Sindhu Jha
THERE has been a decline of 73 per cent in per capita surface water availability in India between 1950 and 2024, as per the Union Government’s India Water Resource Information System. India now ranks 132nd in the world with respect to per capita water availability. This makes the country water stressed If no steps are taken to address the issue, India could become water scarce. Cities such as Delhi, Mumbai, Pune, Hyderabad and Chennai, as well as many small and medium towns, are staring at a scenario where their sources will completely run out of water. Bengaluru faced unprecedented water shortage last year.
As India witnesses rapid urbanisation, the situation may get worse, especially with climate change manifesting itself as an intensification of the water cycle, resulting in frequent floods, droughts and water stress.
Reuse of wastewater is being seen as a new way of supplementing the water supply and mitigating the impending water shortage. Simply put, all used water is wastewater. Its reuse will serve the twin purpose of augmenting water resources while reducing the environmental impacts of disposing untreated wastewater.
Cities in India generate wastewater in large amounts. But most of it is not reused because management of wastewater has largely been considered from a “disposal” perspective, and not from a “reuse” point of view. According to an assessment by the Central Pollution Control Board (CPCB), sewage generation in urban centres across India was 72,368 million litres per day (MLD) for 2020-21, while the installed sewage treatment capacity was 31,841 MLD.
The operational capacity, however, was 26,869 MLD, and of the total urban sewage generated, only 28 per cent (20,236 MLD) was treated. This implies that 72 per cent of the wastewater was untreated and disposed of into waterbodies or on land. This is the resource that can be utilised.
