How Long Do Septic Tanks Last?

When you purchase a septic tank, you’re hoping your investment will provide peace of mind for decades to come. But is that perception the reality?

On average, septic tanks should last between 20 and 40 years. Concrete septic tanks, which tend to be the most common material used today, typically are more durable and last longer than those made out of steel.

As with any product, there are several factors that can affect the lifespan of your septic tank, including the maintenance and care of the tank, the material the tank is made of, and the surrounding environment, including soil acidity. In this article, we’ll outline some of the ways you can help preserve and extend the life of your septic tank.

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Basics of a Septic System

A septic system is most commonly utilized in rural areas and used to process wastewater efficiently. The septic system handles wastewater from everyday appliances like dishwashers, toilets, and sinks. Within the septic tank, solids sink to the bottom, while bacteria helps to dissolve the sludge that sits on top.

A septic system consists of two primary components:

  • The septic tank holds the effluent and waste product from the wastewater.
  • The drain field is the area of soil surrounding the septic tank that helps to treat the water as it is returned to the environment.

Septic tanks can vary in size, depending on the water usage and the volume of water the tank can hold. Many tanks typically range from 1,000 to 2,000 gallons. For commercial or industrial purposes, septic tanks can be as large as 5,000 gallons.

Factors That Affect The Lifespan of a Septic Tank

Due to the cost and inconvenience often associated with procuring and installing a septic system, prolonging the life of the existing septic tank is sensible. If you have an existing system, some of these factors may be out of your control. If you are considering investing in a new septic system, understanding these elements can help ensure it lasts as long as possible.

Tank Material

Perhaps the main factor in the lifespan of a septic tank is the material it was made from, along with its durability. There are three main choices: concrete, steel, and fiberglass.

Concrete is the most durable of these materials, and while it may involve a higher upfront cost, the return on investment is typically justified through its longer lifespan – around 40 years, on average. Steel is rarely used nowadays due to its tendency to corrode and rust. Fiberglass septic tanks can last almost as long as concrete tanks but come with a higher upfront cost.


It stands to reason that the more you use something, the greater the chance of wear and tear – and the same is true with septic tanks. Less frequent usage of the tank – a lower volume of water moving through the system – will allow it to last longer than tanks in constant use.

It is also important to bear in mind that how a septic tank is used can affect its longevity. Only human waste and toilet paper should move through the system. Other substances, such as food waste, chemicals, and baby wipes, can clog the system and prevent it from operating at optimum efficiency.


Routine inspections and maintenance can help extend the life of the septic tank. Periodic checks can help to ensure the system is working correctly and mitigate any issues by identifying them before they become a major issue.


The acidity of the soil surrounding the septic tank can impact its lifespan. Acidic soil can cause erosion, so it is beneficial to test the acidity of the soil before installation to ensure that measures can be taken, such as coating the concrete or using fiberglass, to help protect against potential problems.


Groundwater levels can also affect the lifespan of a septic tank. If the water table on the property is high, then the ground is already saturated and sewer backups are unfortunately more likely to occur, as the water has nowhere to be dispersed to.

Signs of a Failing Septic Tank

Vigilance can help you to identify the problems associated with a failing septic tank before it becomes a major issue. Even if the problem is significant, being aware of it enables you to resolve it.

Common signs of a failing septic tank include:

  • Slow drainage from sinks, bathtubs and showers
  • Toilets flushing slowly
  • Sewage backups
  • Foul odors
  • Wet ground around the tank area

Tips to Prolong The Life of Your Septic Tank

Armed with the factors that can influence the lifespan of your septic system and with an understanding of the warning signs, the final part is to implement tips that can prolong the life of your septic tank. These best practices can ensure your septic system works as intended.

Choose The Right Septic Tank

If you are purchasing a new septic tank, take the time to make the right decision. The main factors to consider are the material (concrete is most durable). In addition, understanding the volume of water that the tank will need to process can help you to choose a septic tank of the most suitable size.  

Make Sure The Tank Is Installed Correctly

There’s little point spending time researching your septic tank options, only to cut corners on the installation and create unnecessary problems. Make sure your tank is installed by a qualified, reputable professional with a successful track record.

Ensure The Tank Is Used Correctly

One of the most common issues with septic tanks is items being introduced which the tank cannot process, or finds difficult to process. Use signage in commercial and industrial settings to emphasize what should – and just as importantly, what shouldn’t – be flushed down toilets and sinks (examples include food waste and baby wipes).

Routine Maintenance

Prevention is usually better than cure, and the same rings true for looking after your septic system. Regular inspections, necessary pumping, and caring for the drain field are all ways to ensure that your septic system is operating as it should. Again, use a qualified professional to carry out these checks on a periodic basis.

In Conclusion

With the correct care and attention, a high-quality septic tank should last approximately 40 years. Understanding the warning signs of failing septic tanks and taking proactive steps to mitigate any issues are key to prolonging your septic tank’s lifespan.

At Jensen Precast, we offer a variety of concrete and fiberglass septic tanks in a range of different sizes. Browse our septic tanks today or contact us for more information.

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