From The Food Encyclopedia by Jacques Rolland and Carol Sherman
Water from an underground source, such as an aquifer or artesian well, that contains minerals, salts and trace elements (referred to as Total Dissolved Salts, or TDS) and may contain some gases. A bottled variety may be sparkling or still, but must have a consistent composition of TDS; to be labeled "mineral water" in the U.S., for example, it must contain a minimum of 250 parts per million TDS. (Currently, no such standards exist in Canada.) In Europe, where the required level of TDS is lower, mineral waters have traditionally been regarded as healthful to drink or to bath in, at such popular spas as Baden-Baden in Germany. Although there is no conclusive science to prove health claims, the consumption of mineral waters is increasing, particularly in North America, where some people prefer it to chlorinated, fluoridated tap water or enjoy it, with a twist of lemon or lime, as a trendy, nonalcoholic drink.
