Ganga's water quality has significantly improved since 2014 with the entire length of the river having more dissolved oxygen than the prescribed minimum level, and 68 out of 97 monitoring locations compliant with bathing standards in terms of biochemical oxygen demand, a senior official said.
In an interview to PTI, National Mission for Clean Ganga Director General Rajiv Ranjan Mishra said 32 out of 53 locations monitoring biochemical oxygen demand (BOD) were compliant with the primary water quality criteria for bathing in 2014, whereas in 2021 the total monitoring stations increased to 97, out of which 68 monitoring locations were found compliant with BOD criteria for bathing.
BOD represents the amount of oxygen consumed by bacteria and other microorganisms. The greater the BOD, the more rapidly oxygen is depleted in the stream, which means less oxygen is available to higher forms of aquatic life.
Mishra said the dissolved oxygen level of the Ganga has also improved.
"At present, the entire length of Ganga has more dissolved oxygen (DO) than the prescribed minimum level of 5 mg/l. The river water quality has shown improvement between 2014 and 2021," he said.
The water quality of Ganga is assessed as per primary water quality standard for outdoor bathing in terms of dissolved oxygen (≥5mg/L), BOD (≤3mg/L) and faecal coliform (FC) (≤2500 MPN/100ml) and (pH) (6.5-8.5).
Mishra said the steps taken to improve the water quality include abatement and control of source pollution by establishment or upgradation of wastewater treatment plants for the towns located on Ganga main stem and its tributaries, construction of crematoria, surface cleaning activities, solid waste management on the riverbanks and floodplains and refraining trash from drains falling into river Ganga by installation of trash racks at the mouth of drains.
"The outcome of these projects has started showing significant results and the water quality of river Ganga will further improve as more and more projects are operationalised," he said.
Mishra said in Uttarakhand up to Haridwar, the river is meeting class A criteria, which is the highest level i.e., it meets DO, BOD and FC criteria.
"The NMCG's efforts towards cleaning of the river have been targeted towards meeting bathing quality criteria for river water. Out of the 351 polluted river stretches identified by the Central Pollution Control Board (CPCB) in India, no stretch of river Ganga falls in the top three priority categories," he said.
Noting that the cleaning of river Ganga is a continuous process, he said many initiatives have started yielding results and the water quality of the river will further improve as more and more projects are commissioned.
Mishra said during the Covid-triggered lockdown, there was visible improvement in the quality of Ganga water.
"It mostly happened due to the shutdown of industrial activities and also no solid waste disposal on ghats as people were not able to visit the ghats and other public places. But at the same time, we also have to realise that the sewage generation continued to take place, which was treated at sewage treatment plants (STP), several of them came during the last few years. They were monitored closely and ran without any disruption," he said.
The NMCG DG said the flow of water was relatively good due to the sufficient rainfall at that time.
Under the NMCG, Mishra said an extensive cadre of volunteers have been developed all along Ganga and major tributaries.
"The cadre is kept energised and dedicated work is ensured by frequent interaction as well as conducting a series of activities on a continuous basis to further the community engagement and awareness to conserve and preserve the Ganga river.
"The major activities include organising events, workshops, seminars and conferences and numerous Information, Education and Communication (IEC) activities were also organised such as Ganga Utsav, Ganga Quest, 5th India Water Impact Summit, rallies, campaigns, exhibitions, 'shram daan', cleanliness drives, competitions, and plantation drives," Mishra said.
He said the efforts made to integrate the diverse components such as sewerage infrastructure, municipal solid waste, river front development, afforestation, river sensitive urban planning, aquatic biodiversity and public engagement are meant to show the long-term impacts on the overall health of river Ganga.
"The short-term results are already visible and with the continuous efforts towards the river rejuvenation, the long term impacts will certainly reflect in the future," he added.
In 2015, the government launched the Namami Gange or National Mission for Clean Ganga with an indicative cost of Rs 20,000 crore, as an umbrella programme with an aim to integrate previous and currently ongoing projects and new initiatives planned as its part.
Under the programme, 347 projects were sanctioned against the cost of Rs 30,255 crore. The projects comprise infrastructure and non-infrastructure development towards rejuvenating river Ganga. The projects directly related with the cleaning process include development of sewerage infrastructure, industrial effluent treatment plants, rural sanitation, and river surface cleaning.
The other activities or projects such as development of ghats and crematoria, ghats cleaning, afforestation and others are also indirectly contributing to the cleaning process of Ganga.
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