Drain Field
If you have a septic system, the final place your home’s wastewater goes is your drain field. Here, the effluent that drains out from your septic tank is percolated into the ground in a natural manner. If you don’t currently use septic or you recently moved into a house with one of these systems, there are a few things you need to know about your drain field.


Most drain fields consist of a series of perforated pipes that are set in shallow, long trenches. These trenches are filled with gravel and then placed beneath the surface of the ground. The gravel serves two main purposes:

  1. To distribute the wastewater over a large surface area
  2. To help the wastewater seep into the underlying layers of soil

How big your drain field is and its capacity to absorb effluent from your home depends on several different factors, including the topography of your landscaping and the texture of your soil.

The Treatment Process

When wastewater leaves your home, it slowly trickles out of your drain field’s pipes and makes its way through the gravel, where it can eventually be absorbed by the soil. Once the wastewater reaches the soil, a wide range of biological, chemical, and physical processes are put into motion. For example, in the soil, bacteria and other small organisms are responsible for consuming any organic matter that was included in the wastewater. These organisms also kill any bacteria that might have been included in the effluent.