What’s That Smell? Common Causes of Sewer Problems
Sewer issues not only cause foul smells but can also lead to health hazards and property damage.
If you’ve ever walked into your home and been greeted by an unpleasant, lingering odor, you know how unsettling it can be. That unmistakable stench is often a sign of a sewer issue lurking somewhere in your plumbing system. As professional plumbers, we encounter these situations daily and know just how disruptive and concerning they can be for homeowners. Sewer problems cause foul smells, pose health risks, and lead to costly property damage if left unchecked. Understanding what causes sewer gas and sewage smells is the first step toward maintaining a safe, comfortable, and odor-free home.
Clogged sewer lines
A clogged sewer line is one of the most frequent culprits behind sewer odors. Over time, everyday materials like grease, food scraps, hair, soap scum, and hygiene products can accumulate inside your pipes. This buildup restricts the wastewater flow, causing it to back up and release unpleasant smells through your drains. If you’ve ever wondered, “can a clogged drain cause sewer smell?” The answer is a resounding yes.
Clogs can develop gradually or suddenly, and the resulting blockage can make it impossible for wastewater to exit your home efficiently. When this happens, you might notice slow-draining sinks, gurgling toilets, or water backing up in your tub or shower. These symptoms are not just inconvenient—they’re also warning signs that something is amiss in your sewer line.
Professional drain cleaning is a safe and effective way to tackle these blockages. A licensed plumber uses specialized tools and techniques to remove stubborn clogs, restore proper flow, and eliminate those foul odors for good. Attempting to fix these issues yourself with chemical drain cleaners often worsen the problem and even damage your pipes.
Tree root infiltration
When it comes to persistent sewer smells and recurring backups, tree roots are a surprisingly common offender. Trees and shrubs naturally seek out water sources, and your sewer line is a prime target. Even a tiny crack in the pipe can attract thirsty roots, which will squeeze their way in and begin to grow. Over time, these roots can create a tangled mass inside your sewer line, blocking the wastewater flow and causing sewage smells to seep into your home.
Tree root infiltration is especially common in older neighborhoods with mature landscaping. If you’ve noticed a broken sewer line smell or recurring clogs, roots could be the cause. Left unchecked, root intrusion can eventually cause the sewer line to collapse entirely, leading to major repairs.
A professional plumber can inspect the sewer line using a camera to pinpoint the location and extent of root intrusion. Solutions may include root removal, pipe repair, or even pipe replacement, depending on the severity. Addressing the issue early can save from more extensive (and expensive) damage.
Broken or collapsed sewer pipes
A damaged sewer pipe is another leading cause of sewer gas and sewage smells. Sewer lines are designed to last for decades but are not immune to wear and tear. Age, shifting soil, heavy traffic above ground, and even construction work can all take a toll on your pipes. When a pipe cracks, breaks, or collapses, wastewater can leak into the surrounding soil, creating a breeding ground for foul odors.
Common signs of a broken or collapsed sewer pipe include persistent sewer line smell, slow drains throughout the home, patches of lush grass or soggy ground in your yard, and even unexplained foundation cracks. These issues should never be ignored, as they can quickly escalate into serious health hazards and structural problems.
A licensed plumber can inspection thoroughly to assess the condition of your sewer pipes. Depending on the damage, repairs may involve trenchless pipe lining, spot repairs, or complete pipe replacement. Addressing these problems promptly can help avoid more significant headaches in the future.
Dry p-traps
If you’re smelling sewage in a specific area of your home—especially around sinks, tubs, or floor drains—a dry p-trap could be to blame. P-traps are the curved sections of pipe located beneath your plumbing fixtures. They hold a small amount of water, acting as a barrier to stop sewer gases from escaping into the living space.
When a drain isn’t used for an extended period, the water in the p-trap can evaporate, allowing those unpleasant odors to waft up from the sewer system. This is common in guest bathrooms, basement sinks, or unused laundry rooms.
Fortunately, the fix is simple: run water down the affected drain to refill the p-trap. If the smell persists, it could indicate a leak or another underlying issue. In these cases, it’s best to call a professional plumber for inspection and ensure that everything functions as it should.
