Detecting Natural Gas

• Natural gas leaks commonly occur at the connection between gas lines and appliances. Strong odors near gas appliances is a common indicator of a natural gas leak. Other indications include hissing or whistling sounds near the leak. Even if these indications are not present, contact the utility company if you suspect a natural gas leak.
  
  

Preventing Sewer Gas

• Sewer gas has a similar smell to natural gas. The gas accumulates in the sewer lines but is prevented from entering the home by the water in the trap. A trap is a U-shaped segment of pipe below most drains. The water in drain prevents gas from the sewer line from entering the home. If the water in the trap evaporates sewer gas enters the home. Keeping the traps of all drains full of water prevents this. Add a couple of cups of water to each drain in the basement at least once a week.
  
  

Ventilating Odors

• Once water has been added to the traps you can ventilate the basement. Open windows and doors and set up fans to force air out of the basement. Spray deodorants can temporarily mask odors but ventilating and clearing the air is the only way to permanently remove the odor.
  
  

Health Concerns

• Natural gas poses a fire and asphyxiation hazard. Any spark can cause an explosion. Sewer gas is not flammable but does pose a health hazard. Sewer gas causes headaches, tiredness and dizziness in lower levels and can cause death in extreme cases.