Why Does My Water Smell Like Rotten Eggs?

Not all water quality issues are easily perceptible, but smelly water is not one of them. You can become accustomed to some water quality issues, but you are unlikely to get over your water smelling like rotten eggs or sulfur, and you shouldn’t.

If you are experiencing this smelly water problem, you may be wondering why it smells and what you can do to fix it.

Why Does My Water Smell Like Bad Eggs?

what's that smell - smelly egg odors

If your water smells like rotten eggs or sulfur, that is because it contains hydrogen sulfide gas. This gas can occur naturally as a result of decay and chemical reactions with soil and rocks, or it can also be produced by certain “sulfur bacteria” called Divibrio Sulfurcans in your groundwater, well, water heater, or plumbing system.

Areas in and around Lexington, Kentucky, are known for high levels of sulfur in the water, which is often the cause of the rotten egg smell. Your municipal water center treats the water to safe, federal regulation standards, but that doesn’t necessarily wholly eliminate any smells.

Most water gets treated with chlorine that will kill any bacteria, but if your water is left stagnant in your plumbing system, it may give bacteria the chance to grow.

How to Determine the Source of the Sulfur Smell

If your water smells like eggs, you should take the time to determine why it does and see what can be done about it.

Bacteria in the drains is the most common cause of odor in the water. Over time, organic matter like hair, soap, grease, and food waste can accumulate in the drains, and this material will feed the bacteria. It may be that those faucets simply weren’t used regularly, and bacteria were given a chance to grow.

Try running the affected faucets for several minutes and see if that eliminates the problem. Once new water has replaced the old, it may no longer be a problem.

Run through this checklist to determine the source of why your water smells:

Does the Smell Only Come Out of Certain Faucets? If this is the case, the problem is probably in the fixtures themselves or in the pipes that lead to those specific faucets. Or, it could be in your water softener system.
Does the Smell Come from All the Water Faucets in Your Home? If so, the problem is most likely in the main water supply.
Does the Smell Only Come from the Hot Water Side? You probably have bacteria living in your water heater tank.
What Happens If You Run the Water for a Few Minutes? Does the problem go away? If it does, it’s likely that the problem is somewhere inside your house’s plumbing system.
Is the Odor Persistent? Then, the problem could be a combination of the plumbing system and the water source. Check with your neighbors and see if their tap water is similar.

If you source water from a well, take a look at these steps from the University of Georgia for disinfecting your well water.

Is Smelly Water Safe to Drink?

If your water smells like sulfur or even chlorine, that doesn’t necessarily mean it is unsafe to drink. However, if you find that your water’s scent, taste, or appearance has noticeably changed, it is wise to get your water tested to find the source of the issue.

Sulfur bacteria produce a slime that helps other bacteria grow, and that slime can clog wells and plumbing systems. While the bacteria itself is not harmful to humans, the hydrogen sulfide gas that it produces can be harmful at high concentrations. It is important to vent the gas and exterminate the bacteria.

How to Stop Your Hot Water From Smelling Like Rotten Eggs

If you’ve identified that the smell is coming from your hot water, it’s either bacteria in your water heater or drains. A chemical reaction with your water heater’s magnesium anode rod can also feed and encourage bacteria.

If your water heater was turned off for a significant period, or if the temperature was set too low, bacteria could have had time to grow. These types of bacteria do not generally pose health problems, but their taste and smell can be unpleasant.

First, double-check that the smelly water is from your water heater by running some hot water and filling a glass with it. Then, run cold water for 30 seconds so any water from the hot water line is replaced, and fill another glass with cold water. Compare the two. If you determine the odorous water is from the water heater, then replace the anode rod or perform water heater treatments to cure the problem.

Unless you are very familiar with water heaters, we recommend having a professional plumber clean your water heater of bacteria. A plumber can eliminate the smell by removing the production of hydrogen from your tank and killing the bacteria.

Here are three other solutions for how to fix smelly hot water:

1. Replace the Magnesium Anode

Many water heaters have a magnesium anode rod installed inside the water tank. It is attached to a plug at the top of the water heater. It is a sacrificial piece that is designed to protect the tank from corrosion by attracting particles of iron, limestone, or other minerals present in the water through an electrochemical process. The process of protecting the tank causes the creation of hydrogen, which creates an odor problem when the hydrogen reacts with sulfur and bacteria.

The anode rod corrodes in place of the tank. Without an anode rode, the tank’s warranty is voided, and the lifespan is significantly shortened.

The magnesium anode can often be replaced with another anode material, such as aluminum, to get rid of the sulfur smell while still preventing corrosion. The tank’s manual or manufacturer will have to be consulted to see if other anode alloys or materials will function properly.

Usually, rods made from zinc or aluminum-zinc alloys will not react with bacteria like rods made of only aluminum or magnesium, and they significantly reduce the chance of hydrogen sulfide from getting into your water. Contact a trusted local plumber to replace your anode with a new one.

2. Disinfect the Water Heater Tank with Chorine Shock

In order to get rid of bacteria in your water tank, you can cleanse the water in your tank with chlorine to kill the bacteria. This may be done in addition to changing the anode rod.

Bacteria can be killed using a number of different methods. A common recommendation for cleaning water tanks is to pour bleach into your tank to kill the bacteria. Bleach will kill the bacteria, but it can increase the chances of corrosion and will need to be thoroughly rinsed out. Bleach will speed up the process of corrosion, create dangerous gasses in your plumbing system, and is unhealthy to put back into the city’s water supply.

Instead, we recommend using hydrogen peroxide, which kills off the bacteria, does not require rinsing, and isn’t as dangerous to your plumbing system. Hydrogen peroxide doesn’t create gases and vapors as it interacts with water and bacteria.

To clean your water tank of bacteria, do the following:

Turn off the gas supply to the water tank.
Remove the magnesium anode rod.
Pour two pints of three percent hydrogen peroxide into a 40-gallon tank.
Let some of the solution run into the water lines and set for two hours.
Run the system and let all the water drain through.
After letting all the water run through, return power and reignite the gas to the water tank.

After following these steps, your water heater should be ready to use.

3. Kill Water Heater Bacteria with Heat

Residential water heaters are typically run at 120 degrees Fahrenheit to prevent scalding while still providing hot water. Commercial plumbing often uses a boiler that keeps water at a much higher temperature and uses a water tempering valve to lower the water to a safe temperature when the water is going to contact humans. The higher temperatures in the boiler prevent the buildup of bacteria.

Sulfur bacteria have evolved to survive in 120-degree water. One way to kill the bacteria is to run your water heater at 160 degrees Fahrenheit for several hours.

CAUTION: Increasing the temperature can be very dangerous. The pressure inside your tank is increased, and it is essential to consult your plumber, manufacturer, or dealer regarding the operation of your pressure relief valve and ensure that it can handle that kind of pressure.

Remember not to let anyone use the hot water while it is set to such a high temperature, or they will get scalding burns on their skin.

If you need help identifying or eliminating the odors in your water supply in Lexington or Louisville, Kentucky, contact Dauenhauer Plumbing. We can advise you on any of the methods above or help you install a water filtration system. Contact us today to set up an appointment to test your water.