Sadly many of the authorities in the World do little to rank clean fresh water - in fact many regimes have adopted the view they can always render foul water "safe". Often in the process the public are told half truths in that the water can be "doctored" to kill the bugs but what of all the toxins and other pollutants. I have no problem with reusing and treating (through largely natural processes) certain of our water but I loathe being misled especially by people who should know better and those that have a vested interest. Water quality rests on a healthy ecosystem - deforestation, pollution and the like will see any real quality unlikely - yes even in your bottled water, friends!