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How long do septic tanks last? Does a septic tank need replacing?

How long is a septic tank good for?

If you’re looking at buying an older house with a septic system, your first question should be, “How old is the septic tank?” A home with a septic tank isn’t a deal-breaker, but you should know a few things before you buy. In this post, we will answer “How long do septic tanks last?” and more about the longevity of your septic system.


What is a septic tank?

A septic tank is a wastewater treatment container designed to hold sewage from a home or business. The tank is typically underground and connected to a building’s sewage system. Septic tanks can vary in size, but most have a capacity of 1,000 to 3,000 gallons.


How long do septic tanks last?

Under normal usage conditions, it’s estimated that most septic tanks last about 20-30 years before they need to be replaced. If you’re wondering if your tank or the entire septic system needs replacing, check with septic professionals in your area to see what they recommend.

Here is what you need to know about the average lifespan of a septic tank and drain field septic system.

How long do septic tanks last


Why do septic tanks need to be replaced?

The lifespan of a septic tank system can have a pretty wide range. There are a variety of reasons why your tank can need replacing. The tank could have cracked from the ground shifting or driving large machinery on top of it or the leach field. While the EPA states that the lifespan of a septic tank is 20 years (though it can be longer if it is a concrete septic tank or a fiberglass septic tank), you may find that your tank needs to be replaced sooner, depending on the circumstances.

The type of tank material can also be a reason for your tank needing to be replaced. Concrete septic tanks will naturally corrode and wear down over time. Plastic septic tanks, much like holding tanks, can crack, and steel septic tanks can rust.

No septic tank is 100% perfect, and depending on your year-long weather conditions, you may live in a climate that is harsher on your septic system and drain field.

If it’s an older house, the tank may just be worn out. This can happen over time.

Need to replace you tank? Find out the difference of a septic tank vs cesspool, or septic tank vs holding tank to see either or better for your house.


How can I tell if a septic tank needs to be replaced?

The best way to test if your septic tank needs service is if you notice that your home’s drainage has improved or worsened in recent months.

If you are starting to have septic tank problems and you are in an older house, you may be at the point where you need to get a new tank.  Here are some signs to look out for when it comes to replacing your septic tank.

  • The grass is green around the tank. This is a warning sign that your tank is likely cracked and needs to be replaced. A septic system is a closed unit, and the grass shouldn’t be any greener around your tank than it is in any other part of the yard. The elements in household waste are similar to the same compounds found in fertilizer which can cause the grass to turn green if there is a crack in the tank because the soil conditions are more favorable for green grass.
  • Septic tank smells start to show up in the house. If you have a foul odor, it could mean that your septic tank is full or the pump out to the leach field is broken, and things are starting to back up. In that case, you may hear the next issue.
  • The Septic tank alarm goes off. This one is an urgent call, and you need to deal with it immediately. This means that there is something wrong in the tank, and the level of waste in the tank has built up to an unsafe level.


How do I make my septic tank last longer?

There are several things you can do to help your septic tank last longer; check out these tips to help keep your home running smoothly.

  • Avoid putting food down in the garbage disposal, and this includes fats and oils. This can create solid chunks that will waft through your pipes and end up clogging your drain field.
  • Don’t pour chemicals like bleach or Pine-Sol into your septic tank; they don’t naturally break down and can cause damage.
  • Don’t flush anything other than human waste and toilet paper. You’ll want to skip the baby wipes or grease as these products won’t fully dissolve in your septic system. See the best septic safe toilet papers to make sure yours is safe.
  • Regularly getting your septic tank pumped will keep solid materials from wafting through the pipes and clogging up your leach field. This will remain a regular maintenance cost, but it doesn’t take too much time out of your schedule.
  • Don’t let your septic system sit unused for more than a few months. While it might not be used every day, the more you use your septic system, the better off it will be.
  • Don’t plant anything over your leach lines. This includes trees near the tank or building up dirt around your drain field; this can cause damage to the system and lead to poor drainage.
  • Keep grass over top of your leach lines. If you don’t have enough room for grass, then consider putting in sand or gravel well away from your leach lines.


Why does my septic tank alarm go off?

Your septic tank alarm will go off when there’s an issue with your septic tank. Normally this is when the float gets stuck in the tank and doesn’t pump out the greywater to the drain field. This can cause the level in the tank to rise, causing it to flow back in towards the house. This is normally when the alarm gets triggered.

