A cesspit (AKA cesspool) is a covered watertight tank used for storing sewage – EVERYTHING that goes in must get sucked out which will cost a fortune! It has no outlet, sewage flows in and is stored, when the tank is full the waste is tankered away. A cesspool requires regular emptying and must not be allowed to overflow. It is the least sustainable option for sewage disposal as no treatment occurs on site.
You should consider a cesspit as a temporary measure pending a more satisfactory solution, such as the provision of mains drainage.