There’s no mistaking a sewer smell inside your house. It’s not something you can ignore, and it shouldn’t be something you get used to. If you’re catching whiffs of rotten eggs or raw sewage in your Encino home — whether it’s near a specific drain, in the bathroom, or just a general odor that comes and goes — something in your plumbing system is allowing sewer gas to escape into your living space.
The good news is that most sewer smell issues have identifiable causes. The bad news is that some of them point to problems that need immediate professional attention.
What Sewer Gas Actually Is — And Why It’s Not Just Unpleasant
Sewer gas is a mixture of gases produced by decomposing organic waste in your drain and sewer system. It contains hydrogen sulfide (the rotten egg smell), ammonia, methane, and carbon dioxide. In small concentrations, it’s just unpleasant. In higher concentrations — particularly in enclosed spaces like a basement or an interior bathroom without ventilation — it can cause headaches, nausea, dizziness, and in extreme cases, pose a flammability risk from methane.
The Occupational Safety and Health Administration (OSHA) classifies hydrogen sulfide as a health hazard at elevated exposure levels. While residential sewer gas leaks rarely reach dangerous concentrations, the smell itself is your plumbing system telling you that the seal between your living space and the sewer system has been breached.
The Most Common Causes of Sewer Smell in Encino Homes
Dried-out P-traps. Every drain in your house has a P-trap — the U-shaped section of pipe directly below the drain opening. This trap holds a small amount of water that acts as a seal preventing sewer gas from traveling back up through the pipe. When a drain isn’t used for an extended period — a guest bathroom, a basement floor drain, a utility sink — the water in the trap evaporates, and the seal breaks. This is the simplest and most common cause of sewer smell, and the fix is literally running water for 30 seconds to refill the trap.
Cracked or damaged sewer pipe. If the sewer lateral running under your property has a crack, break, or separated joint, sewer gas can escape through the soil and enter your home through the foundation or through cracks in the slab. This is especially common in older Encino homes where the original clay or cast iron sewer line has deteriorated. We’ve covered how to recognize this in our post on signs of a cracked sewer pipe.
A belly in the sewer line. When a section of sewer pipe sags below the natural flow grade, waste and water pool in the low point. Over time, this standing waste decomposes and generates gas that travels back through the drain system. Pipe bellies are common in Encino properties on hillside terrain where soil movement causes buried pipes to shift over time.
Damaged or missing wax ring on a toilet. The wax ring that seals the base of your toilet to the floor flange can deteriorate, shift, or fail over time. When it does, sewer gas leaks from the gap between the toilet and the drain pipe. You might notice the smell concentrated near the base of the toilet, especially in bathrooms that see heavy use.
Blocked or damaged vent stack. Your plumbing system includes a vent pipe (usually running up through the roof) that allows air into the drain system to maintain proper flow and releases sewer gas harmlessly above the roofline. If that vent is blocked — by a bird nest, debris, or a damaged cap — the gas has nowhere to go but back through your drains and into the house.
What to Check Before Calling a Plumber
Run water in every drain you haven’t used recently — guest bathrooms, laundry sinks, floor drains. If the smell disappears within a few hours, you likely had a dry trap situation and the problem is solved.
Check around the base of each toilet for any dampness, discoloration, or instability when you sit down. A rocking toilet is a strong indicator that the wax ring has failed.
If the smell is persistent, seems to come from the yard or the foundation rather than a specific fixture, or is accompanied by other symptoms like slow drains or gurgling sounds, the issue is almost certainly in the sewer line itself and requires professional diagnosis.
How a Plumber Diagnoses Sewer Gas Issues in Encino
The first step is a sewer camera inspection to visually assess the condition of the drain and sewer lines. The camera identifies cracks, separations, bellies, root intrusion, and any other defects that could be allowing gas to escape.
If the camera reveals pipe damage, the repair depends on severity. Cracks and joint separations can often be addressed with trenchless pipelining, which creates a seamless interior barrier that eliminates gas leakage. More severe damage may require pipe bursting or targeted excavation for a section replacement.
For vent stack issues, a plumber can inspect the roof vent for obstructions and clear or repair it as needed. And if a toilet’s wax ring is the culprit, that’s typically a straightforward replacement — quick and relatively inexpensive.
Don’t Mask It — Fix It
Air fresheners and open windows don’t solve sewer gas problems. The smell is a symptom. The cause is somewhere in your plumbing system, and it’s not going to resolve itself.
At American Plumbing And Water Damage Restoration, we track down sewer smells in Encino homes using camera diagnostics, pressure testing, and decades of experience with the pipe materials and layouts common in this area. We find the source, explain what’s causing it, and fix it.
Call (818) 765-7240 to schedule a diagnostic visit and get that sewer smell out of your Encino home for good.
