According to the CPCB report, the Ganga water quality did not improve during this period of lockdown. Instead of getting improved the water quality deteriorated, reports said.
However, the report said that 7 rivers out of 19 major rivers showed an improvement in the quality of water in April as compared to before the lockdown.
The report said that the water quality of Ganga might be deteriorated because of low seasonal flow thus increasing the pollution concentration and no freshwater discharges from the upstream.
The CPCB calculates the percentage variation in the quality of water only or parameters such as pH, DO, BOD, and FC. These measures depict if a river can sustain life and is safe for bathing.
During the lockdown, the Ganga’s 42 out of 65 monitored locations and during the lockdown, 25 out of 54 monitored locations were within the desirable limits of primary water quality criteria for the purpose of outdoor bathing.
Convenor of the Yamuna Jiye Abhiyan, Manoj Mishra said that during the lean season for all rivers the lockdown happened. The dilution of pollutants is affected by the flow of rivers. So, the analysis that Ganga’s water quality did not improve during lockdown is right, said Mishra.
He added that rivers like Narmada, Pennar and the Mahanadi constitute low industrial effluent load. This means that these rivers will meet the bathing water quality standards before and the end of the lockdown.
Mishra said that the CPCB compared two very different things. According to him, the lockdown effect was seen in the Yamuna as it has high industrial effluent load which became zero during the lockdown and there was also rain in Yamuna’s catchment thus leading to higher water discharges.
Scientists of CPCB said that behind the improvement of water quality of the Yamuna and the worsening of the condition of Ganga during the lockdown, there might be different reasons.