Georgia · Georgia Rules and Regulations Chapter 511-3-1
The Georgia Department of Public Health writes the rules and county boards of health issue permits and inspect installations.
Minimum tank
One to three bedroom dwelling.
Design flow
Held two days for settling.
Cost index
Regional labour and permits.
Sets the design flow and the legal minimum.
Code sizes on bedrooms, not people.
Used to size the matching drainfield. Unsure? Sandy loam is the common default.
Red clay across the piedmont — slow percolation and the reason so many north Georgia fields are oversized. The coastal plain in the south is sandy and permits easily. Shallow rock appears in the north Georgia mountains.
Conventional trenches with generous field sizing in the piedmont clay. Chamber systems are widely used. Alternative and advanced systems appear where clay percolation fails outright.
| Dwelling | Design flow | Minimum tank | With disposal |
|---|---|---|---|
| 1 bedroom | 300 gpd | 1,000 gal | 1,250 gal |
| 2 bedrooms | 300 gpd | 1,000 gal | 1,250 gal |
| 3 bedrooms | 450 gpd | 1,000 gal | 1,250 gal |
| 4 bedrooms | 600 gpd | 1,250 gal | 1,500 gal |
| 5 bedrooms | 750 gpd | 1,500 gal | 1,750 gal |
Georgia requires a soil classification by a health department official or a certified soil classifier, and the installer must be a certified installer. The county has authority to require more than the state minimum.
The state sets a floor. These Georgia counties are where the largest septic populations sit, and where local requirements most often exceed it.
| County | What makes it different |
|---|---|
| Gwinnett | Heavy suburban septic use on piedmont clay |
| Cherokee | Rapid growth north of Atlanta, clay and rock |
| Forsyth | Fast-growing, large septic population |
| Hall | Lake Lanier area with strict setbacks from the reservoir |
| Paulding | Suburban growth on clay soils |
| Effingham | Coastal plain sand, easier permitting |
A three-bedroom home at 150 gallons per bedroom produces 450 gallons per day of design flow. On sandy loam that needs roughly 750 square feet of absorption area. On clay loam it rises to about 2,250 square feet, and on clay a conventional field is usually not permitted at all. Run your own soil class through the drainfield calculator.
Georgia does not mandate a residential pumping interval, but counties may impose maintenance requirements on advanced systems. Use the pump schedule calculator to work out the interval for your tank size and household.
Regional labour and permit costs in Georgia run about 92% of the national baseline. Here is what typical installations land at for a three-bedroom home:
| System type | Typical installed cost in Georgia | When it applies |
|---|---|---|
| Conventional gravity | $8,300 – $14,700 | Good soil, adequate depth to water |
| Chamber system | $9,100 – $16,900 | Alternative to gravel trenches |
| Mound system | $15,800 – $30,900 | Shallow water table or thin soil |
| Aerobic treatment | $13,300 – $26,500 | Clay soil or small lots |
| Tank pump-out (service) | $290 – $600 | Every 3–5 years |
Replacing an existing system costs more than these figures — old-system removal and re-permitting add to every line. The replacement cost calculator covers that case, and the cost estimator adjusts all of the above for your bedroom count and soil.
Verify before you build. The figures above are state minimums compiled for planning, drawn from Georgia Rules and Regulations Chapter 511-3-1, On-Site Sewage Management Systems. County and health district rules routinely exceed them, code text changes, and only Georgia DPH — Environmental Health, Onsite Sewage or your local health department can confirm what applies to your parcel.
Send your sizing numbers to installers who work under Georgia rules every day.