Ganga water became fit for a dip, aquatic life at many places in lockdown, IIT study finds

Study by cGanga finds that the river's water in places like Haridwar, Kanpur & Varanasi showed marked improvement in key parameters, though overall quality needs more improvement.

The river Ganga in Varanasi | ANI Photo

New Delhi: The water quality of the Ganga river and its major tributaries in some of the polluted stretches in Uttarakhand and Uttar Pradesh has shown improvement during the Covid-19 lockdown, a study by the Centre for Ganga River Basin Management and Studies (cGanga) has found.

The study, led by IIT Kanpur, found that river water in places like Haridwar, Kanpur and Varanasi — some of the most polluted stretches in the Ganga’s course — showed marked improvement in the past few months in key parameters used to measure water quality.

The improvement was primarily on account of restricted industrial and tourism activity, closure of hotels, restaurants and other commercial establishments, and restrictions on bathing and washing clothes in the river during the lockdown period.

The study was carried out during the first and second phases of the lockdown, between 18 April and 17 May, in approximately 60 locations between Devprayag in Uttarakhand and Varanasi in Uttar Pradesh.

The Ganga flows through five states — Uttarakhand, Uttar Pradesh, Bihar, Jharkhand and West Bengal before meeting the Bay of Bengal. However, because of the lockdown, cGanga had got permission only from the Uttarakhand and UP governments to conduct the study.

The IIT Kanpur-led cGanga was established in 2016 to assist the Union Jal Shakti Ministry’s National Mission for Clean Ganga, which was aimed towards sustainable development of the Ganga river basin.

Besides IIT Kanpur, other cGanga partners including IIT Roorkee and IIT Delhi were also involved in conducting the study.

Major findings

According to the study, a copy of which was accessed by ThePrint, the critical dissolved oxygen (CDO) level in the main stem of Ganga river was good enough to support aquatic flora and fauna in most of the locations when compared to the pre-lockdown period, except in some stretches where drains carrying sewage and industrial effluents discharge meet the river’s tributaries.

The CDO level should be more than 5 mg/l to maintain better water quality and to support healthy and indigenous biodiversity. CDO levels between 3 mg/l and 5 mg/l mean the water quality is marginally impacted and less than 3 mg/l implies the water quality is heavily impacted.

Less than 5 per cent of the over 2,500 km-long stretch that the Ganga flows through, from multiple points of origin in Uttarakhand to multiple merging points at the Bay of Bengal, had CDO levels that were inadequate to support freshwater flora and fauna, according to the study.

The CDO level in the samples collected from Bhairo Ghat and Chakeri in Kanpur was greater than 5 mg/l, while in some other stretches in the city, like Bithoor and at the points of confluence with Pandu river, the water quality was found to be marginally impacted (between 3mg/l and 5mg/l).

The study also found that the total coliform count on the main stem of the Ganga in Uttar Pradesh was fairly conducive to daily baths or dips for religious purposes, with low to marginal risk to human health.

Total coliform bacteria are found in faeces of humans and animals and their presence beyond the permissible limit indicates disease-causing microbes or pathogens in water.

Earlier, a study conducted by the Uttar Pradesh Pollution Control Board in 2019 had found that the total coliform count of the Ganga was several hundred times more than the permissible limit, making the water unfit for bathing.

An assessment done by the Uttar Pradesh Pollution Control Board (UPPCB) of the water quality of the river flowing through prominent towns like Farrukhabad, Kanpur, Prayagraj and Varanasi during the lockdown period also showed improvement, when compared to the pre-lockdown period.

The water quality at all the above locations were found to be in Category B — useful for bathing purposes according to the Central Pollution Control Board criteria, said the assessment report accessed by ThePrint.

Water quality still heavily impacted in some stretches 

The cGanga study also found that there are certain stretches of the river where the water quality has shown little improvement despite the lockdown.

In the vicinity of drains and tributaries that bring in sewage and industrial effluents into the river, the study found, the water quality may pose moderate to considerable risk to human health.

Furthermore, the CDO level as well as the total coliform count were found in significant lengths of some of the major tributaries such as stretches of Hindon (flowing through Muzaffarnagar, Meerut, Ghaziabad and Noida), Yamuna (flowing through Delhi), Kali (flowing through Muzaffarnagar, Meerut and Ghaziabad), Ramganga (flowing through Moradabad and Ramnagar) and Gomati (flowing through Lucknow).

The CDO level on these stretches were between 3 mg/l and 5 mg/l and in some stretches less than 3 mg/l, and found to be unfavourable to sustain aquatic flora and fauna. The total coliform levels on these stretches were also found to be unsafe for taking daily baths due to marginal or considerable risk to human health.

‘Overall Ganga water quality needs more improvement’

According to Professor Vinod Tare, from IIT Kanpur’s Department of Civil Engineering and founding head of cGanga, the river has shown improved water quality primarily because of lesser sewage and industrial effluent discharges due to the lockdown.

“The floating tourist population in places like Haridwar, Rishikesh and Varanasi has reduced manifold because of the lockdown. This, in turn, has resulted in lesser sewage generation,” Tare told ThePrint.

“Similarly, in industrial cities like Kanpur in Uttar Pradesh, there was lesser discharge of industrial effluents from tanneries as they were closed. This led to lesser industrial effluent getting generated or discharged into the river,” he added.

Tare, however, cautioned that an improved CDO level in some of the stretches because of lockdown does not mean that the overall quality of water in the Ganga has improved.

“It’s not that sewage generation has stopped. It’s still getting generated in cities and towns through which the Ganga flows. And once industries and businesses open up, the volume of sewage and industrial effluents getting generated will increase. Sewage contributes to coliform. Unless and until steps are taken to manage the sewage scientifically across the entire stretch of the river, there will be limited improvement in the overall quality of the river,” he said.

A senior officer of the National Mission for Cleaning Ganga (NMCG) told ThePrint that the findings of the study will help in addressing the gaps in sewage and effluent management.

“There has been improvement in dissolved oxygen all along the main stem of Ganga, with a significant increase in the downstream of Prayagraj and the downstream of Kanpur owing to closure of industries. However, the dissolved oxygen level remained almost the same as the pre-lockdown level in drains, which continues to be one of the main problem area,” said the official, who did not wish to be named.

“NMCG has been taking a number of measures to check the discharge of sewage and industrial effluents directly from drains into the tributaries of the river, like putting mesh on the mouth of the drains. The sewage treatment capacity is also being augmented by commissioning more sewage treatment plants at various stretches,” he added.

The NMCG, which comes under the water resources ministry, is piloting the Rs 20,000 crore programme to clean the Ganga.