An electric aerator pumps oxygen into the tank so bacteria break down waste faster and more completely, producing much cleaner effluent than a conventional septic tank. That lets the dispersal field be smaller — sometimes even a spray field. Aerobic systems cost roughly double a conventional install and legally require a maintenance contract (commonly $300–$600 a year) because they have moving parts a regulator inspects.
Small or tight lots, marginal soil, or counties that mandate a higher treatment standard before dispersal.
| Bedrooms | Estimated installed cost |
|---|---|
| 1–2 bedrooms (750-gal tank) | $8,500 – $17,000 |
| 3 bedrooms (1,000-gal tank) | $10,000 – $20,000 |
| 4 bedrooms (1,250-gal tank) | $11,500 – $23,000 |
| 5+ bedrooms (1,500-gal tank) | $13,500 – $27,000 |
Soil condition and region can move these numbers 25–35% in either direction — use the full calculator for a range tuned to your site.
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