How a Septic Drainfield Works
What happens after effluent leaves the septic tank and enters the soil treatment area.
The drainfield is not just a place where wastewater disappears. It distributes tank effluent into soil where additional treatment occurs.
Distribution
Effluent reaches trenches, chambers, drip lines or another approved dispersal design.
Soil treatment
Physical filtration, microbial activity and chemical interactions in unsaturated soil reduce contaminants.
Why saturation matters
Too much water too quickly can reduce the soil's ability to accept effluent.
Why solids matter
Solids escaping the tank can clog distribution components or soil interfaces and shorten field life.