When waste decays inside your sewer pipes, the consequences can be severe. Besides causing unpleasant sewer odors, rotting waste and residue can lead to gases such as hydrogen sulfide, ammonia, and methane leaking into your residence. These gases can cause severe health ailments, including headaches, memory loss, poisoning, and asphyxiation. If the problem is severe enough, it could cause a house fire or even an explosion.
Did you know: Sewer gas odor and natural gas odor can both remind you of rotten eggs.
If you believe your home or office is experiencing a sewer gas leak, it’s important to call a professional immediately. This repair isn’t something that should be put off. To help you determine if you have a severe problem on your hands, we’ve outlined some of the common sources of sewer gas leaks:

Time for sewer line repair?
1. Sewer or Septic Pipe Leaks
One common cause of sewer gas leaks comes from damage to your sewer or septic pipes. Your pipes could be leaking from rust, corrosion, a blockage, or holes along the pipes or pipe joints. Common blockages tend to be caused by tree roots, grease, and items that shouldn’t have been flushed down the drain.
The solution your plumber will use depends on the exact cause of the leak or damage to your sewer pipe. Generally, the first step is to use a plumbing camera to detect the exact location of the leak. Your plumber may also use dye or steam to make the leak appear above ground. Once the cause is determined, your plumber may suggest hydro-jetting your pipe, replacing the sewer line, or another solution.

Camera inspections save pipes
Isn’t just for artists
2. Toilet Sewer Gas Leaks
The seal on your toilet might be slipping due to anchor bolts not being attached properly or an old wax ring that needs to be replaced. It’s normal for loose connections to happen over time, and rubber linings tend to wear away.
If you suspect a gas leak because of your toilet, have your plumber go over each area of the appliance. They should also check the mounting nuts and supply tubes. If there is a crack in your toilet, you may need to replace the fixture.
3. Drain Traps
The drain trap generally works by keeping sewer gasses out of your home. It should be tight enough to form an airlock. If a drain trap becomes dry or clogged, it can pass sewer gas into your home. A couple things make this issue worse:
- Cold air outside
- When vents diminish a building’s indoor air pressure
One easy fix that may work is to pour a quart of water down each of your drains. If that doesn’t get rid of the odor, it’s time to call a professional.
4. Roof Vent Pipes
Similar to a drain trap, vents allow sewer gas to leave your home through your roof, rather than going elsewhere. It helps with the pressure of your plumbing system, but if your drain trap is blocked and your home isn’t properly vented, it could cause unsafe conditions. Check all the vents on your roof to keep them free of leaves, animal nests, and ice.
A couple of other reasons vents fail include:
- Corrosion
- Loose fittings
- Vents located in incorrect places
- Not enough vents
Generally, keeping your roof clear can help you avoid issues with your roof vents. If you do run into a problem, a professional can go through the pipes carefully. It is possible to clean every part of the vent until they reach the roof by disconnecting the pipes.
5. Partial Septic Blockage
If your pipes become clogged, they can produce an odor both inside and outside your home. You’ll usually notice the sewer smell during times of heavy water usage or if it’s very windy outside because the gas is forced toward areas that it wouldn’t normally occupy.
Avoid this by flushing only items that are meant to go in the toilet: waste and toilet paper. Things like baby wipes, dental floss, toys, cat litter, and other foreign objects can cause partial or full septic blockages.

Pro Tip: Even if it says “flushable,” it’s not!
6. Frozen Septic Fields
If a septic system is not in use for a long period of time, it’s possible for it to freeze. When this happens, the ice often clogs your whole septic system, causing it to back up completely. This normally transpires in the lowest area of your home.
During the winter, you can reduce the chances of this happening by placing mulch over the system. If it does freeze, call a professional, so they can locate where the ice is. In some cases, a plumber may not be able to fix it right away, but you can use it as a holding tank until the weather warms up and the freeze thaws.
If left unchecked, sewer gasses can be harmful to your health, home, and your plumbing system. If you smell unusual odors or sewage, it’s important to call a plumber straight away. If you suspect the levels of sewer gas in your home are high or have a sewer gas detector that shows signs of a problem, you and your family should leave the premises and contact the fire department. Don’t turn on appliances or light matches; even a small spark could cause a fire.
If you suspect you have a sewer gas leak or another serious plumbing problem, call the professional technicians at CW Service Pros. We serve Lewisville, Allen, Plano, and the surrounding areas with efficient, trustworthy work. We would be happy to help fix your sewer leak or other cause of sewage gas to ensure your home is safe. If you’re experiencing any of the above issues or smell gas or sewage, call us 24/7 at 972-395-2597.