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.

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  1. There’s a smelly spot on my backyard. I think my septic tank is failing because it’s been years since I last had it maintained. It’s true that system failure is difficult to do by myself, so I’ll hire a repairman to fix it for me.

  2. That’s a good point that you need to be careful when you change landscaping with a septic system on the property. My cousin has a septic system that has a lot of issues. They will probably have to get a septic professional to take a look at it. That way they can maintain it and avoid worse problems in the future.

  3. I believe that it’s time to replace my septic system because I’ve been calling people to repair it, but leaks still happen. As you’ve mentioned, it’s reached its maximum lifetime already. For this reason, I should probably hire someone to do it so that I can continue using one.

  4. My friend told me that he did not remember that the house where he lives has a septic system and now, the septic tank is damaged. I totally agree with you when you said that failing systems require major renovations. I will recommend him to contact a septic service company so that they can repair it or replace it.

  5. I like what you said about fixing leaks in your septic system so that you can avoid further issues. My sister has been telling me about how she wants to make sure that her home is working properly in the coming months. I’ll share this information with her so that she can look into her options for professionals who can help her with this.

  6. Thank you for telling me to be careful if I were to do some landscaping on our yard where our septic system is. I’m thinking of redesigning our lawn and turning it into a good nice landscape, but I think I need to take care of my septic system first. I’ll try to hire some professionals who can check if we need any pumping services.

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