Back To Blog Page

How To Get Rid of Sulfur Smell in Water

That “rotten egg” odor coming from your tap water can really put a damper on, well, everything—from pasta nights to morning showers.

Luckily, while the sulfur smell in well water is an unpleasant odor, it is treatable. In most cases, the smell comes from hydrogen sulfide, a gas made from sulfur bacteria. In this guide, we’ll outline how to diagnose your foul water smell and rid your house of contamination.

Step #1: Diagnose the Problem

Before you get your tool belt out from the far corner of the coat closet, you must first find out where the stench is coming from. In general, there are two ways to diagnose and figure out how to get rid of the sulfur smell in water: 

  • Compare your hot and cold water – If your cold water smells and tastes fine but your hot water does not, then the problem is probably with your hot water heater, specifically with the anode rod. 
  • Inspect your water source or well – If both the hot and cold water have a rotten egg smell, then it’s safe to assume you have a problem with your water source. There are a variety of options to consider, including shocking the water system with chlorine or peroxide, as well as implementing ongoing chlorination, potassium permanganate, active carbon filtration, aeration, and ion exchange. Or, you can change your water supply entirely.

The solution you choose will depend largely on where the problem is occurring and how much mg/L of hydrogen sulfide is in the smelly water. While the smell is often an indicator of a presence of hydrogen sulfide, you can also test levels by:

  • Taking a water sample to a state-certified laboratory
  • Using a sulfur stick
  • Implementing a Biological Activity Reaction Test that tests for sulfur bacteria

Alternatively, the issue could also be due to iron bacteria—although it’s less common. This type of bacteria appears on surface waters and deposits “rusty” bacterial cells that can stick to plumbing.

Step #2 Identify if the Smell is Coming From the Water Heater

The bad odor may be emanating from your hot water heater since many types of bacteria thrive in warmer temperatures. Usually, an anode rod works within the water tank to eliminate impurities. However, over time it may become corroded and stop working, leading to sulfur-like smells.

As such, you’ll want to sanitize and inspect the heater to prevent further contamination if you notice a sulfur-like smell coming from the tank.

How to Sanitize the Tank

Sulfur-reducing bacteria thrive in hot water environments like a hot water heater. When these types of bacteria consume sulfur, they can produce high levels of hydrogen sulfide, which can produce a rotten egg smell. 

Once these bacteria are established in the tank, you’ll have to sanitize the tank to remove them:

  • Step #1: Disinfect the tank – Mix four cups of hydrogen peroxide with forty gallons of water. Fill the tank with this solution, allowing some of it to run through the lines but keeping most of it in the tank. Let it sit for at least two hours. 
  • Step #2: Refill the tank – When ready, turn the water back on and let your tank refill. 

Quick Tip: Servicing your hot water heater on your own is not recommended as it may be dangerous, violate the warranty, or make the problem worse.

Reverse Osmosis Systems starting at only $25/mo. Try before you buy!

How to Inspect an Anode Rod for Corrosion

To stave off corrosion, most hot water tanks are equipped with at least one magnesium anode rod on the inside. This rod, aptly known as the “sacrificial anode,” pulls corrosive ion deposits out of the water, keeping them away from the inner surface of the tank. 

However, the rod is not impervious to damage and eventually will corrode beyond the point of functionality, down to a skinny wire. In this corroded state, the rod’s interactions with the sulfates in the water form hydrogen sulfide gas, causing an unpleasant smell. 

Whether or not this is a result of an exhausted anode rod, is something you’ll have to inspect for yourself or with the help of a professional by following these steps:

    • Step #1: Turn off the heater’s power – For electric heaters, flip the breaker switch off. For gas heaters, find the knob to the gas line and turn it clockwise to off.
    • Step #2: Turn off the water – Make sure the water source that runs to your heater is off.  
    • Step #3: Open a hot water faucet – The faucet can be anywhere in the house. The point is to relieve some of the pressure from the hot water heater.
    • Step #4: Drain the tank partially – This will flush some of the water out while also keeping enough water in the tank to keep it in place while dislodging the rod.
    • Step #5: Inspect the anode rod – At the top of your hot water heater, find the hex head. You’ll need a socket wrench (1 1/16 inch) to turn it. Turning the wrench will require a bit of leverage and strength. Have someone hold the tank still, if possible. Pull the rod up to inspect it. If it is thin like a wire hanger, then it’s time to replace the anode rod. Talk to a professional about replacing it with an aluminum rod. While not impervious to corrosion, aluminum is relatively corrosion-resistant.1

Step #3: Treat the Water Source

If you’ve inspected your hot water tank with no success or both your cold and hot water have that rotten egg smell, then it’s time to look into treating the source: the well. The sulfur smell in well water can be eradicated with numerous treatment methods.

Quick Tip: Sulfur bacteria is a stubborn nuisance to deep water containers. In preparation for treatment, it is recommended that you give the inside of your well a thorough scrubbing with a well-cleaning kit. 

Option #1: Chlorination or Peroxide Shock

Implementing a chlorination or peroxide shock will disinfect the tank by killing the bacteria present. Both chlorine and peroxide are good options. However, a peroxide treatment will more effectively stave off any unpleasant stenches. 

Additionally, when using chlorine you’ll most likely need to regularly replenish the tank and consider installing an active carbon filter to remove any leftover chlorine still in the well.

