If you’ve ever turned on your faucet and wondered what that smell is, you’re not alone. It’s not uncommon for water to smell like rotten eggs or other unpleasant odors. And while in most cases it poses no health risk, it’s important to know the cause of the odor so you can decide what (if anything) you need to do about it.
There are actually a number of reasons that your tap water might smell bad, including concentrations of metal from the pipes it flows through. But the most likely culprit for most people is hydrogen sulfide, which results when sulfur-reducing bacteria in water wells or plumbing systems react with sulfates in groundwater.
It’s not uncommon to have some odor in your kitchen faucet, but if you have strong smells, such as rotten eggs or bleach, then it may be time to take care of a problem before it gets worse.
Water odors can be caused by a number of factors. Here’s how to fix them
Faucet water smells like rotten eggs
If you’ve ever gone to visit someone and have noticed a distinct rotten egg smell every time you turned on the faucet, you’re not alone. The fact is that many people live with this issue but have no idea what causes it or how to fix it. 
What causes a rotten egg smell in my water?
Your home or business water can have a rotten egg smell caused by naturally occurring hydrogen sulfide gas in your water. Hydrogen sulfide is a colorless, flammable gas that occurs naturally in crude petroleum, natural gas, and hot springs. It also occurs in volcanic gases, among other sources. It can sometimes be detected by its characteristic rotten-egg odor. At high concentrations, hydrogen sulfide gas has a suffocating odor. The most common cause of hydrogen sulfide gas in water systems is the decomposition of naturally occurring organic matter (dead plants) with the aid of bacteria found in wells or groundwater. The two common types of bacteria associated with hydrogen sulfide production are Sulfur Bacteria and Iron Bacteria. The presence of these bacteria is not necessarily an indication that the water is unsafe to drink or use for cooking purposes; however, boil orders may be issued if elevated levels of bacteria are present.
How do you fix the rotten eggs smell?
The first thing you need to do if your water smells like rotten eggs is to find out exactly what’s causing the problem. In most cases, the odor comes from hydrogen sulfide gas which is dissolved in the water as it travels through old pipes. If this is the case, then you’ll typically get a sulfur odor when using hot water, but not cold water. If you can’t detect anything with your nose, then try using a test kit for your pool or spa – if it tests high for sulfur, then that’s a good indication that hydrogen sulfide gas is indeed present in your water.
Once you’ve determined that hydrogen sulfide gas is the problem with your water, then there are several things you can do to get rid of it:
The water heater
The most common way to fix this problem is to change out your anode rod in your water heater. The anode rod is used to attract the corrosive elements in the water to help protect your tank from rusting out. It is usually made of aluminum or magnesium and has a steel core wire running through it. As time goes on, it gets used up and needs to be replaced before it becomes totally depleted. Without this protection, you could have a rusty looking hot water heater in no time at all and eventually need a costly replacement.
Flushing the pipes
The easiest way to get rid of the rotten egg odor is to flush your pipes. To do this, turn on all hot and cold faucets in your home and let them run for five to 10 minutes or until the water runs clear.
Using bleach
Another way to fix the rotten eggs smell is to add chlorine bleach to your hot water tank. This will remove any contaminants that are causing the smell, but it can also cause problems with your pipes if you have a septic tank. It may also kill beneficial bacteria in your system, which can cause problems with other parts of your plumbing and plumbing fixtures.
A whole house filtration system
If you have a private well or you live in an area with a naturally high sulfur content, a whole house filter will help eliminate the smell.The best way to get rid of the smell is to install a whole house water filtration system with an activated carbon filter.
Water smells like sulfur in one faucet
If the smell is coming only from one faucet, it’s likely that the problem is with the faucet itself. Water that smells like rotten eggs/sulfur means there’s a problem with the water supply. While it may not be harmful, it’s definitely not pleasant. Start by running water through the faucet for 30 seconds to flush out any sediment that might be causing the smell.
If you’re dealing with unpleasant odors in your water, it could be one of a few things:
- If you do not have any sulfur odor in your cold water but only in your hot water, this could indicate a problem with your water heater. Bacteria can grow inside of your tank if it is not regularly cleaned and maintained. This will result in a sulfur odor in hot water faucets because bacteria like warm temperatures.
- If you can smell the sulfur/rotten egg odor in both hot and cold water, there is probably a problem with your water. One of the first steps to take when investigating smelly tap water is to check with your neighbors. If they are experiencing the same issue, it is likely the issue is in the municipal water supply. If you are the only one that has smelly water, there may be an issue with your plumbing.
