Sulfur Smell – Why Water Smells Like Rotten Eggs
Hydrogen Sulfide can give your water a sulfur smell, also known as “rotten egg” odor, and can have several causes. If it is only in the hot water and you have a tank type water heater, it could be coming from a reaction between the sacrificial magnesium anode rod and anaerobic bacteria that can be present in water heaters. This bacteria is harmless to people and will not show up in a coliform bacteria test. The rod is to reduce corrosion of the steel tank and should be replaced periodically to maintain this protection (I have never met a home owner who does, or is even aware of it).
Sulfur can also be in the water in the well. It can be from ground water coming in contact with pollution, minerals containing Sulfur, or sulfate reducing bacteria. Wells drilled into bedrock formed of Shale and Sandstone, which is prominent in central Pennsylvania, are more prone to this issue, according to the Penn State Extensions Water Quality website, leading to a sulfur smell in your water.
If Your Water Smells Like Sulfur, Here’s What You Can Do!
To treat a sulfur odor, it is critical to properly identify the source first. If it is in the cold and hot water, a system to treat all the water in the well, or as it enters your home or business will be needed. There are many methods and systems available, and having an experienced Water Quality Association certified professional diagnose, install, and maintain a system will usually be the best option.
Sometimes a sulfur odor with the source water can mask an additional source, such as a water heater anode rod, or a sulfur bacteria in part of the buildings plumbing or waste water system. Additional treatment may be required, and even a good water quality professional will not be able to detect additional problems until the POE water has been treated.
If the water heater anode rod is the culprit, here are some options. The rod can be removed from the water heater, although this voids any warranty and eliminates any protection that the rod was affording to the water heater tank. I once asked a major water heater manufacturer’s representative about this, and he said if there is a water heater warranty claim, we do not ask for the water heater back, do not volunteer that the anode was removed.
Another option is to replace the magnesium rod with an aluminum or zinc aluminum “multi alloy” rod. The odor often returns, and elevated aluminum levels in the hot water can be a health risk, if water from the hot side is used for drinking or cooking.
You could also use a chlorine injection in the source water that feeds the water heater. Besides the initial expense, and ongoing maintenance, we are back to the downsides of having chlorinated water in your home.
Ozonation of the source water is yet another option, although it has the initial expense and some ongoing maintenance, it does not have the negative effects of chlorine.
The last, and probably best, option is to replace your sacrificial rod with a powered anode. The powered anode consistently protects the water heater tank, consumes very little electricity and cannot cause odors in your hot water. There is an upfront expense, but no ongoing maintenance, unless it needs to be replaced. The powered anode can be transferred to a replacement water heater if needed.
Lingering Sulfur Smell
What if the source sulfur is eliminated, but an individual outlet still has an odor, particularly if it is bad during the first draw, after water has not been used from that outlet for a while? It may be caused by a sulfur bacteria in that branch of the plumbing system. Try super chlorinating that line, and letting it sit in the plumbing for as long as possible. Chlorine may take time to penetrate the slime layer on the piping from the bacteria. Two or three applications may be needed to remove the sulfur smell, and it may need repeated in the future if the odor returns. Also, be sure that the odor is not coming from the drain system.