Sourced from Georgia DPH Manual for On-Site Sewage Management Systems, Section D — Aerobic Treatment Units (March 2026 edition), NSF/ANSI Standard 40, and GA Chapter 511-3-1 — last checked July 2026.
Georgia Septic Guide — Free Tool
Do I Need an Aerobic System?
Georgia’s Piedmont red clay means many properties can’t support a conventional gravity system. This tool gives a directional read on whether your site conditions point toward an aerobic treatment unit (ATU) — or, if you already own one, what that means for your maintenance obligations.
Directional estimate only — a Level 3 soil report by a Georgia Certified Soil Classifier and a county environmental health site evaluation determine what DPH will actually permit on your specific property. Aerobic system maintenance requirements cited from the GA DPH Manual for On-Site Sewage Management Systems, Section D (March 2026).
What Makes an ATU Different
A conventional system is passive — wastewater flows by gravity through a tank and into a drainfield. An ATU is active — it introduces atmospheric air so aerobic bacteria treat the wastewater inside the unit, producing cleaner effluent (Class I quality: CBOD5 of 25 mg/L, TSS of 30 mg/L, tested to NSF/ANSI Standard 40).
That cleaner effluent is why ATUs can be permitted on tighter sites. Georgia allows a minimum vertical separation of just 12 inches above groundwater for ATU-quality effluent, compared to 24 inches for conventional. On a Piedmont lot where the seasonal water table sits 18 inches below the drainfield, a conventional system can’t be permitted but an ATU can.
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Georgia’s ATU Maintenance Requirements
The initial three-year service policy is furnished by the manufacturer, with cost included in the purchase price. Six inspection/service visits covering electrical, mechanical, and other components.
After three years: the owner must purchase an extended service policy or ensure equivalent maintenance. This obligation does not expire.
Emergency service within 48 hours of a request is required under the service policy.
The alarm is mandatory — visible from 50 feet, audible at 60–75 dBA from 5 feet. ATU performance degrades after approximately 48–72 hours without aeration. Do not ignore or disconnect it.
Where ATUs Are Most Common in Georgia
The Piedmont’s Cecil series red clay defines the metro Atlanta region and is the primary driver of ATU prevalence in Georgia. In parts of Cobb, DeKalb, and Gwinnett counties, where lots are small and soils tight, engineered designs — including ATUs — are now the norm rather than the exception. The Blue Ridge mountain counties face similar requirements due to thin soils over bedrock.
Cost Implications
ATU systems cost $10,000–$25,000+ installed in Georgia’s Piedmont region. The ongoing maintenance cost (six-month service visits) adds a recurring expense that conventional system owners don’t have. But on a property where a conventional system genuinely can’t be permitted, the ATU isn’t the expensive option — it’s the only option.
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Frequently Asked Questions
How often do ATUs need inspection in Georgia?
Every six months per DPH Manual. The quarterly figure is Texas's rule, not Georgia's.
How much does an ATU cost in Georgia?
No Georgia agency publishes an ATU price. The EPA puts repair or replacement of a conventional system at $5,000 to $15,000 nationally, and says alternative systems cost more. An ATU is an alternative system, so it sits in the higher category, and it also carries an ongoing maintenance contract a conventional system does not.
Why are ATUs common in metro Atlanta?
Piedmont clay is too slow for conventional systems. Engineered designs are the norm on tight lots.
Can any installer work on an ATU?
No. Must be a manufacturer's authorized representative. Only Approved List models may be permitted.