Benjamin Franklin famously said ‘when the well is dry, we know the worth of water’. There is certainly no denying the fact that water is getting scarce and precious and that the whole planet is facing a global water shortage. All of us are dependent on water for survival and for our energy needs and this makes sustainable water management the need of the hour. Given this scenario, there is a growing need to effectively use all available forms of water including once used water called wastewater but which actually is an unutilised resource.
In India, the situation of water scarcity is grim with close to 600 million people facing acute water shortage. According to a report by Observer Research Foundation (ORF), the demand for water in India is expected to grow at a 2.8 per cent Compounded Annual Growth Rate (CAGR) from 2010 to 2030, facing a potential supply gap of 50 per cent by 2030. This could adversely impact agriculture and other key industries like food processing, beverages, textiles, etc., causing a significant dent to the GDP by 2050.
When we talk about water shortage, industrial water usage is rarely given the needed attention. According to a research by the Central Pollution Control Board (CPCB), industries utilise over 500 billion cubic metres of the total amount of fresh water available each year. There is no doubt there will be a further increase in demand for water for industrial purposes.
While water usage in industries is one side of the story, the other issue is the wastewater discharge that can massively pollute our rivers. Industries can play an important role in sustainably managing their water usage and rethinking the way they manage their wastewater.
Simply put, wastewater is the water used once by domestic, industrial and commercial use. Household activities like washing, bathing, restroom usage, etc., result in waste water while industrial wastewater emerges from activities like manufacturing, production, etc.
Technological development means that waste water can be treated to varying degrees and reused, making it a promising solution to tackle the problem of water scarcity. While treated waste water can be reused for several industrial and domestic purposes, the by-products of wastewater treatment can be invaluable resources for agriculture and possibly energy generation.
While there is a scarcity of freshwater resources, it is observed that a potential source of water which is wastewater, is largely underutilised. According to the ORF report, if India reuses 80 per cent of its untreated wastewater from 110 of its most populous cities, 75 per cent of projected industrial fresh water demand can be met by 2025 replacing fresh water use.
The recently adopted National Framework on the Safe Reuse of Treated Wastewater provides operational guidelines for States to take up programmes on wastewater reuse. Many States have adopted their own wastewater reuse policy which should provide a fillip for the setting up of treatment plants and safe reuse.
Singapore’s policy of wastewater management is a good example, which demonstrates the benefits of implementing an advanced wastewater treatment system using high tech treatment plants. Today the little island country is able to meet 40 per cent of its water demand from recycled wastewater and this figure is expected to rise to 55 per cent by 2060.
Apart from reducing ocean pollution and using treated water for industrial purposes, some part of the treated water is also used for drinking purposes. Even cities like San Diego and communities in Namibia and Australia use recycled water for drinking.
Wastewater reuse is possible and economically feasible at smaller, decentralised scales too. One of the ways in which industries can efficiently manage their water is by converting their wastewater into high quality clean water that can be used for their internal purposes.
One such example is Bengaluru based Vishudh Plastic Recycle and Jeeves India laundry that have installed a unique 11 step filtration process by Boson Whitewater System that converts ETP (effluent treatment plant) water into high quality potable water. All the ETP/STP (sewage treatment plant) water produced by the industry is converted into potable water and used for cooling towers, plastic washing units, laundry and other purposes.
Recognising the real value of treated wastewater, even apartment complexes are making use of modern water recovery technology to convert STP treated water to drinking water quality. Some complexes have gone one step ahead and started generating revenue from the high-quality water by enabling the sales of this water to industries.
This has proved to be a win-win situation with apartments not only becoming self-sufficient but also contributing to the health of the environment in a positive way. Apart from dealing with water scarcity effectively, they are also putting the water to meaningful use while industries reduce the dependency on bore-well water.
With appropriate waste water reuse technology and right implementation, industries and apartments can definitely rethink their wastewater usage and leverage on its potential to the best possible level.
The writer is an urban planner and a water conservation expert