With more than 30 years’ experience in the residential and commercial water treatment space, Mark Nelson is a Class 1 Drinking-Water Operator and a CBWA (Canadian Bottled Water Association) Certified Plant Operator. As founder and president of Nelson Water in Ottawa, Mark focuses on dealing with challenging water treatment system designs for problem water. He also heads the largest water bottling plant in the city of Ottawa with a delivery network throughout the Valley.

If you have pure, clean water, it should have no discernible coloration or smell present. If chemicals or minerals have been added to the drinking water during a specific purification process, you may notice a slight taste or smell. But, if you notice that your drinking water has a strong and unpleasant taste and/or smell, this is a sure sign that there is something wrong. Drinking water with a bad smell is unpalatable to drink, but it may also be harmful for you and your family to ingest. In this article, we will take a closer look at three common causes of certain bad smells in drinking water and some ways to deal with the problem.

  1. A Smell of “Rotten Eggs”

If you have a smell of “rotten eggs” in your drinking water, there is an elevated level of sulfur present. When there are high concentrations of sulfur, there is often an overgrowth of bacteria located somewhere in the plumbing line. Locating the source of the smell will lead you to this bacterial growth, and there are three key areas to check.

The Water Heater

Go to the kitchen sink and pour a glass of cold water and a glass of hot water. Then smell each glass of water to determine if either of them has a strong sulfurous smell. If the hot glass of water has a “rotten egg” smell, then the source of the bacteria is inside your water heater. When the set temperature in your water heater isn’t hot enough, it can encourage the growth of bacteria inside the unit. The bacterial growth will typically occur on the heating rod, and this is the source of the sulfur smell. This is a common occurrence in aging water heaters that have magnesium heating rods. A plumber can clean out the water heater and replace the old magnesium rod with a new aluminum rod. If the water heater is beyond repair, it may be necessary to replace it with a new unit instead.

The Drainage Pipes

If your glass of hot water smells fine, then the water heater isn’t the source of the smell, and it’s time to check the drain pipes. Over time a significant amount of material, such as food, grease, and hair, can buildup in your drain pipes. This will promote the growth of stinky bacteria, and this smell will make its way into your water supply. If you sniff the drain, you may detect the sulfur smell if it’s particularly strong. If the drain pipes are the source of the smell, the drains will need professional cleaning to flush and disinfect them.

The Water Supply

If the water heater and the drain pipes are not the source of the sulfur smell, then it’s time to turn your attention to the water supply. If the cold glass of water smelled strongly of sulfur, then the water source could be the cause. If your home is supplied by well water, the well may need to be purified to disinfect any bacteria that may be present. If your home has a public water supply, it’s time to get in touch with them and inform them about the problem.

  1. A Smell of Bleach

If your home receives water from a public supply, then you may get a slight “swimming pool” or bleach like smell, and this is chlorine. The use of chlorine to disinfect water is a tried and tested method, but the smell typically dissipates very quickly when the water is set aside for a minute or two. But, if the water has a very strong bleach smell, then you should report the problem to your local water provider. There are three things that you need to consider if you have this type of smell in your drinking water.

Nearby Sewer Systems

If there is a sewer system located near to your drinking water supply source, you may experience foul smells. This is an unusual situation in newer homes that have been well planned, but if you live in an older home, the water infrastructure may less well thought out. If you have concerns contact your local authorities for advice on the safety of your drinking water.

Well Water Supplies

The water company that services the groundwater supplies that your well draws from could be using a chlorine stock to disinfect the local area. If you have a very strong smell of bleach in your drinking water, contact the company and inform them. It may be necessary to pump out the water until the chlorine smell has dissipated.

Fishy Odors

Another common problem experienced by well water users is a fishy or musty odor. This is caused by the growth of bacteria located close to the water source. The well may need to be shocked with chlorine and then drained until the smell of chlorine dissipates.

  1. Other Types of Smells

There are two other types of water smells that are less common, but you still need to be aware of them.

Fuel Smells

If your drinking water smells like gasoline, this is usually an indicator that there is a high level of iron in the water. If this odor is accompanied by a red tint in your water, then you’re likely to be safe to use it if you can. If the water looks clear, then it may be tainted with gas.

Sewage Smells

This is related to the “rotten egg” sulfur smell that we detailed earlier. This smell is caused by hydrogen sulfide that has grown inside your water system. This bacteria is not an immediate threat to your health, but it will make your drinking water unpalatable to some, and this could discourage them from staying hydrated. Some of the methods detailed earlier will locate the source of the problem and the actions needed to rectify it.

If you are concerned about the smell of your water in your water supply, you should speak to a water treatment professional. A specialist technician can test your water supply and recommend treatment options best suited to the characteristics of your water.