What is the function of a drain field in a septic system?

The function of a drain field in a septic system primarily revolves around the process of treating and disposing of effluent—liquid waste that has been partially treated by the septic tank. When wastewater flows from the septic tank, it is directed into the drain field, which consists of a network of perforated pipes laid in gravel-filled trenches.

The primary purpose of the drain field is to allow the treated effluent to be absorbed into the soil. As the effluent seeps into the surrounding soil, several important processes occur. Soil microorganisms break down remaining contaminants in the effluent, effectively filtering the water and reducing the harmful effects of pathogens and nutrients. This process transforms the effluent into clean water that can be safely absorbed into the groundwater system.

This absorption and treatment process makes the drain field an essential component of a septic system, ensuring that the system functions effectively and minimizes the potential for groundwater pollution. Other functions, like the filtering of solid waste, storage of untreated sewage, or mixing of treatment types, are not functions ascribed to the drain field itself but rather pertain to other components or processes within the overall septic system.