- In order to rule out whether or not your drain is causing the smell in your water, put a small amount of bleach down each drain. The bleach will kill whatever bacteria is causing the smell. If after doing this you no longer have a sulfur smell in your faucet, then your drain was likely the cause of it.
- If the smell persists, remove and check the aerator on the end of your faucet for a buildup of sediment or corrosion. Clean it, then soak it in a cup of vinegar for an hour. Rinse it well with fresh water before screwing it back on.
Sink water smells like sewage
The strong, foul smell of a sink is caused by bacteria growing in the P-trap. The P-trap is located underneath the sink and is designed to hold standing water that prevents sewer gas from entering the home through the drain.
Bacteria will grow in this standing water when it’s left undisturbed for a long period of time. The smell can be quite strong and offensive. The foul odor of sewer gas will become stronger when the water in the trap evaporates, which can happen if you don’t use your sink regularly or if you run out of water.
How do you get rid of sewer smell?
There are a few ways to stop your sink from smelling like sewage and get rid of that horrible odor:
- Pour water down the drain to create a new seal. If this doesn’t solve the problem, there may be a clog somewhere in your drain.
- There are several products you can use to clean your drains; some are chemical-based and some are natural. If you don’t want to use any commercial products you could try a mixture of baking soda and vinegar.
- Use a liquid drain cleaner or a plumber’s snake to remove whatever is stuck in your P-trap. Once you’ve removed the clog and allowed new water to flow through, the smell should be gone!
Water smells like bleach
If you’re smelling bleach in your water, you may be wondering what causes this smell and how to get rid of it.
Chlorine has a distinct odor that is easily recognizable. Most people associate the smell with swimming pools, as chlorine is often used to disinfect water in swimming pools and drinking water. The smell can be described as either a “clean” or “bleach-like” aroma. Even though chlorine is used to disinfect water, there are only very small amounts of chlorine in our water supply. In fact, there are very small amounts that don’t even register a taste or odor to the average person. So when you smell chlorine in your water, it usually indicates that there is a higher than normal level of chlorine present in your water supply.
What Causes the Smell?
Chlorine is a chemical commonly used to disinfect municipal or public water systems and can also be used to shock clean or disinfect a private well. Chlorine dissipates quickly in water, so the smell often goes away on its own within a day or two after the treatment, even if you do not run any water.
Chlorine is a colorless, irritating gas with a strong odor. It’s used to kill bacteria in public drinking water systems. Chloramines are formed when ammonia combines with chlorine to disinfect water. The compounds aren’t harmful at low levels, but they do have an unpleasant taste and smell.
How do you get rid of chlorine smell in water?
One way to get rid of the smell is to aerate your water by pouring it back and forth between two pitchers or by running the tap until you can no longer smell the chlorine (this can take 5-10 minutes). Filter systems that use activated carbon will also remove chemicals that contribute to the taste and odor of your water, including chlorine and hydrogen sulfide.
Tap water smells like mildew
The smell of mildew or musty odors coming from your tap water is unpleasant. You may be wondering what it means, how safe it is, and how to fix it. Fortunately, this unpleasant odor is easily fixed in most cases.
What Causes Mildew Smell in Water?
The smell of mildew coming from your municipal water supply is probably due to algae growing in the water pipes. If left untreated, this algae can also affect the taste of your drinking water. Another reason could be a buildup of mold or mildew in the internal components of your sink faucet.
How to fix mildew smell in your tap water?
Luckily, there are several things that you can do to fix mildewy smelling tap water. Here are four methods that we will cover:
- The first thing you should try is to simply run the faucet for a few minutes. This will help to flush out any stagnant water that has been sitting in your pipes.
- You should also clean your faucet aerator to remove any debris or mineral buildup that may exist on the screen inside of the aerator. It is fairly easy to unscrew and remove your aerator and then clean it with white vinegar before replacing it onto your faucet again.
- Clean the tank of your hot water heater. Sediment, rust and other debris can collect in the tank over time, and this debris will find its way out through your taps when you turn on the water.
- Chlorinate your well and/or clean out its pipes. If you have a well supplying drinking water to your house, sediment may have accumulated in the well itself or in its pipes. A plumber can determine whether this is the case and take steps to address it.
Conclusion
So, the next time you turn on your faucet and the water smells weird, you know it’s probably safe to use. But if it makes you feel any better, you can invest in a water filtration system to remove any additional contaminants from the water.
