Soil series profile
Grist Mill soil series
Grist Mill is a well drained soil with a sandy loam surface, mapped on 6,245 acres in 2 counties in VA. Hydrologic group C.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- C 100% of mapped acres
- Typical topsoil pH
- 4.8 very strongly acidic · range 4.8–4.8
- Mapped area
- 6k acres in 2 counties, 1 state
Typical Grist Mill profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–6 in (H1) | Sandy loam | 4.8 | 16% | 56% | 0.5% |
| 6–60 in (H2) | Sandy clay loam | 4.8 | 28% | 50% | 0.25% |
What this means
What Grist Mill soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Grist Mill soils is very strongly acidic: pH 4.8. Most vegetables and lawn grasses do best around 6.0 to 7.0, so lime is often needed; blueberries, azaleas and rhododendrons like it as it is.
Loamy topsoil (loam, silt loam and similar) covers 100% of mapped Grist Mill acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is sandy loam (100% of mapped Grist Mill acres).
100% of mapped Grist Mill acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 100% of mapped acres, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.
For a septic system
For conventional septic absorption fields, NRCS rates 100% of the acres in mapped Grist Mill soils very limited, 0% somewhat limited and 0% not limited.
Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Where Grist Mill soil is found
Mapped acres
Grist Mill is mapped in Virginia.
| County | Acres | Share of county land |
|---|---|---|
| Fairfax County, VA | 4,777 | 2.1% |
| Alexandria city, VA | 1,469 | 16.5% |
Septic absorption fields
NRCS rating, share of Grist Mill acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 100.0% |
Drainage, water table and flooding
Share of Grist Mill acres
- Depth to seasonal high water table
- About 3.3 feet (39 in) (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 1–3% (median 3%).
- Topsoil organic matter
- Median 0.5%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 100.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 0.0% |
| C: slow infiltration | 100.0% |
| D: very slow infiltration (clayey, shallow or wet) | 0.0% |
| A/D: D as is, A if drained | 0.0% |
| B/D: D as is, B if drained | 0.0% |
| C/D: D as is, C if drained | 0.0% |
Sources & data dates
- Source
- USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
- Data date
- SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
- Scope
- All map unit components named Grist Mill (component kind "Series") in SSURGO: 6,245 acres.
- Method
- Shares are by mapped acres of Grist Mill components. The profile comes from the single largest Grist Mill component. Full methodology.