Maha Kumbh Water Quality Was Within Permissible Limits For Bathing: CPCB Report

The Central Pollution Control Board (CPCB) has informed the National Green Tribunal (NGT) that as per statistical analysis, the water quality during the recently-concluded Maha Kumbh in Prayagraj was fit for bathing.

The new CPCB report submitted to the NGT said the statistical analysis was necessitated because of "variability of data" in the samples collected from the same locations across different dates and on different locations on the same day, because of which these did not reflect the "overall river water quality throughout the river stretch", India Today reported.

The report, dated 28 February and uploaded on the tribunal's website on 7 March, said the board had conducted water monitoring bi-weekly from 12 January onwards, including on auspicious bathing days, at five locations on Ganga river and two locations on Yamuna river.

"There is a significant variability in the values on various parameters, viz pH, dissolved oxygen (DO), biochemical oxygen demand (BOD) and fecal coliform count (FC) for the samples taken from the same location on different dates. The values of the afore-mentioned parameters also vary at different locations for the samples collected on the same day," the report said.

DO, which indicates amount of oxygen in water, BOD, which measures the oxygen required to decompose organic matter in water, and FC, a marker of sewage contamination, are key indicators of water quality.

According to the report, an expert committee in CPCB examined the issue of "variability in data" and was of the view that "the data represents a snapshot of water quality at a specific location and time and may vary significantly depending upon factors such as upstream anthropogenic activities (human actions), rate of flow, depth of sampling, time of sampling, river current and mixing of currents, sampling location and such other multiple factors".

"As a result, these values reflect water quality parameters at the exact time and place from where these water samples were collected, and may not fully represent the overall characteristics of the river, therefore, not necessarily reflecting the overall river water quality throughout the river stretch," the report said.

The report also said that in view of the variability, a statistical analysis of water quality data of various monitoring locations for the key parameters was undertaken from 12 January to 22 February at 10 locations of "mass bathing" and that 20 rounds of monitoring were done.

"It is submitted that as per the above-mentioned statistical analysis, the median value (central tendency of the data) of pH, DO, BOD and FC for the monitored stretches is within the respective criteria/permissible limits for bathing water," the report noted.

As per the report, the median FC value stood at 1,400, well below the permissible limit of 2,500 units per 100 ml. The DO level was recorded at 8.7 mg/l, surpassing the required norm of 5 mg/l, while the BOD measured 2.56 mg/l, staying within the prescribed limit of ≤3 mg/l.

Earlier, on 17 February, CPCB had informed the tribunal through a report that various locations in Prayagraj during the Maha Kumbh were not conforming to the primary water quality for bathing with respect to the level of faecal coliform.

The tribunal is set to hear the matter on 7 April.

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