Water always contains some amount of dissolved solids (inorganic salts like calcium, magnesium, potassium, and sodium, for example), which influences its pH. According to Nicole M. Hancock, executive director of the Safe Drinking Water Foundation, the higher the total dissolved solids, the more alkaline the water tends to be. The pH of tap water is close to 7, while water with more alkaline compounds in it typically has a pH of 8 or 9.