County soil summary
Soil types in Sussex County, Delaware
The most widespread soils are Rosedale, Hurlock and Pepperbox; the most common drainage class is well drained (26% of the land), and typical topsoil pH is 6.0.
- Well or moderately well drained
- 53% of land · state 54%
- Typical topsoil pH
- 6.0 moderately acidic · state 6.0
- Septic fields very limited
- 91% of land · state 88%
- Subject to flooding
- 12% of land, any frequency · state 11%
Most common soils in Sussex County
Share of mapped land
A county is a patchwork of many soils. These 8 cover 47% of the mapped land; 73 named soil series are mapped here in all.
| Soil | Share of land | Drainage | Topsoil pH |
|---|---|---|---|
| Rosedale | 9.0% | Well drained | 6.2 |
| Hurlock | 7.7% | Poorly drained | 6.2 |
| Pepperbox | 5.8% | Moderately well drained | 5.5 |
| Mullica | 5.4% | Very poorly drained | 4.0 |
| Hammonton | 5.4% | Moderately well drained | 6.2 |
| Fort Mott | 4.9% | Well drained | 6.1 |
| Klej | 4.6% | Somewhat poorly drained | 5.5 |
| Ingleside | 4.6% | Well drained | 6.2 |
What this means
What the soils in Sussex County mean for gardens, lawns and septic systems
For your garden
Typical topsoil in Sussex County is moderately acidic: pH 6.0 (most land between 4.5 and 6.3). Many vegetables grow well here, and some gardens benefit from a little lime. Test before adding any.
Sandy topsoil covers 57% of the land. It drains fast and warms early in spring, but dries out and loses nutrients quickly: mulch, compost and steady watering help. The most common surface texture is loamy sand (49% of the land).
For your lawn and yard
39% of the land is in hydrologic group A, where water soaks in fast. Lawns there dry out quickly; deeper, less frequent watering and organic matter help.
A seasonal high water table comes within 18 inches of the surface on 41% of the land, 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 91% of the land in Sussex County very limited, 0% somewhat limited and 0% not limited (9% not rated, such as urban land, pits or water).
That is close to the state as a whole (88% very 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.
Flooding is mapped on 12% of the land (1% occasional, 11% frequent).
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Drainage
How long the soil stays wet
The most common drainage class is well drained (26%). 53% of the land is moderately well drained or better, compared with 54% across Delaware.
Show as a table
| Category | Sussex County | Delaware |
|---|---|---|
| Excessively drained | 5.4% | 2.7% |
| Somewhat excessively drained | 3.8% | 2.4% |
| Well drained | 25.5% | 31.5% |
| Moderately well drained | 18.5% | 17.7% |
| Somewhat poorly drained | 6.4% | 4.1% |
| Poorly drained | 14.7% | 16.9% |
| Very poorly drained | 16.6% | 14.9% |
| Not rated | 9.1% | 9.7% |
Septic absorption fields
NRCS rating for conventional drain fields
The rating looks at the soil from 24 to 60 inches deep: permeability, depth to a seasonal water table or bedrock, flooding and slope. “Very limited” means at least one feature is unfavorable enough that a conventional field is hard to make work.
Show as a table
| Category | Sussex County | Delaware |
|---|---|---|
| Not limited | 0.0% | 0.3% |
| Somewhat limited | 0.0% | 1.8% |
| Very limited | 90.9% | 88.2% |
| Not rated | 9.1% | 9.7% |
Rain, runoff and water table
Hydrologic soil group, flooding, seasonal water table
Hydrologic soil group
How fast rain soaks in when the soil is already wet. Group A soaks in fastest, D slowest.
Show as a table
| Category | Sussex County | Delaware |
|---|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 39.3% | 24.2% |
| B: moderate infiltration | 9.2% | 17.9% |
| C: slow infiltration | 4.5% | 11.6% |
| D: very slow infiltration (clayey, shallow or wet) | 4.3% | 2.6% |
| A/D: D as is, A if drained | 26.4% | 14.2% |
| B/D: D as is, B if drained | 6.1% | 9.8% |
| C/D: D as is, C if drained | 4.5% | 11.6% |
| Not rated | 5.7% | 8.2% |
Flooding
Show as a table
| Category | Sussex County | Delaware |
|---|---|---|
| No flooding | 82.9% | 83.5% |
| Rare or very rare | 0.0% | 0.0% |
| Occasional | 1.3% | 1.2% |
| Frequent or very frequent | 10.9% | 9.8% |
| Not reported | 4.9% | 5.4% |
Seasonal high water table
Show as a table
| Category | Sussex County | Delaware |
|---|---|---|
| Within 18 inches at some time of year | 41.2% | 37.5% |
| 18 inches to 3.3 feet | 18.5% | 17.7% |
| Deeper than 3.3 feet or none reported | 35.4% | 39.4% |
| Not reported | 4.9% | 5.4% |
Topsoil pH and texture
First mineral layer of each soil
Typical topsoil pH is 6.0 (moderately acidic); 80% of rated land falls between 4.5 and 6.3. Median topsoil organic matter is 1.7%.
Show as a table
| Category | Sussex County | Delaware |
|---|---|---|
| Strongly acidic (below 5.5) | 24.0% | 25.8% |
| Moderately to slightly acidic (5.5–6.4) | 63.4% | 59.0% |
| Near neutral (6.5–7.3) | 2.1% | 3.4% |
| Alkaline (7.4 and up) | 3.0% | 1.9% |
| Not reported | 7.5% | 9.9% |
Texture
Show as a table
| Category | Sussex County | Delaware |
|---|---|---|
| Sandy | 57.3% | 29.9% |
| Loamy (loam, silt loam and similar) | 27.6% | 51.9% |
| Clayey (40%+ clay) | 0.0% | 0.0% |
| Organic (muck or peat) | 9.6% | 10.1% |
| Not reported (rock, urban land, etc.) | 5.5% | 8.1% |
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
- Sussex County, Delaware (FIPS 10005): 507,846 acres of mapped land, 118,488 acres of open water excluded. State comparisons pool all mapped land in Delaware.
- Method
- Shares are by mapped land area: each map unit’s acres in the county times each soil component’s percentage. Open water is excluded. Topsoil values use the first mineral horizon of each component. Full methodology.