Trash Tank
Solids settle out first
Aeration Chamber
Aerator adds oxygen for bacteria
Disinfection
Chlorine or UV treatment
Spray Field
Treated water disperses
The Basic Process
An aerobic septic system treats wastewater in three stages: pretreatment in a trash tank, aerobic treatment in a chamber where an aerator pumps oxygen into the wastewater, and final disinfection or dispersal, often through a spray field. The oxygen feeds naturally occurring bacteria that break down waste far more thoroughly than a conventional system's passive settling process.
Why Oxygen Makes the Difference
Conventional systems rely on gravity and time — solids settle, and the remaining liquid slowly filters through soil in a drain field. Aerobic systems speed this up mechanically. The aerator, essentially a small air pump, keeps the treatment chamber oxygenated around the clock, which lets aerobic bacteria (the same type used in municipal treatment plants) process waste faster and more completely than the anaerobic bacteria in a conventional tank.
Where the Treated Water Goes
Once treated, the effluent is typically disinfected (often with a chlorine or UV unit) and dispersed through a spray field or a smaller drip irrigation system — both of which need much less land than a conventional drain field. This is the main reason aerobic systems are so common on smaller lots and in soil that drains poorly.
The Control Panel
Every aerobic system has an electrical control panel that monitors the aerator, alarms, and (on many systems) the disinfection unit. This panel is also the first place a technician looks when something's wrong — most alarms trace back to a float switch, the aerator motor, or a power interruption.
Key Takeaways
- Aerobic systems use an aerator to add oxygen, speeding up bacterial treatment of wastewater.
- Treated effluent is dispersed through a spray field or drip system, needing far less land than a conventional drain field.
- The electrical control panel is the nerve center of the system and the first diagnostic stop for most issues.
Frequently Asked Questions
Yes. The aerator and control panel run on electricity, which is why power outages can affect system performance and trigger alarms.
Most systems use a chlorine tablet feeder or a UV disinfection unit before the water reaches the spray field.
Most lots can support one, which is exactly why they're popular on smaller or poorly-draining properties where a conventional system isn't feasible.