Septic systems consist of underground tanks into which all household waste and drain water flows. When a septic system is properly functioning, homeowners should not smell any unpleasant odors inside the home or outside near the tank. However, as part of the system begins to fail, these odors are an early warning sign. Not all septic odors are cause for concern, but both indoor and outdoor odors must be investigated thoroughly.
Walk through the home to determine if the septic odors are stronger in bathrooms or near plumbing that is not used often. This is due to pipe water that has evaporated, allowing odors to rise into the home. Flush any toilets and turn on sinks and showers for 30 seconds to add water back into the pipes.
Close the doors to all bathrooms and other locations where plumbing is located. Leave them closed for one hour then walk around the inside of the home, going into each room. If the septic odor is pervasive in all areas, then the problem is with the entire system, not with any individual drain.
Walk outside the home until you locate the area where the septic odor is strongest. Look at the ground in the area to see if it is soggy or damper than the surrounding soil. If needed, put on rubber boots and walk around. This is an indication that the septic tank is not draining properly and requires professional inspection.
Inspect around the home to detect areas of strong odors that do not have soggy or damp soil. Take notice of whether the odors occur mainly during periods of wind. This is caused when air from the vent stack on the roof, which vents out sewer gas, is blown downward by heavy wind gusts. Have a professional install a charcoal filter on top of the vent to eliminate the odors. If you feel competent, you can install the filter yourself.