Concrete septic tanksEquipment for treating feces and filtering out sediments. The principle is that solid matter decomposes at the bottom of the pool, while the hydrated matter above flows into pipes and is removed, preventing pipe blockages and allowing sufficient time for the solid matter (such as feces and waste) to hydrolyze. Septic tank refers to a small treatment structure that separates and sedimentates domestic wastewater and anaerobically digests sludge.