Water Smells Like Rotten Eggs: Identifying and Resolving the Issue

Anthony Barnes

Have you ever turned on your tap and been greeted by an unpleasant smell resembling rotten eggs? You’re not alone – many people encounter this issue, and it can be quite concerning. The rotten egg odor is caused by the presence of hydrogen sulfide gas in your water, which is a natural result of certain chemical reactions. In most cases, the odor is not harmful, but it can be quite off-putting and may indicate underlying issues with your water supply.

The smell of rotten eggs in your water can be attributed to a number of factors. Hydrogen sulfide gas is produced when sulfate-reducing bacteria interact with sulfur compounds found in the environment. This can occur in natural water sources, your plumbing system, or even water heaters themselves. Determining the source of the odor is the first step in addressing the issue and substantiating whether or not there are any health concerns associated with the smell.

Key Takeaways

  • Hydrogen sulfide gas in water is responsible for the rotten egg smell
  • Multiple sources can contribute to this issue, including natural water sources, plumbing systems, and water heaters
  • Identification of the source and appropriate measures can help alleviate the unpleasant smell and ensure water safety

Understanding the Smell

Need to Hire a Plumber?
Get a free estimate online from top local home service pros in your area.
Note: This post may contain affiliate links. This means that at no cost to you, we may receive a small commission for made purchases.

Water that smells like rotten eggs is a common and unpleasant issue that many homeowners face. This bad-smelling water can be quite objectionable, making it difficult to drink, cook, or bathe with. The primary reason behind this odor typically lies in the presence of hydrogen sulfide gas or sulfur bacteria in the water.

Hydrogen sulfide gas is a colorless, corrosive, and poisonous gas that gives off the distinct smell of rotten eggs. This gas can get into the water supply when water comes into contact with organic matter, certain minerals like pyrite, or decaying vegetation source. Bacteria found in groundwater, known as sulfate-reducing bacteria, can also convert sulfate and other compounds into hydrogen sulfide gas. In some cases, water heaters can be the cause of this odor source.

It is important to note that not all instances of rotten egg smell in water indicate a serious problem. Low levels of hydrogen sulfide gas can still produce a noticeable odor, but may not pose any significant health risks. However, continuous exposure to high levels of this gas can be harmful and lead to various health issues, especially for people with respiratory conditions source.

In order to effectively combat the rotten egg odor in water supplies, it is crucial first to identify the source of the problem, be it hydrogen sulfide gas or sulfur bacteria. This can be done by conducting water tests to determine the concentration of hydrogen sulfide in the water. Once the cause has been determined, appropriate treatment methods like water filtration or disinfection can be employed to resolve the unpleasant smell.

In conclusion, understanding the cause behind the rotten egg smell in water is essential to address the issue effectively. By recognizing the presence of hydrogen sulfide gas or sulfur bacteria, homeowners can take appropriate action to restore their water quality, ensuring a safe and pleasant water supply for daily use.

Chemical Causes Behind The Smell

Hydrogen Sulfide

One of the main reasons water smells like rotten eggs is the presence of hydrogen sulfide gas. This gas is produced when water comes into contact with organic matter or some minerals, such as pyrite. It can also be generated by the actions of sulfate-reducing bacteria that convert sulfate and other compounds into hydrogen sulfide gas. This is commonly observed in water heaters.

Other Minerals and Metals

In addition to hydrogen sulfide, water can also become contaminated with a variety of minerals and metals that can impact its taste and odor. Some common examples include iron, magnesium, copper, and manganese. When these metals come into contact with water, they may react with other constituents or chemicals, contributing to the sulfur-like smell.

Organic Material

The presence of organic material in water can also contribute to a rotten egg smell. As plant material and other organic matter decay, they release sulfur compounds that can generate hydrogen sulfide gas, further exacerbating the issue.


Other contaminants in water such as chemicals, inks, and salts can alter the taste and color of water, sometimes leading to a rotten egg-like smell. In some cases, these contaminants can be introduced into the water system through pollution or other anthropogenic activities, resulting in undesirable odors.

Water Treatments and Softeners

Water treatments and softeners can sometimes play a role in the smell of water. Chlorination is a common method used to disinfect water, but excessive amounts of chlorine can also cause an unpleasant smell. Conversely, water softeners, which use salts to treat water, can sometimes introduce a sulfur odor. To mitigate the issue, various filtration methods can be employed, such as activating carbon filters, oxidizing media filters, or simply using carbon filters to filter out the majority of sulfur and other chemicals causing the smell.

Sources of the Smell

In this section, we will explore the common sources of rotten egg smell in water and understand how they originate. There are various reasons why water might smell like rotten eggs, and they can be traced back to the following sources:

Water Heater

A common source of the rotten egg smell in water is the water heater. This smell may be caused by sulfate-reducing bacteria that convert sulfate and other compounds into hydrogen sulfide gas, which has a rotten egg odor. A culprit in this process can be the anode rod inside the water heater. In particular, the magnesium anode rod can react with sulfates in the water to produce hydrogen sulfide. Replacing the rod with an aluminum or zinc one can help to reduce the smell. Additionally, flushing the hot water heater and maintaining it regularly can also help to minimize the odor.

