What purpose does a leach field serve in sewage disposal?

A leach field serves a vital role in the sewage disposal process by distributing effluent from a septic tank into the surrounding soil, allowing for natural filtration and treatment. After waste is processed in the septic tank, where solids settle and some biological treatment occurs, the effluent – which contains nutrients and microbes – is directed into the leach field.

The leach field consists of a network of perforated pipes laid within gravel-filled trenches or beds. As the effluent seeps out of these pipes, it infiltrates the soil surrounding the trenches. This soil acts as a natural filter, breaking down pathogens and nutrients through microbial activity while also absorbing excess water, thereby ensuring that the effluent is treated before it reaches the groundwater or surface water. This process prevents contamination of drinking water and protects the environment.

Therefore, the leach field is essential to effectively managing treated wastewater and safeguarding public health by taking advantage of the natural filtration capacity of soil.