I have coined the term "virginality" to indicate how protected water from a particular source is from its surroundings. The water's nitrate level determines its Virginality rating. Nitrate is an inorganic compound consisting of one nitrogen atom and three oxygen atoms. Nitrate is easily carried through soil by water. The substance can leach into the ground below the root zone through heavy rainfall or irrigation, and it may subsequently find its way into groundwater.
This contamination may come from fertilizer, animal waste products, decaying plant matter, septic tanks, or sewage treatment systems. Only testing can determine nitrate levels in water, as nitrate has no taste, odor, or color. The ability of blood to carry oxygen throughout the body may be impaired by very high nitrate contamination in drinking water; this may cause methemoglobinemia (also known as blue baby syndrome). Cancer, disruption of thyroid function, birth defects, and miscarriages are other risks posed by high nitrate levels. The World Health Organization (WHO) recommends that exposure to nitrate should not exceed 50mg/l for short periods. In the U.S., drinking water may not contain more than 10mg/l of nitrate, a level determined by a study in 1951 of infants suffering from blue baby syndrome. I use the following scale to describe the virginality of bottled water:
Distillation, reverse osmosis, and ion exchange can remove nitrate from water. Several manufacturers offer equipment to apply these techniques to home drinking water. Nitrate isn't removed by standard water softeners or filters, including carbon adsorption filters, and boiling water increases nitrate concentration.
Great water often has to come from remote sources, and remote sources are by definition hard to get to. Building a bottling plant in remote areas, together with the problematic transportation makes water from remote regions more expensive. The virginality concept allows consumers to appreciate the effort made by bottlers to source uncompromised waters and bring them to the table.