Aerobic / ATU Septic System Cost in Maine
Estimated 2026 installed range: $9,400 – $21,200
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Open the cost calculatorWhy Maine prices differ
Statewide cost drivers here are freeze depth, bedrock and older housing stock. Locally, shallow bedrock and frost depth are the two biggest cost drivers. That is why a aerobic / atu system in Maine can land well above or below the national range of $8,000–$18,000.
All system types in Maine
| System | Low | High |
|---|---|---|
| Conventional | $4,100 | $9,400 |
| Chamber | $5,900 | $13,000 |
| Aerobic / ATU | $9,400 | $21,200 |
| Mound | $11,800 | $26,000 |
| Sand filter | $9,400 | $18,900 |
What aerobic / atu systems are for
Aerobic treatment units add oxygen to break down waste faster. They are used on tight or wet lots, require electricity, and need periodic maintenance.