ABSTRACT
The first target of the United Nations's sixth Sustainable Development Goal is, by 2030, to achieve universal and equitable access to safe and affordable drinking water for all. That doesn't seem much to ask given that water is the basis of life, and safe drinking water and proper sanitation are two of the foundation stones of human health and wellbeing. But the UN says, for at least 1.8 billion people, it really is too much to expect as they still have to use sources of drinking water that are contaminated with sewage. Of the 1.3 billion cubic kilometres of water on Earth, the oceans account for about 97% of it, covering about 71% of the planet's surface. The uncomfortable reality is that ours has never been a world where having enough water to drink has been a certainty, or that what water there is will be safe to drink.
