9 Signs of a Full Septic Tank | How to Tell When Your Septic Tank Needs Emptying

A septic tank is a vital necessity of every house. As you flush your toilet or sump pit, the wastewater goes into the septic tank through drain pipes. The proper maintenance and service of the septic tank are very important for optimal efficiency. A full or clogged septic tank generates different signs. You can identify a full septic tank by these symptoms. This article mainly explains “how to identify a full septic tank and need emptying.”

What Does the Full Septic Tank Mean?

A full septic tank indicates a septic system that has reached its capacity and is no longer able to properly store and treat wastewater. The following are some other definitions of a full septic tank:  

  1. Tank is filled to normal level: As the septic tank fills up to the normal level, inlets and outlets permit effluent to flow in and out smoothly. For gravity feed tanks, the wastewater must be at the base of the discharge pipe during the normal process.
  2. Sludge Formation: In the normal process, the sludge collects in the base of the tank. According to the Ontario Building Code, you must perform pumping of your septic tank when sludge and solids take place at one-third of the tank’s working volume. At this one-third level, the effluent generally starts flowing into the leach field, but the sludge can degrade the quality of the effluent fed to the bed. At this stage, pumping is compulsory to restore the tank’s best efficiency.
  3. Tank Overfill: With time, your septic tank can fill up with solids or fat, which may cause drain pipes to clog or the backflow of the wastewater. If you don’t fix this problem on time, the backflow wastewater may enter your home, which may also cause an expensive repair. The situation can worsen if the spread soil becomes clogged, which may eventually need a substitute of the dispersal bed.

How to tell if your Septic Tank is full?

The proper on-time pumping and cleaning of the septic tank are very important for the efficient working of the tank. As the septic tank is full, it starts producing different problems.

septic tank cleaning, a full septic tank

A full septic tank generates different symptoms through which you can identify that your septic tank is full. The most common signs of a full septic tank are given below:

  1. Pooling Water
  2. Slow Discharge
  3. Unpleasant Smell
  4. Healthy Lawn
  5. Backflow of Wastewater
  6. Gurgling Water
  7. Trouble Flushing
  8. Standing water around the tank
  9. A suspiciously lush lawn

1) Pooling Water

The most common sign of a full septic tank is the pool of water that forms around the drain field of ​​the septic tank. This is the first sign of a full septic tank.  

Needless to say, if it hasn’t rained recently and you see a lot of water around your tank, it’s maybe because of your septic tank.

This problem only occurs due to a full or clogged system. As the system clogs, it forces the wastewater to the ground bottom.

Solution: As you observe pooling water around the drain field of your tank, immediately inspect the system. If this problem is because of a full septic tank, call a specialist and ask him to pump the system.

2) Slow Discharge

Slow drainage is a major issue that homeowners most commonly face. As you observe that your bathtub, bathroom sink, sump pit, kitchen sink, or shower drains slowly, it means your drainage pipelines have been clogged, or your septic tank needs pumping.   

Solution: In this case, first of all, inspect the system. First of all, you should use a septic tank-friendly drain cleaner. If you have a clogged pipeline or filter, remove the solid particles and open it. If you are still facing slow discharge issues, it’s best to empty the tank.

3) Unpleasant Smell

All of your home’s effluent goes into the septic tank, so you know it doesn’t produce a pleasant smell. This is a smell that you can easily observe.  

If you start getting an unpleasant smell around the septic tank, this is a sign of a full septic tank. This unpleasant smell may also occur due to wastewater leaks from the drain pipelines or septic tanks.  

This is such a severe unpleasant smell that your neighbor may also notice. Maybe your neighbor will soon complain too.

Solution: Inspect the system. If the smell is coming because of a septic tank or drain pipe leak, immediately fix it; otherwise, it may convert into a costly repair. If an unpleasant smell occurs due to a full septic tank, you must immediately pump it. 

4) Healthy Lawn

A full septic tank has some positive side effects. As your tank is full, it starts leaking, and the grass above the tank is probably the healthiest grass you’ve ever seen.

You will find that this grass is more shiner than the rest of your garden. As you notice this, it is a sign of a full septic tank.  

Solution: Immediately open the lid of your tank and see whether your tank is full or leaking. If it is full, call the specialist for its pumping.

5) Backflow of Wastewater

The backflow of the wastewater is the first and major sign of the full septic tank. As your tank is full, your flushed toilet wastewater doesn’t go into your tank and start backflowing. The backflow of the wastewater generates many problems, such as unpleasant smells.

Solution: Note the lowest drain channels in the house. If the wastewater starts backflow in these drains, you must empty your tank as soon as possible.

6) Gurgling Water

As you flush your wastewater, if it consistently generates gurgling noises, don’t ignore them. This also indicates that the septic tank is full, and you need to pump it.

Solution: As you notice gurgling water noises, observe whether they are consistent or not. If these noises are coming consistently, make a call to the specialist to empty the tank.

