A persistent rotten-egg or sewer gas smell in your bathroom or laundry room is more than an annoyance - sewer gas contains hydrogen sulfide and methane that can cause headaches and nausea. Here is how to diagnose and fix the source.
Sewer gas is a byproduct of decaying organic waste in the municipal wastewater system. It contains hydrogen sulfide (which produces the distinctive rotten-egg odor), ammonia, methane, and carbon monoxide. In addition to smelling terrible, prolonged exposure can trigger headaches, sinus irritation, fatigue, and nausea.
Beneath every sink, shower, bathtub, and laundry drain is a U-shaped bend called a P-trap. Under normal conditions, water sits in this curve to form an airtight seal that physically blocks sewer gases from rising into the room.
In Arizona's ultra-dry desert climate, water inside an unused guest bathroom shower or powder room sink can evaporate completely in less than three weeks. Once the water is gone, sewer gas flows unimpeded into your living spaces.
Every toilet rests on a wax ring that seals the junction between the porcelain base and the sewer drain flange. If a toilet rocks slightly when you sit on it, or if the wax seal dried out over 20+ years of desert heat, sewer gas seeps out from under the baseboard every time the wind blows.
Your plumbing system vents sewer gas out through pipes that exit on the roof. In Sun City West, birds often build nests inside these open roof vents, or severe monsoon dust storms deposit debris inside them. When a vent is clogged, flushed water creates a vacuum that pulls water straight out of your bathroom traps, letting odor escape indoors.
Upfront pricing, fast same-day dispatch, and free camera inspection with every residential service.
Call 24/7: (623) 440-0169Yes, methane in sewer gas is highly combustible in enclosed spaces. If you smell strong sewer odors, extinguish open flames and call for an inspection.
Bleach will temporarily kill surface bacteria, but it will not fix an evaporated P-trap, a broken toilet wax ring, or a blocked vent pipe.
Pour 2 to 3 tablespoons of mineral oil into the drain after running water. The oil floats on top of the water barrier and stops evaporation for months.
