Have you ever experienced gulping some water only to realize it tastes like some nasty rotten eggs? That must and odor taste is actually brought about by organic compounds from plant decays typically present in reservoirs and lakes.

Depending on your area, a water that has the rotten egg smell most likely has the chemical hydrogen sulfide gas. This taste puts a lot of people off but it’s a good thing that this isn’t harmful to the health. But, this is worth reporting to your local Health Department.

If you want to make sure that your water is safe for your family’s consumption, you may opt to have it tested by state certified laboratories. A list of credible labs can be found from the U.S. Environmental Protection Agency State Certification Program.

Important things to note

  • Although a rotten egg smell does not typically mean that your water is not safe for drinking, this may still be a sign of harmful water contamination in rare cases.
  • There are different ways to solve this problem.
  • Across the USA, over 316 chemicals were detected in drinking water. Yikes!

Identifying the cause

One of the first things you should do upon smelling rotten eggs in your water is to locate the source. Follow these steps to determine what is causing the smell.

  1. Does the smell come from the cold water faucet? If NO, it’s a water heater problem
  2. Check the water softener
  3. After running your water for a few minutes
  4. If the smell continues, it’s likely that the hydrogen sulfide gas in the ground water
  5. If the smell goes away, it’s likely that the sulfur bacteria in the well or plumbing system

Hydrogen sulfide hazards

The problem with hydrogen sulfide is that it can corrode metals and induce black stains on silverwares and plumbing systems. In the long run, the pipes can be damaged. While drinking water with a nasty rotten egg smell is almost always safe, keep in mind that in rare events, this may also mean that this odor is from the sewage or other contaminants in your water supply.

How sulfur is created

The smell of sulfur is produced when sulfur bacteria break down organic waste and release hydrogen sulfide gas, which frequently has a rotten egg aroma. Because sulfur bacteria are naturally prevalent in groundwater, the odor is most likely the result of reactions occuring in your hot water and is not harmful to your health.

It’s not uncommon to notice an unusual odor emanating from your water, especially if you get your water from a well or another still source. Water that smells strongly of sulfur or rotten eggs is most often caused by the presence of “sulfur bacteria” or hydrogen sulfide. While the smell of sulfur in your water is not always dangerous, it may indicate high amounts of pollution or chemicals. Over 316 pollutants have been discovered in water reservoirs across the United States, and it is critical to determine the source of the odor in order to maintain safe, clean drinking water.

What causes sulfur in water?

If your water smells strongly of sulfur or rotten eggs, the presence of “sulfur bacteria” or hydrogen sulfide is most likely to blame. Sulfur bacteria thrive in oxygen-depleted habitats such as deep wells or plumbing systems, where they feed on decaying organic matter, producing hydrogen sulfide gas that becomes trapped in water sources.

If you only smell sulfur when you turn on the hot water, the source could be your water heater. When you utilize hot water, reactions between the magnesium rod and aluminum in your water heater produce hydrogen sulfide gas, which gives off a stronger sulfur odor.

Things you can do

Here are some tricks you may try in events when you detect some unusual odor in your water supply.

  • Contact a boiler inspector if your hot water smells like rotten eggs. This may be a water heater issue.
  • If it’s the water treated by a water softener that smells like rotten eggs rather than the untreated water, this may indicate that there’s sulfur bacteria in the water softener. If this is so, the water softener may need to be replaced.
  • If both hot and cold faucet water smells strong during the first few seconds after turning the faucet on and diminishes as the water runs, it may be due to sulfur bacteria in the distribution system or in the well. Another possible reason is that there may be hydrogen sulphide in the groundwater. These are more dangerous problems and may need immediate attention.

How to get the rotten egg smell out of your drinking water?

Carbon filters

Activated carbon filters can help remove hydrogen sulfide from water as carbon absorbs this chemical. But, make sure that the carbon filter is frequently replaced especially if your water contains moderate to high hydrogen sulfide  levels.


Chlorine can turn water with hydrogen sulfide to a tasteless and odorless supply. Little amount of chlorine, such as your laundry bleach, can effectively eradicate hydrogen sulfide.


Oxygen forms odorless and dissolved sulfur upon contact to hydrogen sulfide. Aeration may also form yellow sulfur particles. To do so, compressed air is injected into the system and then is removed afterwards.

Rotten egg odor and health risks

Sulfur levels of 100 PPM and up may cause some hazardous risks. Thankfully, those that are found in home water supplies and well water are in the 1-5 PPM range only. But here are some of the health risks rotten egg odor may cause:

Immediate/short term exposure to low concentration

  • Irritation of eyes, nose, and throat
  • Irritation of the respiratory system, especially in asthma patients

Repeated/prolonged exposure to low concentration

  • Headache
  • Eye inflammation
  • Insomnia
  • Fatigue
  • Irritability
  • Digestive disturbances
  • Weight loss

Moderate concentration

  • Severe eye irritation
  • Severe respiratory irritation
  • Nausea
  • Vomiting
  • Headache
  • Dizziness
  • Staggering
  • Excitability

High concentration

  • Coma
  • Death
  • Shock
  • Convulsions
  • Extreme rapid unconsciousness
  • Inability to breathe

As per OSHA, 250 PPM levels of sulfate or higher in water induces a laxative effect. This can easily be tested with a test kit or a laboratory analysis. On the other hand, hydrogen sulfide is gas and must therefore be examined on-site.