Soil and perc tests in Orange County, North Carolina

USDA rates most of the soil in Orange County Somewhat limited for septic absorption fields — 62.9% of the rated acres. No USDA NRCS Soil Data Access (SSURGO) · checked 2026-10-06

Somewhat limited

USDA rating, 62.9% of rated acres

checked 2026-10-06

Slow water movement

Most common limiting reason

checked 2026-10-06

Yes

Site evaluation required

checked 2026-09-23

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

The rule does not require a percolation test.

N.C. Department of Health and Human Services — On-Site Water Protection · checked 2026-09-23

How USDA rates the ground in Orange County

Somewhat limited across most of the county — 62.9% of the rated acres. A rating describes the ground, not a parcel. The county's site evaluation decides each lot.

Somewhat limited — 154,855 acres — 62.9% of 246,214 rated acres.
Very limited — 91,359 acres — 37.1% of 246,214 rated acres.
Not rated — 4,919 acres, excluded from the denominator — mostly urban land and water.

62.9% of 246,214 rated acres. 4,919 acres unrated. Survey area NC135 version 27, established 2026-08-31.

USDA NRCS Soil Data Access (SSURGO) · checked 2026-10-06

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.

Slow water movement — 237,617 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Depth to bedrock — 56,620 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Depth to saturated zone — 50,060 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Slope — 37,049 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Seepage, bottom layer — 23,313 acres. Reasons overlap — a component can carry several — so these acres exceed rated acres.
Flooding — 14,037 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.

GeB — Georgeville silt loam, 2 to 6 percent slopes — 49,114 acres in this county — rated Somewhat limited. Dominant component: Georgeville (90% of the map unit).
GeC — Georgeville silt loam, 6 to 10 percent slopes — 31,426 acres in this county — rated Somewhat limited. Dominant component: Georgeville (90% of the map unit).
HrB — Herndon silt loam, 2 to 6 percent slopes — 27,054 acres in this county — rated Somewhat limited. Dominant component: Herndon (90% of the map unit).
TaD — Tarrus silt loam, 8 to 15 percent slopes — 15,200 acres in this county — rated Somewhat limited. Dominant component: Tarrus (75% of the map unit).
HrC — Herndon silt loam, 6 to 10 percent slopes — 14,379 acres in this county — rated Somewhat limited. Dominant component: Herndon (80% of the map unit).
ApB — Appling sandy loam, 2 to 6 percent slopes — 14,165 acres in this county — rated Somewhat limited. Dominant component: Appling (92% of the map unit).
HeB — Helena sandy loam, 2 to 8 percent slopes — 13,584 acres in this county — rated Very limited. Dominant component: Helena (90% of the map unit).
Ch — Chewacla loam, 0 to 2 percent slopes, frequently flooded — 11,903 acres in this county — rated Very limited. Dominant component: Chewacla (90% of the map unit).

USDA NRCS Soil Data Access (SSURGO) · checked 2026-10-06

Sources

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

Orange County Government — Septic Systems · checked 2026-10-05
Orange County Health Department — 2023 Installer Handbook · checked 2026-10-05
Orange County Environmental Health — Septic and Well Permit Application · checked 2026-10-05
Orange County Rules for Onsite Wastewater Treatment and Dispersal Systems, Rule .0202(d) · checked 2026-10-05
Orange County — FY 2025-26 Commissioner Approved Fee Schedule · checked 2026-10-05
N.C. Department of Health and Human Services — On-Site Water Protection · checked 2026-09-23
USDA NRCS Soil Data Access (SSURGO) · checked 2026-10-06

Verify before you act. Septic rules are set locally and they change. Check anything here before you spend money on it. Call the Orange County Environmental Health, on 919-245-2360.