What Are Tannins?

Tannins are natural organic matter that can result from nature’s fermentation process as water passes through the ground in peaty areas or through levels of decaying vegetation. Tannins are typically found in shallow wells, in swampy or marshy areas as well as coastal areas.

Tannins as a contaminant are not regulated by a governmental agency however there is a secondary drinking water standard for color. A secondary drinking water standard is not federally enforced.

Common signs of tannins:

  • Yellow water
  • Yellow staining on toilet fixtures
  • Yellow staining on laundry;

Are Tannins Harmful?

Although aesthetically displeasing, tannins do not pose a health issue. However, if tannins are found in the water, it can indicate that your water is significantly influenced by surface water.  Put simply, this means that if tannins can travel easily from surface water to your groundwater source, pathogens can easily travel through as well.  If you are testing for tannins, it is also recommended to test for bacteria.

How Do I Get Them Out Of My Drinking Water?

There are several options for removing tannins, depending on the tannin levels in your drinking water.

  • Activated Carbon Filters
  • Anion exchange
  • Chlorination and subsequent filtration.

If you think you have tannins in your drinking water, contact one of our specialists to discuss your options.