Tips for Taps Blog

Why Is My Water Yellow?

Why Is My Water Yellow?


Sometimes changes in tap water are impossible for us to see. Other times they are impossible to miss. From funny tastes to strange smells, our Tips for Taps blog aims to help you address potential causes of concerns with your drinking water.

One of the easiest changes to spot is tinted water.

So, have you noticed your tap water has turned yellow? It may not smell bad, yet it certainly raises some questions. Fear not and read on–because we have some answers.

Reasons For Yellow Tap Water

Let’s start with the good news. We have a test specifically designed to diagnose the problem: our Yellow Tap Water Test.

This professional laboratory test includes analysis for some of the most common causes of yellow water, such as: iron and tannins–as well as metals associated with corrosion and pipe issues, including manganese, copper, lead, and zinc. Many other contaminants effecting health and other general physical properties of your water (like hardness) are also included. It also includes an at home test for iron-related bacteria.

Not only will you receive a comprehensive, professional water quality analysis (take a look at this example Tap Score Report), each report includes a detailed health (and plumbing) risk analysis, as well as personalized and unbiased treatment recommendations.

The other piece of good news is that, most of the time, yellow water does not pose a significant health risk. Still, it's worth investigating. While we always recommend testing if you notice any changes to your drinking water quality, it’s helpful to answer a few questions:

  1. Is your water is coming from a public water system?
  2. Or is your water coming from a private well?
  3. Is your water always yellow?
  4. Or does it return to normal after running for a few minutes?

With these answers in mind, our guidelines below can help you understand why your water is yellow and what to do about it.

1. My Water Is Yellow and I Am Served by a Public Water System

City Water Test

Likely causes of yellow tap water from a municipal supplier include:

Your water utility is performing repairs: Every water distribution system needs to be repaired from time to time. Utility repair work upstream might be the culprit for yellow tap water, as rust and other materials may enter into your water supply during maintenance work.

Your water utility is “flushing” the water lines: In order to clear out stagnant areas of your system, water suppliers must occasionally increase the water pressure in your pipes and water mains. During this “flushing,” it is common for yellowish rust in the pipes to loosen. As a result, your water quality may change temporarily. You will know that “flushing” is the cause of your colored water when only your cold water is affected.


Both should be temporary. To be sure it's best to call your water supplier to confirm what's going on. If no repairs or maintenance is going on, see heading 4 further below.

2. My Water Is Yellow and I Have a Private Well

Well Water Test

Your Water Could Contain Iron-related Bacteria: Iron bacteria are small organisms which naturally occur in soil and water. They are not known to cause disease, but can tint your water. This occurs when these bacteria combine iron and manganese with oxygen to form a yellowish, slimy buildup. For more information about what iron may mean for your well, take a look at this article here.

If you drink water from a private well, we recommend that you test your well water every 3 years.

Your Water Could Contain Organic Materials: Byproducts of nature's fermentation process, tannins are created as water passes through peaty soil and decaying vegetation. They are one of the most common causes of water coloration. While they do not pose a health risk, tannins can turn your water yellow. The best way to remedy this type of coloration is to treat your water with: 

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

It Might Be a Build Up of Iron And Manganese: Iron (Fe) and manganese (Mn) are common in groundwater supplies and often occur together. Elevated levels of either do not pose any known adverse health risks. In fact, both are regularly required by your body as mineral nutrients to stay healthy. However, they do have less than desirable effects on your water color.

Their presence in water may be in multiple forms. When the water comes from the tap with a yellow tint, the Fe and Mn have combined with organic matter and is called colloidal. While difficult to remove, it can be treated. Treatment options include sequestering, ion exchange, oxidizing filters, and oxidation and filtration or settling.


Test your water professionally. Because certain contaminants are more well-suited to some filtration technologies than others, we always recommend you test BEFORE you treat. This can save you money in the long-run, as you will know the best type of filter for your specific water chemistry.  As we mentioned before, the Tap Score Yellow Tap Water Test includes both certified laboratory testing and treatment advice. 

3. My Water Is Yellow – Always

If you run your tap water for an extended period of time and the color does not clear up, it is likely that the issue caused by a disturbance of pipeline sediments in the water main. These disturbances occur when dissolved iron is stirred up in naturally-occurring sediments that exist in all water systems.


The best thing to do is to contact your water authority. Drink bottled water until the yellow-ish color subsides. Alternatively, you can have a strong home filter installed.

4. My Water is Yellow – But Returns to Normal After a Few MinutesYellow Tap Water

If the color clears after a few minutes, but it's not because of your public utility provider, the issue is most likely in your house plumbing. Old pipes tend to accumulate rust, which in turn can leach into your water.


The best solution is likely to fix your rusty pipes. However, we  recommend having expert do an assessment of the pipes before deciding to replace them in order to make an informed decision.

Still unsure? Test your water! 

Yellow-tinted water can come from a variety of causes and most of the time, it does not mean that your water is unsafe. Still, you should always investigate changes in your water quality.

Yellow Tap Water Test
12 Analytes Tested

Other questions about your water quality? Take a look at our wide array of city, well, and specialized water tests. Our team of chemists, engineers, and treatment experts is always standing by. Send us a message at!


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