Contaminated bottled water can harm your health, including causing gastrointestinal illness, reproductive problems, and neurological disorders. Infants, young children, pregnant women, the elderly, and people with weakened immune systems may be more likely to get sick from some contaminants. It is water derived from varied sources including surface, ground or sea and subjected to treatment like decantation, filtration (including aeration filtration with membrane filter, cartridge filter, activated carbon filtration), demineralisation, mineralisation and reverse osmosis.