My father used to say that if something looks too good to be true, it usually is. However, in the case of ethical water, surely that rule doesn’t apply. After all, the more of it you drink, the more wells, aquifers and drought-busting technology is invested in Africa and India. Good for everyone, no?

But there is a marketing catfight going on between established beverage giants and new, upstart ethical water brands.

In the blue corner, Coke, Nestlé and Danone, among others, point to huge volumes of ethical sales and the sheer amount of funds they invest in developing world projects. It’s hard to argue with their figures and the material difference they have made.

In the red corner, new brands such as Life Water, Belu and One highlight the uniqueness of their social programmes and a more radical take on water poverty, looking at the causes of water shortage as well as bottled water as a solution. They lay claim to a different set of brand values, highlighting what they see as the hypocrisy of the beverage giants who continue selling standard water alongside ethical products.

Meanwhile, for environmentalists, Eden is burning. The carbon footprint of bottled water packaging is huge and for many entirely avoidable as tap water is a ready alternative. The counter from ethical water is not to worry about the means, but focus on the ends. People out there are dying of thirst and if bottled water is a way to combat that, then so be it.

Perhaps neither view is quite right. It feels counterintuitive to use valuable resources to bottle something that comes free from a tap. Yet while in the West, we are all too often dehydrated by choice, in the developing world, dehydration is often an unavoidable fact of life, so it seems churlish not to support ethical water in all its guises.

In an ideal world, we want something not only portable and convenient, but also reusable and ethical - perhaps something that can be replenished with tap water but offer the crisp taste and the chic cachet of bottled water.

Step forward portable water filter brands like Water to Go and Brita. If this new product platform were ethical as well, it really would be to good too be true.

Hamish Renton is MD of Hamish Renton Associates