Have you noticed a rotten egg smell in your drinking water?
If so, it could be due to the presence of hydrogen sulfide gas. Hydrogen sulfide is naturally occurring and can be found in groundwater, surface waters, and even public water supplies. It’s produced by bacteria that live in groundwater and grow in water pipes and even treatment systems. It’s usually not harmful to drink, but it does make for an unpleasant experience.
The good news is there are several ways to get rid of this unpleasant smell from your drinking water. In this article, we cover all of the treatment methods, including aeration systems and carbon filters, and help you select the best one based on where the smell is coming from. We also discuss testing your water, when to seek professional help, and some simple and practical solutions to make your water taste and smell good again!
Keep reading to learn more about that rotten egg smell in your water.
Table of Contents
Why Does My Water Smell Like Rotten Eggs
We all expect to have clean, safe water in our homes for drinking and cooking. Unfortunately, sometimes that’s not the case.
A common problem many people have is a sulfur smell in their water. Most people describe it as a rotten egg smell. Some people report a musty or stale odor in their water. There are many causes of sulfur odors or rotten egg smells in your water.
1. Sulfate reducing bacteria
If you can detect a rotten egg smell in your water, it could be due to the presence of hydrogen sulfide gas. Hydrogen sulfide is found in water, soil, and even tap water. It’s a naturally occurring gas that may be found in groundwater, surface waters, and even public drinking water.
The most common source of hydrogen sulfide is sulfate reducing bacteria. These bacteria metabolize sulfate that is naturally present in water. The byproduct of their biological activity is hydrogen sulfide. The chemical formula for hydrogen sulfide is H2S, and the S indicates that this molecule contains sulfur.
2. Hot water heater reaction
If you just smell the sulfur odor when the hot water is on, then the likely source is the water heater. Electric water heaters have two electrodes, and one is made of magnesium that contains sulfur. If this electrode corrodes, then a chemical reaction occurs in the tank that produces hydrogen sulfide.
Fortunately, this is a simple problem to fix. Any qualified plumber can replace magnesium anode rod in your water heater. This will stop the production of hydrogen sulfide gas.
3. Hydrogen sulfide
Hydrogen sulfide can come from many sources besides sulfate reducing bacteria and the water heater. Other sources include decaying organic matter, volcanic activity, and the groundwater that supplies your well. This source is more difficult to treat and usually requires the help of a professional.
4. Sewage contamination
In some situations, untreated sewage can contaminate your water system. This condition, which is very dangerous, can produce a sulfur or rotten egg smell in your water.
If you have any suspicion that your water may be contaminated, it is best to immediately contact your local health department for further evaluation. You should stop drinking the water immediately until you have a professional resolve the problem.
Is Drinking Sulfur Water Harmful
Chances are you’re wondering if it’s safe to drink water that smells like rotten eggs. Generally, you can safely consume water that contains sulfur and has a sulfur or rotten egg smell. However, in rare circumstances, the concentration of sulfur and/or hydrogen sulfide might be high enough to cause health problems.
Are the sulfur bacteria harmful?
Sulfate reducing bacteria do not cause disease like e. coli and other bacteria do. They do, however, produce a slime that can clog well screens, plumbing, and your irrigation system. Their slime also helps other bacteria grow, such as iron bacteria, which creates other problems in your water system.
Hydrogen sulfide is a toxic gas
H2S is a deadly gas in high concentrations. Fortunately, sulfate reducing bacteria do not produce enough hydrogen sulfide to create a health concern in most cases. Most houses are adequately ventilated to prevent the buildup of toxic gas levels. If you have any concerns, contact your local health agency.
Your nose is very sensitive to sulfur smells
Your sense of smell is extremely sensitive to sulfur smells. This is because sulfur odors are usually an indication that food has gone bad, and our pre-historic ancestors survived by avoiding rotten food.
A person can smell hydrogen sulfide at a concentration as low as 0.5 parts per million (ppm). This is a very low level.
At a concentration of 0.5 to 1 ppm, most people can detect a musty odor.
At concentrations greater than 1 ppm, you smell that distinctive rotten egg odor.
How Do I Get Rid of the Rotten Egg Smell in My Water
Fortunately, there are several effective ways to get rid of the rotten egg smell in your water. We’ll review them here to give you a sense of what works. In the next section, we’ll help you decide which treatment method is the right one for your particular problem.
Treatment methods that can eliminate sulfur and rotten egg odors from water include:
- Activated carbon
- Chlorine disinfection
- Greensand filter
- Ozone disinfection
- Raise hot water temperature
- Upgrade water heater
1. Activated carbon to remove rotten egg smell
Activated carbon is probably the most common way to remove sulfur and rotten egg odors from water. It is a black granular material that is made of carbonaceous materials, such as coal, wood, or coconut shells.
