Water that is a faint yellow to tea-like color, and can cause yellow staining on fabrics, fixtures, china and laundry is caused by tannins. Tannins are a natural organic matter that can result from nature's fermentation process as water passes through peaty soil and decaying vegetation. They appear primarily in river or surface water and swamps, but, often find their way into wells through cracks and fissures in rock formations. While tannins are not harmful to health, they do present a number of other problems in our water. They can contribute to the problem of acid water; and they can render certain other water treatments such as iron removal filters ineffective.
Treatment Methods: Anion exchange, oxidation and filtration, Reverse Osmosis