Soil series profile
Elpaso soil series
Elpaso is a poorly drained soil with a silty clay loam surface, mapped on 245,942 acres in 35 counties across 2 states. Hydrologic group B/D.
- Drainage class
- Poorly drained 100% of mapped acres
- Hydrologic group
- B/D 100% of mapped acres
- Typical topsoil pH
- 6.0 moderately acidic · range 6.0–6.0
- Mapped area
- 246k acres in 35 counties, 2 states
Typical Elpaso profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–21 in (Ap) | Silty clay loam | 6.0 | 31% | 6% | 5.5% |
| 21–44 in (Btg1) | Silty clay loam | 7.0 | 32% | 6% | 1.1% |
| 44–69 in (2Btg2) | Silty clay loam | 7.6 | 29% | 16% | 0.5% |
| 69–79 in (2C) | Silty clay loam | 8.0 | 28% | 16% | 0.3% |

What this means
What Elpaso soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Elpaso soils is moderately acidic: pH 6.0. 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 100% of mapped Elpaso acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silty clay loam (100% of mapped Elpaso acres).
100% of mapped Elpaso acres is somewhat poorly to very poorly drained, so soil stays soggy for long spells after rain and in wet seasons. Raised beds, plants that tolerate wet feet, and not working the soil while wet all help.
For lawns and yards
On 100% 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.
A seasonal high water table comes within 18 inches of the surface on 100% of mapped acres, often in spring. Basements, sump pumps and lawns in low spots feel it first.
For a septic system
For conventional septic absorption fields, NRCS rates 100% of the acres in mapped Elpaso soils very limited, 0% somewhat limited and 0% not limited.
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.
Where Elpaso soil is found
Mapped acres
Elpaso is mapped in Illinois and Indiana.
| County | Acres | Share of county land |
|---|---|---|
| DeKalb County, IL | 66,252 | 16.5% |
| McLean County, IL | 33,906 | 4.5% |
| Woodford County, IL | 32,767 | 9.9% |
| LaSalle County, IL | 26,023 | 3.7% |
| Kane County, IL | 14,253 | 4.3% |
| Will County, IL | 14,133 | 2.7% |
| Lee County, IL | 12,541 | 2.8% |
| Kendall County, IL | 10,482 | 5.2% |
| Marshall County, IL | 4,340 | 1.8% |
| Champaign County, IL | 4,155 | 0.7% |
| Macon County, IL | 3,325 | 0.9% |
| Piatt County, IL | 2,781 | 1.0% |
| Moultrie County, IL | 2,680 | 1.3% |
| Vermilion County, IL | 2,477 | 0.4% |
| Douglas County, IL | 2,180 | 0.8% |
| Edgar County, IL | 1,992 | 0.5% |
| Ogle County, IL | 1,979 | 0.4% |
| Grundy County, IL | 1,632 | 0.6% |
| Livingston County, IL | 1,555 | 0.2% |
| Putnam County, IL | 1,177 | 1.2% |
| Stark County, IL | 1,151 | 0.6% |
| Coles County, IL | 942 | 0.3% |
| Iroquois County, IL | 908 | 0.1% |
| De Witt County, IL | 892 | 0.4% |
| Bureau County, IL | 476 | 0.1% |
| Boone County, IL | 431 | 0.2% |
| Vermillion County, IN | 194 | 0.1% |
| DuPage County, IL | 121 | 0.1% |
| McHenry County, IL | 60 | 0.0% |
| Benton County, IN | 51 | 0.0% |
| Stephenson County, IL | 37 | 0.0% |
| Peoria County, IL | 23 | 0.0% |
| Ford County, IL | 12 | 0.0% |
| Logan County, IL | 11 | 0.0% |
| Cook County, IL | 2 | 0.0% |
Septic absorption fields
NRCS rating, share of Elpaso acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 100.0% |
Drainage, water table and flooding
Share of Elpaso acres
- Depth to seasonal high water table
- About 6 inches (median where reported); within 18 inches on 100% of acres.
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 0–0% (median 0%).
- Topsoil organic matter
- Median 5.5%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 0.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 100.0% |
| Very poorly drained | 0.0% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 0.0% |
| C: slow infiltration | 0.0% |
| D: very slow infiltration (clayey, shallow or wet) | 0.0% |
| A/D: D as is, A if drained | 0.0% |
| B/D: D as is, B if drained | 100.0% |
| C/D: D as is, C if drained | 0.0% |
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 Elpaso (component kind "Series") in SSURGO: 245,942 acres.
- Method
- Shares are by mapped acres of Elpaso components. The profile comes from the single largest Elpaso component. Full methodology.