Water can turn yellow for a variety of reasons, some of which are more common than others. Here are a few of the most common causes of yellow water.
Causes of yellow tap water:

High levels of iron or manganese in the water supply: These minerals can cause discoloration and can also affect the taste of the water. Iron is commonly found in water and can give it a metallic taste, while manganese can give the water a musty or earthy taste. This discoloration may be worse when the water is hot, as the minerals can precipitate out of the water more readily at higher temperatures. Iron and Manganese can be present in both surface and ground water sources and usually need specific treatment to remove them.
Sediment or debris in the water supply: This can include things like dirt or rust, which can discolor the water and make it appear cloudy or yellow. If the sediment is coming from the pipes, running the cold water for a few minutes can clear the pipes and the discoloration will go away. This is a temporary solution as the sediment will settle again over time.
Corroded pipes: If the pipes that transport water to your home are corroded or rusted, they can release particles into the water that can discolor it. This is often caused by the erosion of the pipes due to age and wear, which can be made worse by acidic water or high levels of chlorine in the water supply. Corroded pipes can be a serious problem, not only can they discolor your water but they can also release harmful chemicals into your water supply.
Algae growth in a well or reservoir: Yellow or brown coloration can appear due to presence of Algae growth in the well or reservoir, especially in warm weather conditions. Algae can grow rapidly in warm temperatures and can cause discoloration and a musty smell.
Chemical contamination: Certain chemicals can also discolor water, such as copper or lead. These chemicals can leach into the water supply if the pipes that transport the water are made of copper or contain lead solder. These chemicals can be harmful to your health if consumed in high amounts.
Bacterial growth: Microorganisms such as Iron-related bacteria can cause yellow-brown discoloration in the water, They can also affect the taste and odor of the water, making it musty or earthy. These bacteria are commonly found in water sources with high levels of iron or manganese and can be removed through specific treatment.
What to do about yellow tap water
It is important to note that discoloration can be a sign of other issues as well, such as bacterial growth or chemical contamination, so it’s always best to have your water tested to determine the cause of the discoloration and to ensure that it is safe to drink. If you are unsure of the cause, it is advisable to contact your local water department or a professional to conduct a water test to find out the cause and solution for the discoloration.
The testing will give you detailed information about the water’s quality and its impurities, which will help you in identifying the right treatment solution. If the discoloration is caused by corrosion or sediment, replacement or a deep cleaning of the pipes may be necessary. If the discoloration is caused by mineral buildup, a water softener or a reverse osmosis system may be needed. In case of bacteria growth, disinfection of the water source and specific treatment for the bacteria may be required.
If you’re concerned about your yellow tap water, or you’d just like a free water test from a top rated local plumber, please feel free to call us. This is what we do. We’re available 24/7, anytime you need, even on weekends and holidays at 626.448.6455