Sewage Smells From a Septic Tank When It Rains

Heavy Rainfall

• Too much water in your septic system's leach field, or draining area, causes it to slow down or stop treating sewage and other effluents. In a worst-case scenario, the waste material could back up into the house, creating a huge mess. A leach field may work well when the ground is dry, but rains may saturate it and not allow effluent to leach out into the soil. If you have previously smelled sewage after a rainfall, try to reduce septic use when the ground is very wet. This includes not doing laundry or taking baths or showers.

Other Signs of System Failure

• Bad smells after a rainfall are only one indicator of problems with the septic system. Other things to look out for include slow drainage of sinks, tubs, showers or toilets. If the grass is always greener over the septic tank, as humorist Erma Bombeck once wrote, that is a warning sign. This is especially true if the grass is exceedingly lush in the leach field after heavy rains. A well-functioning septic system does not smell, so odors at any time bear professional attention.

Septic Basics

• All wastewater and effluent from your house feeds into the septic tank. The actual tank has baffles to retain any solids, but water flows into the leach field. To allow it to work properly, keep the leach field free of any heavy objects, such as parked cars, playground equipment or sheds. Underground, the leach field contains a pipe with perforations inside a trench filled with gravel. The wastewater flows through the area and the soil absorbs it. The natural soil absorption filters out small particles and cleanses the water as it percolates down. Before construction, soil testing is done on septic-dependent areas to see if the parcel will "perk," or percolate.

Flooding

• If your area experiences flooding and you already have issues with the septic system after a rainfall, this could spell real disaster. The wastewater from your house cannot enter the ground, bringing insects and possibly disease. If the flooding is limited to your property or one or two neighbors, you may be able to remediate, but larger scale flooding may not permit remediation. If you have sufficient property, it may be possible to find another leach field area.