Soil series profile
Grundy soil series
Grundy is a somewhat poorly drained soil with a silt loam surface, mapped on 611,862 acres in 69 counties across 4 states. Hydrologic group C/D.
- Drainage class
- Somewhat poorly drained 100% of mapped acres
- Hydrologic group
- C/D 94% of mapped acres
- Typical topsoil pH
- 6.4 slightly acidic · range 6.0–6.4
- Mapped area
- 612k acres in 69 counties, 4 states
Typical Grundy profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–6 in (Ap) | Silt loam | 6.4 | 25% | 4% | 2.6% |
| 6–13 in (A) | Silt loam | 6.4 | 26% | 4% | 2.4% |
| 13–18 in (Bt) | Silty clay loam | 5.6 | 31% | 4% | 1.7% |
| 18–27 in (Btg1) | Silty clay | 5.5 | 46% | 2% | 1.6% |
| 27–36 in (Btg2) | Silty clay | 5.8 | 45% | 2% | 0.86% |
| 36–55 in (Btg3) | Silty clay | 5.5 | 46% | 2% | 0.9% |
| 55–79 in (Cg) | Silty clay loam | 5.8 | 39% | 4% | 0.86% |
What this means
What Grundy soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Grundy soils is slightly acidic: pH 6.4 (most land between 6.0 and 6.4), the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 100% of mapped Grundy acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (64% of mapped Grundy acres).
100% of mapped Grundy acres is somewhat poorly to very poorly drained, so soil stays soggy for long spells after rain and in wet seasons. Raised beds, plants that tolerate wet feet, and not working the soil while wet all help.
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.
A seasonal high water table comes within 18 inches of the surface on >99% of mapped acres, often in spring. Basements, sump pumps and lawns in low spots feel it first.
For a septic system
For conventional septic absorption fields, NRCS rates 100% of the acres in mapped Grundy 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 Grundy soil is found
Mapped acres
Grundy is mapped in Missouri, Iowa, Kansas and Nebraska. The 60 counties with the most Grundy acres:
| County | Acres | Share of county land |
|---|---|---|
| Clinton County, MO | 64,498 | 24.1% |
| Daviess County, MO | 46,490 | 12.9% |
| Harrison County, MO | 39,422 | 8.5% |
| Gentry County, MO | 31,645 | 10.1% |
| Jefferson County, KS | 28,728 | 8.4% |
| Leavenworth County, KS | 26,498 | 8.9% |
| Chariton County, MO | 23,558 | 4.9% |
| Carroll County, MO | 23,300 | 5.3% |
| Lee County, IA | 22,009 | 6.7% |
| DeKalb County, MO | 21,073 | 7.8% |
| Clarke County, IA | 19,632 | 7.2% |
| Caldwell County, MO | 19,562 | 7.1% |
| Lucas County, IA | 17,712 | 6.4% |
| Miami County, KS | 15,654 | 4.2% |
| Atchison County, KS | 15,504 | 5.6% |
| Johnson County, KS | 14,505 | 4.8% |
| Livingston County, MO | 14,114 | 4.1% |
| Howard County, MO | 11,812 | 4.0% |
| Marion County, IA | 9,734 | 2.8% |
| Ray County, MO | 9,633 | 2.6% |
| Decatur County, IA | 9,487 | 2.8% |
| Grundy County, MO | 9,037 | 3.3% |
| Linn County, MO | 8,441 | 2.1% |
| Ringgold County, IA | 8,259 | 2.4% |
| Wapello County, IA | 7,685 | 2.8% |
| Jefferson County, IA | 7,579 | 2.7% |
| Monroe County, IA | 7,314 | 2.6% |
| Van Buren County, IA | 6,792 | 2.2% |
| Warren County, IA | 6,518 | 1.8% |
| Worth County, MO | 5,950 | 3.5% |
| Wayne County, IA | 5,540 | 1.7% |
| Andrew County, MO | 4,609 | 1.7% |
| Appanoose County, IA | 4,337 | 1.4% |
| Henry County, IA | 4,117 | 1.5% |
| Randolph County, MO | 4,008 | 1.3% |
| Jackson County, KS | 3,941 | 0.9% |
| Nemaha County, KS | 3,913 | 0.9% |
| Brown County, KS | 3,734 | 1.0% |
| Union County, IA | 3,122 | 1.2% |
| Marshall County, KS | 2,650 | 0.5% |
| Wyandotte County, KS | 2,064 | 2.1% |
| Pawnee County, NE | 2,043 | 0.7% |
| Johnson County, MO | 1,714 | 0.3% |
| Johnson County, NE | 1,460 | 0.6% |
| Otoe County, NE | 1,450 | 0.4% |
| Clay County, MO | 1,351 | 0.5% |
| Pottawatomie County, KS | 1,335 | 0.2% |
| Shawnee County, KS | 1,325 | 0.4% |
| Cass County, MO | 1,324 | 0.3% |
| Davis County, IA | 1,208 | 0.4% |
| Lancaster County, NE | 1,074 | 0.2% |
| Des Moines County, IA | 985 | 0.4% |
| Mahaska County, IA | 612 | 0.2% |
| Nemaha County, NE | 453 | 0.2% |
| Wabaunsee County, KS | 437 | 0.1% |
| Douglas County, KS | 345 | 0.1% |
| Jackson County, MO | 198 | 0.1% |
| Seward County, NE | 182 | 0.0% |
| Washington County, KS | 69 | 0.0% |
| Mercer County, MO | 38 | 0.0% |
Septic absorption fields
NRCS rating, share of Grundy 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 Grundy acres
- Depth to seasonal high water table
- About 1.5 feet (18 in) (median where reported); within 18 inches on >99% of acres.
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 3–5% (median 4%).
- Topsoil organic matter
- Median 3%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 0.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 100.0% |
| 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 | 0.0% |
| D: very slow infiltration (clayey, shallow or wet) | 5.8% |
| 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 | 94.2% |
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 Grundy (component kind "Series") in SSURGO: 611,862 acres.
- Method
- Shares are by mapped acres of Grundy components. The profile comes from the single largest Grundy component. Full methodology.