What is the primary purpose of a wastewater infiltration trench?

The primary purpose of a wastewater infiltration trench is for the treatment and disposal of domestic wastewater. Infiltration trenches are designed to manage the effluent from septic systems by allowing it to percolate through the soil, where natural processes provide the necessary treatment. This involves microbial action that breaks down contaminants, thus ensuring that the treated water is safely absorbed into the ground and does not pose a risk to groundwater or surface water quality.

While options that mention storage or filtering heavy metals might describe certain aspects associated with some wastewater management systems, they do not accurately reflect the main function of an infiltration trench, which is focused on the effective treatment and safe disposal of wastewater through soil medium. Emergency storage is also not a primary function of infiltration trenches, as they are not designed to hold wastewater but rather to facilitate its infiltration and treatment.