Soil series profile

Skumpah soil series

Skumpah is a well drained soil with a silt loam surface, mapped on 651,922 acres in 10 counties across 3 states. Hydrologic group D.

#379 by mapped area fine-silty Typic Natrargids (Aridisols)

Drainage class
Well drained
83% of mapped acres
Hydrologic group
D
82% of mapped acres
Typical topsoil pH
8.8
strongly alkaline · range 8.8–8.8
Mapped area
652k
acres in 10 counties, 3 states

Typical Skumpah profile

Texture and pH by depth

Typical Skumpah soil profile by depth 0 in 10 in 20 in 30 in 40 in 50 in 0–5 in · H1 · pH 8.8 · 23% clay Silt loam 5–14 in · H2 · pH 8.8 · 31% clay Silty clay loam 14–60 in · H3 · pH 8.5 · 31% clay Silty clay 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 Skumpah horizons (representative values)
Depth Texture pH Clay Sand Organic matter
0–5 in (H1) Silt loam 8.8 23% 10% 0.75%
5–14 in (H2) Silty clay loam 8.8 31% 7% 0.25%
14–60 in (H3) Silty clay loam 8.5 31% 9% 0.25%

Representative values from the most extensive Skumpah map unit (Skumpah silt loam, 0 to 2 percent slopes, survey area UT611). 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 Skumpah soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Skumpah soils is strongly alkaline: pH 8.8. Acid-loving plants such as blueberries and azaleas struggle without amended beds, and some trees and shrubs show iron chlorosis (yellow leaves with green veins).

Loamy topsoil (loam, silt loam and similar) covers 83% of mapped Skumpah acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (82% of mapped Skumpah acres).

83% of mapped Skumpah acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On 83% 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 83% of the acres in mapped Skumpah soils very limited, 0% somewhat limited and 0% not limited (17% 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 Skumpah soil is found

Mapped acres

Skumpah is mapped in Utah, Colorado and Nevada.

Counties with the most mapped Skumpah soil
County Acres Share of county land
Tooele County, UT 353,712 8.1%
Box Elder County, UT 267,479 7.3%
Iron County, UT 17,879 1.0%
Mesa County, CO 5,241 0.3%
Sanpete County, UT 2,745 0.4%
Sevier County, UT 1,014 0.2%
Elko County, NV 144 0.0%
Grand County, UT 39 0.0%
Davis County, UT 36 0.0%
Juab County, UT 1 0.0%

Septic absorption fields

NRCS rating, share of Skumpah acres

Not limited 0%
Somewhat limited 0%
Very limited 83%
Not rated 17%
Septic tank absorption field rating across mapped Skumpah acres. Scale 0 to 100% of mapped land.
Show as a table
Septic tank absorption field rating across mapped Skumpah acres.
CategoryShare of acres
Not limited0.0%
Somewhat limited0.0%
Very limited83.1%
Not rated16.9%

Drainage, water table and flooding

Share of Skumpah acres

Depth to seasonal high water table
About 4.3 feet (51 in) (median where reported).
Flooding
Not mapped as flooding on most acres.
Slope
Typically 1–2% (median 1%).
Topsoil organic matter
Median 0.8%.

Drainage class

Excessively drained 0%
Somewhat excessively drained 0%
Well drained 83%
Moderately well drained 0%
Somewhat poorly drained 0%
Poorly drained 0%
Very poorly drained 0%
Not rated 17%
Drainage class across mapped Skumpah acres. Scale 0 to 100% of mapped land.
Show as a table
Drainage class across mapped Skumpah acres.
CategoryShare of acres
Excessively drained0.0%
Somewhat excessively drained0.0%
Well drained83.1%
Moderately well drained0.0%
Somewhat poorly drained0.0%
Poorly drained0.0%
Very poorly drained0.0%
Not rated16.9%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%
B: moderate infiltration 0%
C: slow infiltration 2%
D: very slow infiltration (clayey, shallow or wet) 82%
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 17%
Hydrologic soil group across mapped Skumpah acres. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group across mapped Skumpah acres.
CategoryShare of acres
A: fast infiltration (mostly sandy or gravelly)0.0%
B: moderate infiltration0.0%
C: slow infiltration1.5%
D: very slow infiltration (clayey, shallow or wet)81.6%
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 rated16.9%

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 Skumpah (component kind "Series") in SSURGO: 651,922 acres.
Method
Shares are by mapped acres of Skumpah components. The profile comes from the single largest Skumpah component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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