What is the primary purpose of a septic system?

The primary purpose of a septic system is to treat and dispose of household wastewater. This system is designed to handle sewage from bathrooms, kitchens, and laundry areas, breaking it down through natural processes. A septic system typically consists of a septic tank and a drain field (or leach field). In the septic tank, solid waste settles at the bottom, and bacteria begin to decompose it, while the liquid effluent flows into the drain field where it is further treated by soil microorganisms before it reenters the groundwater.

The functionality of a septic system is essential for public health, as it prevents untreated sewage from contaminating groundwater and surface water, which can lead to environmental and health hazards. This core function distinguishes septic systems from other options, which either pertain to stormwater management, rainwater harvesting, or soil management and fertility. These alternatives serve different purposes and are not part of the typical septic system installation or operation.