With water an ever more scarce resource, authorities are turning their attention to getting the most out of wastewater.
The Community of Valencia in Spain suffers from unreliable natural sources of water. But it's turned this disadvantage into an advantage, by becoming a centre of excellence for water management.
In this interview, Juan Ángel Conca, the General Manager of EPSAR ( Entidad Pública De Saneamiento De Aguas Residuales De La Comunidad Valenciana), tells us how wastewater treatment techniques are evolving.
"There's a popular song that says that in our country, the rain doesn't know how to rain. Either it rains a little and there's a drought, or it rains a lot and there's a disaster. For centuries, we've lived by learning to live with the constraints of water supply. We're not the country in Europe with the most water resources, but we're the place in Europe with the greatest environmental awareness in terms of water use. One hundred per cent 100% of the water is treated, but in addition, in this region, the Community of Valencia, there are places where a hundred per cent 100% of the treated water is also reused in fields and on crops to produce the fruit and vegetables that end up on tables all over Europe.
"Some buildings used to have outside toilets. Little by little, they've been moved inside houses. The same will happen with wastewater treatment plants. Nowadays, they're generally next to rivers: Some rivers start where water from the sewage plant comes out. But it wouldn't be surprising to see wastewater treatment plants inside cities, because it's a public service that gives us water, that gives us energy, and that we need in the same way we need inside toilets.
"There are places in the world where the water that comes out of treatment plants is drinking water intended for human consumption. This isn't the norm in Europe, we don't think it will happen, but I'm sure that water that comes out of sewage treatment plants could soon be drunk by human beings from a glass of water."