As most of the world grapples with a severe water scarcity situation, Malthus’ ominous warning about population growth surpassing (food and) water availability appears closer than ever to reality Other unforeseen occurrences like rapid industrialization, urbanization and global warming have only added to the problem.
India’s population is 1.3 billion and is expected to grow by nearly half a billion over the next four (4) decades. Currently about 377.1 million live in cities with an estimated 225 million more people expected to be added over the next twenty (20) years. About 740 billion cubic metres of water are required annually to cater to the current Indian urban population, this is expected to grow by approximately 200%, to 1.5 trillion cubic metres over the next two (2) decades. This significant growth in population and lack of treatment options creates dual problems i.e. discharge of (untreated) waste water into the waterways polluting the source water and water for drinking extracted from the same source, often not adequately treated, leading to significant health problems.
While the situation appears grim, appropriate and timely measures for water management can help tackle this challenge to a great degree. That wastewater treatment and reuse is considered one of the most viable and sustainable models is evident from the priority accorded to it in the 2012 National Water Policy. World Water Day 2017 has also adopted ‘Wastewater’ as its central theme and emphasized treatment and reuse of water.
The concept is not new, indeed domestic wastewater was used for irrigation in prehistoric civilizations i.e. Mesopotamia, Indus Valley and Minoa (even in the Bronze Age), more recently Israel is recognized as a world leader in the successful reuse of wastewater especially for irrigation. About 90% of the wastewater generated in Israel is treated and about 86% of the treated water is reused. Singapore’s ‘Toilet to Tap’ initiative NEWater is increasingly being recognized as an efficient means of recycling wastewater to highly purified water which can even be used for drinking, it caters to as much as one third of the country’s total demand for water. Namibia has also been recycling wastewater into drinking water for about five (5) decades now.
The water reuse market holds huge opportunity in countries like Australia, United States, India and China where the water recycling rate is less than 20%. India’s Central Pollution Control Board indicates that the country has an installed capacity to treat only about 30% of the household waste, the rest is released into open drains or straight into the ground. The good news is that there has been significant increase in investment in water and sanitation projects in India over the last decade. While government investment and sound policy are crucial, greater involvement of private sector could also give a boost to the extensive deployment of wastewater recycling which is increasingly becoming a necessity for India.
It is probably time for corporates and all of us in general to adopt centralized and de-centralized means to contribute towards this cause.
Malthus was an 18th Century economist who had predicted that while world resources will grow arithmetically, global population will grow exponentially, thereby rendering food, water and other resources inadequate to cater to all.
Part II of the editorial (to be covered in June issue) details viable options in ‘Waste to Water’ and provides case stories of organizations that have successfully employed ZLD (Zero Liquid Discharge).