Every septic system—whether it’s conventional, Infiltrator, Eljen, Ecoflo, Jet, or a sand mound—follows the same basic path. Here is the full treatment sequence from the house to the earth:
1. Wastewater Leaves the Home
All drains (sinks, showers, laundry, and toilets) flow out through the building sewer line and into the septic tank.
2. Primary Treatment – The Septic Tank
Inside the tank, three things happen:
- Solids sink to the bottom (sludge)
- Oils and grease float to the top (scum)
- Clear effluent remains in the middle
The tank performs the first major cleaning step by separating solids and starting anaerobic digestion.
3. Secondary Treatment (If Required)
Some properties use an additional treatment unit depending on soil conditions and design:
- Ecoflo Biofilter
- Eljen GSF modules
- Jet or Norweco ATU
- Other advanced treatment units
These systems improve effluent quality before it enters the soil.
(Conventional systems skip this step.)
4. Effluent Distribution
Treated wastewater is then delivered to the soil absorption area by either:
- Gravity flow,
- A pump (pressure dosing), or
- A distribution box or manifold.
This ensures even dispersal throughout the field.
5. Final Treatment – The Soil
This is the most important step.
Once effluent reaches the absorption trenches, at-grade bed, sand mound, or drip field, the natural soil performs the final purification:
- Filters remaining solids
- Breaks down bacteria, viruses, and pathogens
- Removes nutrients
- Protects groundwater and wells
The soil is always the last and most critical treatment stage in every septic system.
6. Clean Water Returns to the Ground
After passing through the soil, the fully treated water percolates down and safely reenters the groundwater.