We had a huge scandal in Britain, a very famous and respected brand of expensive bottled water with Royal connections, was found to have been filling it's bottles for years, straight from the local taps!   I would hazard a guess that the same is bound to happen in every country on the planet.   After all, water is water and money is money.

there are few kinds of bottled water.

those "purified" don't tastes well, partly because taste comes from many elements that are... filtered out. so really purified water is tasteless (and it could be felt like little bitter)

I think, that some companies may add some ingredients to purified water to make it's taste better, have to read the label

and most of bottled water in China is purified.

check if water is clean or not is not so easy at home... 
- place same amount of water on two pieces of glass, on first - from tap, on second - from bottle, let it dry, and compare what was left on the glass. glass with leftovers of purified water should be cleaner off course
- to check it there is some "live" in water - do as described before but FIRST let both samples to be exposed on direct sunlight for few days (in closed bottles),

if the will be more "leftovers" then in the first samples... definitely something was living there ;) 

this is not very accurate, but can give general view

its china and the bottle water has traces of metal in it says it right on the bottle