Richard Arconti 
If your well water has a rotten egg smell, you probably find it unpleasant to drink. You may even be wondering if it is safe to use. There are several issues that could be causing your problem, and we will explain exactly how to get rid of sulfur smell in well water once and for all!
Causes Of Rotten Egg Smell In Water
The most common cause of water that smells like rotten eggs is sulfur bacteria or sulfate. Hydrogen sulfide gas typically emerges as a result of a mixture of sulfate, often located in sedimentary rocks, and sulfate-reducing prokaryotes. These bacteria act on the sulfates producing hydrogen sulfide, and this gas can give water a rotten egg smell or even taste.
Hydrogen Sulfide Gas In Well
Hydrogen Sulfide does cause the water to smell bad, but it is not harmful. The hydrogen sulfide present in cold water is sulfur-reducing bacteria (SRB’s), which leads to symptoms like biofilm, slime, or odor. This problem is actually common for homeowners who have private wells.
There are several issues that may cause the problem, such as pipes that have become contaminated with sulfur bacteria, or it could be that bacteria found in the groundwater got into your well water. It could also be caused by underground sewage pollution. Or, if your wellhead is not sealed adequately, local runoff could enter your well and pollute it.
Hydrogen Sulfide In Electric Water Heater Tank
It is also possible that your electric water heater tank has become contaminated with sulfur bacteria. Water heaters possess an anode rod that is intended to prevent the inside of your water heater tank from corroding due to the presence of certain bacteria.
This anode rod which is essentially a steel wire covered in aluminum, zinc, or magnesium, does this by attracting the corrosive particles in the tank, which sacrifices the rod, causing it to corrode, but reduces the damage that would otherwise occur to your tank.
However, when the protective coating wears away, and the steel inside begins to corrode, this can cause a reaction that allows certain microorganisms to flourish, including those that produce hydrogen sulfide. In order to keep your water heater’s protection in working order, it is expected that you will regularly replace the anode rod.
How To Identify the Cause of a Rotten Egg Odor in Water
Although it may not be harmful, you will likely want to eliminate the rotten egg smell in your water. However, to do this, you will need to identify what is causing the smell. There are some steps you can take to do this, as explained below.
Check the Difference Between Hot and Cold Water
The first thing you will need to do is determine whether or not the odor is being caused by hydrogen sulfide present in the water or whether the sulfur bacteria is coming from your water heater and the plumbing connecting it instead. Check the smell of both the hot and cold water. If the rotten egg smell is only present in your hot water, then it is likely coming from the water heater and the plumbing connected to it.
Test Your Well Water for Sulfur
If you find that all of your water smells like sulfur regardless of temperature, then you should have your water tested to find out if the smell is being caused by hydrogen sulfide. You could buy a test and test for hydrogen sulfide yourself. You should be able to purchase a test for approximately $25. Or, if you want to make sure you get accurate results, you could have your water professionally tested. This may cost more, but you can be more sure of accuracy, and they can give you information about the overall quality of your water in addition to telling you how the smell originated.
Negative Impact Of Sulfur Water
Too much sulfur can damage your plumbing and stain your sink, toilets, and even your clothing. If your well water has a high concentration of sulfur, here are the negative effects:
- Black Water Staining: When copper, brass, and steel are corroded from hydrogen sulfide, they form ferrous sulfide or “black water.” This leads to staining appliances, utensils, sinks, and silverware.
- Damage Laundry: Hydrogen sulfide will not only corrode exposed metal in your laundry machine, but it can stain your clothes. The black water will leave your clothes dark and dingy looking.
- Bacteria Risk: Bacteria that produce hydrogen sulfide gas also produce a biofilm that harbors other bacteria Iron bacteria, for example, produce reddish-brownish slime that leads to plumbing corrosion and clogging.
- Rust Colored Staining: Common well water contaminants that go hand in hand with sulfur, include iron and magnesium. These minerals appear colorless, but once exposed to oxygen, they create a reddish rust-colored stain that will stick to all your appliances.
Is Smelly Water Safe To Drink?
Sulfur is actually present in a number of foods and is an important part of a healthy diet. For example, a boiled egg will contain approximately 100 mg of sulfur!
