Montgomery County, Pennsylvania
The most common soil here is Readington, on about 9% of the land: a silt loam, smooth, like flour. Penn and Reaville come next.
About 20% of the land drains well, and 14% stays wet for long stretches; groundwater comes within two feet of the surface under 28% of it.
USDA rates 67% of the land very limited for a standard septic drain field, and 63% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 6% of the land floods occasionally or more, and bedrock lies within 40 inches under 21% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Montgomery County, Pennsylvania, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Moderately well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). The most common soil order is Alfisols — moderately leached forest soils with a clay-enriched subsoil. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Montgomery County, Pennsylvania. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Urban land-Udorthents, shale and sandstone complex, 0 to 8 percent slopes | 25K | Somewhat limited | Somewhat limited | ||
| Readington silt loam, 3 to 8 percent slopes | 23K | Moderately well drained | C | Very limited | Very limited |
| Reaville silt loam, 3 to 8 percent slopes | 16K | Moderately well drained | D | Very limited | Very limited |
| Urban land, 0 to 8 percent slopes | 14K | Not rated | Not rated | ||
| Urban land-Penn complex, 0 to 8 percent slopes | 13K | Not limited | Not limited | ||
| Bowmansville-Knauers silt loams | 10K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Urban land-Udorthents, schist and gneiss complex, 0 to 8 percent slopes | 10K | Somewhat limited | Somewhat limited | ||
| Urban land-Udorthents, shale and sandstone complex, 8 to 25 percent slopes | 9K | Very limited | Very limited | ||
| Abbottstown silt loam, 3 to 8 percent slopes | 8K | Somewhat poorly drained | D | Very limited | Very limited |
| Penn silt loam, 3 to 8 percent slopes | 8K | Well drained | B | Very limited | Very limited |
| Urban land-Readington complex, 0 to 8 percent slopes | 7K | Not limited | Not limited | ||
| Lehigh silt loam, 3 to 8 percent slopes | 7K | Moderately well drained | C/D | Very limited | Very limited |
| Urban land-Udorthents, schist and gneiss complex, 8 to 25 percent slopes | 7K | Very limited | Very limited | ||
| Croton silt loam, occasionally ponded, 3 to 8 percent slopes | 5K | Poorly drained | D | Very limited | Very limited |
| Urban land-Gladstone complex, 0 to 8 percent slopes | 5K | Not limited | Not limited | ||
| Rowland silt loam, terrace | 5K | Moderately well drained | C | Very limited | Very limited |
| Penn silt loam, 8 to 15 percent slopes | 5K | Well drained | B | Very limited | Very limited |
| Urban land-Lawrenceville complex, 0 to 8 percent slopes | 5K | Somewhat limited | Somewhat limited | ||
| Neshaminy gravelly silt loam, 8 to 25 percent slopes, extremely bouldery | 5K | Well drained | C | Very limited | Very limited |
| Readington silt loam, 0 to 3 percent slopes | 4K | Moderately well drained | C | Very limited | Very limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 63% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 67% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.