Sewer vent blockages
Your home’s plumbing system relies on vent pipes to allow sewer gases to escape safely outside. These vents also help regulate air pressure in the pipes, ensuring wastewater flows smoothly. However, if a vent pipe becomes blocked—by leaves, debris, animal nests, or even snow—sewer gases can become trapped inside your home, leading to persistent odors.
Blocked vents can also cause slow drains, gurgling sounds, and sewer gas from your sink or other fixtures. Clearing a blocked vent is not a DIY job; it often involves working on the roof and using specialized equipment to remove the obstruction safely.
A professional plumbing company can quickly diagnose and resolve vent blockages, restoring proper airflow and eliminating those stubborn sewer smells.
Septic system problems
Unpleasant odors can signal trouble with the tank or drain field for homes with septic systems. Common causes include an overloaded tank, a blocked or failing drain field, or damaged pipes. When a septic system isn’t functioning properly, waste may not be processed as it should, leading to backups, slow drains, and foul smells inside and outside the home.
Routine septic maintenance is essential to prevent these issues. A licensed plumber can inspect your system, pump the tank if needed, and recommend repairs to keep everything running smoothly. Ignoring septic problems can result in costly repairs and environmental hazards, so it’s always best to address them promptly.
Improperly installed or damaged plumbing fixtures
Sometimes, the source of a sewer smell is closer to home than you might think. Improper installation or damage to plumbing fixtures—such as toilets, sinks, or bathtubs—can create openings that allow sewer gases to escape. For example, a faulty wax ring seal around the base of a toilet can let odors leak out, while cracked or poorly fitted pipes can do the same.
If there is persistent sewer smell in a specific room, it’s important to have a professional plumber inspect your fixtures and connections. They can identify any faulty seals, cracks, or installation errors and make the necessary repairs to restore a fresh, clean environment.
Sewer leaks and the subway smell
Have you ever noticed a strong, unpleasant odor in public spaces like subway stations? Often, this is due to sewer leaks beneath the surface. When wastewater escapes from damaged or aging sewer lines, it can create a pervasive, unpleasant smell that’s hard to ignore. This same principle applies in residential settings—if you’re experiencing a persistent sewer leak, you may notice a similar odor around your property.
Professional plumbers have advanced leak detection equipment to locate and repair hidden sewer leaks, ensuring your home remains safe and odor-free.
Why professional help matters
While it might be tempting to tackle sewer smells and plumbing issues alone, these problems are often more complex than they appear. Many causes of sewer gas smell—such as tree root infiltration, broken pipes, or vent blockages—require specialized tools and expertise to diagnose and repair safely.
Working with a licensed plumber ensures that the root cause of the problem is identified and addressed correctly. Professional services resolve the immediate issue and help prevent future problems, protecting your home and your family’s health.
Preventing future sewer problems
The best way to avoid unpleasant sewer smells and costly repairs is through regular maintenance and timely repairs. Here are a few tips to keep your plumbing system in top shape:
Schedule annual plumbing inspections to catch small issues before they become significant.
Avoid flushing anything besides toilet paper down the toilet.
Keep grease, coffee grounds, and food scraps out of your drains.
Have your sewer lines professionally cleaned every few years, especially if you have large trees near your home.
If you have a septic system, follow recommended maintenance schedules for pumping and inspections.
Final thoughts
Sewer odors are more than a nuisance—they’re a warning sign that something is wrong with your plumbing system. Whether a clogged drain, tree roots, a broken pipe, or a blocked vent, addressing the issue promptly with the help of a professional plumber is the best way to protect your home and your health.
If you notice any of the symptoms described above, don’t wait for the problem to get worse. Contact a trusted local plumbing company for a thorough inspection and expert repairs. With the right care and attention, you can enjoy a fresh, clean, and odor-free home for years.
Trust the licensed plumber at Simba Plumbing when in need of leak detection and repair, sink installation and repair, toilet installation and repair, sewer services, water heaters, tankless water heaters, and automotive shutoff valve solutions in Phoenix. Our services are affordable and aim to offer the best results. Call today to book a service and ask about our special offers.
