Drinking water, regardless of the category to which it belongs, must be healthy and clean, that is, it must not contain microorganisms or other substances in concentrations that represent a potential danger to human health

Drinking water is a primary natural resource intended for human consumption.

Water purification processes are designed to provide water suitable for food use, possibly purifying it, improving its hygienic properties; classic examples are the possible addition of chlorine as a disinfectant; or calcium that is possibly introduced to raise the pH and safeguard the integrity of metal pipes from corrosion.