Septic tanks, while not a complex component of the system, must be designed, constructed, and installed for the system to function satisfactorily.
Tanks must be watertight to retain solids, and should perform their intended purpose. However, specifications of concrete tanks have been found to change and should be "spot-checked" on occasion.
Top and sidewall thickness must be observed, the overall dimensions are measured, and the height of the inlet and outlet, and air space (clearance above outlet pipe invert) at the top of the tank. You can also hire professionals to install concrete septic tank via https://ecoseptic.com.au/septic-tanks/
An often overlooked item relating to the septic tank is the proper orientation of the inlet and outlet. The outlet will be at least two inches lower than the inlet in a well-designed tank.
Septic tanks must be installed level. Measuring the level of the tank with good levels of carpenters or building level. The laser level works well for this purpose as well.
Tanks that are badly out of the level should be suspected to have drifted. Even heavy concrete tanks will float when empty due to ground or surface water entering the tank excavation during wet periods or storm events.
This can happen regardless of whether the holes have been dumped or not. If the tank has floated, it to be removed and re-set.
The bottom of the tank excavation must be smooth and uniform to support the weight of the tank and the tank contents without the potential for cracking.
Water must be pumped out and the bottom of the excavation is ready to provide support even from the tank.