Why is your tap water yellow? There are several possible causes for this color change, and each change needs to be approached differently. It’s probably rust, but it could also be tannins, sediment, or contamination from broken pipes.
Sometimes, this problem is temporary. Other times it requires repairs or changes to your plumbing. In some cases, it can even be dangerous to your health. How do you identify the source of the discoloration, and how do you fix it?
Are You Dealing with Damaged Pipes?
Most of the time, yellow water is safe, even if it looks and tastes bad. However, if the color comes from dirt entering your water supply, this is a serious problem. Burst or broken pipes let soil and contaminates enter the water stream, including bacteria and dangerous chemicals.
Do You have Tannins in Your Water?
Tannins are formed by the decay of organic matter. If your municipality sources its water from a surface water supply with high levels of tannins, they’ll make it to your tap. Tannins don’t cause health problems, so they’re not regulated by the EPA, and usually aren’t part of the city’s water filtration process. However, high levels can make water taste musty and leave a bitter aftertaste. Tannins also leave stains on clothing, toilet bowls and sinks.
If you normally don’t have tannins in your water, and your water service hasn’t changed water sources, this may indicate a leak in the plumbing, either on your land or somewhere in the city’s pipes. In this case, your water may also contain other contaminants, including dangerous bacteria.
Oxidation is the best way to remove tannins. There are several treatment options available, but the simplest method is an air bubble system. As water is sprayed through this bubble, the tannins are exposed to oxygen. This chemical change forces them out of suspension, where they collect at the bottom of a tank. Activated carbon and reverse osmosis filters are also effective at removing tannins.
If I Have Rust in My Water, Why is it Yellow?
Brown and red rust is iron oxide, which contains iron and oxygen. Yellow rust is Iron oxide-hydroxide, a combination of iron, oxygen and hydrogen. Iron oxide-hydroxide forms in high moisture environments, like the inside of pipes and plumbing fixtures. This rust’s color is so vivid and stable that it’s commonly used as a pigment in paints, cosmetics and tattoo ink. While it may look different from the rust you’re used to, it still comes with all the same problems.
Are Your Faucets Starting to Rust?
While faucets are made from corrosion-resistant materials like stainless steel and copper, they can still break down over time. If this is the case, it might be time to replace them. Alternatively, you can try flushing the faucet with high pressure water or clean it with white vinegar to neutralize the rust.
Are You Only Getting Yellow Water from Hot Water Taps?
Do you only get yellow water when you open the hot water taps? The source is probably your water heater. Heat speeds up chemical reactions, so your water heater is more susceptible to rust than the rest of your plumbing system. To prevent corrosion, it has a sacrificial anode.
This anode is made of magnesium or aluminum, which oxidizes before iron does. The oxygen attacks the anode first, protecting the rest of the heater. Eventually, the anode is eaten away to a point that it can’t protect the tank, and rust forms on steel and iron components.
On average, an anode lasts between 3-5 years. Fortunately, anodes screw into the side of your hot water tank, so they’re easy to replace. With a new anode in place, rust formation will stop, but you may need to flush out your water heater to remove any remaining rust.
Keep in mind that water heaters are only meant to last a decade. If your model is over 10 years old, it’s due for a replacement. At this age, the heating element and other components are wearing out. Not sure how old your water heater is? Look at the serial number. Typically, the second and third digits are the manufacturing year.
If the water heater is working fine, you may have sediment in the bottom of your water heater. Here’s how you get the sediment out of your tank:
Do You or Your Utility have Rusting Pipes?
For the past 30 years or so, most plumbing has used plastic or copper lines that are less prone to corrosion. However, if you have an older home, you may still have steel pipes. Over time, rust can form in these pipes and flake off into your water. If you only get yellow water from some of your faucets, it’s usually just the pipes leading up to them that are corroded.
Of course, water travels a long way from the processing plant to your home. The rust’s source may be municipal pipeline. Even if your home is new construction, some of the pipes that connect to your plumbing might be decades old. If you’ve determined the rust isn’t coming from inside your home, contact your water utility.
Was a Fire Hydrant Recently Used in Your Area?
Fire hydrants are built for maximum flow from the water main, delivering the water needed to keep fire trucks supplied. Opening these giant taps can knock rust and sediment loose from surrounding pipes, changing the color of your water. Opening your taps and letting them run 20 minutes or so should be enough to flush contaminated water out of your plumbing.
Is Your Utility Conducting Pipe Maintenance?
Part of maintaining municipal plumbing is flushing pipes with water. Like using a fire hydrant, this process knocks rust and sediment loose from pipes. You may notice a sudden increase in water pressure when you open your taps. Letting the faucets run for a few minutes should flush the rust out of your water.
Did Your Water Utility Change Water Sources?
Is your region experiencing a drought? Your water utility may need to switch where they’re getting their water. Putting unused pipes back into service releases rust, while the new water source may have some added contaminates. This changeover also affects water pressure, which may knock rust and sediment off pipes.