How a Residential Septic System Treats and Disposes of Wastewater This image illustrates the full process of a modern residential septic system, showing how wastewater moves from a home through multiple treatment stages before being safely released into the environment. Each component plays a specific role in protecting human health, groundwater, and surrounding soil. Wastewater Flow from the Home The process begins inside the house, where wastewater from toilets, sinks, and showers flows downwa