Union County, Tennessee
The most common soil here is Clarksville, on about 21% of the land: a gravelly silt loam, smooth, like flour. Fullerton and Berks come next.
About 76% of the land drains well.
USDA rates 81% of the land very limited for a standard septic drain field, and 79% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 3% of the land floods occasionally or more, and bedrock lies within 40 inches under 37% 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 Union County, Tennessee, 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 Union County, Tennessee. 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 |
|---|---|---|---|---|---|
| Clarksville cherty silt loam, steep phase | 23K | Somewhat excessively drained | A | Very limited | Very limited |
| Berks-Weikert complex, 20 to 75 percent slopes | 22K | Well drained | B | Very limited | Very limited |
| Water | 14K | Not rated | Not rated | ||
| Fullerton cherty silt loam, steep phase | 11K | Well drained | B | Very limited | Very limited |
| Fullerton gravelly silt loam, 15 to 25 percent slopes | 10K | Well drained | B | Very limited | Very limited |
| Rough stony land, talbott soil material | 10K | Very limited | Very limited | ||
| Clarksville cherty silt loam, hilly phase | 6K | Somewhat excessively drained | A | Very limited | Very limited |
| Montevallo shaly silt loam, steep phase | 5K | Well drained | D | Very limited | Very limited |
| Fullerton gravelly silt loam, 5 to 12 percent slopes, cool | 4K | Well drained | B | Somewhat limited | Somewhat limited |
| Rough stony land, Fullerton soil material | 4K | Very limited | Very limited | ||
| Clarksville cherty silt loam, rolling phase | 4K | Somewhat excessively drained | A | Somewhat limited | Somewhat limited |
| Armuchee silt loam, hilly phase | 4K | Well drained | C | Very limited | Very limited |
| Armuchee silt loam, steep phase | 3K | Well drained | C | Very limited | Very limited |
| Fullerton silt loam, 5 to 12 percent slopes, cool (cr-sil) | 3K | Well drained | B | Somewhat limited | Somewhat limited |
| Claiborne silt loam, hilly phase | 2K | Well drained | B | Very limited | Very limited |
| Philo fine sandy loam (sl) | 2K | Moderately well drained | C | Very limited | Very limited |
| Claiborne silt loam, steep phase | 2K | Well drained | B | Very limited | Very limited |
| Talbott silty clay loam, eroded rolling phase | 2K | Well drained | C | Very limited | Very limited |
| Sequoia silty clay loam, eroded rolling phase | 2K | Well drained | C | Somewhat limited | Very limited |
| Leadvale silt loam, rolling phase | 2K | 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 79% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 81% 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.