Why do septic systems malfunction?

By Karen Mancl, Professor Food, Agricultural & Biological Engineering

A soft, smelly spot in the yard or sewage backing up into the home are obvious signs of a septic system malfunction. Other failures are not always apparent, however, and can result in untreated wastewater contaminating streams, ditches, or groundwater. In these cases, the property owner may not even be aware their system is creating a public health concern.

Malfunction or failure?

Systems that are not functioning properly can either be malfunctioning or failing. Malfunctioning systems are those that were properly designed and installed but are not operating as designed. Issues with malfunctioning systems can usually be easily resolved to bring the system back into compliance. A failed system is one that was not properly designed and/or installed, has been used improperly, or has reached its maximum lifetime of about 20 to 30 years. Failing systems require major renovation or replacement to be brought back into compliance.

Prevent system malfunction

The soil in the yard must accept and treat all of the water coming out of the house. To avoid a system malfunction:

• Avoid excess water use. Don’t use more water than the system was designed to use. Systems are designed based on the number of bedrooms in the home. A 3-bedroom home is designed to treat less than 300 gallons per day.
• Space out water-using activities such as laundry and showers
• Promptly fix water leaks
• Be careful when changing landscaping
• Ensure that excess water from sources outside the home is not entering the system
• Don’t drive or pave over the system
• Install risers and inspection ports. Install small inspection ports at the end of each lateral line to check for ponding. Install risers over the septic tank to enable easy inspection and septic tank pumping.
• Get regular professional inspections. An annual quick inspection of the lateral lines can reveal problems. If ponding is present, check for excess water use or changes in drainage of rainwater on the lot
• Check septic tanks for damage, clean filters and pump when needed.

Prevent a system failure

Most failures can be avoided at the time of construction. The soil, which is the most important portion of any septic system, must be carefully considered and protected during and after construction.

• Hire a trained soil evaluator
• Install the system when the soil is dry. Construction in wet soil can result in soil compaction and smearing that reduces the ability of the soil to absorb and treat wastewater
• Do not pipe sewage to the ditch or storm sewer. This practice will only move untreated sewage to Ohio’s streams and lakes.

System failure is a difficult situation that may require a property owner to make major modifications to a system or to install an entirely new system. Work with your local health department to determine your options. In Ohio, about 25% of septic systems are malfunctioning and polluting the environment. By carefully using water and having a trained service provider check and maintain the system, all rural residents can protect the health of their family, neighbors and Ohio’s stream, lakes and groundwater.

To find out more about septic system maintenance check the website for the Ohio State University Soil Environment Technology Learning Lab at setll.osu.edu.