What is the function of absorption fields in septic systems?

The function of absorption fields in septic systems is to absorb and treat effluent. After wastewater from a home flows into the septic tank, solids settle at the bottom while lighter materials such as fats and oils float to the top. The liquid that remains, known as effluent, is then directed to the absorption field, also referred to as a drain field.

In the absorption field, the effluent percolates through soil layers, which act as natural filters. The soil microorganisms help break down bacteria and contaminants present in the effluent, ensuring that the treated water can safely re-enter the groundwater system. This process is crucial for preventing groundwater contamination and protecting public health.

While filtering solid waste primarily occurs in the septic tank and not in the absorption field, it is the absorption field's role in the absorption and treatment of effluent that is vital for the overall function of the septic system. Storing sewage is not a function of the absorption field, as it is designed for temporary treatment and not for long-term storage. Additionally, although greywater may be part of the effluent entering a septic system, the absorption field's primary task is to handle and treat all wastewater rather than specifically processing only greywater.