Fairfax City, Virginia
The most common soil here is Wheaton, on about 28% of the land: a channery silt loam, smooth, like flour. Glenelg and Codorus come next.
About 59% of the land drains well, and 5% stays wet for long stretches; groundwater comes within two feet of the surface under 6% of it.
USDA rates 60% of the land very limited for a standard septic drain field, and 12% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 5% of the land floods occasionally or more.
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 Fairfax City, 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 C (slow infiltration, moderate runoff). 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 Fairfax City, 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 |
|---|---|---|---|---|---|
| Wheaton - Glenelg complex, 2 to 7 percent slopes | 1K | Well drained | C | Not limited | Very limited |
| Urban land | 1K | Not rated | Not rated | ||
| Wheaton - Glenelg complex, 7 to 15 percent slopes | 396 | Well drained | C | Somewhat limited | Very limited |
| Urban land-Wheaton complex | 327 | Not rated | Not rated | ||
| Codorus silt loam, 0 to 2 percent slopes, occasionally flooded | 103 | Somewhat poorly drained | B/D | Very limited | Very limited |
| Wheaton - Meadowville complex, 2 to 7 percent slopes | 102 | Well drained | C | Not limited | Very limited |
| Glenelg silt loam, 7 to 15 percent slopes | 88 | Well drained | B | Somewhat limited | Somewhat limited |
| Wheaton loam, 2 to 25 percent slopes | 85 | Well drained | C | Not limited | Very limited |
| Wheaton - Sumerduck complex, 2 to 7 percent slopes | 83 | Well drained | C | Not limited | Very limited |
| Codorus and Hatboro soils, 0 to 2 percent slopes, occasionally flooded | 76 | Somewhat poorly drained | B/D | Very limited | Very limited |
| Hattontown - Orange complex, 2 to 7 percent slopes | 76 | Well drained | C | Very limited | Very limited |
| Wheaton - Codorus complex, 0 to 2 percent slopes | 58 | Well drained | C | Very limited | Very limited |
| Wheaton - Fairfax complex, 2 to 7 percent slopes | 55 | Well drained | C | Not limited | Very limited |
| Glenelg silt loam, 2 to 7 percent slopes | 45 | Well drained | B | Not limited | Somewhat limited |
| Glenelg silt loam, 15 to 25 percent slopes | 38 | Well drained | B | Very limited | Very limited |
| Hattontown-Orange complex, 7 to 15 percent slopes, very stony | 28 | Well drained | C | Very limited | Very limited |
| Urban land-Hattontown complex | 28 | Not rated | Not rated | ||
| Wheaton - Glenelg complex, 15 to 25 percent slopes | 24 | Well drained | C | Very limited | Very limited |
| Hattontown silt loam, 0 to 25 percent slopes | 23 | Well drained | C | Somewhat limited | Very limited |
| Sumerduck silt loam, 2 to 7 percent slopes | 19 | 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
Most soils are generally favorable for residential construction. Standard foundations are usually viable, though site-specific evaluation is always recommended.
Septic Systems
About 61% 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.