How a leach field works
Liquid from the tank flows to a distribution box, which sends it evenly into several trenches. In each trench, perforated pipe lets it trickle into gravel or plastic chambers, then into the soil below, where natural processes treat it before it reaches groundwater.
What sets the size
- Soil — how quickly it absorbs water and how well it treats it.
- Depth — to rock, caliche or groundwater.
- House size — usually based on bedrooms.
- Setbacks — from wells, property lines, buildings and drainages.
Gravel or chambers
Gravel trenches
The traditional build: pipe set in washed gravel and covered.
Chambers
Plastic arches that leave open space under them; lighter to install. See chamber systems.
A reserve area
Good planning leaves room on the lot for a future replacement field. On larger Edgewood lots that's usually easy; on smaller lots it takes planning.
See leach field replacement in Edgewood.
Septic questions
How long does a leach field last?
Many last 20–30 years or more with regular tank pumping and normal water use.
Can I drive on my leach field?
No — vehicles compact the soil and can crush pipes or chambers.
Can I plant over it?
Grass and shallow-rooted plants are fine; keep trees and shrubs away.