A plumbing customer in Ripon recently asked us if she should be worried about the rotten egg smell coming from her kitchen sink.

If your water smells like rotten eggs, the culprit is likely hydrogen sulfide gas that has been produced by hydrogen sulfide bacteria. Although the smell usually isn’t a hazard, infants can be affected by it. They may become dehydrated from its mild laxative effect.

Of course, no adults want to drink rotten egg water, even though it isn’t technically harmful. Plus, the bacteria can cause black stains on your plates and cutlery, and cause a build-up in your pipes. You’ll need a professional to discover exactly where the bacteria has come from to clean it. Depending on your water system, there are a few possibilities.

Where are the Bacteria?

Depending on your water system, the bacteria may have gotten into your water through a few different paths. Sulfide bacteria occurs naturally in the ground, so if you have a well, the bacteria may have naturally seeped in through the ground or groundwater.

Those who don’t have wells are most likely to have grown the bacteria in their hot water tank, which can create the perfect conditions for the bacteria. Heat, close access to corrosive metal and water softeners can all support the bacteria. In fact, hot water heaters that are rarely used, like at your vacation spot, are also more likely to harbor the bacteria, because the water sits for a long period of time.

If your home is connected to a city’s water system, it’s quite possible that the closest water plant or the city’s pipes have become infected with the hydrogen sulfide bacteria. If that’s the case, your neighbors should also experience the smell. If they do, you’ll have to alert the city so they can clean out the bacteria. After they have done so, you’ll also have to remove the infection from your own sewage system.

In rare cases, the bacteria may have gotten into your plumbing through a sewage leak. It’s critical to have a plumber check to ensure you don’t have a leak before they start cleaning out the bacteria—or your system will just become infected again.

How Do I Clean My Water?

If the bacteria is in your own system, it’s just a matter of cleaning it out. If you get your water from a well, then you will need to add a new purification method to your well-water regimen. There’s no way to eliminate the bacteria from the ground, so you’ll have to filter it out of your water or kill it with chemical or UV treatments.

Normally a well treatment plan should filter out this bacteria, with all other bacteria, so if your well water isn’t doing that, there may be more harmful bacteria that is also bypassing your filter system. If so, it’s wise not to drink from the well until you have a plumber come look at your filter and purification system.

If your problem is in your hot water tank, then you can have a plumber clean out the tank with a full or partial flush. The plumber will drain the water from your tank and use a special chemical solution to kill the bacteria.  Or, as this bacteria needs corrosive metal to make the foul smelling gas, you could also replace your hot water tank’s metal rod with an aluminum or zinc rod to reduce the smell. This doesn’t kill the bacteria though.

The best long-term solution to stop your water from smelling like rotten eggs is to have a plumber find where the bacteria is hiding and kill it with a chemical treatment. Then, your water will get back to smelling clean.