What's My Soil

A field guide to the soil under your feet

Soil series profile

Felton soil series

Felton is a well drained soil with a sandy loam surface, mapped on 32,258 acres in 5 counties in CA. Hydrologic group C.

#7973 by mapped area fine-loamy Ultic Argixerolls (Mollisols)

Drainage class
Well drained
99% of mapped acres
Hydrologic group
C
98% of mapped acres
Typical topsoil pH
5.8
moderately acidic · range 5.6–6.5
Mapped area
32k
acres in 5 counties, 1 state

Typical Felton profile

Texture and pH by depth

Typical Felton soil profile by depth 0 in 20 in 40 in 60 in 0–11 in · H1 · pH 6.5 · 16% clay Sandy loam 11–43 in · H2 · pH 6.5 · 31% clay Clay loam 43–63 in · H3 · pH 5.8 · 23% clay Sandy clay loam 63–67 in · H4 Weathered bedrock
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 Felton horizons (representative values)
Depth Texture pH Clay Sand Organic matter
0–11 in (H1) Sandy loam 6.5 16% 65% 0.75%
11–43 in (H2) Clay loam 6.5 31% 35% 0.75%
43–63 in (H3) Sandy clay loam 5.8 23% 63% 0.75%
63–67 in (H4) Weathered bedrock Not reported Not reported Not reported Not reported

Representative values from the most extensive Felton map unit (Ben Lomond-Felton complex, 50 to 75 percent slopes, survey area CA087). 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 Felton soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Felton soils is moderately acidic: pH 5.8 (most land between 5.6 and 6.5). 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 99% of mapped Felton acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is sandy loam (86% of mapped Felton acres).

99% of mapped Felton acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On 98% 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 99% of the acres in mapped Felton soils very limited, 0% somewhat limited and 0% not limited (1% 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 Felton soil is found

Mapped acres

Felton is mapped in California.

Counties with the most mapped Felton soil
County Acres Share of county land
Santa Cruz County, CA 27,581 10.0%
Santa Clara County, CA 3,673 0.4%
Contra Costa County, CA 957 0.2%
Alameda County, CA 23 0.0%
San Mateo County, CA 23 0.0%

Septic absorption fields

NRCS rating, share of Felton acres

Not limited 0%
Somewhat limited 0%
Very limited 99%
Not rated 1%
Septic tank absorption field rating across mapped Felton acres. Scale 0 to 100% of mapped land.
Show as a table
Septic tank absorption field rating across mapped Felton acres.
CategoryShare of acres
Not limited0.0%
Somewhat limited0.0%
Very limited99.0%
Not rated1.0%

Drainage, water table and flooding

Share of Felton 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 18–63% (median 60%).
Topsoil organic matter
Median 5%.

Drainage class

Excessively drained 0%
Somewhat excessively drained 0%
Well drained 99%
Moderately well drained 0%
Somewhat poorly drained 0%
Poorly drained 0%
Very poorly drained 0%
Not rated 1%
Drainage class across mapped Felton acres. Scale 0 to 100% of mapped land.
Show as a table
Drainage class across mapped Felton acres.
CategoryShare of acres
Excessively drained0.0%
Somewhat excessively drained0.0%
Well drained99.0%
Moderately well drained0.0%
Somewhat poorly drained0.0%
Poorly drained0.0%
Very poorly drained0.0%
Not rated1.0%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%
B: moderate infiltration 2%
C: slow infiltration 98%
D: very slow infiltration (clayey, shallow or wet) 0%
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 1%
Hydrologic soil group across mapped Felton acres. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group across mapped Felton acres.
CategoryShare of acres
A: fast infiltration (mostly sandy or gravelly)0.0%
B: moderate infiltration1.5%
C: slow infiltration97.5%
D: very slow infiltration (clayey, shallow or wet)0.0%
A/D: D as is, A if drained0.0%
B/D: D as is, B if drained0.0%
C/D: D as is, C if drained0.0%
Not rated1.0%

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 Felton (component kind "Series") in SSURGO: 32,258 acres.
Method
Shares are by mapped acres of Felton components. The profile comes from the single largest Felton component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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