What is the difference between a cesspool and a septic system?

Answer: Cesspools do not have a leach field, septic tanks have a leach field where water and effluent are treated by bacterial activity. Cesspools are no longer legal anywhere that I know.

Answer: A cesspool is the result of accidental waste pooling. A septic system is designed to treat waste.

Answer: A cesspool is an underground collection of waste; a septic tank is an underground collection of waste which is treated and then leached out into the underground regions.