Soil and perc tests in Polk County, Florida

USDA rates most of the soil in Polk County Very limited for septic absorption fields — 97.4% of the rated acres. State rule 62-6.004 requires a site evaluation of the lot's soil, water table and slope. The department must have that evaluation before it issues a construction permit. USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-22

Very limited

USDA rating, 97.4% of rated acres

checked 2026-09-22

Depth to saturated zone

Most common limiting reason

checked 2026-09-22

Yes

Site evaluation required

checked 2026-09-23

What is a perc test and does Polk County require one?

Yes. State rule 62-6.004 requires a site evaluation of the lot's soil, water table and slope. The department must have that evaluation before it issues a construction permit.

An engineer, a department employee, a contractor or a soil scientist may do the evaluation. It must include two soil checks. Each must reach six feet deep in the drainfield.

Florida Administrative Code, Rule 62-6.004, Application for System Construction Permit · checked 2026-09-23

How USDA rates the ground in Polk County

Very limited across most of the county — 97.4% of the rated acres. A rating describes the ground, not a parcel. The county's site evaluation decides each lot.

Very limited — 1,065,138 acres — 97.4% of 1,093,152 rated acres.
Somewhat limited — 25,968 acres — 2.4% of 1,093,152 rated acres.
Not limited — 2,046 acres — 0.2% of 1,093,152 rated acres.
Not rated — 148,789 acres, excluded from the denominator — mostly urban land and water.

97.4% of 1,093,152 rated acres. 148,789 acres unrated. Survey area FL105 version 23, established 2025-08-29.

USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-22

What limits absorption here

The reasons USDA gives for the rating, by the acres they affect. A component can carry several, so the acres overlap.

Depth to saturated zone — 889,144 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Seepage, bottom layer — 868,689 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Filtering capacity — 490,740 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Slow water movement — 366,355 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Ponding — 264,269 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Subsidence — 118,832 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Flooding — 24,042 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Slope — 19,380 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Depth to bedrock — 2,465 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.

Ratings by soil map unit

The largest map units in the county, each with its rating. A soil survey names the ground. The county's evaluation of your lot is what a permit turns on.

17 — Smyrna and Myakka fine sands — 144,718 acres in this county — rated Very limited. Dominant component: Smyrna (41% of the map unit).
99 — Water — 105,018 acres in this county — rated Not rated. Dominant component: Water (100% of the map unit).
3 — Candler sand, 0 to 5 percent slopes — 97,496 acres in this county — rated Very limited. Dominant component: Candler (90% of the map unit).
7 — Pomona fine sand — 91,570 acres in this county — rated Very limited. Dominant component: Pomona (70% of the map unit).
13 — Samsula muck, frequently ponded, 0 to 1 percent slopes — 53,893 acres in this county — rated Very limited. Dominant component: Samsula (85% of the map unit).
15 — Tavares fine sand, 0 to 5 percent slopes — 53,679 acres in this county — rated Very limited. Dominant component: Tavares (85% of the map unit).
35 — Hontoon muck, frequently ponded, 0 to 1 percent slopes — 50,474 acres in this county — rated Very limited. Dominant component: Hontoon (85% of the map unit).
8 — Hydraquents, clayey — 49,435 acres in this county — rated Very limited. Dominant component: Hydraquents, clayey (95% of the map unit).

USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-22

Sources

Each figure on this page has a government source and a checked-on date.

Florida Department of Health in Polk County — Septic Tanks, Onsite Sewage Treatment & Disposal Systems · checked 2026-09-23
Florida Department of Health in Polk County — Environmental Health · checked 2026-09-23
Florida Administrative Code, Rule 62-6.030, Fees · checked 2026-09-23
USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-22

Verify before you act. Septic rules are set locally and they change. Check anything here before you spend money on it. Call the Florida Department of Health in Polk County, Environmental Public Health, on 863-519-8330.