Rehash/Sai Sindhuja K/MSM)