How Long Do Septic Systems Last?

Kenneth Wilson

Wondering how long septic systems last? Septic systems are made and designed to function for many years, but there are several factors that affect the longevity of your septic system. Maybe you cannot help but wonder how long will your septic system last, especially if you know that it has not received any form of maintenance work in decades.

The answer is a little complicated so we will keep things simple so you will really know how septic systems work, and ultimately, how long they last. But first, let’s delve in and get to know more about septic systems.

What are Septic Systems?

Septic systems are underground tanks beneath your home or empty yard. Septic is defined by the dictionary as having been infected with contaminants and microorganisms, and it is indeed true because septic systems store your poop and any other thing you throw in your toilet. Septic systems are connected to your toilet, so literally, everything you flush out of your toilet goes into your septic system. After you flush your toilet, solid waste travels the underground pipes and goes into the inlet of your septic system. There, solid waste such as poo eventually sinks into the tank and forms a sludge. Other contaminants and waste products such as grease float in the wastewater. Septic systems have outlets, a pipe that redirects wastewater from the tank leaving the sludge in the bottom of the tank. After the wastewater goes into the outlet, it then goes into the drain field where wastewater is distributed and drained into the ground which the soil and sand underground filter.

You may wonder if properties with septic systems violate environmental codes, but if they are, septic systems will most likely be banned in the first place. Wastewater from septic tanks is not clean, but they have been separated from dirtier and grosser solid waste such as human poo and are left behind to be eaten by bacteria inside the tank. The wastewater is then filtered naturally underground as rocks, soil, and sand trap the dirt and contaminants leaving behind clean water which eventually tops up the supply of groundwater underground. (Related: Plumbing Terms Every Homeowner Should Know When Remodeling Their Bathroom)

Septic System Lifespan

Septic systems are not permanent and maintenance-free features in your house. A typical household-type septic system generally lasts anywhere between 15-40 years.  There are many factors that affect the lifespan or service life of your septic tank. Here are the major factors in play that determine the longevity of your septic system:

  • How it was installed - septic systems might be simple by the book, but the installation of one is heavy and complex work and needs professional expertise. If you hire someone who does not have the necessary knowledge and experience of handling and installing septic systems, you need to consult an expert to correct the problem as soon as possible.
  • Maintenance and cleaning - as we said before, septic systems are not maintenance-free. Since septic tanks have capacities, you need to call your septic technician every 3 - 5 years or so depending on the capacity of your septic tank and the number of people living in your house. If you are not sure about the capacity of your tank, you can have it inspected by the technicians.
  • Location - certain septic tank locations can be detrimental to your system. If your system is in acidic soil, nearby bodies of water, and old trees, your system might not last long. If your tank is placed in acidic soil, the materials will most likely be damaged. If it is near bodies of water, the excess water from the ground can overwhelm your system. If it is near the location of trees, tree roots might damage the tank. Location is probably one of the most important factors to make your system last longer.
  • Material used - septic tanks are different. Some are made with plastic, some with fiberglass, steel, or concrete. Concrete ones tend to be the most long-lasting septic tank material. Plastic and fiberglass tanks tend to be strong and resistant to acidity, steel is versatile but is affected by soil acidity, and concrete can last forever but is subject to construction quality.
  • Usage frequency - septic tanks are called “tanks” for a reason. They are only meant to store a certain amount of wastewater, sludge, and other solid waste. If you use it too often, it will most likely decrease its service life. If your home houses a lot of people, be sure to have your system replaced with a larger capacity one so you will prevent capacity problems in the future.
  • What goes inside - restaurants and malls often have signages in their comfort rooms telling you to refrain from flushing out tissue and wipes in the toilet. The reason is that these things will most likely cause a clog in the pipes since they do not dissolve inside the tank, or worse, cause a buildup in the tank itself causing severe problems since they do not dissolve inside the tank. Wipes, tissue, napkins, and even diapers are always present in septic systems that are severely clogged, so make sure not to flush them in the toilet to prevent major clogging problems.
  • System Age - if you recently bought a home that had tenants in the past, you might need to call technicians to determine the age of the septic system. The age of the system is often the basis for complete system replacement or upgrades.

If you take care of your system and do all the necessary maintenance activities, your septic system will most likely last for a few decades, and even forever if you have a concrete septic system. Some septic system parts do fail though so you need to make replacements and even parts upgrades whenever possible to keep your system’s lifespan long.

Initial Signs of Septic System Problem

Septic systems fail, that is an indisputable fact. No matter how you take care of your septic system, there would always come a time where your septic system will encounter problems. One of the most common septic system problems is drain field problems. This problem happens when wastewater is combined with solid particles that have not settled in the bottom of the tank and clog the outlet pipes leading to the drain field which causes a foul-smelling drain field and worse, wastewater gets stagnant causing a lot more problems.

There are other problems too and you can confirm them by when you see these initial signs:

  • Your toilet drains slowly.
  • Grass grows healthier above the drain field.
  • Sewage backs up into your toilet.
  • Toilet problems arise when it rains, and much worse when it floods outside.
  • You have wet and smelly spots in the yard (which indicates drain field problems).
  • You need constant tank pumping and cleaning (more than once a year)
  • Your toilet makes odd noises after flushing.

If you see these signs in your toilet and septic system, be sure to call a septic technician or a plumber to have your system inspected for abnormalities. Some states will require you to replace your system if your sewage is completely broken and is causing environmental concerns, so make sure to have your septic system regularly checked to see problems and prevent them from getting worse in the future.

Kenneth Wilson
October 17, 2021

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

Ask The Author Your Question In The Comments!

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

More From This Author

9 of the Best Ring Security Cameras: Home Security 101
Where You Should Place Security Cameras Around Your Home: Best Locations
How Long Do SimpliSafe Camera Batteries Last?
SimpliSafe vs. Ring: Which Home Security System is Best Suited for Your Needs?
The Best Plug-in Outdoor Security Lights to Keep Your Home Safe
Everything You Need to Know About Residential Laser Grid Security Systems