Activated carbon works by adsorbing (not absorbing) the bad-smelling molecules from the water. This leaves behind fresh tasting and smelling water.
Carbon filters work very well for low concentrations of hydrogen sulfide – up to 1 ppm. If the levels are higher, than you end up changing the filter frequently. This will work, but it’s expensive and inconvenient.
2. Aeration to remove rotten egg smell
Hydrogen sulfide is a very volatile gas – this means that it doesn’t want to stay dissolved in your water. Aeration is a process where air is bubbled up through water to strip out undesirable gases like H2S.
This method doesn’t remove 100% of the hydrogen sulfide, but it might be able to remove enough to solve your problem. Many people use aeration in combination with a carbon filter. The aerator removes most of the hydrogen sulfide and the carbon filter polishes it (removes the last residual amounts).
3. Chlorine disinfection to remove rotten egg smell
Chlorine is a very powerful disinfectant. It is used to kill bacteria and other organisms that can cause disease in public water treatment plants. Chlorine is also very effective at removing sulfate reducing bacteria which is the source of hydrogen sulfide in water.
To permanently remove the sulfur smell, you have to continuously inject chlorine into your water supply. There are chemical injection systems that meter in a small amount of chlorine to disinfect your water. This type of treatment works very well if sulfate reducing bacteria are in your plumbing system.
However, chlorine can leave a bad taste in your water, and it is not the best choice for people who are sensitive to it. Chlorine also needs to be monitored closely to make sure that the level does not get too high. Many people use carbon filters to remove chlorine. This works very well and is simple to do.
4. Greensand filter to remove rotten egg smell
A greensand filter is a type of water filter that uses sand coated with manganese oxide. The manganese oxide acts as a catalyst to oxidize the hydrogen sulfide in the water. The reaction converts hydrogen sulfide into solid particles of sulfur that are filtered out. The filter must be regenerated periodically to restore the treatment capacity of the greensand filter.
This method can be very effective at removing hydrogen sulfide from water, but it can be expensive to operate. The filter also needs regular maintenance, and the manganese oxide coating must be replaced every few years.
5. Ozone disinfection to remove rotten egg smell
Ozone is a very powerful oxidizing agent that is used for water treatment. It will quickly react with hydrogen sulfide and other organic molecules to destroy them.
Ozone is a very effective way to remove sulfur and rotten egg odors from water, but it can be expensive to operate. Ozone also needs to be monitored closely to make sure that the level does not get too high.
6. Raise hot water temperature to remove rotten egg smell
If the sulfur smell is coming from your water heater, then you can have a plumber increase the temperature to 165 degrees Fahrenheit. This temperature will kill the sulfate reducing bacteria and get rid of your rotten egg problem.
Warning: If the water temperature is set too high, you run the risk of serious burns. Have a plumber adjust the water temperature. You should not do this yourself.
7. Upgrade water heater to remove rotten egg smell
If you have an electric water heater and the rotten egg smell is only present in your hot water, then you can replace the magnesium anode. Any good plumber can do this for you in about an hour. You can also purchase a new water heater that is designed for sulfate containing water.
This solution only works if the source of the foul odor is your hot water heater. Make certain before you upgrade your water heater!
Identifying the Source of the Rotten Egg Smell in Your Water
As you can see from the previous discussion, there are several effective treatment methods for removing the rotten egg smell from your water. But, before you can treat the problem, you first have to identify the source of the odor.
If you are experiencing a bad sulfur smell in your drinking water, it is most likely caused by sulfate reducing bacteria that live in your plumbing system. The best way to determine if this is the source of your problem is to have your water tested for hydrogen sulfide.
Use a stepwise approach to find the problem
To identify the source of your odor issue, start with a good plan. You should collect enough data, with a logical approach, to help you narrow your investigation to the root cause of the problem.
Step 1: In the morning, turn on the cold water and check for sulfur or rotten egg odors. Let it run for 5 minutes while constantly checking the smell. Note whether or not there is an odor. Also pay attention to whether it increases, decreases, or stays the same as the water runs. Write down the result.
Step 2: After completing the cold-water test, turn on just the hot water. Pay attention to any smells just as you did before. Does the smell increase as the temperature increases (this suggests the hot water heater is the culprit)? Does it decrease after a few minutes or stay the same?
Step 3: If you have a water softener, check the odor of both treated and untreated water. Depending on how your softener is plumbed into your home, you may have to use a drain valve upstream of the softener to test untreated water. Follow the same procedure you did in step 1.
Step 4: This is a visual test. Go to every sink and faucet in your home and look for black stains. These black stains are a sign of corrosion caused by hydrogen sulfide. Open you water softener (if you have one) and look for slime. Sulfate reducing bacteria produce a slimy substance that looks like gelatin. If this is present, your problem is caused by bacteria.
