How Long Does It Take to Empty a Septic Tank?

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We recently discussed how when you get closer to completely filling your septic tank, you will find that your drains don’t remain as effective – along with presenting a few hazards to you and your family.  The best way to avoid these problems is to check whether your tank needs to be pumped.

In our previous articles we discussed the process of pumping out a septic tank. A common question people ask is how long it takes to empty a septic tank. The answer to this varies, depending on the process you use.

On average, the process takes up to 20 minutes if you have professional equipment. However, this can vary depending on the size of your tank, the method you use, and even the pump you use. The best pump to empty a septic tank is a submersible one attached with a grinder. In this article, we will discuss more about the process, and the intricacies involved.

What Happens If My Septic Tank Gets Full?

An empty septic tank

The biggest problem you’ll face if your septic tank goes beyond the 70% range is that you will start experiencing slow drainage in your kitchen sinks or toilets. In some custom new construction homes, shower drains are separate from sewage lines since these drains only have liquids in them.

However, that is not the case in many US and UK homes.

Once the tank reaches 90% capacity, you will find that your pipes get clogged quite often – not to mention the bubbling you’ll start seeing. Turn your sink faucet all the way and check for bubbles. Usually, it takes up to 2 to 3 seconds before you start seeing bubbles. These bubbles go away in a few seconds, after which you will find that the water drains – albeit a bit slow.

However, when the tank is full, you will find that these bubbles usually start arising after 5 to 10 seconds and don’t really go away. The frequency of bubbling is not as much as when it is at 90% capacity, but they will be continuous.

Another prime indicator of your septic tank being full is that when you get closer to your drains, you will find that the corner is relatively warmer than the rest – not to mention smelly.

An unorthodox measure of a full septic tank is that if you have a pest problem (particularly cockroaches, since they enjoy living in sewage lines), they will start abandoning the drains and try to move in with you – in your room!

If you find any of the following happening, it is time to get your septic tank pumped.

How Long Does It Take to Empty a Septic Tank – The Considerations

The first thing to consider when determining how long it takes to empty a septic tank is the capacity of your system. According to the table we included in our previous article, the average 3 to 4 bedroom house requires a tank ranging from 1,000 to 1,250 gallons. With the right equipment and expertise, such a tank can be emptied within 20 minutes. If you are doing it yourself and don’t have the expertise or luxury (if we can even call it that) of doing the same thing every day, it may take up to 30 to 45 minutes.  

Someone putting a pipe into a septic tank to empty it
Someone putting a pipe into a septic tank to empty it

Then comes the past maintenance habit, or the repair work involved. If not maintained properly, it is very likely that the baffle will rupture during the normal course of operation. Even poking the same with a pole can lead to holes, introducing complexities in the process. Repairing the baffle doesn’t necessarily require you to replace the tank, but can cost $300 to $500 to repair – taking up roughly half an hour.

The third consideration you need to make is the equipment you are using – with the most important one being the pump you use. As mentioned above, the best pump you can use is a submersible pump – but it isn’t uncommon for some companies to use regular suction pumps as well.

You will require the following if you are going to empty your septic tank yourself (not recommended, by the way).

  • A pump truck to haul the sludge away. This bit is pretty obvious. You can’t just fill bottle upon bottle with the sludge you pump out – nor can you leave it lying on the ground. The truck should have an industrial-grade vacuum to be able to suck out all the sludge and waste.
  • A video inspection kit. You can’t just go around popping your head into the septic tank – even with a gas mask – to check what is going on in the tank. For septic inspections, you need a video camera that feeds directly on a screen, a light, and a rod to mount the camera securely on.
  • A sewer jet. This can actually be a hydro jetting setup, but make sure it is dedicated to being used specifically for sewers and septic tanks – and not for plumbing. This is for those hard-to-reach areas or clogs in the system. This isn’t routine or standard equipment, but one that can definitely make a difference.
  • A pump. Of course, the most important bit you need to pump the tank is a pump.
    • Turbine or submersible pumps are the most effective solutions. They need to be lowered into the tank, wherefrom they suck water from underneath and pump it directly into the truck. These can be rated from 10 to 20 gal/minute and can therefore reduce the time needed to empty the tank.
    • Sump or effluent pumps are also submersible pumps that discharge more water than turbine pumps. These are often attached to grinders in order to reduce the size of solid waste before it enters the pump to ensure there are no clogs.
    • Sewage ejector pumps are another type of submersible pumps that can handle even the most difficult of sewage pumping needs. These are great for tanks that have large chunks of solid material – as large as 4 inches.
    • And last, but not the least, are the sewage grinder pumps. These pumps have a built-in grinder to help reduce the size of sewage solids. These are slower, but one of the most heavy-duty pumps on our list.
  • Sewage-specific hoses. These are hoses that are much stronger than traditional hoses. However, it is important to note that these are designed specifically for septic tank waste. Items such as diapers, rocks, and other items that can’t break down quickly will clog these pipes. The purpose of these pipes is to ensure they don’t spring a leak even under the toughest conditions.

Whether you are emptying your septic tank yourself or hiring professionals, it is important to keep a provision for complications. In a majority of cases, complications arise. These can range from clogged pipes all the way to something in your septic system breaking down.

On average, getting a septic tank emptied and cleaned costs about $400. If you do it yourself (by renting equipment for an hour or two), it might cost you somewhere between $286 and $350 if everything goes well.

However, this also depends heavily on the size of your tank. Larger tanks – such as those under larger apartment or office buildings – can cost up to $1,000.

Once this is all completed, your septic tank will slowly but surely fill up – so keep an eye on its levels, since it will (eventually) need emptying in the future too.

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About Charlie D Paige

Charlie is a massive DIY fan, with dozens of DIY projects under his belt - ranging from tiling to electrics, and concrete pads to walls. Charlie loves tinkering, seeing how things works, the outdoors and playing with power tools... so is it any wonder that he's completed so many DIY jobs over the years?

Charlie loves spreading his hard-won DIY experience with the world via this blog.