Hard water is water containing high concentrations of dissolved minerals, usually calcium or magnesium carbonates (CaCO­3 or MgCO3), chlorides (CaCl2or MgCl2) or sulphates (CaSO4or MgSO4) and is not a health risk. View these articles: (1) www.healthline.com/health/hard-water-and-soft-water#bottom-line (2) www.mcgill.ca/oss/article/health-you-asked/you-asked-hard-water-dangerous-drink