Take your notes and compare your results with the information presented below.
Hot water heater is causing rotten egg smell
If you only noticed the bad smell when the hot water is on, then your water heater is the source of your problem. This is a common problem in many homes.
Before you go any further, you need to determine what’s going on inside your water heater. If you have an electric water heater, the problem could be corrosion on the magnesium anode OR sulfate reducing bacteria. The easiest way to tell is to have a plumber open up your heater an look inside.
Bacteria will produce a slime that is an obvious sign of your problem. If you don’t have slime, then look for corrosion on the electrode. This is also easy to see.
Once you know whether your problem is biological or chemical, you can address it. Replace the magnesium electrode with an aluminum one or switch to a high-sulfate model that doesn’t use magnesium rods.
For bacteria, you can have the plumber increase the temperature to 160 degrees. This should only be done by a plumber to avoid scalding children when bathing!
Water softener is causing rotten egg smell
Sometimes, water softeners can become overgrown with sulfate reducing bacteria. These treatment units are the ideal breeding ground for bacteria. If you only notice the smell in treated water, than you can easily address the issue using chlorine.
Add 1 quart of bleach to your water softener and allow it to react for 1 hour. Flush your system by turning on the water and allowing it to run until you can’t smell chlorine in the water.
You will have to periodically shock your water softener to keep the bacteria in check. You’ll know when it’s time because the rotten egg smell will come back. To avoid having the smell, put the chlorine treatment on your calendar and do it frequently enough to prevent the bacteria from becoming re-established.
Well water is causing rotten egg smell
For people who have a private drinking water well, sulfate is often present in their water. This sulfate is used by sulfate reducing bacteria to produce hydrogen sulfide which is the source of the rotten egg smell.
If you determine that your well is the problem, then you may be able to solve this yourself – although I recommend hiring a professional. Problems with bacteria in your well often require several strategies – shocking the well with chlorine, mechanically scrubbing the well screen, and adding chemicals to the groundwater to neutralize bacteria.
These remedies are generally beyond the skill and capabilities of a do-it-yourself homeowner.
Sulfate reducing bacteria is causing rotten egg smell
If the water coming into your home contains hydrogen sulfide, you won’t be able to address the sulfate reducing bacteria. They might be in the public water supply piping or the water source they use.
In this case, you will need to install a treatment system to remove the H2S. You can use activated carbon filters (for low levels) or aeration with carbon filters (for moderate levels). For high levels of hydrogen sulfide, you should look at greensand filters. These are well-suited for removing hydrogen sulfide and can readily get rid of the foul rotten egg smell.
Can I safely drink water that smells like rotten eggs?
Although the rotten egg smell in your water is disgusting, it is generally considered safe to drink. In most cases, the level of sulfur is not high enough to be of concern. However, if the concentrations are high, the sulfur can cause stomach aches and nausea.
Is it safe to shower in sulfur water that smells like rotten eggs?
You can shower in water that contains sulfur. If the hydrogen sulfide concentration is dangerously high, you could be exposed to this toxic gas at levels that are a concern. Usually, ventilation is adequate to avoid the buildup of hydrogen sulfide to toxic levels.
How much does it cost to get rid of the rotten egg smell in my water?
The cost to remove that annoying rotten egg smell from your drinking water depends on which treatment method you select. A point-of-use carbon filter can be installed for less than $100. A whole-house aeration system might cost $4,000.
Do Brita filters remove rotten egg odors from drinking water?
Britia filters use activated carbon to purify drinking water. Activated carbon is very effective at removing low levels of hydrogen sulfide (the source of the rotten egg smell) from water. Brita filters are effective at removing rotten egg odors from drinking water.
Do refrigerator filters remove rotten egg odors from drinking water?
Refrigerator filters use activated carbon to purify water used for drinking and making ice. Carbon is very effective at taking out hydrogen sulfide. Most refrigerator filters can remove the rotten egg smell from drinking water.
Do reverse osmosis filters remove rotten egg odors from drinking water?
Reverse osmosis filters do not remove rotten egg odors from water. The RO membrane does not filter out hydrogen sulfide which is the source of the bad smell. However, most RO filters use activated carbon filters to pre-treat the water, and activated carbon is very effective at treating this problem.
My Take on Sulfur Smells in Drinking Water
We hope this article has helped you understand why your water may smell like rotten eggs, what the health risks are of drinking sulfur water and how to identify where the problem is coming from. Once you know the cause of the foul odor, you can take measures to get rid of it. This might be as simple as having a plumber upgrade your water heater or as complicated as installing a whole-house carbon filter. Regardless, there are several tried and true solutions to help you purify your water and get rid of that rotten egg smell.