All A Siphon Tank consists of two chambers separated by an internal divider, with a built in siphon through which effluent is discharged. No sewage pump is necessary, as the siphon works on a gravity flow basis. After initial priming, the siphon regulates the amount of effluent distributed to the field upon each discharge. This allows for even dispersal of effluent throughout the field in sufficient quantities to prevent freezing of the system.