Water that is red, orange, yellow, brown, or cloudy can signal iron, rust, or other contaminants in the water mains or your household plumbing. A “rusty” or metallic taste in water is a result of iron, and sometimes manganese, in ground water. They not only create a bad taste, but they also can stain pipes and clothing.

Two metals that are typically to blame for staining are iron and manganese. While these minerals serve as essential nutrients for your body, they aren’t so kind to plumbing fixtures, appliances and even clothing. Reddish and yellow-tan discoloration is often caused by iron, while black or dark brown discoloration points to manganese. Due to their similarities and their frequent occurrence in tandem, iron and manganese are generally treated in much the same way.

Discoloration usually results from the exposure of these metals to oxygen, known as oxidation. In your plumbing, water often has limited exposure to oxygen, keeping any soluble (ferrous) iron or manganese in solution. Once these metals come out of a faucet and are exposed to the air, oxidation occurs and chemical reactions may cause them to form a substance that creates visible staining.