What is the function of a leach field in wastewater treatment?

The function of a leach field in wastewater treatment is to allow treated effluent to percolate into the soil. This process is critical for the final treatment of wastewater, as it relies on the natural filtration and biological processes that occur in the soil. When treated effluent is discharged into the leach field, the soil acts as a filter that further purifies the water by removing harmful pathogens, nutrients, and contaminants through various mechanisms, including absorption, microbial activity, and physical filtering.

The design of a leach field typically includes a network of perforated pipes laid in gravel or stone beds, enabling the effluent to spread out and come into contact with a larger surface area of soil. This enhances the overall treatment process and ensures that only clean water eventually rejoins the groundwater or is naturally assimilated into the environment.

The other options do not accurately reflect the primary role of a leach field in the wastewater treatment process. Storing untreated sewage contradicts the purpose of effective wastewater management, while chemical disinfection and sludge treatment pertain to different aspects of wastewater processing altogether.