Soil series profile
Penn soil series
Penn is a well drained soil with a silt loam surface, mapped on 378,061 acres in 30 counties across 4 states. Hydrologic group B.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- B 71% of mapped acres
- Typical topsoil pH
- 6.4 slightly acidic · range 4.6–6.4
- Mapped area
- 378k acres in 30 counties, 4 states
Typical Penn profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–10 in (Ap) | Silt loam | 6.4 | 17% | 23% | 2% |
| 10–15 in (Bt1) | Silt loam | 5.8 | 23% | 25% | 0.36% |
| 15–19 in (Bt2) | Silt loam | 5.8 | 25% | 23% | 0.36% |
| 19–22 in (Bt3) | Channery loam | 5.8 | 21% | 32% | 0.14% |
| 22–28 in (Cr) | Bedrock | Not reported | Not reported | Not reported | Not reported |
| 28–38 in (R) | Bedrock | Not reported | Not reported | Not reported | Not reported |
What this means
What Penn soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Penn soils is slightly acidic: pH 6.4 (most land between 4.6 and 6.4), the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 100% of mapped Penn acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (50% of mapped Penn acres).
100% of mapped Penn acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
Most land is in hydrologic groups B and C, where rain soaks in at a moderate pace.
For a septic system
For conventional septic absorption fields, NRCS rates 100% of the acres in mapped Penn 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 Penn soil is found
Mapped acres
Penn is mapped in Pennsylvania, New Jersey, Maryland and Virginia.
| County | Acres | Share of county land |
|---|---|---|
| York County, PA | 60,067 | 10.5% |
| Hunterdon County, NJ | 36,589 | 13.3% |
| Somerset County, NJ | 34,433 | 17.9% |
| Adams County, PA | 33,410 | 10.1% |
| Montgomery County, PA | 27,920 | 9.1% |
| Frederick County, MD | 26,700 | 6.3% |
| Carroll County, MD | 21,885 | 7.6% |
| Bucks County, PA | 18,702 | 4.9% |
| Chester County, PA | 18,579 | 3.9% |
| Montgomery County, MD | 17,950 | 5.6% |
| Berks County, PA | 17,744 | 3.2% |
| Culpeper County, VA | 9,058 | 4.4% |
| Loudoun County, VA | 8,297 | 2.9% |
| Fauquier County, VA | 7,720 | 2.1% |
| Dauphin County, PA | 6,790 | 2.1% |
| Mercer County, NJ | 5,731 | 4.0% |
| Fairfax County, VA | 3,513 | 1.6% |
| Morris County, NJ | 3,112 | 1.1% |
| Campbell County, VA | 3,093 | 1.0% |
| Lynchburg city, VA | 3,093 | 1.0% |
| Lancaster County, PA | 2,776 | 0.5% |
| Albemarle County, VA | 2,632 | 0.7% |
| Lebanon County, PA | 2,271 | 1.0% |
| Lehigh County, PA | 1,905 | 0.9% |
| Orange County, VA | 1,692 | 0.9% |
| Middlesex County, NJ | 1,198 | 0.6% |
| Perry County, PA | 559 | 0.2% |
| Madison County, VA | 468 | 0.3% |
| Northampton County, PA | 173 | 0.1% |
| Philadelphia County, PA | 1 | 0.0% |
Septic absorption fields
NRCS rating, share of Penn 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 Penn acres
- Depth to seasonal high water table
- About 4.9 feet (59 in) (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 4–12% (median 5%).
- Topsoil organic matter
- Median 2%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 100.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| 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 | 70.8% |
| C: slow infiltration | 29.2% |
| 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 | 0.0% |
| 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 Penn (component kind "Series") in SSURGO: 378,061 acres.
- Method
- Shares are by mapped acres of Penn components. The profile comes from the single largest Penn component. Full methodology.