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.
Sometimes, a householder can experience unpleasant odors emanating from their water supply. The cause of this odor can be hard to discover with a water test, and a more thorough investigation may be required. In this article, we will take a closer look at four of the most common unpleasant water odors and what they may mean.
How to Locate the Odor
This may seem simple. After all, the water smells bad, but in actuality, this may not be the case. The sink drain, plumbing fixtures, and other factors may be the source of the foul odor and not the water. The best way to check is to run the water from your faucet for a few minutes and pay close attention to the odor.
If the smell seems to dissipate after a couple of minutes, the source of the odor could be located in your home plumbing system. But, if the odor is persistent, the source could be the water or a combination of the water and your plumbing system. If the smell is only noticeable at a single tap, then it’s likely that you have a problem with that particular fixture. If you can smell the odor at every plumbing fixture, the problem is more widespread, and the water supply could be to blame.
If you find that the bad smell is only present when you’re running the hot water, it’s likely that the magnesium rod in your water heater is failing. If the smell is present when running the hot and/or cold tap, it’s likely that your main water supply is the cause. If you’re a well user, the source of the bad smell is located in your well water supply system.
- Chemical, Bleach or “Swimming Pool” Odor
Most public water suppliers disinfect water use chlorine or chloramine (chlorine and ammonia) to remove any bacteria or microorganisms. Chlorine has traditionally been highly effective in this role, and a typical level of chlorine would be 2-5 ppm (parts per million). If water is exposed to air for a few minutes, the chlorine odor tends to dissipate quite quickly. But, the levels of chlorine can vary a great deal, and they tend to be more noticeable if your home is located closer to the water treatment plant. Chlorine can interact with certain organic materials that may be present in the plumbing system. If your well is affected by a strong chlorine odor, the system should be flushed by a professional. If your problems lies with a municipal water supplier, contact them about the problem.
- Moldy, Musty, Earthy or Fishy Odors
These types of odors are often caused by organic material that is decaying in the drain. If you’re a well water user, you may have some surface drainage pollution. In both cases, the odor is caused by bacterial growth, and the water will be extremely unpalatable. To confirm that the smell is not in the well, fill a glass of tap water, swirl the water a few times, and if there is no odor in the glass, the problem lies in the drain. The solution is the clean, disinfect, and flush the drain line to remove the odor. Another possible cause is the water reservoir or pressure tank where bacteria can grow to cause a foul odor. Sometimes algae, bacteria, and fungi can be growing in your water supply, and this is especially noticeable during hot weather. If you have a problem like this in your well, shock chlorinate, flush with water until the odor dissipates, and consider an automatic chlorinator or activated carbon filter. If the problems lies with your water supplier, inform them about the problem.
- A “Rotten Egg” Odor
This type of sewage or sulfurous odor is usually caused by bacterial growth from a number of possible sources. The most likely source is bacteria growing in the drain due to organic matter accumulation. This bacteria can create foul odors that smell like rotten eggs or raw sewage. Ensure that the source of the odor is coming from one or more faucets and the hot or cold water, as discussed earlier. In many cases, you can solve the problem by disinfecting and flushing the drain with clean water. If you have a sulfurous smell in your hot water only, the problem lies in your water heater. This can occur if the hot water hasn’t been used for a while, perhaps when you return from a vacation. Another possible cause is a water heater thermostat that is set too low. Replacing the magnesium rod in the water tank may fix the problem, but if it persists and you have well water, check that the septic tank is not located too close to your well. The bacteria that create these types of odors are not harmful to health, but most people are very sensitive to this smell.
- Gasoline, Turpentine, Petroleum
These types of foul odor problems are less common, but they can be very serious. The most common causes are pollution from agricultural or industrial runoff or a leaking fuel tank near your well. If you experience any of these odors in your water supply, you must stop drinking and using your water immediately. Consuming water contaminated with these contaminants can cause a number of health problems, including liver problems, kidney issues, increased cancer risks, and anemia. It’s important to report this issue to your local health authority and take steps to correct the problem. Once the pollutants have been removed, consider installing an activated carbon filtration system that can handle the problem. If you are using public water and you notice these odors contact your water supplier immediately.
If you have a foul odor in your water, it’s important to take steps to identify the cause and deal with the problem. These issues never get better on their own, and they need to be dealt with to get your water quality back to normal. If you’re using public water, ask your neighbors about their water quality, and you may discover that they are suffering from similar problems.
If you’re concerned about the hardness of your drinking water supply, contact a local water treatment specialist for expert advice.