The olfactory sense, or your sense of smell, is one of the most powerful senses humans have. Odors, aromas … smells … conjure memories that affect how we react and behave. So when a smell is unpleasant, the sniffers respond and react with an immediate behavior. And with sewer gas smells, the behavior is usually to remove themselves from the foul-smelling location. If that location is your business – or worse – your restaurant, you might just lose a paying customer. And, what could be worse, turn off some very loyal and hard-working employees!
About the sense of smell
You might not realize that smell, just like the sense of taste, is a chemical sense. Your nose detects chemicals in the environment and the chemicals dissolve in the mucus on the roof of the nose. Underneath the mucus, olfactory receptor neurons in the olfactory epithelium detect the odor. Those neurons send the message to the brain, which perceives the odor and accesses memories associated with the olfactory sensations.
So, if you are a restaurant and customers come in and smell baking bread, savory entrees, or sweet cinnamon rolls, their mouths water.
On the flip side, if they walk in and smell sewer gas … well, that might trigger a gag and an immediate about face going out the door.
What creates sewer gas and why does it smell so bad?
Sewer gas, is generally a mixture of inorganic gases created by anaerobic (needing no oxygen) bacteria on sewage and sludge. The gas can contain several different component gases:

  • Hydrogen sulfide
  • Ammonia
  • Carbon dioxide
  • Methane
  • Nitrogen
  • Hydrogen

Usually, it is the hydrogen sulfide causing the bad smell. Also this gas is toxic, it usually will not do harm to humans at the concentrations that exist in a building with sewer gas odor problems.
Why does sewer gas become a problem?
Sewer gas becomes a problem when there is a problem with your plumbing. The most common problem is untrapped drains. Traps work by creating a seal to prevent sewer gases from entering the environment. Vents are also used to allow the sewer gases to exit the plumbing system through exits to the outer air. Although drains without traps are often the culprit, you could also get that sewer gas odor from these issues:

  1. A dry trap. If there is a drain with a trap that is not used often, the water creating the seal could evaporate allowing the sewer gases to escape into the room.
  2. A damaged trap. If the trap is cracked, that obviously allows the water to run out, breaking the seal to trap the smells.
  3. A damaged drain line. If the line is cracked or broken, there is nothing to stop the flow of gases through the crack or break in the line. This situation could also allow sewage to actually seep into a basement, crawlspace under your structure and the smell may actually be coming from an accumulation of sewage.
  4. A damaged or plugged vent. IF a vent is not functioning properly, or is damaged, especially if there is not a trap on the line as well, gases escape through the damaged area into the building.

What can you do when you smell sewer gas?
The first thing Fite Plumbing will suggest when you contact us is to check to see if any of the drains are dry. Pour water into them and see if the smell goes away. If it does, great! If it doesn’t, call us at 317-271-5400. Fite Plumbing services both residential and commercial clients and after 20 years, we know what we are doing! We will be able to diagnose the problem and provide you with the solutions and options you need to transform a stinky situation into one where you come out smelling like a rose!