Many older homes with systems installed prior to 1970 may have these systems presently in use. Cesspools are constructed of open-jointed walls (concrete block or stone) and open bottoms. The solids in the wastewater settle in the bottom of the cesspool, while the effluent seeps through the jointed walls and bottom. If the cesspool is not properly cared for, the sidewalls and bottom tend to plug up with solids. This may result in sewage backing up into the house or being discharge to the ground surface. Seepage pits are simply cesspools proceeded by a septic tank.