Why Is My Well Water Yellow? And Is It Harmful?

Private wells do not receive the same treatment and monitoring as public water systems. The quality of the water in this case is the responsibility of the well’s owner. A change in the color of domestic water indicates the presence of pollutants. It is important to know whether these aesthetic effects have any impact on your health.

If your well water turns yellow, it is likely due to iron bacteria, organic material, ferric iron, rusty pipes or a combination of these factors. Generally, these contaminants do not represent a significant risk to human health in the short term but can cause certain complications in the long term. 

In this article, we will discuss the most common components that give well water a yellow tinge. We will mention any risks and recommend the best treatment options to restore the quality of your well water. 

Organic Materials

Tannins are byproducts of the natural fermentation that occurs when decaying vegetation starts to break down. These natural organic materials are picked up as water seeps through peaty or swampy soil on the way to your well’s aquifer.

Tannins do not present a health risk but give water a yellow or tea-like color, tangy aftertaste and musty smell. Plus they can produce yellow staining on laundry, porcelain fixtures and dishes.

This type of water pollutant is most common in marshy, low-lying or coastal areas, and generally affects shallow water wells. 

A simple test involves filling a glass of water and letting it sit overnight. If the yellow tinge remains homogenic, then your water is probably contaminated with tannins.

A certified laboratory will be able to confirm the presence of tannins and other contaminants in your well water, and even advise which plant the organic material is derived from. Depending on the source, the filtration method might vary. 

A typical tannin filter works as a water softener, as it captures the contaminants through an anion exchange process. It is important to clean the filtration system regularly, especially if the water begins to smell like fish.

Tannins can also be removed through an oxidation and filtration method, or with an activated carbon filter.


One of the most common reasons for your taps to spit yellowish or brown water is the presence of rust in your home’s plumbing system, faucets or water heater.

Yellow water is generally found in older houses with galvanized pipes as the zinc lining wears off over time.

While rust contamination rarely causes any health issues, a rusty environment can promote the growth of disease-causing bacteria and mold.

If your yellow water smells like bleach, you should probably hire a professional to conduct some maintenance in your home’s water lines. Installing a filtration system surely helps, but fixing the problem from the source will avert damages to your property caused by faulty plumbing systems.

If the discoloration appears in the morning or after not using the faucets for a while and it clears after a few minutes, then you might have some corroded pipelines.

If the yellow water only comes out of a certain faucet, then you need to replace that specific fixture.

When the tint only affects hot water, you probably need repairs in your water tank. 


Iron is a common contaminant found in private wells for it naturally occurs in the ground. The iron that does not dissolve in water and, instead, sets somewhere along your water supply is called ferric iron.

When this sediment comes in contact with oxygen, it rusts and leaches into the water that comes from your private well. This is one reason why water comes out red, yellow or orange from the tap. 

There are no known health risks associated with ferric iron, but it does give your water a metallic taste and, in high levels, even an unpleasant smell.

It can also damage property, causing stains on laundry, dishes, sinks and tubs.

Over time, it accumulates and clogs dishwashers, washing machines, sprinklers, wells, water pumps, and any appliance in contact with the contaminated water.

Again, filling a glass of water and letting it sit overnight is a simple way to test for iron. If the color is stronger at the bottom of the glass, the discoloration is probably caused by this mineral.

Depending on the levels of iron in your private water supply, you can install different types of filters to eradicate the problem.

A cartridge filter can effectively remove small amounts of ferric iron. But you will need to double up with a second backwashing sediment filter for extra filtration when dealing with significant amounts.

Sequestering, ion exchange, oxidizing filters, and settling are other treatment options. 

Iron Bacteria

When iron combines with a type of bacteria naturally found in soil and surface water that enters your well, it turns your water yellow and slimy. These small organisms that feed from iron do not present a direct risk to your health.

But the sludge buildup creates conditions that favor the growth of other organisms that could cause disease, such as mold, mildew or even E. Coli.

Also, the biofilm can cause clogs in well screens and pipes and affect your water flow. 

If you notice unpleasant tastes or odors resembling sewage, petroleum or rotten vegetation, slime buildup in toilet tanks or filters, and an oily sheen on the water surface, it is likely due to the oxidation of iron by these bacteria.

Test your water for nitrate and coliform bacteria, and make sure to keep regular maintenance of your private well.

Iron bacteria contamination should be handled by a licensed well contractor and requires frequent inspection to keep under control.

Treatments include physical removal, pasteurization and chemical disinfection. Any service done to your well should be handled with care, not placing any equipment on the ground, using only disinfected water and making sure the well casing is watertight and properly capped. 

Is it safe to drink yellow well water?

When well water comes out of taps with a yellow tint, it surely affects the perception of quality. But while aesthetic effects are undesirable, they do not necessarily mean that the water is not drinkable.

It is typically safe to drink yellow well water, although it might have an unpleasant odor and aftertaste. The contaminants that turn water yellow are usually not harmful in moderate amounts, but they can provide a favorable environment for the development of other dangerous components. 

Testing your private well water to identify the source of the yellowish tinge and rule out any hazardous pollutants is the most prudent initiative.

Annual advanced testing for contaminants including volatile organic compounds is a recommended precaution, as well as performing a radiological analysis every three to five years. 

Is it safe to bathe or shower in yellow well water?

It might seem counterintuitive to wash yourself in yellow water. But the contaminants typically causing this kind of discoloration are readily absorbed by the human body.

It is safe to bathe or shower in yellow well water. Yet long term exposure to high mineral content can cause dry skin, hair and scalp, as well as itchiness. Also sediment, rust, tannins and bacteria can damage your faucets, showerhead and bathtub. 

Why is my well water yellow after rain?

It is a different story when discoloration occurs after a heavy rain. In this case, every faucet in your house is spitting yellow water because there is probably surface water leaking into your well. 

There are higher risks involved when drinking yellow water after a heavy rain. Water runoff may carry dangerous elements such as pesticides, fertilizers or animal waste. Rain can also overflow a leaky septic system in the area, threatening to deliver fecal coliform and E. Coli into your home. 

This is another reason why regular testing and maintenance are crucial to keep a safe domestic water source.

Older wells are more vulnerable to rain damage as seals deteriorate over time, plus they are often more shallow than newer wells.

To prevent problems, make sure that any installation, repair or replacement of a private well is properly conducted by a reliable professional. 

To Conclude

The quality and safety of the water supplied by a private well depends on its owner. They are responsible for taking the necessary measures to ensure that the property’s drinking water is clear of hazardous contaminants.

Preventive action is always better than reacting after detecting signs of pollutants.

But if your well water suddenly acquires a yellow tint, there is no need to panic.

Chances are you are dealing with rather harmless culprits. Some simple checks mentioned above will give you peace of mind while you schedule a proper testing procedure and organize the best treatment.

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