Ha. I’m glad everyone’s caught on to this story, and I really wish I’d mentioned it at the time I saw it. Basically Coke’s new Dasani water is “purified” tap water.
My top tip for any bottled water is to look carefully at what it says on the label. If it doesn’t say “bottled at source”, then you don’t know where it comes from. If it doesn’t say “Natural Mineral Water” then it’s nothing special at all. Waters like Highland Spring, Buxton, Evian and Volvic are all Natural Mineral Waters that come out of the ground at the place specified on the label. And don’t be fooled by anything called “Spring Water” without also being natural mineral water. We have some stuff at work in the cooler called “Cotswold Spring”, and as far as I understand it, although it comes from a spring somewhere in the Cotswolds, it doesn’t mean much more. The full UK legislation can be found here.
The Food Standards Agency lists all UK Natural Mineral Waters (nothing called Cotswold Spring on that list) and the EU publishes a European list (PDF).
One other thing to note is that nearly all carbonated mineral water sold in the UK is produced artificially with carbon dioxide being added later. Even water like Perrier which is carbonated at source, has the co2 removed and then pumped back in. I’ve drank one naturally carbonated mineral water which you used to be able to get from Sainsburys, and the thing to note is that it was very lightly carbonated in comparison to most waters you can buy.
Personally, I’m more than happy with my Thames Water, even if it does scale everything up!