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Tannins In Well Water


If you have been a rural homeowner for any length of time, you are most likely acquainted with some of the challenges associated with owning a home with water supplied by a well. While homeowners in the city are able to rely on their municipal water being regulated and treated by a public water supply, if your home’s water is supplied by a well, you are directly responsible for the quality and safety of the water that is being used in your home. You may have encountered everything from high amounts of hardness and iron content to strong sulfur odors and discoloration of your water. And since you’re a responsible well owner, you have had your well water tested for contaminants once a year and are always on the lookout for reports of groundwater contamination in your area, especially if you live near large farms or an industrial operation.

If you have a shallow well or live in a low-lying or coastal area, you may have encountered a less common problem that affects well water users called tannins. And while this issue has no potential health or safety concerns associated with it, it can have an unpleasant influence on the way your household uses water.

What Are Tannins?

If you’ve spent some time exploring the outdoors, you have likely encountered a lake or river flowing with light brown or amber colored water. In especially quick moving rivers, this water can even take on the look of root beer as it cascades over rocks and down small waterfalls. While this color is often mistaken for dirt or pollutants in the water, it’s actually caused by tannins.

Tannins are fermented organic materials that are created by the breakdown of vegetation. When water passes over and through this material it takes on a yellow to amber color. In the case of a root beer colored river, water passes through nearby swamps, marshes, or other areas that contain a lot of decaying vegetation, and collects these small plant particles which gives the river its color.

Tannins can affect the water in a private well in the same manner. As surface water makes its way downwards towards the aquifer that feeds your well, it can pass through decaying, fermenting vegetation or peaty soil. And, just like the root beer river, the water supplied to your home will begin to take on a light yellow to brown color depending on the concentration of the decaying material.

Effects Of Tannins In Your Home

While water affected by tannins does not pose any health or safety risk when consumed or used in the home, it can create some unique problems. Besides the unappealing color, affected water can have a plant-like, musty odor to it and will have an unpleasantly tangy aftertaste when consumed. The tea-like color also works similarly to a dye and has the potential to permanently stain laundry and even porcelain fixtures and dinnerware in your home.

Testing For Tannins📷

Tannins can be tricky to test for since high iron content can also cause discolored water. An easy way to gauge if your water contains tannins is to fill up a clear glass and let it sit overnight. In the morning, if the discoloration is more noticeable at the bottom of the glass, the color is likely caused by iron as the heavier iron particles will naturally settle. If the entirety of the water remains the same color, tannins are likely the culprit.

Getting your water tested by a certified laboratory will offer more accurate results. In addition to testing for tannins, a lab will be able to look for any other component in your well water that may be affecting the color or taste, such as hardness and iron.

Treating Tannins

If you have determined that your well water contains tannins and would like to have them removed, there are a number of options at your disposal. Even with these options, though, tannins can be somewhat difficult to treat. For example, even if two wells are within a few miles of one another, the treatment method may be slightly different due to the fact that different tannins derived from different plants are present in the water.

Tannin filtration is somewhat unique due to the fact that it operates more like a water softener than a true water filter. Like a softener, a tannin filter uses an ion exchange resin media to capture tannins and other organic compounds. When the fine, white resin beads that comprise the media have reached capacity, the unit is regenerated and washed with a brine solution and the filtration process is ready to begin again.

If you’re experiencing drinking water that looks like a glass of iced tea but smells and tastes bitter and earthy, it may be time to get your well water tested and treated for tannins. Evolve’s EVT water filter can address your well’s tannin problem and reduce problem minerals, odors, tastes, and other discoloration issues that are commonly found in homes with a well water supply. Contact us today to schedule a water test and begin the process of fixing your well water for good!


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