Plastic septic tanks are relatively inexpensive and easy to install. In addition, they are not chemically reactive and do not rust. However, they do have their own set of problems that include:
The plug at the bottom of your plastic septic tank can get dislodged and allow effluent to flow through. This is probably due to the slight flexibility of plastic, which is not an issue with concrete tanks. To make matters worse, the plug can be removed with the waste when pumping the tank.
Pressure from within or outside the tank can force out the plug, you are likely to notice that the effluent level is not where it should be after some time. This is why it is important to confirm that the plug is still intact pumping and cleaning the tank. Since you should never enter the tank without appropriate safety gear and training, you should ask your plumbing contractor to confirm the presence of the plug during inspection.
Floating Out of the Ground
Plastic tanks aren't particularly heavy. They are usually kept grounded by the weight of the effluent they carry. Therefore, if you install your tank and leave it for a long time without using it, then it may float out of the ground. The same thing can happen if you pump and clean your tank and then let it remain in disuse for a long time.
This may not be much of a risk if you have installed your tank in a firm ground. However, if the soils around the tank contain rising ground water, or are generally wet, then an empty tank may easily float out. Apart from damaging/distorting the tank, the moving tank may also break the pipes connected to it.
Poor transportation, installation or even transportation of tanks can crack them. The breaks may not be easily visible to the eyes, and they may not even be visible until after you pump your tank. One of the symptoms of cracks in the tank is a low effluent level, especially if you have confirmed that the plug is there. Again, an inspection for a crack should be left to a professional since it involves getting into the tank.
If you have to install a plastic septic tank, then ask your plumbing contractor for a sturdy brand that will not get damaged easily. Also, install the tank when you are ready to use it to minimize risks of floating. Lastly, get your pump inspected every time it is pumped and cleaned.Share