Does Your Water Smell Like Sewage? How to Identify the Sewage Smell

There’s nothing worse than a foul odor coming from your drinking water and it’s even worse when the smell of sewage is seeping out of your faucet. The sewage smell you’re experiencing, which may also resemble the smell of dirt or rotten eggs, could be the result of a few different factors including, but not limited to, gases in your drain caused by bacteria from food and waste, or an issue with your hot water heater.

The smell of sewage in water is usually down to a buildup of bacteria found in your pipes, usually, a buildup of hydrogen sulfide due to your hot water heater either running at a low temperature or having been out of use for a period of time.

A sewage smell in your drinking water is most often caused by sewer gas escaping into your space through a dry P-trap, a blocked plumbing vent or hydrogen sulfide gas in the water supply. To find the source, check these common problem areas:

• Bathroom/Kitchen: A sink drain smells like sewage when biofilm (a buildup of soap scum and hair) accumulates or the water seal in the U-shaped pipe has evaporated.
• Basement/Production Floor/Breakroom: A sewage smell in the basement or on production floors often comes from floor drains that aren’t used frequently, allowing the protective water barrier in the trap to dry out.

Your water may smell like sewage due to the presence of bacteria from food, soap or other materials sitting in your drain. This bacteria causes a heavy gas to fill the drain near the sink, and when the water is turned on, the gas is forced upwards and into the air around the sink, making it seem like the water smells like sewage.

If the sewage smell in the bathroom is persistent, check your P-traps. The U-shaped pipe under the sink is designed to hold a small amount of water to block sewer gases. If this water evaporates from disuse, the gas can flow freely into the room.

Sometimes, the smell only occurs when using hot water. If this is the case, the it’s likely coming from bacteria growing in your hot water heater. This can happen if your hot water heater temperature is too low or if it’s turned off for a long period.

Additionally, sewage smell in the bathroom could be the result of hydrogen sulfide. The presence of this gas can be toxic, but more than likely it will be detected before reaching a toxic level. People can detect hydrogen sulfide at as low as 0.5 parts per million (PPM).

• 0.5 PPM: The “threshold of detection,” where most people can notice that faint, sulfurous rotten egg scent.
• 1 PPM: The odor becomes distinct and offensive.
• 1-2 PPM: The smell is strong and pervasive; at this level, it can begin to cause nausea or headaches in sensitive individuals.

Although activated carbon filters are effective for hydrogen sulfide levels below 1 mg/L, higher concentrations may require oxidizing media filtration or reverse osmosis.

Beyond the bathroom, odors can plague utility areas. A sewage smell in the basement is frequently caused by a dried-out floor drain. Pouring a bucket of water down the drain can often restore the seal.

Appliances are common suspects for plumbing related odors. If an appliance smells like sewage, it’s often due to mold or bacterial buildup in the drum or drain hose. Similarly, in office environments, biofilm in sink drains or dishwasher lines can mimic sewage smells. High-flow bottleless coolers provide a dedicated, sealed path for clean water to bypass these issues.

To find out if the bad smell is coming from your pipes or from your water, fill a glass with water and move it away from the faucet before smelling it. If it doesn’t smell, the culprit is likely the pipes and drain. If there are bacteria inside your drain, you need to disinfect the sink and pipes using a small amount of soap and a small brush to clean the pipes.

If your hot water heater is the issue, try turning your hot water heater temperature up for up to 24 hours and running the hot water taps to flush the pipes out. Remember to be very careful and proceed with caution if you turn up the temperature of the hot water heater.

Use the chart below to identify why your workplace smells like sewage and find the solution:

While many odors can be fixed with a DIY flush of the pipes, certain signs indicate a bigger problem. You should contact a plumbing or water technology expert if you experience:

• Persistent odors or smells after cleaning
• Weird sounds from the drains
• Widespread odor or sewage smell in or throughout the building

If you have a well as your water source, the hydrogen sulfide may be originating there. If this is the case, you may need to consider contacting your local water testing lab to have your water source tested for contaminants.

For workplaces, guarantee that water smelling like sewage is never a problem. Contact Culligan Quench, and our expert customer service agents will recommend the countertop or freestanding bottleless water dispenser to protect your office.

Get a free quote on any of Culligan Quench’s bottleless water filtration systems today!