Table 1.
Standard chemical characteristics of Danish drinking water from 2000 to 2010 (mean and range)
| Mean | Range | Per cent of total | |
|---|---|---|---|
| Physicochemical characteristics | |||
| Evaporation residue (mg/L) | 434 | 177–886 | – |
| Ionic strength (mol/L) | 0.010 | 0.004–0.023 | – |
| pH | 7.57 | 7.14–7.92 | – |
| Water hardness (odH) | 16.0 | 7.4–30.0 | – |
| Gases (mg/L) | |||
| Aggressive carbon dioxide | 4.6 | 0.0–77.2 | 0.8 |
| Oxygen | 8.8 | 6.0–10.6 | 1.6 |
| Cations (mg/L) | |||
| Ammonia and ammonium | 0.06 | 0.01–0.39 | <0.1 |
| Calcium | 91.2 | 42.0–163.0 | 16.4 |
| Iron | 0.13 | 0.02–2.91 | <0.1 |
| Magnesium | 14.5 | 3.9–41.2 | 2.6 |
| Manganese | 0.06 | 0.01–1.82 | <0.1 |
| Potassium | 3.6 | 1.3–10.5 | 0.6 |
| Sodium | 33.7 | 11.0–103.0 | 6.1 |
| Anions (mg/L) | |||
| Chloride | 54.7 | 14.5–164.1 | 9.8 |
| Fluoride | 0.38 | 0.09–1.35 | 0.1 |
| Hydrogen carbonate | 287 | 112–427 | 51.6 |
| Nitrate | 4.15 | 0.63–23.97 | 0.7 |
| Nitrite | 0.02 | 0.00–0.10 | <0.1 |
| Inorganic phosphorus | 0.03 | 0.01–0.09 | <0.1 |
| Sulfate | 50.7 | 4.0–237.0 | 9.1 |
| Organic compounds (mg/L) | |||
| Organic carbon | 1.86 | 0.62–9.43 | 0.3 |
| Saturation indices as log10 (IAP/Ksp) | |||
| Hydroxyapatite* | 2.66 | −1.82 to 6.05 | – |
| Brushite† | −2.68 | −3.45 to −2.12 | – |
| Mg-whitlockite* | 4.87 | −4.04 to 11.58 | – |
| Calcium carbonate* | 0.26 | −0.64 to 0.87 | – |
| Octacalcium phosphate† | −5.35 | −8.74 to −2.81 | – |
| Fluorapatite* | 7.91 | 3.25 to 11.47 | – |
Weighted average values for 20 standard chemical characteristics, as well as ionic strength and saturation indices, of Danish drinking water from 2000 to 2010 in the 98 Danish municipalities. The part of each ion and compound relative to the total amount of ions and compounds is given in the right hand column in per cent of total by weight. Saturation indices were determined by calculation.
*Denotes general (mean) supersaturation.
†General undersaturation. It should be noticed that the result for Mg-whitlockite is based on a temperature of 25°C. In addition to the total concentrations of all species, pH is known as well. For this reason, the hydrogen carbonate concentration was treated as variable, which seems justified as the value may easily change by exchange with the atmosphere.