a cross-section diagram of a typical residential septic system, specifically focusing on the secondary treatment stage known as the drain field (or leach field). The graphic illustrates how wastewater travels from the home, through initial treatment, and finally back into the soil. COMPONENT BREAKDOWN • Septic Tank: This is the primary treatment area. Waste from the house enters this underground, watertight container. Heavy solids settle to the bottom (sludge), while grease and lighter solids fl