Soil series profile

Bibb soil series

Bibb is a poorly drained soil with a silt loam surface, mapped on 2,293,716 acres in 246 counties across 12 states. Hydrologic group B/D.

#27 by mapped area coarse-loamy Typic Fluvaquents (Entisols)

Drainage class
Poorly drained
>99% of mapped acres
Hydrologic group
B/D
70% of mapped acres
Typical topsoil pH
4.6
very strongly acidic · range 4.6–5.2
Mapped area
2.3M
acres in 246 counties, 12 states

Typical Bibb profile

Texture and pH by depth

Typical Bibb soil profile by depth 0 in 20 in 40 in 60 in 0–8 in · Ag · pH 5.3 · 16% clay Silt loam 8–28 in · Cg1 · pH 5.3 · 14% clay Silt loam 28–80 in · Cg2 · pH 5.3 · 20% clay Silt loam
Depth to scale. More strongly shaded layers hold more clay. Horizon names are the soil survey's (A = topsoil, B = subsoil, C = parent material).
Show as a table
Typical Bibb horizons (representative values)
Depth Texture pH Clay Sand Organic matter
0–8 in (Ag) Silt loam 5.3 16% 14% 2.25%
8–28 in (Cg1) Silt loam 5.3 14% 33% 0.75%
28–80 in (Cg2) Silt loam 5.3 20% 30% 0.5%

Representative values from the most extensive Bibb map unit (Bibb silt loam, 0 to 1 percent slopes, frequently flooded, survey area AR011). Other map units of this series vary within the series range.

Hands holding dark garden soil
Stock photo for illustration, not a sample of this soil series. Credit on the Sources & method page.

What this means

What Bibb soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Bibb soils is very strongly acidic: pH 4.6 (most land between 4.6 and 5.2). Most vegetables and lawn grasses do best around 6.0 to 7.0, so lime is often needed; blueberries, azaleas and rhododendrons like it as it is.

Loamy topsoil (loam, silt loam and similar) covers 86% of mapped Bibb acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is fine sandy loam (43% of mapped Bibb acres).

>99% of mapped Bibb acres is somewhat poorly to very poorly drained, so soil stays soggy for long spells after rain and in wet seasons. Raised beds, plants that tolerate wet feet, and not working the soil while wet all help.

For lawns and yards

On >99% of mapped acres, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.

A seasonal high water table comes within 18 inches of the surface on >99% of mapped acres, often in spring. Basements, sump pumps and lawns in low spots feel it first.

For a septic system

For conventional septic absorption fields, NRCS rates >99% of the acres in mapped Bibb soils very limited, 0% somewhat limited and 0% not limited.

Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.

Flooding is mapped on >99% of the acres (6% occasional, 93% frequent).

Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.

Generated from the mapped numbers above using fixed rules, not a site visit. See how these notes are written.

Where Bibb soil is found

Mapped acres

Bibb is mapped in Alabama, Georgia, Mississippi, North Carolina, Arkansas, Florida, Virginia, Tennessee, Louisiana, South Carolina, Texas and District of Columbia. The 60 counties with the most Bibb acres:

Counties with the most mapped Bibb soil
County Acres Share of county land
Bradley County, AR 71,975 17.3%
Newton County, MS 65,209 19.0%
Escambia County, AL 58,188 10.8%
Washington County, AL 40,262 6.5%
Sampson County, NC 38,696 6.8%
Monroe County, AL 38,336 6.8%
Neshoba County, MS 36,357 10.5%
Clarke County, MS 35,118 8.2%
Choctaw County, AL 34,691 6.8%
Baldwin County, AL 32,939 3.4%
Henderson County, TN 32,397 9.8%
Liberty County, FL 31,247 5.8%
Southampton County, VA 28,072 8.2%
Mobile County, AL 27,965 4.0%
Santa Rosa County, FL 27,603 3.8%
Wayne County, MS 27,069 5.6%
Twiggs County, GA 27,045 12.4%
Houston County, GA 25,924 10.9%
Conecuh County, AL 25,720 5.4%
Clarke County, AL 25,051 3.6%
Marion County, MS 24,663 7.4%
Coffee County, AL 24,135 6.4%
Johnston County, NC 23,919 5.2%
Bibb County, AL 23,739 6.7%
McNairy County, TN 23,723 6.6%
Jones County, MS 23,300 5.5%
Ouachita County, AR 23,085 4.9%
Harnett County, NC 22,757 6.4%
Washington Parish, LA 22,565 5.3%
Emanuel County, GA 22,368 5.7%
Moore County, NC 22,070 5.5%
Dodge County, GA 21,577 7.9%
Covington County, AL 20,260 3.4%
Columbia County, AR 20,244 4.2%
Crenshaw County, AL 19,827 5.7%
Perry County, MS 19,708 4.9%
Robeson County, NC 19,681 3.4%
Union County, AR 19,083 2.9%
Autauga County, AL 19,020 6.2%
Butler County, AL 18,686 4.2%
Greene County, MS 18,032 4.0%
Pitt County, NC 17,617 4.6%
Jasper County, MS 17,519 4.3%
Holmes County, FL 17,386 5.6%
Washington County, GA 17,205 4.6%
Wayne County, NC 16,802 5.1%
Duplin County, NC 16,689 3.6%
Marion County, GA 16,590 7.1%
Wilson County, NC 16,587 7.5%
Hale County, AL 15,978 4.5%
Martin County, NC 15,693 5.8%
Nevada County, AR 15,629 4.0%
Gadsden County, FL 15,511 4.7%
St. Tammany Parish, LA 15,487 2.8%
Geneva County, AL 15,425 4.8%
Pearl River County, MS 15,003 3.3%
Barbour County, AL 14,874 3.1%
Grant County, AR 14,598 3.6%
Bertie County, NC 14,355 3.5%
Aiken County, SC 14,348 2.1%

Septic absorption fields

NRCS rating, share of Bibb acres

Not limited 0%
Somewhat limited 0%
Very limited >99%
Not rated <1%
Septic tank absorption field rating across mapped Bibb acres. Scale 0 to 100% of mapped land.
Show as a table
Septic tank absorption field rating across mapped Bibb acres.
CategoryShare of acres
Not limited0.0%
Somewhat limited0.0%
Very limited99.5%
Not rated0.5%

Drainage, water table and flooding

Share of Bibb acres

Depth to seasonal high water table
About 8 inches (median where reported); within 18 inches on >99% of acres.
Flooding
Mapped as flooding on >99% of acres (6% occasional, 93% frequent).
Slope
Typically 0–1% (median 1%).
Topsoil organic matter
Median 2%.

Drainage class

Excessively drained 0%
Somewhat excessively drained 0%
Well drained 0%
Moderately well drained 0%
Somewhat poorly drained 0%
Poorly drained >99%
Very poorly drained 0%
Not rated <1%
Drainage class across mapped Bibb acres. Scale 0 to 100% of mapped land.
Show as a table
Drainage class across mapped Bibb acres.
CategoryShare of acres
Excessively drained0.0%
Somewhat excessively drained0.0%
Well drained0.0%
Moderately well drained0.0%
Somewhat poorly drained0.0%
Poorly drained99.9%
Very poorly drained0.0%
Not rated0.1%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%
B: moderate infiltration 0%
C: slow infiltration 0%
D: very slow infiltration (clayey, shallow or wet) 1%
A/D: D as is, A if drained 25%
B/D: D as is, B if drained 70%
C/D: D as is, C if drained 3%
Not rated <1%
Hydrologic soil group across mapped Bibb acres. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group across mapped Bibb acres.
CategoryShare of acres
A: fast infiltration (mostly sandy or gravelly)0.0%
B: moderate infiltration0.0%
C: slow infiltration0.0%
D: very slow infiltration (clayey, shallow or wet)1.4%
A/D: D as is, A if drained24.5%
B/D: D as is, B if drained70.1%
C/D: D as is, C if drained3.4%
Not rated0.5%

Sources & data dates

Source
USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
Data date
SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
Scope
All map unit components named Bibb (component kind "Series") in SSURGO: 2,293,716 acres.
Method
Shares are by mapped acres of Bibb components. The profile comes from the single largest Bibb component. Full methodology.

Independent reference site. No government affiliation or endorsement.

Full narrative description: USDA Official Soil Series Description for Bibb.