Unmasking the Rotten Egg Smell in Your Water: Causes, Solutions, and How to Fix It for Good

Why Does Your Water Smell Like Rotten Eggs?

If you’ve ever turned on the tap and been hit with a strong rotten egg smell, you’re not alone. That sulfur-like odor is usually a sign of hydrogen sulfide gas in your water supply. While it’s not typically harmful in low concentrations, it can make drinking, cooking, and even showering unpleasant experiences. At Pure Souther Water, we know that if left untreated, it can damage your plumbing, stain fixtures, and contribute to bacterial growth in your pipes.

So, what’s really causing that smell? And more importantly, how do you get rid of it? As experienced water treatment experts, we’ve helped countless homeowners diagnose and fix smelly water problems, and we’re here to guide you through everything you need to know.

The Science Behind the Smell: Hydrogen Sulfide in Water

Hydrogen sulfide is a naturally occurring gas that can find its way into your water supply through underground decay of organic matter, certain types of bacteria, or even interactions with your plumbing system.

This gas dissolves into water, producing that distinct sulfur odor. It’s most common in well water, but it can also appear in municipal water systems due to aging infrastructure or biological activity in water heaters.

Is It Dangerous?

In most cases, no—but that doesn’t mean you should ignore it. While the Environmental Protection Agency (EPA) does not classify hydrogen sulfide as a health risk at low levels, it can corrode plumbing and appliances over time. According to the EPA, nuisance contaminants like hydrogen sulfide should be addressed to improve water quality and protect home systems.

How Can You Tell If Hydrogen Sulfide Is in Your Water?

Determining whether hydrogen sulfide is present in your water requires some simple diagnostic steps. If you notice the rotten egg smell only when running hot water, the source of the issue is likely within your water heater. Over time, magnesium anode rods inside water heaters can react with naturally occurring sulfates, leading to the production of hydrogen sulfide gas. In contrast, if the odor is present in both hot and cold water, it suggests the contamination is coming from the well or the plumbing system itself.

Localized odors, where only certain faucets emit the smell, may indicate bacterial growth within the plumbing or pipes leading to those fixtures. According to the CDC, certain bacteria, such as sulfur-reducing bacteria, thrive in anaerobic environments, breaking down sulfur compounds and releasing hydrogen sulfide as a byproduct.

Why Well Water Often Smells Like Sulfur (And What to Do About It)

If you have well water, you’re more likely to experience a rotten egg smell. That’s because groundwater sources are more prone to hydrogen sulfide contamination due to natural geological conditions. Sulfur compounds in underground rock formations can dissolve into the water supply, leading to noticeable odors when the water is drawn from a well. The U.S. Geological Survey (USGS) notes that hydrogen sulfide is more commonly found in deep wells where oxygen levels are low, creating the perfect conditions for sulfur-reducing bacteria to thrive.

What You Need to Check First

Before deciding on a treatment solution, it’s important to diagnose the extent and cause of the problem.

• Test your water: Conducting a thorough water test can confirm hydrogen sulfide levels and uncover any other contaminants. Many water treatment professionals offer lab-based testing to measure gas concentration accurately.
• Check for bacterial contamination: Sulfate-reducing bacteria commonly grow in well water and plumbing systems. The presence of these bacteria indicates that organic matter is interacting with sulfates, producing hydrogen sulfide gas.
• Inspect your well system: Cracks in the well casing or poorly sealed plumbing can allow organic material to seep into the water, providing fuel for bacterial growth. Regular maintenance and inspections can prevent this.

Well Water Treatment Options

Once you’ve identified hydrogen sulfide as the cause of the odor, various treatment methods are available to improve your water quality.

• Oxidation Filtration Systems: These systems use air injection or chemical oxidizers (such as chlorine or potassium permanganate) to convert hydrogen sulfide gas into a solid form that can be filtered out. The EPA recommends oxidation-based filtration as an effective method for removing nuisance contaminants.
• Activated Carbon Filters: Best for lower hydrogen sulfide concentrations, activated carbon filters absorb the gas, improving water taste and odor. However, they require regular maintenance and replacement.
• Shock Chlorination: If bacteria are responsible for the sulfur smell, a one-time shock chlorination treatment can eliminate bacterial colonies. The World Health Organization (WHO) suggests chlorination as an effective way to disinfect well water.
• Continuous Chemical Feed Systems: These systems inject a controlled amount of chlorine, hydrogen peroxide, or ozone into the water supply to neutralize hydrogen sulfide before it reaches household plumbing. The CDC emphasizes that maintaining proper chlorine residuals can prevent bacterial regrowth.

Why Your Water Heater Might Be the Problem

If the rotten egg smell is only noticeable when running hot water, your water heater is the likely culprit. Here’s why:

• The Magnesium Anode Rod: Reacts with sulfates in water to create hydrogen sulfide gas.
• Bacterial Growth Inside the Tank: Water sitting at lower temperatures can allow bacteria to grow.

Fixing a Smelly Water Heater

• Flush your tank regularly.
• Replace the magnesium anode rod with an aluminum or zinc one.
• Increase your water heater temperature to 140°F for a few hours to kill bacteria.

The Best Long-Term Solutions for Smelly Water

If you’re tired of dealing with foul-smelling water, permanent filtration is the answer. The right system depends on whether the odor is caused by hydrogen sulfide gas, bacterial activity, or plumbing reactions.

• For well water: Oxidation filters or chemical injection systems work best.
• For municipal water: Carbon filters or reverse osmosis can remove odors and improve taste.
• For water heater-related smells: Anode rod replacement or a whole-house filter can prevent the issue.

Take Action: Stop Water Odors for Good

Dealing with smelly water isn’t just about getting rid of an unpleasant odor—it’s about ensuring cleaner, high-quality water for you and your family. Whether you’re on well water or city water, fixing the issue now can prevent long-term damage to your plumbing and appliances. Call Us Today at 615-570-1496 or Request a Free Water Test Here to get fresher, odor-free water—guaranteed!

If you’ve been struggling with water that smells like rotten eggs, now you know why—and how to fix it. Hydrogen sulfide, bacterial activity, and plumbing reactions are the usual suspects, but the right filtration system can address the issue.

As local water experts, Pure Southern Water has been serving the local Clarksville, TN, and surrounding areas for many years, and we’re here to help you every step of the way. Whether it’s testing, filtration, or long-term maintenance, you can trust us to find a solution that works for you and your home.