I have recently bought a house built in 1843. It has a cesspool. What ever that is. I have always been on town sewer and know absolutely nothing about about any other kind of sewage system. The sales disclosure says there is a septic tank but there isn't a sewage pump. Isn't that kinda important? What are some signs I might need to service the system? How often should it be done? Is it expensive? Do they dig up the yard to do it?