Stinky Water: Why Does My Tap Smell Like Rotten Eggs?

If your tap water smells like rotten eggs or anything else, the plumbers at Mr. Rooter Plumbing are the right experts to call. Let our experts help you figure out what the culprit is and make repairs. In this article, we’ll explain why your tap smells like rotten eggs.

What Causes the Rotten Egg Smell?

The rotten egg smell in tap water is usually caused by the presence of hydrogen sulfide gas. This gas can be naturally occurring in groundwater or produced by sulfur-reducing bacteria that thrive in warm, low-oxygen environments. When water containing hydrogen sulfide is released through your faucet, the gas escapes and releases the signature rotten egg odor.

There are a few common culprits:

• Bacteria in the Water Heater: If the smell is only present in your hot water, the issue likely lies in your water heater. Sulfur-reducing bacteria can grow in the heater’s tank, especially if the water sits for extended periods or the temperature is set too low. These bacteria react with the magnesium or aluminum anode rod inside the heater, creating hydrogen sulfide gas.
• Contaminated Well Water: Homes that rely on well water are more susceptible to naturally occurring hydrogen sulfide. If both your hot and cold water smell bad, the problem may originate from your well. Testing your water for contaminants and bacteria is essential in this case.
• Decaying Organic Material in Pipes: In some instances, organic debris in your plumbing system can provide a breeding ground for bacteria that produce foul-smelling gases.

Is It Harmful?

While hydrogen sulfide in low concentrations isn’t considered toxic, it can still pose problems. Prolonged exposure can corrode your plumbing system and stain your fixtures. In higher concentrations, it may cause nausea, headaches, or eye irritation. More importantly, the presence of this gas can indicate other underlying bacterial issues in your water that may be harmful to your health.

How to Fix It

The first step is identifying the source of the smell. Try running cold water from multiple faucets. If only hot water smells, flush your water heater and consider replacing the anode rod with a zinc alloy version. If the smell is in both hot and cold taps, have your water tested, especially if you're on a well system. Disinfecting the well and installing a water filtration system may be necessary.

For persistent issues, it’s best to contact a licensed plumbing service or water treatment specialist. They can help you identify the source and recommend solutions such as whole-house filtration systems, aeration units, or chlorination systems.

Prevention Tips

• Schedule regular water heater maintenance
• Set your water heater to at least 140°F to discourage bacterial growth
• Test well water annually
• Install a filtration system if your water has recurring odor issues

Call Mr. Rooter Plumbing for Professional Plumbing Service

As a homeowner or business owner, you deserve clean and pure water for drinking and household use. If you’ve noticed signs of water quality issues, get in touch with Mr. Rooter Plumbing for help. Our plumbers can help you with water filtration installation, pipe repair, water softener installation, water quality testing, and more. We have over 50 years of plumbing experience and have received thousands of 5-star reviews for doing an excellent job.