Wastewater, want water...

Wastewater, want water...

Looking out of the window on a March morning in Scotland, it is easy to forget that the water that falls unrelentingly from above is in fact becoming a scarcity throughout the world.

It is easy to take our water for granted, given it covers 70% of our planet. However, the water that fuels us, our farms and our industries is freshwater, and this makes things difficult. Only 2.5% of the world’s water is fresh water, and two thirds of this is frozen in glaciers and thus out of reach.


As a result, 1.1 billion people lack access to water and a third of the population find water scarce for at least one month a year. Unfortunately, the outlook is no better - with a growing population, urbanisation and rising temperatures it is estimated that by 2025 two thirds of people will face water shortages. 


So, what are our options? Well, we can reduce the volume of water that we use, we can try to make “new” freshwater, or we can recycle the water that we currently use. In reality, there isn’t one golden ticket to a sustainable freshwater supply and a combination of all of the above will be required.

  • Water reduction - There are actions to be taken by individuals and companies to reduce the amount of water used and it is becoming easier to do through technology. The textiles industry, for example, is on the blacklist when it comes to water usage. It is the second most water-intense industry (after agriculture) and produces nearly 20% of global wastewater. A key technology company working to reduce water wastage and push towards sustainable textile manufacturing is Kornit Digital. Kornit’s textile production solution enables 93% - 95% less water usage in textile printing.


  • New freshwater – Desalination is the removal of salt from seawater to create freshwater. The International Water Association estimates that desalination is both more expensive and more energy intensive than water recycling. However, the cost and efficiency of desalination is falling as technology develops. Energy Recovery Inc has developed a reverse osmosis product which is estimated to reduce the energy costs of desalination by 60%.


  • Water recycling - Water recycling has historically been the uglier sister to desalination. Public acceptance is typically lower as some struggle to accept drinking water that has passed through toilets or drains. However, a study by Stanford University engineers recently discovered that recycled wastewater is not only as safe to drink as conventional drinking water it may even be less toxic than water from sources we drink from every day.

Water recycling works by passing water through a number of steps. Typically, water is pushed through microfilters to remove impurities, then treated with UV light and chemicals in order to destroy any unwanted organic molecules. Recycling is a particularly favourable solution as it not only reduces the need to import water and therefore drain natural ecosystems, but it also cleans up wastewater that would typically be discharged into environments. Further, technology has been developed to reduce the number of steps required and increase efficiency.


Tetra Tech designed the Albert Robles Recycling and Environmental Learning treatment plant in Southern California to help reduce reliance on imported water for 4 million people. The plant has the potential to treat 28 million gallons of groundwater per day and the facility also includes a learning centre to teach the local community about water reuse and water education.


It is progress from companies like Kornit, Energy Recovery and Tetra Tech (all held in our sustainable portfolio), which will pave the way for sustainable fresh water supplies throughout our world. I will happily toast a glass of tap water to that.

Important disclosures

More about the authors

Emma Hall Investment Analyst

Emma Hall, investment analyst, is a member of the equities team and is responsible for company research for the Global Sustainable Equity strategy.

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