In general, sulfur is low in toxicity to humans. But, if your drinking water contains too much sulfur, it can have health effects, such as:
- Diarrhea
- Dehydration
- Burning sensation
- Irritation of the skin and eyes
How To Treat Sulfur Smell In Water
If your water does have too much sulfur in it, you’ll definitely want to have your water treated. But, even if your water just smells bad due to having some sulfur in it, it could still be worthwhile to treat your water to make it more pleasant to use. Here are the best ways to get rid of the sulfur smell in well water.
1) Water Filtration Systems For Sulfur Smell
There are a few very effective water treatment systems that you could use to solve your water problem, and we will explain these options.
Air Injection Oxidation
An air oxidation system is probably the best choice for removing sulfur from your water. An air injection system works by filtering water through a tank with a small pocket of air at the top. By doing this, the gases, including hydrogen sulfide, are oxidized. This allows them to be captured by the filtration media, which holds them until the system runs a “backwash” process, which flushes them down your drain.
These AIO systems use an oxidizing media filter. This type of filter contains media such as manganese-treated green sand to oxidize the hydrogen sulfide upon contact and then remove it the same way. You would install this filter at the entry point of your water supply in order to ensure the rotten egg smell is eliminated from all of your home’s water.
Hydrogen Peroxide Treatment
You can use a hydrogen peroxide injection system, which is among the most effective treatment options for heavy sulfur levels. It works by deoxidizing the hydrogen sulfide gas by injecting hydrogen peroxide into the water.
The injection pump detects how much hydrogen peroxide your water needs and mixes it with your water before the water enters your home. You use this system to add the correct amount of hydrogen peroxide to your water supply, and then the water will be stored in a receptacle by the system in order to give the hydrogen peroxide time to work.
After the hydrogen peroxide has had time to work, the water will be returned to your plumbing system. If you use this method, it is best to also use a backwashing filtration system with a catalytic carbon medium to improve the smell of your water even more and remove any remaining chlorine in the water.
Activated Carbon Filter
Activated carbon can eliminate the bad smell from your water if the sulfur concentration is relatively low. This method is effective if the hydrogen sulfide level in your water is less than 1 milligram per liter (mg/L). Activated carbon works by trapping the gas in the carbon until the filter is full. They are installed at the point of entry, so the filters protect your plumbing, water heaters, and appliances from unpleasant odors. A carbon filter works to remove a variety of substances other than sulfur, so its useful life will depend on your specific water quality.
2) Chlorination Solution Disinfection (Shock Treatment)
Sulfur problems in well water can be fixed with a chlorine bleach solution to disinfect the system. Shock chlorination treatment will kill the iron bacteria, sulfur, and other microorganisms in the plumbing and the private well, resulting in pure drinking water with a pleasant odor. Doing this process is also recommended to do once a year as best practice for well water maintenance.
Shocking your well can be done on your own with a kit for less than $50, and you can follow this guide.
3) Water Heater Treatments
Water heaters frequently harbor bacteria that lead to unpleasant rotten egg smells. Below are the top three water heater hacks to get rid of those bad odors.
Replace the Water Heater’s Magnesium Anode
If you find that your bad-smelling water is due to sulfur bacteria on your water heater’s anode, you should have the anode replaced. It is best to have a plumber do this. They can double-check to be sure this is your problem and then replace the anode if necessary.
Increase Your Water Heater Temperature
A quick way to kill sulfur bacteria in your hot water heater is to turn up the temperature in the heater to 160 degrees Fahrenheit. Although, you will want to flush the system afterward to get rid of the dead bacteria.
Flush Water Heater With Bleach Solution
Another way to help get rid of the smell of sulfur bacteria is to disinfect and flush your water heater with a solution of chlorine bleach since chlorination can kill this type of bacteria. But, if the chlorination does not kill all of the sulfur bacteria, you may find the smell returning in a few weeks. If that is the case, a more permanent solution will be required.
Final Thoughts
If your water smells like rotten eggs, it can certainly be unpleasant. But, it is generally not dangerous, and there are ways to fix the problem. If you use one of the methods we described in this article, you should soon find that your water no longer smells bad.
