An underground storage area to allow liquids from primary treatment or graywater to soak into the ground. Typically a soil covered, stone filled pit with perforated distribution pipes.
Treatment Level: Secondary
Relative Cost: medium
Amount of Maintenance Interaction: low
Beneficial Byproduct: none
- Very little maintenance needed.
- Nutrients and water source are beneficial for healthy ground cover over the field.
- Groundwater recharge.
- Takes up a lot of space that cannot be built upon.
- Success depends on ability of soils to absorb water.
- Not suited for areas with high groundwater, lots of rock or clay, or within a 50 ft radius of drinking water source.
Operation & Maintenance
- Inspect for ponded water on surface.
- Inspect the primary treatment measure to ensure that solids cannot migrate downstream.
- Typical life of a drainf ield is 50 years. If it fails, it must be relocated or replaced with an alternative technology.
- Best to keep stormwater drainage directed away from the drainf ield as much as possible.
- Important not to compact the field with heavy equipment or impervious surfaces.