Hard water is unfortunately a common issue in homes today, and it often occurs in cities. Minerals seep down through the ground and into the pipes carrying fresh water from the municipal treatment plants to residential and commercial buildings—this is why hard water can affect homes even with the best city treatment plants.
The good news is that hard water isn’t dangerous to drink. The concentration of minerals that cause hard water—mostly magnesium and calcium—are found in many foods people eat on a daily basis, and the levels in hard water are not harmful. The problems with hard water show up elsewhere: deposits on fixtures, filmy surfaces on glass, and the difficulty working up soap lather.