Many of the big bottled water brands are reverse osmosis filtered and UV sterilised - Aquafina and Dasani definitely are, as is Nestle Pure Life IIRC. Water sou

Many of the big bottled water brands are reverse osmosis filtered and UV sterilised - Aquafina and Dasani definitely are, as is Nestle Pure Life IIRC. Water sources with low total dissolved solids are preferable for cost reasons, but it isn't much of a problem if the water source is dirty or brackish.