Soil series profile

Exeter soil series

Exeter is a well drained soil with a loam surface, mapped on 136,353 acres in 8 counties in CA. Hydrologic group C.

#2702 by mapped area fine-loamy Typic Durixeralfs (Alfisols)

Drainage class: Well drained
Hydrologic group: C
Typical topsoil pH: 7.0
Mapped area: 136k

Typical Exeter profile

Texture and pH by depth

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 Exeter horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–9 in (Ap)	Loam	7.3	15%	44%	0.5%
9–26 in (Bt1)	Sandy clay loam	7.5	23%	60%	0.25%
26–28 in (Bt2)	Clay loam	7.5	31%	35%	0.25%
28–46 in (Btqm)	Indurated	Not reported	Not reported	Not reported	Not reported
46–72 in (2Bt)	Stratified very gravelly loamy coarse sand to gravelly loam	7.9	9%	81%	0.25%

Representative values from the most extensive Exeter map unit (Exeter loam, 0 to 2 percent slopes, survey area CA659). Other map units of this series vary within the series range.

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

What this means

What Exeter soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Exeter soils is neutral: pH 7.0 (most land between 6.7 and 7.3), the range most vegetables, flowers and lawn grasses prefer.

Loamy topsoil (loam, silt loam and similar) covers 91% of mapped Exeter acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is loam (61% of mapped Exeter acres).

91% of mapped Exeter acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On 91% 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.

For a septic system

For conventional septic absorption fields, NRCS rates 91% of the acres in mapped Exeter soils very limited, 0% somewhat limited and 0% not limited (9% not rated, such as urban land, pits or water).

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 51% of the acres (0% occasional, 0% 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 Exeter soil is found

Mapped acres

Exeter is mapped in California.

Counties with the most mapped Exeter soil
County	Acres	Share of county land
Tulare County, CA	86,681	3.5%
Fresno County, CA	17,994	0.4%
Kern County, CA	13,975	0.2%
Riverside County, CA	10,140	0.3%
San Joaquin County, CA	4,668	0.5%
Stanislaus County, CA	2,337	0.2%
Sutter County, CA	502	0.1%
Kings County, CA	56	0.0%

Septic absorption fields

NRCS rating, share of Exeter acres

Not limited 0%

Somewhat limited 0%

Very limited 91%

Not rated 9%

Septic tank absorption field rating across mapped Exeter acres. Scale 0 to 100% of mapped land.

Show as a table

Septic tank absorption field rating across mapped Exeter acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	0.0%
Very limited	91.0%
Not rated	9.0%

Drainage, water table and flooding

Share of Exeter acres

Depth to seasonal high water table: None reported within about 6.5 feet (median where reported).
Flooding: Mapped as flooding on 51% of acres (0% occasional, 0% frequent).
Slope: Typically 1–4% (median 1%).
Topsoil organic matter: Median 0.5%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained 46%

Moderately well drained 45%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

Not rated 9%

Drainage class across mapped Exeter acres. Scale 0 to 100% of mapped land.

Show as a table

Drainage class across mapped Exeter acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	46.4%
Moderately well drained	44.6%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%
Not rated	9.0%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%

B: moderate infiltration 0%

C: slow infiltration 89%

D: very slow infiltration (clayey, shallow or wet) 2%

A/D: D as is, A if drained 0%

B/D: D as is, B if drained 0%

C/D: D as is, C if drained 0%

Not rated 9%

Hydrologic soil group across mapped Exeter acres. Scale 0 to 100% of mapped land.

Show as a table

Hydrologic soil group across mapped Exeter acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	0.0%
C: slow infiltration	89.3%
D: very slow infiltration (clayey, shallow or wet)	1.7%
A/D: D as is, A if drained	0.0%
B/D: D as is, B if drained	0.0%
C/D: D as is, C if drained	0.0%
Not rated	9.0%

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 Exeter (component kind "Series") in SSURGO: 136,353 acres.
Method: Shares are by mapped acres of Exeter components. The profile comes from the single largest Exeter component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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