Soil series profile

Comfort soil series

Comfort is a well drained soil with a very stony clay surface, mapped on 212,983 acres in 8 counties in TX. Hydrologic group D.

#1678 by mapped area clayey-skeletal Lithic Argiustolls (Mollisols)

Drainage class
Well drained
100% of mapped acres
Hydrologic group
D
92% of mapped acres
Typical topsoil pH
7.5
slightly alkaline · range 7.5–7.5
Mapped area
213k
acres in 8 counties, 1 state

Typical Comfort profile

Texture and pH by depth

Typical Comfort soil profile by depth 0 in 10 in 20 in 30 in 40 in 0–6 in · A · pH 7.5 · 45% clay Very stony clay 6–13 in · Bt · pH 7.5 · 65% clay Extremely stony clay 13–40 in · R 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 Comfort horizons (representative values)
Depth Texture pH Clay Sand Organic matter
0–6 in (A) Very stony clay 7.5 45% 25% 6%
6–13 in (Bt) Extremely stony clay 7.5 65% 10% 4.5%
13–40 in (R) Bedrock Not reported Not reported Not reported Not reported

Representative values from the most extensive Comfort map unit (Comfort-Rock outcrop complex, 1 to 8 percent slopes, survey area TX604). 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 Comfort soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Comfort soils is slightly alkaline: pH 7.5. 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).

Clayey topsoil covers 92% of mapped Comfort acres. Clay holds water and nutrients but drains slowly and compacts if worked wet: add compost, avoid tilling soggy soil and consider raised beds. The most common surface texture is very stony clay (82% of mapped Comfort acres).

100% of mapped Comfort acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On 92% 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 92% of the acres in mapped Comfort soils very limited, 0% somewhat limited and 0% not limited (8% 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 Comfort soil is found

Mapped acres

Comfort is mapped in Texas.

Counties with the most mapped Comfort soil
County Acres Share of county land
Hays County, TX 80,990 22.6%
Comal County, TX 78,420 18.2%
Kendall County, TX 26,204 6.2%
Kerr County, TX 17,419 2.5%
Medina County, TX 5,203 0.6%
Uvalde County, TX 3,330 0.3%
Bandera County, TX 1,199 0.2%
Real County, TX 218 0.0%

Septic absorption fields

NRCS rating, share of Comfort acres

Not limited 0%
Somewhat limited 0%
Very limited 92%
Not rated 8%
Septic tank absorption field rating across mapped Comfort acres. Scale 0 to 100% of mapped land.
Show as a table
Septic tank absorption field rating across mapped Comfort acres.
CategoryShare of acres
Not limited0.0%
Somewhat limited0.0%
Very limited91.9%
Not rated8.1%

Drainage, water table and flooding

Share of Comfort 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 3–5% (median 5%).
Topsoil organic matter
Median 6%.

Drainage class

Excessively drained 0%
Somewhat excessively drained 0%
Well drained 100%
Moderately well drained 0%
Somewhat poorly drained 0%
Poorly drained 0%
Very poorly drained 0%
Drainage class across mapped Comfort acres. Scale 0 to 100% of mapped land.
Show as a table
Drainage class across mapped Comfort acres.
CategoryShare of acres
Excessively drained0.0%
Somewhat excessively drained0.0%
Well drained100.0%
Moderately well drained0.0%
Somewhat poorly drained0.0%
Poorly drained0.0%
Very poorly drained0.0%

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) 92%
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 8%
Hydrologic soil group across mapped Comfort acres. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group across mapped Comfort 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)91.9%
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 rated8.1%

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 Comfort (component kind "Series") in SSURGO: 212,983 acres.
Method
Shares are by mapped acres of Comfort components. The profile comes from the single largest Comfort component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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