Septic Tank Pumped And It's Full Again? (We Have A Fix)

Patricia Oelze
by Patricia Oelze
Pumping a septic tank is dirty and necessary work, but it can be frustrating when it quickly becomes full again. If you just had your septic tank pumped and it’s full again, it can be a sign that there is something wrong with the drain field. Whether it’s plumbing problems, excessive water use, or a problem with the drain field, let’s take a look at why your septic tank fills up right after you pump it.

If you have a septic tank, you know it can be a lot of maintenance. Perhaps you just had your septic tank pumped and it’s full again. There could be a number of reasons why this happens.

The tank must be pumped regularly, depending on the size and how much wastewater flows through it. Even after it’s been pumped, it can fill up again right away. However, there’s a difference between a full tank and an overfull tank.

If you just had your septic tank pumped and it’s full again, you may be seeing the normal operating level. The tank reaches its normal water level a few days after pumping. However, if the level is above the outlet pipe, the tank is overfull. In this case, you may have a problem in the drain field, a plumbing issue, or excess water usage.

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What is a Septic Tank?

Your septic tank is a large plastic or concrete container in the ground that holds about 1,500 to 2,000 gallons of water. One end of your tank connects to the wastewater pipe coming from your home, and the other goes to your drain field.

There are two chambers in the septic tank. As the waste flows through one chamber, solids settle in the bottom, and scum rises to the top. The solids will be digested anaerobically by bacteria to reduce the volume.

In the second chamber, more solids and scum are removed and allowed to settle before sending the liquid into the drainpipe leading to your drain field. The drain field is where your water is cleaned further by the soil and other natural anaerobic bacteria.

Inlet and Outlet Pipes

There are two important pipes in a septic tank: the inlet pipe and the outlet pipe. The waste from your house enters the septic tank from the inlet pipe which sits about 3 inches above the outlet pipe. As the tank fills with liquid, it drains via the outlet pipe into the drain field.

The Drain Field

The drain field is a disposal area just under the ground where contaminants are removed from the water coming from the septic tank. Usually found beneath lawns or other soft landscaped surfaces, the drain field consists of trenches fitted with perforated pipes and gravel.

Drain fields perform 55% of the work of a septic system, with septic tanks performing the other 45%. You may also hear drain fields referred to as leach fields or leach drains.

Is My Septic Tank Full or Overfull?

If your tank is 1500 gallons, the normal liquid level is 1500 gallons at the outlet pipe. This means the tank is full but not overflowing. In other words, this is a normal scenario.

If the liquid rises above the outlet pipe, your tank is overfull. And if you just had your septic tank pumped and it’s full again—to the point of overflowing—then you have a problem.

Signs Your Septic Tank is Full (but Not Overfull)

To determine if your tank is overfull, look for any of the following signs.

Clogged Toilets and Sinks

If your toilets are not flushing or your sinks are clogged up, it’s time for the tank to be emptied. However, if just had your septic tank pumped and it’s full again, there’s likely another problem with your septic system.

There may be a damaged pipe or the drain field could be compressed. If it’s the drain field, you need to dig up the line to replace it, which is a laborious job, or you can hire a professional. Keep in mind, a compressed drain field is an expensive thing to fix.

Bad Odors

Bad odors from the sinks, toilets, and even the washing machine can signify that your tank is full. You may also notice a strong odor coming from your tank outside or bright green grass growing only in that area. But if you just had your tank emptied, you need to have the rest of your system inspected.

Waste Backup

In extreme cases, there could be septic waste working its way back up your drains. Waste can backup through your bathtub drain or your toilet—even your sink drains.

Pay attention when you flush the toilet. If you flush and the tub drain starts bubbling up some yuckies, then you most likely have an overfull septic tank.

Causes For Tank Overfilling

If your septic tank was just drained and it’s backing up again, then other parts of your septic system need to be checked for damage or clogs. One of the most common issues a tank overfills after pumping is an inadequate drain field. However, there are other places to look first.

Too Much Wastewater

If you’re using an excessive amount of water, then your septic tank will fill faster. Are you running unnecessary loads of laundry? Is someone in the house taking ridiculously long showers? All of this contributes to wastewater that eventually makes its way into your septic tank.

One of the most common reasons for too much wastewater is leaking. If you find the source of the excess water inside the house, you’re lucky. You can fix the leak, and everything should go back to normal. However, sometimes, the leak is in the underground equipment.

Clogs And Blockages

A clog or blockage in any area of the septic system can cause overfilling and backup both inside and outside the house. Inside clogs occur when you pour inappropriate matter, like grease, down the drain.

Outside clogs can be caused by tree roots, line leaks, or line blockages. Tree roots are stubborn and strong. They will grow through anything that’s in their way, including your pipes or tank. Concrete septic tanks are best for preventing this.

Have your pipes cleaned and inspected for line leaks or blockages. They can even run a camera through the lines to check every nook and cranny. Once they find the problem, you can address it, and things should run smoothly again.

Problems in the Drain Field

If you have addressed all of these issues and found nothing, you probably have a problem in your drain field. It could be something as simple as ground saturation from too much rain. Or it could be something more complicated like a faulty system that needs to be replaced.

Older septic drain fields may have used up the efficiency of the soil in that area. This means you need to move the drain field to another location of your property or add more branches to your existing one. Both options are costly, but there is no way around it. However, it’s possible to prevent this from happening.

Preventing Septic System Problems

Taking care of your septic system is a daily task, but it’s not difficult. It only takes a few adjustments, and the result is a tank with normal levels.

There are many things that you do not want to do when you have a septic tank versus a sewer system. The anaerobic bacteria levels have to be considered every time you turn on the water, flush the toilet, or run the dishwasher or washing machine.


For a healthy septic system, regular and proper maintenance must be done. It’s a yearly expense that saves you thousands of dollars to replace or rebuild the drain field. The typical septic tank should be cleaned or pumped every three to five years. However, this can vary depending on the tank’s size and how many people live in the house.


Never pour grease or cooking oil down the drain. Oils and grease do not degrade easily and can cause a clog in one of the pipes as well as too much waste in the septic tank.


Flushing non-biodegradable items in the toilet is a common issue that clogs up the system. Some of the things you should never flush include baby wipes, diapers, condoms, feminine hygiene products, cotton balls or swabs, and cigarette butts.

Harsh Chemicals

There are certain chemicals that will kill the bacteria needed to break down the waste in the tank. They include bleach, paint, solvent, herbicides, and pesticides. Never send these solutions down the drain.

Water Softeners

Using the wrong kind of water softener can be a problem, too. Certain water softeners can hurt the bacteria with too much brine discharge. Make sure you use a water softener that is safe for septic tanks.

Garbage Disposal Use

Using the garbage disposal improperly is another common problem for septic tanks. For example, you don’t want to put eggshells, large food scraps, and other solid waste in the garbage disposal. Even though your disposal will break down most substances, the pieces are still too large for a septic tank to handle.

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One Final Note

Only a professional should pump out your septic tank. The risk of damaging the system by doing it yourself is great.

Not to mention, septic waste is toxic waste. So, whoever pumps your septic tank needs to be able to get rid of the waste properly. Improper removal of toxic waste can result in tens of thousands of dollars in fines. No one wants that! It’s better to call a professional, and in the meantime, fix your leach lines!

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Patricia Oelze
Patricia Oelze

I am a DIYer who loves writing about anything home-related. When I am not writing, you can find me studying for my PhD in Psychology, photographing nature, and swimming at the lake with my grandkids.

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