Pierce County Area, Washington
The dominant drainage class is Moderately well drained and the dominant hydrologic group is B (moderate infiltration). 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 Pierce County Area, Washington.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Kapowsin gravelly ashy loam, 0 to 6 percent slopes | 52K | Moderately well drained | B | Very limited | Very limited |
| Harstine gravelly ashy sandy loam, 6 to 15 percent slopes | 38K | Moderately well drained | C | Very limited | Very limited |
| Spanaway gravelly sandy loam | 29K | Somewhat excessively drained | A | Not limited | Very limited |
| Alderwood gravelly sandy loam, 8 to 15 percent slopes | 23K | Moderately well drained | B | Very limited | Very limited |
| Kapowsin gravelly ashy loam, 6 to 15 percent slopes | 18K | Moderately well drained | B | Very limited | Very limited |
| Everett very gravelly sandy loam, 0 to 8 percent slopes | 18K | Somewhat excessively drained | A | Not limited | Very limited |
| Alderwood gravelly sandy loam, 0 to 8 percent slopes | 14K | Moderately well drained | B | Very limited | Very limited |
| Buckley gravelly silt loam, 0 to 3 percent slopes | 11K | Poorly drained | C/D | Very limited | Very limited |
| Water | 11K | Not rated | Not rated | ||
| Xerochrepts, 45 to 70 percent slopes | 9K | Well drained | A | Very limited | Very limited |
| Everett very gravelly sandy loam, 8 to 15 percent slopes | 9K | Somewhat excessively drained | A | Somewhat limited | Very limited |
| Indianola loamy sand, 5 to 15 percent slopes | 9K | Somewhat excessively drained | A | Not limited | Very limited |
| Puyallup fine sandy loam | 8K | Well drained | A | Very limited | Very limited |
| Barneston gravelly ashy coarse sandy loam, 8 to 15 percent slopes | 8K | Somewhat excessively drained | A | Somewhat limited | Very limited |
| Harstine gravelly ashy sandy loam, 15 to 30 percent slopes | 7K | Moderately well drained | C | Very limited | Very limited |
| Alderwood gravelly sandy loam, 15 to 30 percent slopes | 6K | Moderately well drained | B | Very limited | Very limited |
| Dupont muck | 6K | Very poorly drained | D | Very limited | Very limited |
| Scamman silt loam, 6 to 15 percent slopes | 5K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Sultan silt loam | 5K | Moderately well drained | C/D | Very limited | Very limited |
| Indianola loamy sand, 0 to 5 percent slopes | 5K | Somewhat excessively drained | A | Not limited | Very limited |
What This Means
Building & Foundations
About 69% 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 96% 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.