india

Updated: Apr 28, 2020 15:50 IST

Authorities in Uttar Pradesh and Uttarakhand have said the quality of water in the Ganga has improved during the nationwide Covid-19 lockdown, with samples collected by a research facility in Varanasi recording a nearly 30% decrease in pollution levels.

A study of Ganga water samples collected on March 24, before the lockdown was imposed, and those collected on April 20 showed pollution had decreased by 25% to 30%, said BD Tripathi, chairman of the Mahamana Malviya Research Centre for Ganga, River Development and Water Resource Management at Banaras Hindu University (BHU).

Composite samples of the river water were collected from five locations – Shooltankeshwar Ghat, Samne Ghat, Asi Ghat, Dashashwamedh Ghat and Raj Ghat – on the two dates, he said. He explained that the term composite samples means an average of five samples were collected from different spots of every site to ensure accurate results.

“We tested biochemical oxygen demand (BOD) and the dissolved oxygen (DO) level in the samples. We found the concentration of DO increased by 20% to 30% and the concentration of BOD decreased by 35% to 40%. In total, the Ganga pollution load has decreased by 25% to 30%,” Tripathi said.

“There has been a very positive effect on the Ganga and the river shows it can rejuvenate itself,” he added.

Tripathi attributed the decrease in pollution to many reasons, including a decrease of around 40% in the number of bodies cremated at Manikarnika Ghat and Harishchandra Ghat, and a check on immersion of remains of cremated bodies in the river.

The discharge of toxic effluents from more than 1,000 small-scale and cottage industries and motor workshops too has completely stopped at Varanasi, he said.

The “highest transparency” was observed during the sampling of water because fish were seen swimming up to a depth of one metre from the surface of the Ganga, Tripathi said.

In Uttarakhand’s capital Dehradun, authorities said a comparison of water quality of the Ganga at different locations from Devaprayag, done between March and April, showed the quality had improved significantly. The water at Har Ki Pauri was found fit for drinking in April, and the state government now plans to work on measures to keep the quality consistent and pollution-free.

State forest and environment minister Harak Singh Rawat said: “With the latest data on improved water quality of the Ganga, we are going to study it with experts and decide on short-term measures which will help us maintain this quality even after the lockdown.

“Clearly, nature has cleaned the river on its own due to fewer anthropological activities.”

Tripathi too said authorities need to take a cue from the lockdown to improve the water quality in future.

Data released amid the lockdown by the Uttarakhand Environment Protection and Pollution Control Board (UEPPCB) showed there was a 47% reduction in fecal coliform at Lakshmanjhula.

At the barrage in Rishikesh, there was a 46% reduction in fecal coliform and 25% reduction in total coliform. Similarly, at Bindughat Dudhiavan, there was a 25% and 11% reduction in fecal coliform and total coliform, respectively.

At Har Ki Pauri, there was a 20% reduction in BOD, 34% reduction in fecal coliform and 17% reduction in total coliform, whereas at Jagjeetpur in Haridwar, officials observed a 17% reduction in BOD and fecal coliform and a 27% reduction in total coliform.

UEPPCB officials said there was a significant improvement in water quality at Har ki Pauri during the lockdown. UEPPCB member secretary SP Subudhi said fewer pollutants are entering the river as factories are closed.

“We studied data from March and April and saw significant changes in water quality after the lockdown. This is mostly due to factories being shut, hotels being closed, and less mobile population in and around Haridwar,” said Subudhi.

“We will be taking samples from the same spots again to reconfirm the findings, based on which suggestion can be made to the state and Central government on how to keep the water quality of the Ganga consistent.”

Sewage treatment plants in the state are working according to norms and without extra load because of the lockdown, reducing pollutants in rivers.

BD Joshi, an environmental scientist and founder of the Indian Academy of Environmental Sciences, said the water quality has improved due to reduced anthropological pressures on the Ganga but this will be very difficult to maintain once the lockdown ends.

“In the past five to six weeks, the Ganga has cleansed itself but it is very difficult to say how much of this will continue after the lockdown. There is definitely a psychological impact on people due to the pandemic, on how people should respect nature and the environment, which can help us keep the river clean. The government and law enforcement agencies can use this to spread awareness among more people, which gives us hope the water quality might be maintained,” said Joshi.