If it keeps going off, then there might be a leak in the system that you’ll need to get fixed by a professional.


What to do if your septic system needs to be replaced?

The first step is to contact a septic professional for a clean-out.

Once you do contact a septic professional, be sure to ask them what the average life expectancy is for your tank and what signs indicate it might be time to replace it. Most tanks last about 20-30 years, any less than that, and you’ll most likely want a replacement before trying all of the possible maintenance options.

It’s important to know, however, that certain factors can decrease the life expectancy of a tank. For example, if you have fewer than two people living in your home over the course of a year, it could improve the number of years your tank lasts.


Septic Tank Lifespan FAQ

How often does a septic tank need to be replaced?

Under normal usage septic tank lasts about 20-30 years; if the septic system is on the smaller side and/or needs to be serviced 50 or more times in its lifetime, replacement is recommended. A well-maintained septic tank with proper maintenance (including regular septic tank pumping) can last even longer.


How much do septic tanks cost to replace?

A new septic tank costs between $3,000 and $10,000 depending on size, location of the tank, type of system used, and whether or not a leach field needs to be installed as well.


How long can a septic tank go without being pumped?

Depending on its usage, a septic tank should be pumped every 1-3 years to avoid reaching capacity and causing damage.


Do septic tanks ever need to be replaced?

Yes, they do. Most tanks last about 20-30 years, so if your tank hasn’t been replaced yet, it’s probably also time to replace the septic system.


Can septic system fumes be harmful?

Yes, fumes from septic systems can be harmful. Septic fumes can cause a wide range of illnesses, including respiratory infections and headaches if the tank isn’t properly functioning. If your septic system doesn’t have proper ventilation or is located in an especially damp area, then it’s likely that you’ll experience these ailments from time to time.


Can septic tanks be repaired?

Yes, they can. Septic tanks have a 20-30 year service life, and most of that time depends on how well it’s been maintained. Cleaning out your septic tank every 2-3 years will help to extend its lifespan as well as prevent blockages from developing in your drain field. Some parts can easily be replaced, like the lid, but other pieces may need to be completely replaced, meaning it may be best to replace the entire tank at that point.


Can septic tanks freeze?

If properly installed, they shouldn’t be able to freeze. If the area where your tank is located gets below freezing temperatures, then there’s a possibility that it could freeze up. This would be more of an issue if you lack proper insulation in your system or if the pipes were not installed below the frost line, so make sure that you’ve got some sort of insulation, so this problem won’t occur.


What can shorten the septic system life expectancy?

A septic tank depends largely on the pump and the family usage. That is, a 1,000-gallon tank would most likely last more than 20 years (on average), while a 500-gallon tank might only last 10-15 years under similar conditions.

The size of your household has an impact as well: If you have 4 or 5 people living in your home, it’s more likely to need a septic tank replacement than if you have only 2-3 people. The number of showers or baths that are used within a week or month can affect the life expectancy of your system as well, so be sure to take this into account when looking at how long a septic tank lasts.


Can concrete septic tanks last forever?

No, but they do last a long time. A concrete septic tank will typically last 20-40 years, while a plastic tank will only last 30-40 years.


What is the average life of a steel septic tank?

Steel septic tanks are not a good option when installing septic systems; they tend to last 20 years, whereas the concrete and plastic ones can last 30 to 40 years.


Do concrete septic tanks go bad?

Most steel tanks last about 10-20 years, a well-constructed concrete tank will last longer, so if your tank hasn’t been replaced yet, it’s probably also time to replace the drain field.


How often should you replace a conventional septic drain field?

The average life of a conventional septic system is about 20-30 years if properly maintained.


What causes septic drain field failure?

General causes of septic leach field failure include: Old age, poor installation, heavy usage, and increased waste load.


Is it time to get your septic tank checked?

There are many factors that contribute to the lifespan of septic tanks, so it’s important for homeowners and property managers to take preemptive measures by cleaning out the tank on a regular basis. Failing to do so can lead to clogs in your system, which may require expensive repairs or replacement.

If you’re experiencing any of these signs, such as smells, leaks around the system, or if the grass over your leach lines isn’t growing, then it might be time for service. The best way to test if your septic needs service is with an inspection from a professional who will let you know what options are available for repair and maintenance.

Use the link below to find a septic professional in your area.

The point is to make sure to seek expert advice before you decide to replace your tank.


Click Here to Find a Local Septic System Professional



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