Walla Walla County Area, Washington
The most common soil here is Ritzville, on about 34% of the land: a silt loam, smooth, like flour. Walla Walla and Quincy come next.
About 91% of the land drains well.
USDA rates 79% of the land very limited for a standard septic drain field, and 68% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 4% of the land floods occasionally or more, and bedrock lies within 40 inches under 8% 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 Walla Walla County Area, Washington, 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 Mollisols — grassland soils with a thick, dark, fertile topsoil rich in organic matter. 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 Walla Walla County Area, Washington. 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 |
|---|---|---|---|---|---|
| Ritzville silt loam, 8 to 30 percent slopes | 131K | Well drained | B | Very limited | Very limited |
| Walla Walla silt loam, 8 to 30 percent slopes | 74K | Well drained | B | Very limited | Very limited |
| Ritzville silt loam, 30 to 45 percent slopes | 35K | Well drained | B | Very limited | Very limited |
| Ritzville silt loam, 0 to 8 percent slopes | 33K | Well drained | B | Not limited | Somewhat limited |
| Walla Walla silt loam, 30 to 45 percent slopes | 28K | Well drained | B | Very limited | Very limited |
| Ritzville very fine sandy loam, 0 to 8 percent slopes | 28K | Well drained | B | Not limited | Somewhat limited |
| Athena silt loam, 8 to 30 percent slopes | 25K | Well drained | B | Very limited | Very limited |
| Ritzville very fine sandy loam, 8 to 30 percent slopes | 24K | Well drained | B | Very limited | Very limited |
| Walla Walla silt loam, 0 to 8 percent slopes | 21K | Well drained | B | Not limited | Somewhat limited |
| Water | 18K | Not rated | Not rated | ||
| Adkins loamy fine sand, 0 to 15 percent slopes | 18K | Well drained | B | Not limited | Somewhat limited |
| Basalt rockland, steep | 17K | Very limited | Very limited | ||
| Quincy fine sand, 0 to 30 percent slopes, eroded | 16K | Excessively drained | A | Very limited | Very limited |
| Adkins fine sandy loam, 0 to 15 percent slopes | 14K | Well drained | B | Not limited | Somewhat limited |
| Palouse silt loam, 8 to 30 percent slopes, eroded | 12K | Well drained | B | Very limited | Very limited |
| Onyx silt loam, 0 to 3 percent slopes | 11K | Well drained | B | Very limited | Very limited |
| Gwin rocky silt loam, 30 to 60 percent slopes | 8K | Well drained | D | Very limited | Very limited |
| Ellisforde silt loam, 15 to 30 percent slopes | 8K | Well drained | C | Very limited | Very limited |
| Hezel loamy fine sand, 0 to 15 percent slopes, eroded | 7K | Somewhat excessively drained | C | Not limited | Very limited |
| Quincy loamy fine sand, 0 to 8 percent slopes, eroded | 7K | Excessively drained | A | Not 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 68% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 79% 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.