Foul Odor

• When your home's septic system causes a foul odor in a drain, you'll smell sewage in a shower or bathroom drain. This usually occurs in bathrooms that go unused for long periods of time, like a guest bathroom or one in a vacation cabin. The smell is strongest right at the drain, but if left unaddressed can spread to fill the room and eventually drift out into the rest of your home. Exposure to the smell can lead to health issues like headaches and nausea.
  
  

Cause

• The reason the terrible smell from your septic system is coming up through the drain is the tap inside the drainpipe has gone dry. The drainpipes in your home contain a section shaped like the letter U. This curving section fills with water whenever you use the drain, creating a barrier between your home and the septic system. The water in the tap slowly evaporates but is replenished every time you run water. If the drain goes unused for weeks, the water can evaporate until the trap goes dry.
  
  

Solutions

• Refilling the trap with water will block the smell of the septic system from getting into your home. Just run the faucet for 15 seconds; that is all the water required. For a guest bathroom, run the faucet every other week to replace any water that has evaporated out of the trap. For a vacation home, place a plug or a cap on drains. This keeps the bad smell out until you visit the home and can run water to fill the trap again.
  
  

Considerations

• The gas coming up from your septic tank does more than make your home stink; it also puts your health and safety in jeopardy. The smell is created by harmful gases like methane. Exposure to it can lead to vertigo and could even knock you unconscious. If enough of the gas builds up inside your home, it can be a fire danger.