Soil series profile

Pentz soil series

Pentz is a well drained soil with a silt loam surface, mapped on 112,966 acres in 9 counties in CA. Hydrologic group D.

#3196 by mapped area loamy Ultic Haploxerolls (Mollisols)

Drainage class: Well drained
Hydrologic group: D
Typical topsoil pH: 5.8
Mapped area: 113k

Typical Pentz 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 Pentz horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–6 in (A)	Silt loam	5.7	15%	25%	2.29%
6–10 in (Bw)	Silt loam	6.1	17%	24%	0.95%
10–12 in (Bt)	Silt loam	6.0	18%	22%	0.79%
12–22 in (Cr)	Bedrock	6.7	Not reported	Not reported	Not reported

Representative values from the most extensive Pentz map unit (Pentz-Peters association, 2 to 15 percent slopes, survey area CA632). 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 Pentz soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Pentz soils is moderately acidic: pH 5.8 (most land between 5.7 and 6.7). Many vegetables grow well here, and some gardens benefit from a little lime. Test before adding any.

Loamy topsoil (loam, silt loam and similar) covers 90% of mapped Pentz acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (29% of mapped Pentz acres).

98% of mapped Pentz acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On 93% 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 98% of the acres in mapped Pentz soils very limited, 0% somewhat limited and 0% not limited (2% 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.

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 Pentz soil is found

Mapped acres

Pentz is mapped in California.

Counties with the most mapped Pentz soil
County	Acres	Share of county land
Stanislaus County, CA	56,884	5.8%
Merced County, CA	17,990	1.5%
San Joaquin County, CA	16,576	1.9%
Sacramento County, CA	9,447	1.5%
Calaveras County, CA	4,537	0.4%
Shasta County, CA	3,148	0.2%
Tuolumne County, CA	2,243	0.1%
Amador County, CA	2,066	0.6%
Placer County, CA	76	0.0%

Septic absorption fields

NRCS rating, share of Pentz acres

Not limited 0%

Somewhat limited 0%

Very limited 98%

Not rated 2%

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

Show as a table

Septic tank absorption field rating across mapped Pentz acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	0.0%
Very limited	97.6%
Not rated	2.4%

Drainage, water table and flooding

Share of Pentz acres

Depth to seasonal high water table: None reported within about 6.5 feet (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 5–33% (median 10%).
Topsoil organic matter: Median 2%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 3%

Well drained 95%

Moderately well drained 0%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

Not rated 2%

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

Show as a table

Drainage class across mapped Pentz acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	2.8%
Well drained	94.8%
Moderately well drained	0.0%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%
Not rated	2.4%

Hydrologic soil group

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

B: moderate infiltration 5%

C: slow infiltration 0%

D: very slow infiltration (clayey, shallow or wet) 93%

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 2%

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

Show as a table

Hydrologic soil group across mapped Pentz acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	4.7%
C: slow infiltration	0.0%
D: very slow infiltration (clayey, shallow or wet)	92.8%
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	2.4%

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 Pentz (component kind "Series") in SSURGO: 112,966 acres.
Method: Shares are by mapped acres of Pentz components. The profile comes from the single largest Pentz component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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