Concrete septic tanksEquipment for treating and filtering feces. The principle is that the solid matter decomposes at the bottom of the pool, while the hydrated matter on top flows into the pipeline and is carried away, preventing pipeline blockages and allowing sufficient time for the solid matter (faeces and other waste) to hydrolyze. Septic tank refers to a small treatment structure that separates and sedimentates domestic wastewater and undergoes anaerobic digestion of sludge.