How to Treat Well Water Smells – Rotten Egg Smell From Sulfur?

When it comes to water quality issues, some are imperceptible while others less discreet. One such example of obvious water quality issue is if you notice that your water is starting to smell like rotten egg. The unpleasant odor is not something that you’ll likely be able to ignore or get used to.

What Causes the Sulfur (Rotten Egg) Smell in Well Water?

The main reason behind sulfur odor in water is the presence of hydrogen sulfide gas produced naturally by sulfur bacteria or hydrogen sulfide. A hydrogen sulfide concentration of just 0.1 milligrams per liter will result in most individuals noticing a rotten egg smell in the water.

Sulfur bacteria can be found in environments that lack oxygen, such as conditions found in deep wells. These microorganisms combine with sulfate in your water to produce hydrogen sulfide as a byproduct when the bacteria feeds off of the sulfate, reducing sulfate to sulfide.

Such issues may also be found in areas with plumbing systems and organic matter. If you smell a strong rotten egg odor from a hot water tap, you could be having the same issue in your water heater that’s caused by the magnesium rod and aluminium used inside that are used to prevent corrosion of the heater.

If the magnesium sulfate anode rots, it can result in the production of free electrons in the water that will stimulate the chemical reactions between sulfur-reducing bacteria and sulfate present in the water to produce hydrogen sulfide.

This can occur when water is left in the water heater for a period of time. Fortunately, the smell caused by hot water heater may go away once the water in the heater is used. In more severe cases, hydrogen sulfide could buildup overnight and may require a water treatment system to eliminate the root case.

Source of Hydrogen Sulfide

Iron bacteria and sulfur bacteria are naturally present in groundwater and they use iron and sulfur as an energy source. The bacteria usually chemically react with sulfur from decaying plants, rocks, or soil to produce hydrogen sulfide gas.

These harmless non-toxic bacteria naturally exist in oxygen-deficient environments, like deep wells and plumbing systems. Such bacteria usually do not cause health problems although you may experience bad taste and/or odor problems.

Hydrogen sulfide gas may also naturally be present in wells drilled in shale or sandstone, near coal or peat deposits, or oil fields. Although H2S can be found in wells, the gas can also enter surface water through springs and quickly escape into the atmosphere.

Your house heater can also become a source for H2S gas as the magnesium rod used in heaters for corrosion control can chemically reduce sulfates present in drinking water to hydrogen sulfide gas. For such cases, the rod can be replaced with a different type of anode.

Health Effects of Hydrogen Sulfide

While low levels of H2S won’t pose harm, high levels of 100ppm or more can cause sickness and death in humans. The typical H2S concentration levels found in homes or well water is in the range of 1 – 5 ppm.

Low Concentration Immediate/Short Term Exposure:

  • Irritation to eyes, nose, and throat.
  • Irritation to the respiratory system (cough and shortness of breath).

Low Concentration Repeated/Prolonged Exposure:

  • Eye inflammation
  • Headache
  • Fatigue
  • Irritability
  • Insomnia
  • Weight loss with digestive disturbances

Moderate Concentrations:

  • More severe eye irritation
  • Severe respiratory irritation (cough, difficulty breathing, accumulation of fluid in the lungs)
  • Headache and dizziness
  • Nausea
  • Vomiting
  • Staggering
  • Excitability

High Concentration:

  • Shock
  • Convulsions
  • Inability to breathe
  • Extreme rapid unconsciousness
  • Coma
  • Sometimes death

Sulfate is a naturally occurring mineral that’s dissolved in water. However, high levels of sulfates at 250 ppm or more can cause a laxative effect if the water is consumed. A test kit of laboratory analysis can be used to analyse the levels of sulfates in water.

Hydrogen sulfide is a gas and must be tested on-site. Sulfate by itself does not have odor but high levels of sulfates can be reduced by bacteria to cause hydrogen sulfide.

Potential Problems with Hydrogen Sulfide

Hydrogen sulfide doesn’t just cause your hot water to smell like rotten eggs, but it can also lead to other damages as it corrodes different types of metal and can cause black stains on silverware and plumbing fixtures.

Although drinking water with a strong rotten egg odor may be particularly unpleasant, they’re perfectly safe to drink in most cases. However, in rare occasions where the odor is caused by sewage or other contaminants in the building’s water supply, it could lead to more serious health problems.

What To Do if You Smell Rotten Eggs Odor in Your Water

If you experience any rotten egg smell in your water, it is important to find the source of the problem by checking your taps and water supply into the building.

If you notice the rotten egg smell from your hot water, it’s likely coming from your heater. In this case, it’s better to engage a trained inspector to see how this can be fixed.

If your cold water that’s treated by water softener has a rotten egg odor and is not in the untreated water, the problem could be due to sulfur bacteria in the water softener system. You may be able to fix this by changing the water softener solution.

If you notice the smell in both hot and cold water faucets and it goes away after the water has run, or if the smell varies throughout the day, you may have a problem with sulfur bacteria in well or distribution system. This could be an indication of more dangerous problems in your water supply.

If the rotten egg odor is present in both hot and cold water faucets and doesn’t go away after letting the water run, then the problem could be due to hydrogen sulfide in your groundwater. This could also be a sign of more dangerous problems in your water supply.

How to Treat Well Water Smells

Here are a few steps that you can take if you are experiencing a sulfur smell in your well water:

Step 1: Check for Water Smells in both Cold and Hot Water

The first thing to do is to find out where the water is coming from – if it’s only from hot water or if it’s also coming from cold well water.

