How to Get Rid of Rotten Egg Smell in Well Water

Good clean well water shouldn’t smell any different from your municipal water. A rotten egg smell (people who know how sulfur smells will call it a sulfur like smell) hints on a serious hydrogen sulfide gas contamination.

Why Does My Water Smell Like Rotten Eggs?

Hydrogen sulfide will give your water that nasty rotten egg smell and taste. Your water might have the smell when you drill the well or might develop it over time. The biggest causes of such contamination are:

  • Natural hydrogen sulfide gas from decay, rocks and chemical reactions in the soil leaking into the well water
  • Sulfur producing bacteria in your plumbing, groundwater or the well
  • Chemical reactions between the water and heaters
  • Pollution

Troubleshooting Rotten Egg Smell in Your Water

Finding where the smell is coming from determines how you will fix the problem. Luckily, you can narrow down your search by applying three simple checks.

Is the Smell on the Hot Water Only?

In some cases, the sulfur smell is a result of a reaction between your water heater’s anode rode and random sulfate ions that exist in water naturally. Water heater tanks have aluminum or magnesium rods designed to prevent the steel tank from rusting.

Magnesium will react with the sulfate ion faster than aluminum. Swapping out a magnesium rod for an aluminum one like this might fix the problem. In case the swap doesn’t fix the odor or you are already using an aluminum anode, you should consider removing sulfate ions from the water before it hits the boiler.

If the odor is in both the hot and cold side of your plumbing, then sulfate ions reacting with your heater anode might not be the primary source of the rotten eggs smell.

well water smells like rotten eggs

Cold Water Odor that Goes away After Water Flow

If you have a smell that goes away after you run the taps for a while, chances are that the rotten eggs smell comes from sulfate reducing bacteria somewhere in your plumbing.

These bacteria take in sulfate ions and produce hydrogen sulfide. An increase in the water flow will wash away the gas they produce hence giving you the fresh water smell after a while.

Smell on Hot and Cold that Doesn’t Decrease as Water Flows

A steady rotten eggs smell on both hot and cold water lines means the hydrogen sulfide is in the well or the aquifer feeding your well. If you use a large storage tank or a pressure tank, ensure that you check the water between your well and the tank to ascertain that it still has the sulfur smell.

If the water straight from the well (before it hits any tanks) smells fresh, you could still be dealing with bacteria in your storage tanks and not the well.

How to get rid of the Rotten Egg Smell

Once you have identified the cause of the smell, you can go ahead and select the most appropriate fix to the problem.

Is the Water Heater the Problem?

If the problem is the water heater, you can fix the problem by handling how your water heater deals with the free sulfide ions in the water. Your possible solutions include:

Replacing or Getting Rid of the Anode

If your boiler has a magnesium anode, consider replacing it with an aluminum one. Aluminum is less reactive and might not turn as much of the sulfide ion into the hydrogen sulfide gas that causes the terrible rotten eggs smell.

In case you still get the smell, you could consider doing away with the anode and plugging the hole it leaves. While this might work, it will leave your steel water heater container open to corrosion. It will solve the problem in some cases but reduce your water heater’s lifespan.

Removing the Sulfide Ions from the Water

Sometimes, the sulfide ions in the water might still be too much for even the relatively gentle aluminum anode. If removing the anode is not an option at all, you should consider removing the sulfide ions from the water in the first place.

Your options here include using the following systems:

ProTip: Sediment filters, water softeners or carbon filters can’t remove the sulfate ions in your water

Treating any Sulfate Reducing Bacteria

A Sulfate Reducing Bacteria testing kit can help you prove if the bad odor is due to these bacteria. Once you prove they are present, you can get rid of them by:

  • Shock-chlorinating the well, your plumbing, tanks and water heater
  • Increase water heater temperature to around 160 degrees Fahrenheit for around 4 hours to destroy any bacteria in the heater before flushing the tank (this might be dangerous, consult with your manufacturer or manual before attempting)
  • If the smell keep recurring, you can constantly chlorinate your water. Using safe amounts of chlorine should kill the and any other bacteria in the water. If you don’t love the lingering taste, you can add a filter that is specifically designed to get rid of the chlorine smell and taste

Disinfecting specific accessories in your water system might be easier said than done. If your water heater, well pressure tank, water softeners, or filters don’t respond to your treatment, contact the manufacturer for specific instructions before considering complete replacements.

Further Reading: How Long Does a Well Pump Last?

Get Your Water Tested

If you just sunk your own well, the contractor must have tested the water for all common contaminants before letting you use it. This test also gives you the sulfate composition hence helping you identify if your water might have the rotten eggs problem or not.

Having the well water tested again is a good way to identify any problems at the source. It could help you find if you have a bacterial infection in the well or if the hydrogen sulfide gas started seeping into your well.

Testing your well water every now and then is also a great way to ensure that your water remains safe for consumption throughout. Some of the main tests to conduct include:

  • Arsenic test once a year
  • Nitrates test every other year
  • Caliform bacteria every year
  • Lead at least once a year
  • Manganese before a baby takes the water
  • Fluoride if you have kids and teenagers
  • Agricultural chemicals
  • Volatile organic chemicals

Quick Well Water Smells and Their Meaning

If you want to find out if your well water has a problem before calling in the experts, you can draw some water from the well before it goes into the pressure tank. Get around 5 gallons for the smell test.

  • Rotten Eggs Smell: Hydrogen Sulfide gas. Could be from natural gas deposits in the soil of from Sulfate reducing bacteria
  • Oil or Asphalt like smell: Manganese in the water
  • Cucumber or raw sewage smell:  Sulfur and iron combination

Bottom Line

Finding the source of the rotten egg smell source is the first step to fixing the problem. The source will identify what treatment procedure to follow and whether you have to call in an expert. You can always take the smell as an opportunity to run a comprehensive check of the entire system and run some common contaminant tests.

Oscar

In his spare time, Oscar loves tinkering with electronics. Solar panels, wiring, old TVs and sometimes DIY powerwalls. When he is not busy trying not to electrocute himself, you can find him in the garden tending to his vegetables and chickens.

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