Soil series profile
Markham soil series
Markham is a moderately well drained soil with a silt loam surface, mapped on 179,698 acres in 14 counties across 3 states. Hydrologic group C.
- Drainage class
- Moderately well drained 100% of mapped acres
- Hydrologic group
- C 100% of mapped acres
- Typical topsoil pH
- 5.8 moderately acidic · range 5.8–5.8
- Mapped area
- 180k acres in 14 counties, 3 states
Typical Markham profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–8 in (Ap) | Silt loam | 5.8 | 24% | 10% | 2.5% |
| 8–21 in (2Bt1) | Silty clay loam | 6.2 | 39% | 12% | 0.6% |
| 21–32 in (2Bt2) | Silty clay loam | 7.6 | 36% | 12% | 0.3% |
| 32–60 in (2Cd) | Silty clay loam | 8.1 | 32% | 15% | 0.25% |

What this means
What Markham soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Markham soils is moderately acidic: pH 5.8. Many vegetables grow well here, and some gardens benefit from a little lime. Test before adding any.
Loamy topsoil (loam, silt loam and similar) covers 100% of mapped Markham acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (>99% of mapped Markham acres).
100% of mapped Markham 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 Markham 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 Markham soil is found
Mapped acres
Markham is mapped in Illinois, Wisconsin and Indiana.
| County | Acres | Share of county land |
|---|---|---|
| Cook County, IL | 33,942 | 5.6% |
| DuPage County, IL | 32,145 | 15.2% |
| Will County, IL | 21,665 | 4.1% |
| Lake County, IL | 21,379 | 7.6% |
| Lake County, IN | 17,891 | 5.6% |
| Racine County, WI | 14,479 | 6.8% |
| Kenosha County, WI | 14,240 | 8.2% |
| Kankakee County, IL | 6,548 | 1.5% |
| Warren County, IN | 5,924 | 2.6% |
| Kane County, IL | 5,795 | 1.8% |
| Porter County, IN | 3,818 | 1.4% |
| Benton County, IN | 1,280 | 0.5% |
| Milwaukee County, WI | 481 | 0.3% |
| Waukesha County, WI | 112 | 0.0% |
Septic absorption fields
NRCS rating, share of Markham 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 Markham acres
- Depth to seasonal high water table
- About 2.3 feet (28 in) (median where reported).
- 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 | 100.0% |
| 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 Markham (component kind "Series") in SSURGO: 179,698 acres.
- Method
- Shares are by mapped acres of Markham components. The profile comes from the single largest Markham component. Full methodology.