At Varanasi, a major river popullant is untreated waste water. A wall or dam can be built along the city-stretch to prevent the dirty water from entering the river 

Despite all possible attempts at all levels to clean the Ganga at Varanasi in the past three decades, the river remains polluted. This is due to several socio-politico-technical reasons. For example, the use of arbitrarily evolved effluent standards, which have no regard for the polluters’ location, and quality goals for the river, so that it may be fit for aachman (direct inhaling of the river water for religious rites) by pilgrims and devotees, haven’t helped. Also, the self-purifying abilities of the Ganga have either been ignored or disregarded. Allowing untreated wastewater to enter the river has made matters worse as has the decision to lay sewer pipes (wastewater collecting pipes) in the thickly populated but narrow lanes of Varanasi, adjoining the Ganga. Open defecation and disposal (poverty-based) of the dead in the rivers are the other long-standing problems.

In terms of flawed conservation efforts, huge amounts of money have been spent in repetitive water quality surveys, even though the results are already well-documented. Also, the Government has often entrusted pseudo-environmentalists, who have zero knowledge of hydraulics and the science of water-flow, or non-environmental engineers and technologists, with decision-making in matters related to the cleaning of the river. Consequently, there has been little improvement in the health of the Ganga.

In almost all Indian cities, about half of the generated waste water flows directly into the adjacent river as also does the wastewaters from un-sewered areas such as slums etc. Thus, even if the 50 per cent of the wastewater is given complete secondary and/or the most sophisticated treatment with foreign expertise, the remaing 50 per cent of that flows into the river untreated is large enough to keep the river in a highly polluted state.

In such a situation, the only effective and economic way to prevent Ganga pollution at Varanasi is to create a barrier between the river and the city, so that not a drop of wastewater enters the Ganga’s city stretch. A dam-like structure (as done for the Gomti river at lucknow) or a retaining wall can be constructed along the city stretch. A parallel covered canal or a huge pipe can be laid between the dam/wall and the city to trap all the dirty water coming towards the river. This sewage water can be carried some two to three kilometres downstream, where, together with the sewer-collected wastewater, it can be given zero treatment or primary treatment or secondary treatment, before the water is disposed off into the river.

The river will also get self-purified by the time it reaches the next urban centre, thanks to the extremely high self-purifying character of the Ganga, which is 15 to 25 times more than that of other rivers. The dam-wall like structure can be beautified architecturally as ghats (bathing-platforms). They can also make for attractive site-seeing spots, ideal for pleasure-walks and recreation.

Also, a part of the organic manure rich wastewater can be diverted into agricultural fields. Expensive organic crops are in fashion these days and offer more profits to the farmers. Also, farmers will be able to rely on this source of irrigation even during droughts. This will make farmers confident and help prevent suicides. The plan can be executed in a short time by employing huge amounts of abundantly available manpower. To make the execution cost-effective, students, retired professionals and party workers can be infused with a spirit of shramdaan (free service).

(The writer is an environmental activist and teacher)