What Causes Smelly Tap Water and How Can You Fix It?

What’s Causing Your Smelly Tap Water?

There’s probably a pretty distinct offensive odor you’re dealing with if you’re asking what causes smelly tap water. There’s no shortage of funky smells water can have but most of the smells fit in the categories below. Here are the most common smelly water problems you’ll run into and the best solutions for each.

What Causes Water to Smell Like a Swimming Pool?

Chlorine and chloramine are commonly added to public water supplies in order to disinfect them and prevent bacterial growth. While it’s perfectly safe at the levels used by public utilities, the smell doesn’t inspire most people to want to keep up with their hydration habits. Also, the use of these chemicals can react to organic material and create disinfection byproducts like trihalomethanes (THMs). Disinfection byproducts can be dangerous with enough exposure to them.

If your water supplier uses chlorine, it's fairly easy to remove. Most activated carbon water filters  can reduce chlorine, including simple water filter pitchers. Increasingly, water companies are using chloramines as a secondary disinfectant because they don’t break down on the trip through the pipes. This resistance to breaking down also makes standard activated carbon filters ineffective at removing it. If you have chloramines in your city water, you’ll need a specialized carbon filter known as a catalytic carbon filter or a reverse osmosis filter.

Our Upstream 4-Stage Whole House Water FIlter uses catalytic carbon for this reason.

If you have a private well that you’ve recently had to shock chlorinate with bleach, the scent should weaken. If it’s still very strong, try to flush your plumbing system by running all of your taps for several minutes. If this doesn’t work, you may need to call in a professional.

Chlorine does dissipate when exposed to air. So, if you’re worried about consuming your water, you can leave it exposed to air in a well-ventilated location until the smell goes away. Pouring it back and forth between containers can speed this process up.

What If My Water Smells Like Rotten Eggs?

The sulfur smell is a problem shared by many. It’s usually caused by hydrogen sulfide gas which is poisonous and flammable. This gas can make you sick at a high enough concentration, but the stench is so bad that you’ll probably distance yourself before it hits critical levels.

The smell is most likely produced by decaying organic matter deep in the earth or by sulfates in your water. There are three common sources of this gas which all have different ways of dealing with them.

Do You Have a Private Well?

If you have a private well, you might be very familiar with this sulfur smell. This gas often forms deep underground where these wells are drilled. Luckily, chlorine can make short work of hydrogen sulfide in well water.

When chlorine meets hydrogen sulfide, the stinky gas is oxidized and turned into a yellow solid that can be easily removed by a sediment filter.

If the well is not new but the odor is, you may want to check the integrity of your well or a nearby septic tank. If your well is not properly sealed, it could be contaminated by an outside source.

Just because private well owners will deal with this most often doesn’t mean those with city water are immune. If you have a public water supplier, check out these next two options.

Is the Smell Coming from Your Water Heater?

If it’s coming from your hot water heater, you’ll either need to replace the magnesium anode or disinfect the inside with bleach. These can be tricky and dangerous options that could also decrease the lifespan of your hot water heater. Make sure to get proper help if you aren’t confident in your ability to safely perform these actions.

To find out if it's coming from your hot water heater, simply check if your hot water smells worse than your cold water. If the foul odor is just coming from your hot water, you know the culprit. This usually only happens if the heater isn’t turned up to a high enough temperature or if it’s been turned off for a while.

Is the Smell Coming from Your Drain?

If the odor is only happening in one location in your home, it could be your drain. Pour a glass of water and take it to another room. Does it smell? If not, it’s most likely your drain. Food, hair, and other debris can get into your drain and attract smelly bacteria.

If you find it's your drain the odor is coming from, you can disinfect it with baking soda and vinegar. Just pour 1/4 cup of baking soda down the drain and an equal amount of white vinegar and let it foam for 10 minutes.

While the foam works its magic, boil a large pot of water and carefully pour it down the drain. This should clean out all the bacteria-producing nasties and the stench they brought with them.

What Causes Tap Water to Smell Metallic?

Metal from water mains, plumbing, and fixtures can alter the smell and taste of an otherwise enjoyable glass of clean water. This is especially true if there’s corrosion in the pipes. Iron, manganese, and other metallic contaminants can also be leached from the ground.

If your tap water smells metallic, point-of-use reverse osmosis is the best way to go. Point-of-use means the water filter is the last thing to touch your water before it hits your glass. A good example would be an under-sink water filtration system.

If you have very hard water and are noticing rust stains on your surfaces, a whole house water softener could be even better for you. Water softeners can reduce iron in your drinking water as well as calcium and magnesium.

What Causes Your Tap Water to Smell Fishy, Earthy, Swampy, or Musty?

Many people describe an earthy or fishy odor coming from their faucet. While this is usually harmless, when your water tastes and smells like it came from a swamp, it’s not very pleasant to drink.

The source of the odor is usually organic matter in the source water your utility is using. As plants and algae grow and die, their odor and taste can stay in the water even after water treatment.

The best way to deal with this is a reverse osmosis water filter. Or if you’re in a pinch, a twist of lemon.

What Causes Tap Water to Smell Like Gasoline or Oil?

This is another problem that is mainly suffered by private well owners. While rare, if your water smells like gasoline or oil, it could indicate a serious problem. You should refrain from drinking your water in this instance until you can get to the bottom of the issue.

A gas or oil smell could indicate a local spill that's contaminated your groundwater. You should report the problem to your local health department and find out if anyone knows of a recent spill or contamination. If no one can give you answers, perform a water test and report your findings to local authorities so you can get to the source of the odor and deal with it.

If you have city water and it suddenly smells like gas or oil, contact your water supplier immediately and report the problem. Do not drink the water until you know it's safe.