Several factors, such as faulty vents, dry drains or improper seals, can cause a septic tank to emit odors inside a home. Common plumbing problems that give off sewer smells occur when the water in drain traps dry out.
Water sits in the curve of U-shaped pipes and traps sewer gases, preventing it from escaping up through the toilet or sink opening. A blocked opening of a tank vent prevents the release of sewer gas to the outside air. Common obstructions include debris, animals, hardened waste or faulty equipment. Leaks in the seal of the ejector or sump pump allow sewage odors to enter into the home as well.