Sewer Gas Smell Explained: Causes, Risks, and the Fastest Way to Get Rid of It

Nothing disrupts your home like a foul, lingering odor. If you notice a scent similar to sulfur, rotten eggs, or decay, you may be dealing with a sewer gas smell. This issue is more than just annoying. It can indicate plumbing problems, potential leaks, or even sewage buildup hidden somewhere in your system.

Sewer gas contains hydrogen sulfide and methane. In small amounts, it doesn't smell good. In larger quantities, it can cause headaches, nausea, or lightheadedness. If the odor becomes strong or persistent, it is important to investigate quickly.

In this guide, we’ll help you recognize the scent of sewer gas, uncover the common sources behind it, show you how to address it, and explain when professionals should step in to handle the problem safely. Let’s dive in!

What is Sewer Gas?

Sewer gas is a mixture of toxic and foul-smelling gases that can escape from your home’s plumbing system when something isn’t working properly. It’s often made up of hydrogen sulfide, methane, and ammonia — all of which have strong odors and can be harmful in high concentrations. Even a small leak can make your home smell unpleasant and signal a deeper plumbing or ventilation issue that needs attention.

Most people describe sewer gas as:

• Rotten eggs
• Sulfur or burnt match smell
• Musty or stale bathroom odor

If the smell comes and goes, the issue may be minor, such as a dry drain trap. However, if it’s strong, spreads through multiple rooms, or becomes noticeable at certain times of the day, the problem may be deeper within your plumbing system. It’s important to address it early to avoid potential health risks or damage to your home.

When sewer gas enters your home, it’s usually a sign that something has gone wrong with your plumbing seals, venting, or drainage. Below are the most common culprits:

• Dry P-Traps: When a drain isn’t used often, the water inside the P-trap evaporates, removing the barrier that blocks gases from entering your home.
• Damaged or Loose Toilet Seal: A cracked or deteriorated wax ring beneath the toilet can let gas escape around the base.
• Clogged Drains or Vent Pipes: Blockages prevent air from flowing properly through your plumbing system, creating pressure that forces gas back into your home.
• Leaky or Broken Sewer Line: A damaged underground line can allow sewer gas to seep into walls, crawlspaces, or basements.
• Sewage Backup: Wastewater that sits in drains or floors can emit a strong, persistent odor until it’s professionally cleaned.

If you suspect sewer gas in your home, don’t ignore it. These odors can signal more than a minor inconvenience, they could point to a serious plumbing issue or even a health hazard. Professionals can inspect the problem, locate the source, and ensure your home is safe and odor-free again.

How to Get Rid of Sewer Gas Smell

You can start with these steps:

• Run water in every rarely used drain to refill traps
• Pour baking soda and vinegar into drains to loosen buildup
• Clean hair and grime from the shower and sink strainers
• Press gently around the base of toilets to check for leaks

If you notice wet flooring, bubbling paint, or discoloration near plumbing fixtures, trapped moisture or a hidden backup may be to blame.

How to Prevent Sewer Gas from Returning

• Keep water flowing through all drains: Even unused bathrooms should be flushed or run weekly.
• Watch for loose toilets: Movement or rocking usually means the wax ring needs replacement.
• Clean drains monthly: Use enzyme cleaners or a vinegar rinse to prevent buildup.
• Cap unused plumbing lines: Old or disconnected fixtures can become direct openings to the sewer system.
• Control moisture in basements and crawlspaces: Damp areas intensify odor and may signal a leak.

If you follow these steps and the smell continues, it is no longer a surface issue. The problem may involve hidden water damage or sewage contamination.

When to Call in the Professionals

If you suspect a sewer gas leak, the first step is determining the source. A licensed plumber can help identify and repair plumbing-related issues such as cracked pipes, loose seals, or blockages in your system.

However, when the problem goes beyond simple repair (especially if sewage has entered your home or left behind lingering odors, moisture, or contamination), that’s when Restoration 1 of Cary becomes essential.

We handle the part that plumbers don’t.

Restoration 1 of Cary specializes in:

• Sewage cleanup and waste removal
• Water damage restoration
• Odor elimination at the source, not just masking it
  

Our team uses industrial drying systems, sanitation equipment, and professional deodorizing solutions to safely clean affected areas and ensure no harmful bacteria or smells remain. We focus on restoring both health and comfort, so your home feels safe to live in again.

Take Action If You Smell Sewer Gas

Whether the odor is faint or overpowering, the sewer gas smell in a house should never be ignored. Small issues can quickly turn into costly and hazardous problems if not addressed.

Call Restoration 1 of Cary today for cleanup or odor removal services. We will locate the source, sanitize your home, and restore fresh, clean air so you can breathe easy again.