Does your house have that rotten egg smell commonly associated with hydrogen sulfide? Is it safe? Where does it come from and what can you do about it?
Inspect Your Water
The most popular source of a rotten egg smell in a residence is the water. Your water, be it tap water or well water, can smell like rotten eggs thanks to hydrogen sulfide gas that is dissolved in your water. This gas, known as H2S, is highly detectable in water, with humans being able to detect concentrations as low as 0.5 mg/L (0.5 parts per million or 500 parts per billion).
This amount is considerably lower than the point at which the H2S would affect your health so it’s not considered to be a serious threat to water quality. The water would become undrinkable before it became a health problem.
If this is occurring when your water is hot, your hot water heater is a likely culprit. The part known as the “anode” in your hot water heater is likely worn out and you’ll need to replace it. This is usually a quick, affordable fix with an anode costing somewhere between $20 for a basic model and up to $150 for a powered model (sometimes called a “imposed current anode”) which will boost the effectiveness and often work more effectively in homes with water softeners.
If this also happens when your water is cold, the source of the hydrogen sulfide is your water source — either your water supplier or your well water. In this case you’ll need to filter the water in order to remove for treat for the rotten egg smell. The solution will vary based on the concentration of the H2S.
Where Does The Hydrogen Sulfide Come From?
Hydrogen sulfide — which is what’s causing the rotten egg odor — is a natural byproduct of bacteria which release the sulfide after consuming sulfur which is in the water. This is a common situation where sulfate-reducing bacteria (SRB) are something that happen to be present in your area. They release hydrogen sulfide, which is soluble in water, and all of a sudden your water, and even your home, can smell like sulfur (or rotten eggs). The sulfate-reducing bacteria can live in your well or in your pipes, either way, you’ll want treat for them as the water enters your home.
Is The Hydrogen Sulfide Bad?
In most cases the H2S is an annoyance, but it’s something you quickly acclimate to, so visitors will notice the issue much more than people who experience it regularly.
Hydrogen sulfide can be hazardous at high levels, but if you can drink your water then the amount in it won’t be anything to worry about.
The H2S at higher levels, but sometimes still drinkable, can shorten the lifespan of plumbing, pipes, and faucets. Iron, galvanized steel and stainless steel are susceptible to H2S which can mean expensive fixes down the road or, in the shorter term, clogs due to iron sulfide accumulating in pipes where iron is degrading.
Luckily you can test for hydrogen sulfide level and you can treat for it. A mail-in water test or a water professional can tell you the H2S levels in your water and what to do about it.
You can treat for the rotten egg smell in your water in a number of ways, but they will depend on the concentration level. At low levels, a simple carbon-based water filter will do the job. As concentrations rise you might need a change your water heater (usually an upgraded anode) or some form of water treatment like a neutralizer or a whole-home oxidizing filter.
Sources And More Reading:
- PSU Extension: An excellent guide for treating hydrogen sulfide