You can rune a hose bib or tap close to the well and fill a 5-gallon bucket or any other kind of container and see if you notice any odor. If you smell something like a rotten egg, then you have a hydrogen sulfide gsa issue. If it smells like oil or asphalt, then you could be dealing with manganese. If the water smells like cucumber or sewage, your water could have iron and/or sulfur bacteria.

If you notice that the odor is only from your hot water tap and not apparent in cold water, then you could have a problem with the water heater. The anode rod in water heaters could interact with sulfates in water to create hydrogen sulfide gas that smells like rotten eggs.

Switching the anode rod to an aluminum rod can often solve this problem. Alternatively, you could also hook up a “water heater odor killer” filter screen to get rid of sulfur smell in hot water. You may need to periodically add store-bought hydrogen peroxide to the water heaters via the device to instantly kill the odor.

Step 2: Test Your Water

The next step is to determine the source of the sulfur smell in your water supply. If the source of your water is a public water system and you have smells in cold water, it is best to contact your water utility.

If the source is from a well, you can conduct a general mineral water analysis in order to select the right system for treating the problem. The general water analysis should include a test for pH, iron, manganese, hardness, and total dissolved solids. You can also consider tests for sulfate, hydrogen sulfide, and tannin to better understand what is present in your well water.

When testing well water, try to take a sample that’s closest to the well. After running the test, you can better identify which is the best water treatment and system to use based on your water chemistry.

Step 3: Choose a Treatment Method

There are different treatments available for different root causes:

One – sulfur odor in both cold and hot water with no iron or manganese issue. For such cases, you can consider using Activated Carbon Filters with a peroxide cleaning kit to solve your problem.

Two – extreme sulfur odor from cold well water. If you’re experiencing strong odor directly from the well, you can try shocking the well with chlorine and install a peroxide injection system with a backwashing activated carbon filter.

Three – sulfur odor in both cold and hot water with iron or manganese issue. For this, you can install a chlorinator followed by an iron filter.

Four – sulfur odor in hot water only. As mentioned in the section above, you can consider installing a heater odor killer if you only detect sulfur smell in your hot water.

Top methods to get rid of the sulfur smell in water

  • Shocking well water with chlorine bleach or hydrogen peroxide to get temporary relief from sulfur odors. This is a temporary solution and can only keep odor away for 1-2 months.
  • A chlorine injector system (chlorinator) can be installed on your wellhead for continuous injection of chlorine when water is running. Chlorination will eliminate odor-causing sulfur bacteria and if combined with an Air Charger self-cleaning backwash iron removal filter, the system can eliminate odors continuously and take out chlorine residual before it reaches your home.
  • Installing a system that’s similar to chlorinator but use hydrogen peroxide instead of chlorine bleach solution. This system can be installed with a backwashing catalytic iron removal filter to remove any residual salts or residues in the water.
  • An Air Charger Catalytic Carbon Filter will inject peroxide to make the catalytic carbon last longer without needing to change filter cartridges or use chemicals.
  • Air Compressor Tank Aeration System injects a lot of pressured air to eliminate odor caused by low-oxygen conditions.
  • Ozone gas can quickly eliminate insoluble sulfur odor. This is very effective but can be expensive as well.

Frequently Asked Questions

My water smells like sulfur. What can I do to get rid of the sulphur smell?

The first step is to determine where the odor is coming from. Is it only from hot water or is it present in both cold and hot water? If it’s from hot water, you can consider replacing the anode rod in the water heater. If it’s from both cold and hot water, you may need to consider other treatment options for the water source.

I have sulphur smell from hot water only. What should I do?

You can replace the anode rod with an aluminum rod or powered anode. Other than that, you can also add a Water Heater Odor Killer that makes it easier for you to add store-bought hydrogen peroxide into the water heater.

Both hot and cold water smells like rotten eggs. What should I do?

If your water source is well water and you have sulfur odor with no iron or manganese, the best option is to get an Air Charger Carbon Filter with the peroxide cleaning kit.

How do I get rid of sulphur smell in well water when I also have rust staining from iron and manganese?

If you have unpleasant rotten egg smell and rust staining, you can consider installing a chlorinator followed by an iron filter.

What is the Difference Between Sulfate and Hydrogen Sulfide?

Sulfate is a naturally occurring mineral that dissolves in water and can cause laxative effects with concentration levels of 250ppm and above. High levels of sulface can be tested with a water test kit or laboratory analysis.

Hydrogen sulfide is a gas and must be tested on-site. Sulfate by itself does not have odor but high levels of sulfates can be reduced by bacteria to cause hydrogen sulfide.

What are some of the health effects of sulfur in well water? health effects”?

High levels of hydrogen sulfide at 100 PPM or more can cause sickness and death in humans. Nonetheless, the typical levels found in homes or from well water is in the range of 1 – 5 PPM. The health effects of repeated exposure to low concentrations of hydrogen sulfide in water are:

  • Eye inflammation
  • Headache
  • Fatigue
  • Irritability
  • Insomnia
  • Weight loss with digestive disturbances

How can I test for hydrogen sulfide? Can I send a sample to a lab?

You must test on-site. Samples cannot be sent to a lab. There are various hydrogen sulfide testing kits available. Most do not give exact results but can you give you a range.

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