This is where treated wastewater enters the soil; failures are common in this component of the OWTS. Since the plastic (PVC) pipes in the bed are usually one foot deep or less, they are quite susceptible to damage.
Vehicles should never be driven or parked on an absorption bed. In addition, to the potential pipe damage, the soil may be compacted. This will prevent proper absorption of the sewage. Animals such as cattle or horses may also compact the soil and damage pipes. If your OWTS is in a pasture, it should be fenced to keep out livestock.
Erosion can seriously affect an OWTS by removing the soil cover and allowing sewage to escape from the bed. This can be prevented by maintaining proper drainage and establishing a good vegetative cover (excluding trees) above the bed. If the bed is located in a lawn area, watering should be restricted to prevent saturation of the ground.