Pune: In yet another proof of the nature thriving in absence of constant human intervention, the Pune Municipal Corporation (PMC) has determined that the pollution level in Mula-Mutha river has decreased roughly by around 50 per cent after lockdown.
The Indradhanushya Environment Education and Citizenship Centre of Pune Municipal Corporation (PMC) have verified this by comparing the quality of water samples from the river taken before and after the lockdown. The data showed that the Biochemical Oxygen Demand (BOD) contents in the river have reduced by around 50 per cent, while the Chemical Oxygen Demand (COD) contents have decreased by 42 per cent. The Dissolved Oxygen (DO) levels have positively increased, reflecting better water quality.
“We had taken samples from different locations across the length of Mula-Mutha in the city before the lockdown began. We compared those to the new samples taken after the lockdown from the same locations, and noted a significant decline in the BOD and the COD contents,” said PMC Environment Department Head Mangesh Dighe.
The lesser the content of BOD and COD in the river, the healthier is the water quality. The DO content has increased from 3.19 milligram (mg) per litre in March to 4.6 mg per litre in April 2020.
The PMC has attributed these changes to the reduction in commercial activity in the city.
“Small and medium scale industrial units that emit waste into the river, along with commercial places like restaurants, hotels, malls and other establishments like schools, colleges and offices are shut almost completely for over two months now. This has reduced the pollutants, and improved the river water quality,” Dighe added.
However, urban river expert Sarang Yadwadkar pointed out that not the domestic sewage but the industrial effluents could be responsible for the decline in the pollution of Mula-Mutha.
“While the PMC has stated that the decline can be attributed to the shutdown of commercial establishments, I would like to point out that domestic sewage has not reduced, just shifted from malls, offices to people’s homes. The number of people who have migrated from Pune has also been not too large to bring about this feat,” Yadwadkar said.
He added that while the pollution in Mutha is from domestic waste, in Mula is from the industrial effluents.
“The industries remaining non-functional during lockdown might be a reason behind the reduction in pollution levels. However, the question that we need to ask is why wasn’t this pollution regulated in the pre-lockdown period by the Maharashtra Pollution Control Board (MPCB),” Yadwadkar questioned.
