Florida · Florida Administrative Code Chapter 64E-6
Regulatory authority for onsite systems transferred from the Department of Health to the Florida Department of Environmental Protection, with county health department staff continuing to handle permitting.
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.
Sand, and a water table that is rarely far below it. Florida's soils percolate well but the seasonal high water table is the constraint on almost every site. Limestone karst in parts of the state adds groundwater protection concerns.
Mounded and filled systems are extremely common because of the water table. Aerobic treatment units appear where nitrogen reduction is required, and performance-based treatment systems are used on constrained sites.
| Dwelling | Design flow | Minimum tank | With disposal |
|---|---|---|---|
| 1 bedroom | 300 gpd | 900 gal | 1,150 gal |
| 2 bedrooms | 300 gpd | 900 gal | 1,150 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 |
Florida requires a site evaluation establishing the seasonal high water table, and the system is then set at an elevation that maintains required separation. Nitrogen reduction requirements apply in springs protection areas and parts of the Keys and coastal zones.
The state sets a floor. These Florida counties are where the largest septic populations sit, and where local requirements most often exceed it.
| County | What makes it different |
|---|---|
| Marion | Ocala area; large septic population over the Floridan aquifer with springs protection rules |
| Polk | Central Florida growth on sandy soils |
| Lee | Southwest coast; high water table and dense septic development |
| Volusia | Springs protection area requirements |
| Pasco | Rapid growth north of Tampa |
| Santa Rosa | Panhandle growth, sandy soils and coastal setbacks |
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.
Florida requires operating permits and maintenance contracts for aerobic treatment units and performance-based systems. Use the pump schedule calculator to work out the interval for your tank size and household.
Regional labour and permit costs in Florida run about 98% of the national baseline. Here is what typical installations land at for a three-bedroom home:
| System type | Typical installed cost in Florida | When it applies |
|---|---|---|
| Conventional gravity | $8,800 – $15,700 | Good soil, adequate depth to water |
| Chamber system | $9,700 – $18,100 | Alternative to gravel trenches |
| Mound system | $16,700 – $33,000 | Shallow water table or thin soil |
| Aerobic treatment | $14,100 – $28,300 | Clay soil or small lots |
| Tank pump-out (service) | $310 – $640 | 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 Florida Administrative Code Chapter 64E-6, Standards for Onsite Sewage Treatment and Disposal Systems. County and health district rules routinely exceed them, code text changes, and only Florida DEP — Onsite Sewage Programs or your local health department can confirm what applies to your parcel.
Send your sizing numbers to installers who work under Florida rules every day.