Virginality

This deals with the concentration of nitrate in the water, which may come from the natural breakdown of organic material (decaying vegetation) in low concentrations and is often an indication of contamination from fertilizers, sewage, or animal waste if the concentration is higher. Drinking water quality (DWQ) guidelines use 10 mg/L as an upper limit for nitrate due to its impact on babies and young infants that drink water with elevated nitrate concentrations developing ‘blue baby syndrome’, which is caused by nitrate breakdown affecting iron in the hemoglobin by blocking the iron from carrying oxygen to individual cells. This does not appear to be an issue for older children or adults. All of the waters listed are less than 1.0 mg/L and well within the DWQ guidelines. For Lanark (Seven 0.19 mg/L), the nitrogen source is from the natural decay of vegetation (leaf litter, etc.) on the ground surface being incorporated into the precipitation during infiltration to the subsurface.

Minerality

This category equates the “subtle taste and terroir” of the water to their total dissolved solids (TDS) content. This is basically true, with high iron and manganese concentrations leading to the greatest number of complaints among consumers. High sodium concentrations can give water a slippery feel while excessive calcium, magnesium and bicarbonate/carbonate (hardness and alkalinity) can at times leave a chalky taste. Organic constituents dissolved in the water can lead to odour and colour issues which often are related to taste.

DWQ guidelines recommend less than 500 mg/L of TDS, and mineral waters have TDS values greater than 250 mg/L. Some bottled mineral waters from eastern Europe have concentrations exceeding 1000 mg/L TDS. The presence of various chemical elements and compounds are important for body functions (see WHO report on Nutrients in Drinking Water, 2005), while pure (distilled or reverse osmosis (RO)) water can lead to deficiencies in essential elements and even leaching of essential elements from the body. The Lanark water contains essential elements, such as calcium, magnesium and bicarbonate,
while maintaining low enough TDS concentrations to provide a clean and fresh taste.

Orientation/pH

pH, the measure of the hydrogen ion activity, is an important parameter for water. DWQ guidelines recommend that the pH should be between 6.5 and 8.5. Although a pH of 7.0 is considered neutral, a higher (alkaline or basic) level is recommended. Water with a pH below 7.0 is acidic and is considered corrosive for metal pipes and fixtures. The VOSS water has a pH of 5.5, below the recommended range and is probably due to low alkalinity (bicarbonate) which is also reflected in the low TDS.

Sweetness is a marketing term but is correct in that the taste is neither bitter nor sour. In ancient times, the Greeks often referred to ‘fresh’ water as ‘sweet’ water in contrast to the bitter taste of highly mineralized water like sea water. It should be noted that in the comparison information (under the heading alkaline) it states that water with a pH of 7.1 to 7.5 “may be perceived as sweet”. Lanark water at a pH of 7.7 is slightly above this definition but is labelled as “with a hint of sweetness”, which is either stretching the range or demonstrating the arbitrary limits of “sweetness”. Nevertheless, the optimum pH range is 7.0 to 8.0.

Hardness

Hardness is the combined concentration of calcium and magnesium ions in the water and for DWQ purposes it is probably better to look at the individual concentrations of the two elements. Municipal water supplies often adjust the hardness of their water by using water softeners (Sodium cation exchange) to values between 80 and 100 mg/L. Individual well owners who depend on their well water for household use also often run the water through a water softening system to reduce the hardness. When high concentrations of calcium and magnesium are present in water, it depresses the ability of soaps to create suds, and can cause precipitation of scale/lime when the water is heated. These are technical issues that are unrelated to drinking/consumption of the water; DWQ guidelines for both calcium and magnesium are <250 mg/L for each. In fact, calcium is very beneficial for our bones and teeth, blood coagulation, nervous system function, and enzyme and hormonal responses. A deficiency (low concentration) of calcium in drinking water increases the risk of coronary disease and bone fractures (WHO 2005). Likewise, magnesium supports the immune system and is very important for many metabolic functions and muscular and nerve activity. Magnesium is responsible for the relaxation of muscles, while calcium is responsible for the contraction of muscles. Magnesium deficiencies in drinking water have been associated with increased risk of cardiovascular disease. One should not drink soft water, especially if it has been artificially softened by sodium cation exchange, as will be discussed in the next section.