In a septic system for handling household waste water, used vehicle tires are employed to form the septic tank and the leaching galleries. Vehicle tires sealed to one another and in combination with end caps provide a watertight and lighttight enclosure in the septic tank. An inlet conduit permits the influx of sewage into the enclosure while an outlet conduit allows egress of effluent from the enclosure via hydrostatic pressure. The drain field used with the system and also useful for other purpose has tires axially aligned forming an array with each tire defining an interior hollow chamber. A delivery conduit leading from the outlet conduit of the septic tank introduces effluent into the hollow chambers of the vehicle tires where it is allowed to seep therefrom into the surrounding earth through apertures in the walls of the tires. The tires in the drain field can be horizontally aligned or can be in a vertical stacking arrangement similar to the arrangement found in the septic tank.