Well Water

Another reason behind the rotten egg smell in water is the presence of hydrogen sulfide gas in well water. This can occur when groundwater filters through organic material or rocks, such as sedimentary rocks like limestone and gypsum rock. In such cases, it is advisable to install a water filtration system to remove the hydrogen sulfide gas from the well water.

Public Water Systems

Sometimes, the rotten egg smell can also be traced back to the public water systems that supply drinking water to homes. These systems may use groundwater sources that contain hydrogen sulfide gas, resulting in an unpleasant smell in the tap water. To address this issue, water treatment plants often use aeration or chlorination methods to remove hydrogen sulfide and other contaminants from the water.

Reservoirs and Lakes

In some cases, the smell might be originating due to water contamination in lakes and reservoirs. This can happen if the water in these bodies has been in contact with decaying organic matter or certain minerals that contribute to the production of hydrogen sulfide gas. To ensure that the drinking water obtained from these sources is free from any unpleasant odor, it is essential for the water authorities to maintain and monitor the water quality in these reservoirs and lakes regularly.

By understanding the different sources and causes of the rotten egg smell, it becomes easier to identify and address the issue in various water systems, whether it is a water heater, well system, or public water system.

How To Test Water Hardness

Detecting and Testing

One of the first steps in addressing water that smells like rotten eggs is to detect and test the water for potential contaminants. Homeowners may notice a foul odor coming from their water, which can often be attributed to the presence of hydrogen sulfide gas. Contacting a professional plumber can help in identifying the cause of the rotten egg smell and recommending appropriate solutions.

To confirm the presence of hydrogen sulfide or other contaminants, it is essential to have the water tested. Homeowners can reach out to their local health department or the Environmental Protection Agency (EPA) for guidance on testing procedures and recommendations for certified labs. Working with certified labs ensures accurate and reliable results, enabling homeowners to make informed decisions on how to treat their water.

Another option is to contact the local health department directly. Health departments are typically well-versed in common contaminants affecting their region’s water supply and can provide valuable insights and resources for testing and treatment. They may also have information about EPA-approved test kits, which can simplify the testing process for homeowners.

In some cases, the health department or the EPA might recommend a specific certified lab for water testing. These labs adhere to strict guidelines and employ qualified professionals, ensuring accurate and thorough testing of your water supply. Once the test results are available, they can guide you on the next steps to take, such as installing water treatment systems or consulting with a plumber for repairs.

By following these steps, homeowners can confidently address the issue of their water smelling like rotten eggs. Proper testing and expert guidance will aid in identifying the source of the problem and implementing effective solutions for clean and safe water.

Health Concerns

The presence of a rotten egg odor in drinking water is often attributable to the presence of hydrogen sulfide gas. This characteristic smell is unpleasant and can impact the taste and odor of water, potentially affecting its palatability. Although it is typically not considered a direct health risk, it is essential to understand its causes and potential implications on health.

In terms of health concerns, an objectionable odor caused by hydrogen sulfide in drinking water is usually not harmful to health. However, the odor can also be caused by other constituents, and it is always best to consult with a local health department when encountering an unknown or foul-smelling odor in the water.

It is important to note that long-term exposure to high levels of hydrogen sulfide gas may lead to nausea, headaches, and other irritations. While the concentrations found in most drinking water supplies are less likely to pose significant health risks, the unpleasant smell alone can still discourage individuals from consuming the necessary amount of water essential for general well-being.

When addressing the presence of hydrogen sulfide in water, a common solution is the installation of water filtration systems designed to remove this gas alongside other potential contaminants. Additionally, regular maintenance of water heaters and plumbing systems can help prevent the buildup of sulfate-reducing bacteria and other odor-causing elements, ensuring the overall quality of drinking water.

In conclusion, while the rotten egg odor often doesn’t constitute a harmful health risk, it is essential to remain aware of its presence and take steps to maintain and improve water safety and quality. By doing so, one can ensure better drinking water that is not only safe but also free of unpleasant odors and tastes.

When is it time to call your local plumber or serviceman? 

Fixes and Solutions

Water smelling like rotten eggs can originate from various causes. One common solution to eliminate this unpleasant odor is to check the magnesium anode in your water heater. Over time, the magnesium anode may corrode, leading to the breakdown of sulfate into hydrogen sulfide and producing a rotten egg smell. Replacing the anode with one made of aluminum may help resolve the issue.

Another effective solution is installing a carbon filter. These filters can efficiently remove hydrogen sulfide from the water source. Having a carbon filter will significantly reduce the rotten egg smell, leaving you with clean and odorless water. Ensure to maintain the filter regularly to maintain its effectiveness.