7) Trouble Flushing

If there is a problem with the toilet flushing or if the wastewater is draining slowly, it indicates that there is a problem with the septic system. You may face effluent flushing problems due to a full septic tank or clogged drain lines.

Solution: Clean or pump the septic tank.

8) Standing Water Over the Tank

The water over your tank may stand due to different reasons. You may have accidentally left the hosepipe running or due to recent rain.

However, if you see pooling water or a large amount of standing water over your building but it has not rained heavily recently, and other factors do not work, this indicates that your septic tank is full and needs pumping. This can happen near your home, but probably near the tank itself.

Solution: If the septic tank is the cause, the overflow may be due to a blockage in the drainage system or accumulated sludge in the tank itself. In any case, the problem must be addressed immediately, and the tank emptying service should be contacted by a qualified professional as soon as possible.

9) A Suspiciously Lush Lawn

Abundantly healthy grass could be an indicator of a leaking septic tank. While it might sound unconventional, if the grass situated directly above your septic tank appears exceptionally vibrant and lush, it’s likely that your septic tank has reached its capacity.

The surplus water and nutrients originating from the tank can contribute to the nourishment of your lawn, and this may occur even prior to the onset of visible water pooling issues.

Read More: Types of Septic Tanks

Why is septic tank maintenance so important?

  1. Domestic sewage has different harmful viruses and bacteria as well as a high level of phosphorus and nitrogen. These viruses and bacteria may cause different diseases. If you do not properly maintain your tank, you and your family may fall into different diseases. Therefore, the septic tank is must be pumped and cleaned on time.
  2. Inadequate treatment of septic tank wastewater can lead to groundwater contamination and transmit diseases to humans and animals.
  3. Inadequate wastewater treatment risks contaminating nearby surface water and exposing bathers to a variety of infections, from eye and ear infections to acute gastrointestinal infections and hepatitis.
  4. The proper maintenance prevents the wastewater backflow from the septic tank to your home.
  5. The maintenance reduces the slow drainage or difficult drainage-related issues.
  6. The regular maintenance and pumping of the septic tank eliminate the risk of an expensive repair or tank failure.

When should I pump out my septic tank?

The proper pumping and maintenance of the septic tank are very important for efficient working. The septic tank pumping or cleaning time varies according to the following factors:

  1. Septic tank size
  2. Number of people in a household
  3. The volume of solid waste
  4. Amount of wastewater produced by the home

So, many tank pumping companies suggest that the sludge and scum in your tank shouldn’t be more than one-third of the septic tank’s working capacity. You must pump your septic tank every 3 to 5 years.

Read More: Septic Tank Pumping Cost

FAQ Section 

What happens if a septic tank is never pumped out?

  1. You may notice an unpleasant smell in your home
  2. Backflow of the wastewater into your home
  3. Slow drainage of the wastewater
  4. Standing water around the tank
  5. Troubles in flushing the wastewater

How Often Should You Pump Your Septic Tank?

The septic tank pumping or cleaning time varies according to the size of your family, the size of the tank, and the amount of water produced by the house. Maximum tank pumping industries suggest that you must pump out your tank every three to five years.

Can I shower if my septic tank is full?

Yes or No. Your shower wastewater goes into your septic tank. If your septic tank is already full and its wastewater is overflowing, then you shouldn’t take a shower. In this condition, your shower wastewater may start backflow, and you may face an unpleasant smell in your house.

Will toilet flush if septic tank is full?

No. You shouldn’t flush your toilet if your septic tank is full. In this case, if you flush your toilet, you may face different issues such as the backflow of the wastewater.

What are the symptoms of a full septic tank?

A full septic tank has the following symptoms:

  1. Pooling Water
  2. A suspiciously lush lawn
  3. Slow Discharge
  4. Standing water around the tank
  5. Unpleasant Smell
  6. Trouble Flushing
  7. Healthy Lawn
  8. Gurgling Water
  9. Backflow of Wastewater

What causes septic tank to get full?

Water flow can reverse when the drain field becomes inundated, resulting in elevated water levels in the septic tank. Additional frequent problems involve excessive water usage and plumbing problems. Your septic system operates as a sequential process that requires a certain amount of time to complete each step.

What happens when septic tank is full?

When your septic tank is full, it may cause backflow of the wastewater, structural damage, ineffective wastewater treatment, and possible contamination of the surrounding area. Therefore, proper pumping and maintenance of your system are important to ensure its optimum performance.

Read More
  1. Working of Septic Tank
  2. Latest cost of Septic Tank Pumping and Cleaning
  3. What is a Leach field or Drain field?
  4. Working of Sump Pit
  5. Working of Mound Septic System
  6. Working of Aerobic Septic System

1 thought on “9 Signs of a Full Septic Tank | How to Tell When Your Septic Tank Needs Emptying”

  1. It got my attention when you said that there will be a need for expensive repair when the backflow wastewater enters your home. Our septic tank has never been serviced since it was installed more than 5 years ago. It is crucial for me to ensure that it will be repaired right the first time as the sewage odors in our house caused by the water backing up have been making me feel sick.


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