Cleaning the Ganga

Govt should build on gains in recent years

If the status of aquatic biodiversity is any indication of the sanitary and biological health of a natural water body, then the river Ganga, once severely polluted, has begun to recover. A survey of the river’s main stream (without tributaries), conducted by the Wildlife Institute of India between 2017 and 2019, shows that 49 per cent of it now has “high biodiversity”, thanks to improved water quality. The sightings of aquatic fauna, including Gangetic dolphins and otters, which had become rare or nil in many stretches of the river, have now increased considerably. The population of Gangetic dolphins, which exceeded 10,000 at one time, had declined gradually to a mere 3,500 by 2000 due to steady deterioration in life-sustaining faculties of Ganga water. They disappeared totally in the pilgrim town of Haridwar, as also in most of the Ganga’s tributaries. The count of other fresh water species had also dipped sharply due to habitat degradation and alterations in the river’s morphology caused by the construction of dams and barrages, realignment of embankments, sand mining, and other human activities, including agriculture. The revival of these species is being viewed as the outcome of mitigation of pollution and a relatively healthy state of the river.

Apart from being revered by the Hindus, the Ganga and its tributaries constitute the lifeline of about 26.3 per cent of the country’s geographical area, spanning 11 states. The main stem of the river runs through five states — Uttarakhand, Uttar Pradesh, Bihar, Jharkhand, and West Bengal. Efforts to clean up this river, initiated in the mid-1980s, during the tenure of Rajiv Gandhi as prime minister, got the real impetus with the launch of the Namami Gange Programmes in 2014 by the Narendra Modi government in its first term. Going by the Jal Shakti ministry’s claim, all the three parameters that determine the river’s competence to support aquatic life have undergone perceptible improvement in the past few years. While the dissolved oxygen content, the key for life in water, has gone up at 27 locations, the biochemical oxygen demand and faecal Coliform load have ameliorated at 42 and 21 places, respectively. The maximum qualitative recovery has, as could be expected, occurred in Uttarakhand, where discharging sewage into the river and its streams has been effectively curbed to ensure the steady flow of fresh and clean water into the river.

However, much still remains to be done to rejuvenate this river of national importance. Special attention is needed to augment the sewage treatment capacity in 97 major towns and industrial hubs along the route of the river. The present cumulated sewage treatment capacity of around 1,800 million litres a day is too meagre compared to the total sewage generation of 3,000 million litres. Untreated or improperly treated industrial wastes are the other major sources of water pollution, which need to be checked. But the most important is the maintenance of the river’s water flow, which has been gravely restricted due to excessive impounding, diversion through canals, and indiscriminate use. The need, therefore, is to stop putting up new dams, rationalise water releases from the existing ones, and plug the inflow of untreated sewage and industrial wastes. Otherwise the goal of restoring the Ganga to its pristine state would remain elusive.