What Happens When A Septic Tank Is Full?

28 February 2022
 Categories: , Blog


A septic tank plays a vital role in facilitating the smooth flow of waste out of your home. However, like any other system, it requires regular maintenance. Observing the prescribed waste level is essential for a seamless waste inflow and outflow process.

A full septic tank can point to two things –– an overflowing reservoir that no longer accepts waste or the accumulation of sludge that blocks outlet pipes.

So, how can you tell when your septic tank is full?

Unpleasant Odors Around the Septic Drain Lines

Foul smells are an obvious sign of something wrong with your septic tank. When the waste level is normal, the septic tank is usually intact, keeping in pungent odors produced by human waste, laundry water, and general waste.

Unfortunately, when the septic tank is full, the pressure from the waste pushes the sewer cap releasing pungent odor to the surrounding environment. These sewer gases are harmful to your health and often leave behind lingering foul smells.

Bubbling Sounds Along the Drain Lines

If you suddenly notice gurgling or bubbling sounds along the septic system drain lines, that's a serious warning sign that your tank might be full. When the sewer tank is full, the smooth inflow of waste becomes disrupted.

The excess waste is then pushed back into the drain pipes. The pipes sometimes bleed at the lowest point. That said, the reverse movement traps air creating an unmistakable bubbling sound. Besides indicating a full septic tank, bubbling noises can also point to blocked drains, defective drain vents, or clogged sewer pipes. A pumping service expert can advise on how to diagnose all these issues.

A Slow-Draining Bathtub, Shower, or Sink

A slow-draining toilet or bathtub can be quite unhygienic. And if you encounter a fixture with sluggish drainage, the septic tank could be full. The main cause of slow draining fixtures is blockage along outlet pipes. The tank might be too full to accommodate new waste, causing solid debris to remain lodged inside the drain pipes.

Also, when the outlet pipes become clogged, the septic tank doesn't have an outlet. Consequently, the blockage creates a repelling force against the normal flow of waste, which makes toilets, bathtubs, or sinks lose their ability to drain at the normal rate.

Stagnant Sewage

When the septic tank becomes full, pressure builds within the holding area pushing the wastewater out. Over time, a pool of water forms at the base of the manhole cover or inspection pipes. So, if you notice stagnant water, your septic tank may be due for a pumping appointment.

Blocked drain pipes are another reason behind pooling. Keep in mind, drain pipes are designed to sieve out sludge. So when an excess amount of sludge is trapped in the septic tank, it rises, blocking the outlet pipes. Consequently, wastewater escapes through the sewer caps and forms a pool.

Schedule an appointment with a septic pumping service if you notice any of these signs.