If you’re on a private well and your water smells like rotten eggs, you’re not the only one. We get this call constantly from homeowners all over SE Wisconsin, Waukesha County, Muskego, Brookfield, Menomonee Falls, Burlington… you name it.
The smell is gross, it makes you second-guess drinking your own water, and it usually shows up at the worst time (like when guests are over). The good news is this problem is almost always fixable. The key is figuring out what’s actually causing it in your well so the fix lasts.
Here’s what that smell usually means around here and what we do to get rid of it for good.
What causes the rotten egg smell in well water?
In Wisconsin wells, that odor almost always comes back to sulfur. It shows up in a couple different ways, and each one points to a slightly different solution.
Hydrogen sulfide gas
This is the classic “rotten egg” smell. Hydrogen sulfide is a naturally occurring gas that can be present in groundwater. When your water comes out of the faucet, that gas releases, and you smell it right away.
You’ll usually notice:
- The smell is in both hot and cold water
- It’s worse first thing in the morning or after water hasn’t been used for a while
- It can come and go depending on season or rainfall
Sulfur bacteria
Some wells have bacteria that feed on sulfur compounds. They aren’t uncommon, and they can create that same rotten egg odor.
You might notice:
- A slippery, slimy buildup inside toilet tanks
- The smell is stronger at some faucets than others
- It gets worse after the home sits unused for a day or two
Often, sulfur comes with iron
A lot of SE Wisconsin wells have sulfur and iron together. That’s why some people also deal with orange staining, black gunk, or metallic taste at the same time. If iron is part of the problem, you want a system that handles both, otherwise you’ll fix the smell and still hate your water.
Is it dangerous?
Most of the time, this is a quality-of-life issue more than a safety emergency. Low-level hydrogen sulfide usually isn’t harmful. It just makes water taste bad, smell worse, and can be rough on plumbing over time.
But here’s the important part: you can’t diagnose this by smell alone.
Two wells can smell the same and have totally different issues behind it. That’s why testing matters.
Why is it so common to have rotten egg smell in well water in SE Wisconsin
Our groundwater in this region naturally carries sulfur compounds, and well conditions vary a lot from house to house. Depth, recharge rate, seasonal changes, and mineral makeup all play a role. That’s why your neighbor’s fix might not work for you, even if you live down the road.
It also explains why the “quick fix” stuff rarely holds up.
What people usually try first (and why it comes back)
I get why homeowners try the DIY route. Nobody wants to buy equipment if they don’t have to. But here’s what we see most often:
- Shock chlorination: sometimes helps short-term, especially if bacteria is involved, but the smell usually returns if sulfur gas is still present.
- Drop-in tablets or pour-in treatments: can mask odor for a bit but don’t treat the entire house.
- Basic carbon filters: might work briefly but get overwhelmed fast when sulfur (or iron) is high.
They’re fine as a temporary band-aid. They just don’t solve the root problem.
What actually works long-term
Most sulfur odor problems in Wisconsin wells are best solved with oxidation and filtration. That sounds technical, but the concept is simple:
- We change the sulfur into a form that can be trapped.
- We filter it out before it reaches your pipes and fixtures.
Oxidizing filter systems
This is the workhorse solution for rotten egg smell. It doesn’t just hide odor, it removes it.
And when sulfur and iron show up together (which happens a lot here), these systems can take care of both at the same time. That’s usually the difference between “it’s better for a while” and “it’s gone.”
If the smell is only in hot water
When odor only shows up on the hot side, we look at the water heater first. Sometimes the issue is happening inside the heater, and fixing that can solve the smell without adding a whole-house filter you don’t need.
How do we figure out the right fix for your rotten egg smell in well water
We don’t guess. We test.
A proper well water test shows:
- How much sulfur is in the water
- whether bacteria is involved
- iron and manganese levels
- overall mineral balance
Once we have that, we can recommend the simplest system that actually solves your specific problem, not a generic “sulfur filter” that might be wrong for your well.
Ready to get rid of the smell?
If your well water smells like rotten eggs, let’s stop the guessing and fix it the right way.
Schedule a free Water Doctors well-water test.
We’ll pinpoint what’s causing the odor and walk you through the best permanent solution for your home.
Frequently Asked Questions
Why does my well water smell like rotten eggs all of a sudden?
Most of the time the smell comes from sulfur in the well, either hydrogen sulfide gas or sulfur bacteria. It can show up “out of nowhere” because groundwater shifts seasonally, after heavy rain, or when the water sits longer than normal. If the smell started recently, it’s a good sign that something changed in the well or plumbing, and a quick test will tell us exactly what.
Why does the smell only happen when I use hot water?
If the rotten egg smell is only on the hot side, your water heater is often the culprit. Some heaters create a reaction between sulfur in the water and the anode rod inside the tank. That reaction can produce a strong sulfur smell even if cold water is fine. In some cases, fixing the heater solves the problem without needing a whole-house system.
Can sulfur water make you sick?
Sulfur odors are usually more of a nuisance than a health risk, especially at low levels. It won’t normally make you sick, but it can make water taste terrible and can be rough on plumbing and appliances over time. The bigger concern is that sulfur smells can sometimes come along with other well issues like bacteria or iron, that’s why testing matters instead of guessing.
Will boiling my water get rid of the sulfur smell?
No, boiling doesn’t remove sulfur. In fact, it can make the smell worse because heat releases hydrogen sulfide gas faster. If you’re smelling rotten eggs, boiling is not a real fix. You need treatment designed to remove sulfur at the source.
What’s the best filter for rotten egg smell in well water?
In SE Wisconsin, the most reliable long-term fix is usually an oxidizing filter system. It removes the sulfur instead of masking it, and it often handles iron at the same time (which is a common combo here). The right system depends on your sulfur level and whether bacteria or iron are also part of the problem, that’s why we start with a water test first.
How do I know what kind of sulfur problem I have?
Smell alone won’t tell you. Two wells can smell the same and need different solutions. A proper test checks sulfur level, bacteria presence, iron/manganese, and overall chemistry. Once we see those results, we can recommend the simplest permanent fix for your home.
Common in SE Wisconsin Wells
This rotten egg smell shows up a lot in our area because of the way sulfur naturally occurs in local groundwater. We see it regularly in wells across Waukesha County, Jefferson County, Racine County, Walworth County, Washington County, and into parts of Dodge and Milwaukee Counties.
If you’re on well water in places like Muskego, Brookfield, Menomonee Falls, Oconomowoc, Sussex, Merton, Hartland, Lake Country, Burlington, Waterford, and the surrounding communities, and your water has that sulfur smell, it’s a familiar problem for us — and one we can solve with the right test and treatment.