Loudoun County, Virginia
The most common soil here is Purcellville, on about 13% of the land: a silty clay loam, smooth and slightly sticky. Catoctin and Tankerville come next.
About 69% of the land drains well, and 21% stays wet for long stretches; groundwater comes within two feet of the surface under 27% of it.
USDA rates 87% of the land very limited for a standard septic drain field, and 52% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 13% of the land floods occasionally or more, and bedrock lies within 40 inches under 38% 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 Loudoun County, Virginia, 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 Well drained and the dominant hydrologic group is B (moderate infiltration). The most common soil order is Ultisols — strongly weathered soils with clay-enriched subsoils, common in warm humid climates. 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 Loudoun County, Virginia. 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 |
|---|---|---|---|---|---|
| Purcellville silt loam, 2 to 7 percent slopes | 27K | Well drained | B | Not limited | Very limited |
| Purcellville and Tankerville soils, 7 to 15 percent slopes | 21K | Well drained | B | Somewhat limited | Very limited |
| Middleburg silt loam, 2 to 7 percent slopes | 17K | Well drained | A | Somewhat limited | Very limited |
| Catoctin channery silt loam, 15 to 25 percent slopes | 12K | Well drained | B | Very limited | Very limited |
| Mongle silt loam, 0 to 7 percent slopes, frequently flooded | 10K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Purcellville and Tankerville soils, 15 to 25 percent slopes | 10K | Well drained | B | Very limited | Very limited |
| Sycoline-Kelly complex, 2 to 7 percent slopes | 9K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Albano silt loam, 0 to 2 percent slopes, frequently flooded | 9K | Poorly drained | C/D | Very limited | Very limited |
| Eubanks loam, 2 to 7 percent slopes | 8K | Well drained | A | Not limited | Very limited |
| Myersville-Catoctin complex, 7 to 15 percent slopes | 8K | Well drained | B | Somewhat limited | Somewhat limited |
| Penn silt loam, 2 to 7 percent slopes | 8K | Well drained | B | Very limited | Very limited |
| Udorthents | 8K | Not rated | Not rated | ||
| Purcellville-Swampoodle complex, 2 to 7 percent slopes | 8K | Well drained | B | Not limited | Very limited |
| Dulles silt loam, 0 to 2 percent slopes | 7K | Somewhat poorly drained | D | Very limited | Very limited |
| Ashburn silt loam, 0 to 7 percent slopes | 6K | Moderately well drained | C | Very limited | Very limited |
| Codorus silt loam, 0 to 2 percent slopes, occasionally flooded | 6K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Jackland and Haymarket soils, 2 to 7 percent slopes | 6K | Well drained | C | Very limited | Very limited |
| Swampoodle silt loam, 2 to 7 percent slopes, occasionally ponded | 6K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Elbert silty clay loam, 0 to 2 percent slopes, frequently flooded | 6K | Poorly drained | C/D | Very limited | Very limited |
| Catoctin channery silt loam, 25 to 45 percent slopes | 5K | Well drained | B | 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 52% 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 87% 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.