This research study describes the chemistry and suggested treatment of manganese in drinking water, with the goals of reducing customer complaints and improving perceived water quality. Complaints caused by manganese in drinking water are very common. The problems are aesthetic--water discoloration (usually black or dark red), clothes and fixture staining, turbid water, sediments, and, at very high levels, metallic taste. Manganese has no negative health effects at the levels commonly found in drinking water.