Tannins occur naturally in nature, and help give wine and tea color. These tannins tend to be flavenoids. In tea brewing and wine making tannins also affect flavor, generally imparting a tart or bitter flavor. Tannins in drinking water are undesirable. These tannins found are a natural organic material that are the byproducts of the natural breakdown of decaying vegetation and are created as water passes through soil and peat. This decomposing vegetation can be from leaf matter, algae, moss, even animal tissue, resulting in humic and fulvic acids. Tannins can give water a:
Municipalities can draw water from underground aquifers, from lakes or rivers, or from a combination of both. Water drawn from lakes or rivers often contains tannins, and this can be especially problematic during certain times of the year, such as when algae blooms. Tannins can also be found in shallow wells.
- Faint yellow to tea-like color. This can lead to unsightly water and yellow staining.
- Musty or earthy taste or smell.
- Tart or bitter tasting water
Suspended tannin particles and light dissolved tannin can be removed or reduced simply and cost-effectively with a point-of-use water filtration system that features activated carbon. However, high dissolved tannins may require an anion exchange resin to remove.