+22 How Do Septic Tanks Work Ideas
+22 How Do Septic Tanks Work Ideas. The sewage then forms the three layers as mentioned. Septic tanks work by collecting the water waste and human excreta in a large underground tank, basically this is how it is used in rural areas. A septic tank should only need emptying when the solids levels have built up within the tank. Septic tanks work by collecting the water waste and human excreta in a large underground tank, basically this is how it is used in rural areas. To understand more easily how a septic tank works we have broken it down into stages: