Delhi’s government has proposed mandatory zero liquid discharge (ZLD) systems in the schools it runs, reports the Hindustan Times. The purpose of this measure is to save water in school compounds: reusing reclaimed water will reduce freshwater consumption. The proposal was approved earlier this month and is expected to be notified before the month ends.
The city plans to start with government schools because they have a larger area to use recycled water in their compounds, for example to water lawns. Once the model is well established in government schools, it will be extended to public-private schools.
Dinesh Mohaniya,Vvice-chairman of the Delhi Jal Board, said ‘the idea is to put even the last drop of water to use by recycling waste water from kitchens and toilets, among others’. Schools will have 90 days to install the systems. ZLD systems employ advanced wastewater treatment technologies to treat and recycle virtually all of the waste water produced. Different techniques may be used such as constructed wetlands or small mechanised plants. Treated water can be reused for uses that do not require drinking water quality.
The measure comes after a scheme to implement rainwater harvesting systems in city-run schools, yet to be completely rolled out. Indian’s National Green Tribunal directed educational centres in the capital city to implement rainwater harvesting systems. Moreover, Arvind Kejriwal, Chief Minister of the government of Delhi, stated recently the cabinet intended to require rainwater harvesting systems in all government buildings.
Experts encourage forward-looking measures such as water recycling and rainwater harvesting to increase water use efficiency and ensure water security into the future. According to Manu Bhatnagar, from the non-profit Indian National Trust for Art and Cultural Heritage (INTACH), ‘This is a good beginning. There is no escape from recycling used water as sources of water are becoming scarcer day by day’.