Flushing your water heater periodically is also crucial. Sediments and bacteria may accumulate over time, contributing to the sulfate breakdown and hydrogen sulfide production. Regularly flushing the tank can help eliminate any build-up, reducing the rotten egg smell in your hot water.

For treating a sulfur-smelling water source, consider using a specialized filtration system designed to remove the compounds causing the odor. These systems can help get rid of the rotten egg smell by filtering out hydrogen sulfide and other contaminants.

In summary, addressing water that smells like rotten eggs involves several possible solutions, ranging from replacing the magnesium anode to installing carbon filters, flushing the water heater, and using specialized filtration systems. By implementing these fixes, you can achieve a clean and odor-free water supply.

Preventing the Smell

It is essential to address the root cause of the issue when dealing with water that smells like rotten eggs. By understanding the sources and reasons behind the odor, one can effectively prevent it from occurring in the future. Here are some essential steps to take in preventing the smell in your water.

First and foremost, it is important to inspect and maintain your plumbing system regularly. A well-functioning plumbing system will help prevent the buildup of bacteria and other contaminants that can cause unpleasant odors. Additionally, ensure that your plumbing is made from materials that are resistant to corrosion and degradation. This will help prevent the release of unwanted substances into the water supply.

Another essential factor to consider is the geological makeup of the area where you source your water. Some regions are more prone to having water that smells like rotten eggs due to the presence of certain elements and minerals within the ground. Specifically, rocks and minerals rich in sulfur, such as pyrite, can contribute to this issue. To minimize the odor, it is necessary to identify and mitigate such contributing factors within the water source.

Apart from addressing the geological factors, it is also crucial to implement green practices within your home or workplace. This might involve the use of water-efficient fixtures and appliances, as well as proper management of water waste. By reducing the amount of organic material that enters the plumbing system, you can limit the growth of bacteria and other compounds responsible for the rotten egg smell.

Finally, water filtration systems can be highly effective in preventing the smell of rotten eggs in your water supply. By selecting the appropriate filtration system based on the specific contaminants present in your water, you can address the issue head-on and create a more pleasant, odor-free environment for everyone to enjoy.

In conclusion, regular maintenance of your plumbing system, consideration of geological factors, the implementation of green practices, and the use of water filtration systems play crucial roles in addressing and preventing the rotten egg smell in your water.

Frequently Asked Questions

How to eliminate rotten egg odor from water heater?

To eliminate the rotten egg odor from a water heater, one approach is to flush and cleanse the tank with a low concentration of hydrogen peroxide or chlorine bleach. This can help kill the bacteria causing the hydrogen sulfide gas, which is responsible for the smell. Additionally, replacing the anode rod in the heater with an aluminum-zinc alloy rod can minimize the chances of future odor issues.

Why does water smell like rotten eggs in one bathroom?

If only one bathroom has water that smells like rotten eggs, the issue may be localized in the plumbing fixtures or pipes in that specific area. Bacteria can build up in the pipes or drains, leading to the formation of hydrogen sulfide gas, which causes the rotten egg smell. It could also be due to a dry p-trap, which needs water to create a seal and prevent sewer gases from entering the room. Pouring water into the drain may resolve the issue.

What causes water to smell like rotten eggs after vacation?

When a house is vacant for an extended period, such as during a vacation, the bacteria in the plumbing may multiply due to the water sitting stagnant in the pipes and water heater. This can lead to the production of hydrogen sulfide gas, causing the rotten egg smell in the water. Once the water begins to flow regularly again, flushing the system should remove the odor.

Why does only one faucet emit a rotten egg smell?

A single faucet emitting a rotten egg smell suggests a localized issue within that particular fixture or the pipes connected to it. Bacteria growing in the aerator or in the pipe leading to that faucet may cause hydrogen sulfide gas production, which leads to the odor. Removing and cleaning the aerator or flushing the pipes may help eliminate the problem.

How to get rid of smelly water?

To get rid of smelly water, first identify the source of the smell. If the issue is caused by hydrogen sulfide gas, flush the plumbing system thoroughly and treat the water heater as mentioned earlier. In some cases, installing a water treatment system, such as a water softener or an activated carbon filter, can improve the water quality and remove unpleasant odors.

Is it safe to shower in water that smells like sulfur?

Showering in water that smells like sulfur is generally safe, as hydrogen sulfide gas in low concentrations is not typically harmful to humans. However, the smell can be unpleasant and indicates a bacterial problem in the water system. It’s advisable to address the source of the smell and treat the water system to ensure a comfortable and clean experience.

Need to Hire a Plumber?
Get a free estimate online from top local home service pros in your area.

Recent posts

Need help with a repair or install?

Free Online Quote

By Anthony Barnes

Anthony Barnes is the founder of Water Heater Hub and a second-generation plumber by profession. Before developing Water Heater Hub, Anthony Barnes was a full-time plumber, and he has undertaken a wide variety of projects over the decades. As a second-generation plumber, it was easy for Anthony to get used to the technicalities of all from a tender age