Sewer Gas: Definition, Dangers, Health Risks, and More

What is sewer gas? Where does it come from? If I smell sewage in my home, should my family and I evacuate? In this blog post, we’ll cover the basics on sewer gas exposure and what to do if you think you might be experiencing side effects.

What is Sewer Gas?

Sewer gas is a byproduct of the breakdown of natural human waste. Sewer gas is composed of hydrogen sulfide, carbon dioxide, methane, and ammonia; the hydrogen sulfide is what gives sewer gas that intense, “rotten egg” smell. While not toxic in small quantities, sewer gas can cause health issues in larger quantities, as well as create a number of other issues to you, your home, and your plumbing.

Causes Of Sewer Gas

Although sewer gas is caused by the breakdown of human waste and is therefore a naturally occurring process, the presence of sewer gas means that something is wrong with your plumbing system. Below are several common causes of sewer gas. 

• Leaks - Improperly placed pipes or vents, as well as piping that is old or cracked, can result in leaks in the piping where sewer gas can seep out. Blockages can also result in leaks; common suspects include tree branches and items that shouldn’t have been flushed down the drain.
• Loose Toilets - In order to prevent septic gas from leaking out, toilets need to be tightly fastened to sewer lines. Even if your toilet was installed correctly, rubber linings and wax rings can wear away over time; it is normal and common for a sewer gas leak to occur this way.
• Unused or Dry Plumbing - If a sewer system isn’t regularly used, piping can dry up and make room for sewage gas to build up. Because water normally provides a barrier between the gas and the outside world, a dried up pipe or toilet bowl can allow gas to seep in. Additionally, an unused sewer system could also cause your leach field to freeze over (without the constant flow of house-temperature water, the field will freeze). The ice will cause the system to back up completely.

What You Need To Know If You Smell Sewer Gas

What does sewer gas smell like? Many people report that the gas smells like sewage, rotten eggs or decay. While one whiff won’t kill you, sustained exposure to sewer gas can cause adverse health effects.

Symptoms of Sewer Gas Exposure

Can sewer gas make you sick? Is sewer gas toxic? Is sewer gas dangerous? Can breathing sewer gas be harmful? The answer to all four of these questions is “yes” when inhaled for an extended period of time. The following health effects are common sewer gas poisoning symptoms: 

1. Fatigue
2. Soreness or irritation of the eyes, throat, and mouth
3. Dizziness or lightheadedness
4. Nausea or vomiting
5. Headaches
6. Coughing and shortness of breath
7. Memory and concentration issues
8. Loss of smell