How long your septic system lasts depends in large part on how well it’s built and how well you care for it.

While you should get 20 to 30 years out of your system if you care for it well, a design flaw, neglect, or misuse could cause it to fail within 15 years.

Choose the Right Type of Tank

The material your septic tank is made from affects its longevity. Well made concrete tanks have the longest potential lifespan at 40 years or longer. They’re impervious to rust and heavy enough not to work their way to the surface as some lighter tanks can.

High-quality plastic and fiberglass tanks can last 30 years or longer, while steel tanks typically last 20 to 30 years.

Construction matters, though. A steel tank will outlast a tank made from low-quality, incorrectly mixed concrete.  

Your soil quality also has an influence. Acidic soil and groundwater are the biggest threats to concrete and steel tanks, but they’re less destructive to plastic and fiberglass models.

Plastic and fiberglass tanks are, however, more vulnerable to damage from vibrations or the weight of vehicles driving over them. Each material has its place, and your installation company can help you decide which is best for your situation.

Use Your Septic System Correctly

Being mindful of how you use your system will keep it in good condition longer. When a septic system is installed, the drain field (leach field) is sized to accommodate the number of people who’ll be using it. This is calculated by assuming two people for each bedroom. So the drain field for a two-bedroom house is sized for four people.

Typically, the drain field is the first part of the septic system to start having problems, and it’s often due to hydraulic overload caused by overuse.

When your tank gets more water than it’s designed to handle, the wastewater can be forced out of the septic tank and into the drain field before the solids have been broken down. The solids then end up in the drain field where there aren’t enough of the right bacteria to break them down efficiently.

Today’s Homeowner Tips

To prevent this problem, be aware of how much water you’re putting into the system each day. Try to avoid doing two water-using tasks, such as showering, doing laundry, or running the dishwasher, at the same time.

If you have several loads of laundry every week, break the loads up over several days. Repair leaky fixtures or replace them with low-flow fixtures. Direct downspouts and yard runoff away from the drain field. If your septic system wasn’t sized for a whole-house water softener, don’t use one. Water softener backwash can overload the drain field soil.

Avoid rinsing or flushing away any solids. This includes food scraps that aren’t first run through the garbage disposal, cooking grease, and coffee grounds. Using the garbage disposal won’t damage your system, but it will put more strain on it.

Nothing other than human waste and toilet tissue should go into the toilet. Not even so-called “flushable” wipes, toilet tissue rolls, and other products should go into the system. Choose toilet tissue labeled septic-safe or biodegradable.

Some household cleaning products contain chemicals that can kill the beneficial bacteria that make your septic system work. Products containing chlorine, ammonia, and antibacterial chemicals are particularly harmful. Take care to use only septic-safe products.

Today’s Homeowner Tips

Avoid driving, parking, building, or letting livestock walk on the drain field. This kind of weight can compact the soil and make it less able to absorb effluent.

Don’t pave the drain field. Doing so blocks oxygen necessary for soil bacteria to break down material in the effluent. To protect your system from root damage, don’t plant trees within 25 feet of the tank or drain field.

Stay on Top of Maintenance

No septic system will enjoy a long lifespan without regular professional maintenance.

Over time, scum accumulates in the tank and must be removed before it exceeds the tank’s storage capacity.

Let the tank get too full, and you’ll soon have slow drains and backups in the house and a swampy drain field that smells of sewage. Eventually, your drain field will fail, which usually means you’ll need a new one.

The average household system requires pumping once every three to five years, or more often when the garbage disposal is used regularly. Some systems might need pumping every year. Most septic system maintenance companies also perform an inspection and take care of any necessary repairs when they come to pump the tank. The cost of pumping a septic tank can be well worth it to ensure the system stays clean and operational.

Repairing a crack in the tank or replacing a broken pipe or damaged baffle early on prevents more severe problems that could destroy your system. Once you know how often your system needs service, put a date on your calendar and update it for changes, such as another person moving in.

Make sure your septic tank’s lid is accessible, so you aren’t tempted to delay service because it’s inconvenient. Uncover the lid if it’s buried and install a septic riser. Septic risers are large, lidded wells of concrete, plastic, or steel that bring the septic tank opening to the surface where it’s easy to reach.

The more you know about your septic system, the better you can provide the care it needs. Learn where the tank and drain field are, what type of tank you have and how much it holds, and the last time the tank was pumped. If you don’t have the original plans or permit, the local agency responsible for septic tank permits can most likely provide a copy.

Correct use and good professional care pay off for years. While most septic systems start having drain field problems after around 20 years, a system that’s well-maintained and not overloaded could serve you for 30 years or longer.

Editorial Contributors
avatar for Henry Parker

Henry Parker

Henry Parker is a home improvement enthusiast who loves to share his passion and expertise with others. He writes on a variety of topics, such as painting, flooring, windows, and lawn care, to help homeowners make informed decisions and achieve their desired results. Henry strives to write high quality guides and reviews that are easy to understand and practical to follow. Whether you are looking for the best electric riding lawn mower, the easiest way to remove paint from flooring, or the signs of a bad tile job, Henry has you covered with his insightful and honest articles. Henry lives in Florida with his wife and two kids, and enjoys spending his free time on DIY projects around the house. You can find some of his work on Today’s Homeowner, where he is a regular contributor.

Learn More

Browse Local Plumbers in These Major Markets