This is a temporary solution that will last anywhere from one to two months. Although if it works, you’ll know that hydrogen sulfide is the culprit. 

Option #2: Continuous Chlorination and Filtration

Chlorine can remove medium to high levels (amounts higher than 6 mg/L) of hydrogen sulfide through oxidation. Through the use of a feed pump, chlorine can be added to your water continuously to rid it of hydrogen sulfide. 

Rather than a one-time shock, the feed-pump method keeps your well continuously sanitized. 

Through oxidation, the chlorine converts (soluble) hydrogen sulfite into (insoluble) sulfur, at which point a water filter can easily sieve it out of the stream before getting into your pipes and home. 

Bonus Points: Chlorine also keeps your water supply equipment nice and clean.

Option #3: Potassium Permanganate

Similar to chlorination, potassium permanganate cleans the tank by making contaminants insoluble. These include:

  • Hydrogen sulfide
  • Iron
  • Manganese

The solids are then easily sifted out before ever having the chance to stink up your home.

When implementing potassium permanganate, make sure you replenish the well continuously and perform routine cleaning to backwash the filtration system.

Warning: Potassium permanganate is a poisonous compound and a major skin irritant. When using it, be sure to follow the handling instructions carefully and store it in a safe place where little ones and pets can’t get to it. 

Option #4: Aeration

Sometimes your water system just needs a little bit of fresh air—if the amount of sulfur in your water is 2 mg/L or lower, then aeration could be the best option for you. 

Sulfur bacteria thrive in oxygen-deprived environments. The aeration method uses an aerator to inject oxygen into your water supply, forcefully displacing hydrogen sulfide gas and creating an oxygen-rich environment that is less hospitable to sulfur bacteria. 

Quick Tip: When nearby the aeration site, you’ll still be able to smell a sulfur stench. However, ventilation may help reduce the problem.

Option #5: Ion exchange

Using a charged resin, ion exchange is a way for pulling hydrogen sulfide out of the water in exchange for chloride. A salt solution replenishes the resin’s charge after depletion. While the process is similar to that of a water softener, it’s not the same.

Quick Tip: Not all resin can withstand sulfides, so it’s important to consult a professional to choose the right option for you. 

Option #6: Ozone

A relatively effective, efficient, and safe choice for oxidizing hydrogen sulfide is ozone. No additional chemicals or filtration is required. 

Instead, ozone is generated in a container and injected into the water source. The oxidizing effects of the ozone turn hydrogen sulfide into filterable, insoluble sulfur, while killing:

  • Viruses
  • Bacteria

Option #7: Activated Carbon Filters

Often used in conjunction with another solution mentioned, carbon filters are often installed under sinks to treat drinking and cooking water that has small amounts of particles that need to be removed—say, less than 1 mg/L. 

The activated carbon adsorbs the hydrogen sulfide after it’s insoluble. On its own, this is an economical choice for people dealing with small amounts of hydrogen sulfide.2 

Quick Tip: This method requires routine replacements of carbon filters, which have varied and unpredictable lifespans. 

Step #4: Determine if Your Water is Safe to Drink

The smell and taste of hydrogen sulfide-affected water can be so offensive that many people consider it undrinkable. While the odor might make you think it’s poisonous or toxic, it’s not. 

While hydrogen sulfide is lethal in large, concentrated amounts, there is no concern with regard to the amount found in water systems.  

Furthermore, the EPA categorizes water contaminated by hydrogen sulfide as a secondary, or merely aesthetic, concern. For reference, the EPA has two standards for water, primary and secondary:

  • National Primary Drinking Water Regulations (NPDWR) – The EPA’s primary standards are mandatory and meant to ensure that water is safe to drink. The standards detail the amount of a certain contaminant that can exist in water for it still to be considered safe and not a health concern. The term for these limits is the “maximum contaminant limit” (MCL).3 
  • National Secondary Drinking Water Regulations (NSDWR) – The EPA’s secondary standards relate to cosmetic issues of water (appearance, taste, and smell) and are not considered health concerns, which is why they are not enforceable. The maximum level for these contaminants is called the “secondary maximum contaminant limit” (SMCL). The purpose of secondary standards is to serve as a key for people who might be alarmed by unusual-looking or smelling water in their homes. 

Get Back Into the Flow of Things with Rayne Water

Foul-smelling water can disrupt the natural flow of things within your household, but with careful inspection and precision, your water can smell rain-fresh in no time.

If you’re looking to keep your water clean, recruit the experts at Rayne Water. 

We offer groundwater and well inspections, so you can stop pinching your nose and start enjoying your life. Wondering why your tap water is yellow or brown? There might be tannins in your water. From sulfur to limescale, Rayne Water is your solution.

Sources: 

  1. Kloeckner Metals Corporation. Aluminum Oxidation: Is Aluminum Corrosion-resistant? https://www.kloecknermetals.com/blog/aluminum-oxidation-is-aluminum-corrosion-resistant/
  2. Wellowner.org. Hydrogen Sulfide.https://wellowner.org/resources/water-quality/contaminants/hydrogen-sulfide/
  3. United States Environmental Protection Agency. Secondary Drinking Water Standards: Guidance for Nuisance Chemicals. https://www.epa.gov/sdwa/secondary-drinking-water-standards-guidance-nuisance-chemicals