If you rely on well water at home or work, you may have been surprised to encounter a very unpleasant smell when turning on the faucet. Certainly, this can be off-putting, but you also want to figure out the cause and, if necessary, take steps to fix it. Could your water supply have been contaminated somehow, and will this present any risks in the future? Importantly, will you need to perform any well water testing to determine what’s going wrong?

Understanding the Risk

The first thing to remember is that many environmental factors can come into play, and may give well water an unpleasant odor. Some of these factors could cause issues with health, like E. coli infection linked to coliform bacteria.  While others may be less hazardous, but may make drinking, washing or bathing a bit disagreeable. Still, there are almost always treatment options available that can deal with various well water odors, and get things back to normal.

The Nose Test

What kind of smell is it?

Musty Odor

You may notice an earthy or musty smell, indicating that you have some minerals leaching into the water. Lead, copper or iron may be present in the surrounding soil, and if this does get into your well water, bacteria may develop that feed on those specific minerals.

Fuel Smell

You certainly want to take action if you notice a smell of oil or diesel, as this may indicate an issue with an underground tank in the area. Stop using the water and conduct some well water analysis to confirm what you’re dealing with. For sure, this will be quite rare, but you may need to drill a new well into uncontaminated land to take advantage of a cleaner water table. Alternatively, you could have a new lining installed within your existing well but would also likely have to source your water from uncontaminated land.

Something Fishy?

Occasionally, people report a smell that is similar to rotting fish. This may be due to organic metals leaching out from iron ore mixed into the soil. Usually, this is not harmful to health, and once again, this is a rare occurrence.

Rotten Egg Smell

Perhaps the most common complaint in situations like this involves the smell of rotten eggs. This is linked to hydrogen sulfide gas, which is often naturally occurring and may be caused by chemical reactions in the nearby soil. Sometimes, bacteria that feed on sulfur may be present in the well water, although this can cause some tell-tale side effects. After all, sulfur bacteria can lead to slime buildup, which can harden and clog the plumbing system over time.

Dealing with Those Rotten Eggs

So, what do you do next?

Effects of Hydrogen Sulfide

Note that high levels of hydrogen sulfide could be harmful. If this gas is present in your well water, you need to take steps to remove it by venting the well to the surrounding atmosphere.

If you have high levels of hydrogen sulfide gas, you may begin to notice dark stains on the inside of your plumbing fixtures. Metal components may begin to corrode when exposed to high levels of this gas, and this will cause additional costs and disruption in the future.

Ruling Out Pollution

In almost every case, your rotten egg smell is linked to hydrogen sulfide gas, but there is a chance that it’s related to pollution. In this situation, sewage may be leaching into the well, leading to a buildup of coliform bacteria.

Pinpointing the Source

Before you take any action, perform a process of elimination. If the rotten egg smell is coming from the hot water tap, the problem may lie within the water heater. Sometimes, the sacrificial magnesium anode can cause the smell, which you may need to replace. Otherwise, you could disinfect the water heater with chlorine bleach solution.

If the rotten egg smell comes from the cold tap, you should conduct some well water analysis to pinpoint the cause. You can bring in experts to do this and can then take action based on what they say.

Well Water Smells Like Sulfur? Fixing the Issue

Hydrogen sulfide gas may be present in your well due to relatively low oxygen levels. To fix this, you may need to install an aeration system. This system has catalytic carbon to convert this gas into a solid before filtering it out. You may be able to get rid of the smell altogether by adding a “shock” of chlorine.

If you have sulfur bacteria, you’ll need to conduct a full well disinfection. The casing of the well will need to be scrubbed clean using treatment chemicals approved for the job. The water will then need to be disinfected carefully, especially if you need to get rid of any iron bacteria. Usually, you will want to outsource this difficult work to a licensed well contractor to ensure that it is done correctly.

Regular Well Water Testing

It’s important to carry out well water testing from time to time to be on the safe side. After all, you never know when contamination may enter the water table due to human activities elsewhere or natural events. While you can certainly smell rotten eggs and know that you probably have hydrogen sulfide gas in your well, it’s not always possible to taste or smell other contaminants.

Other Risks

Certainly, you’ll want to avoid coliform bacteria like E. coli, which can lead to fever, vomiting or diarrhea if ingested. You should also check for the presence of lead, arsenic or nitrate, and talk with the local authorities in your area to determine any acceptable levels. If you live in an area where industrial or commercial activity is prominent, carry out well water testing to look for the presence of any volatile organic chemicals. Similarly, look for the presence of any pesticides like atrazine, which could be used within agriculture, if your well is close to any working farms.

What to Do Next

So, the first thing to do is pinpoint the source of the smell. If it comes from the well, it will usually be caused by hydrogen sulfide gas, and this can be confirmed through testing. 

Expert Advice

If you are in need of expert help from professional home inspectors, reach out to us here at Pro Inspect Solutions for advice.