Grundy County, Illinois
The most common soil here is Drummer, on about 9% of the land: a silty clay loam, smooth and slightly sticky. Reddick and Ashkum come next.
About 12% of the land drains well, and 81% stays wet for long stretches; groundwater comes within two feet of the surface under 81% of it.
USDA rates 97% of the land very limited for a standard septic drain field, and 86% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 6% of the land floods occasionally or more, and bedrock lies within 40 inches under 5% 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 Grundy County, Illinois, 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 Poorly drained and the dominant hydrologic group is C/D (varies with drainage). The most common soil order is Alfisols — moderately leached forest soils with a clay-enriched subsoil. 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 Grundy County, Illinois. 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 |
|---|---|---|---|---|---|
| Drummer silty clay loam, 0 to 2 percent slopes | 27K | Poorly drained | B/D | Very limited | Very limited |
| Reddick clay loam, 0 to 2 percent slopes | 25K | Poorly drained | C/D | Very limited | Very limited |
| Ashkum silty clay loam, 0 to 2 percent slopes | 22K | Poorly drained | C/D | Very limited | Very limited |
| Elliott silt loam, 0 to 2 percent slopes | 18K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Selma loam, 0 to 2 percent slopes | 15K | Poorly drained | B/D | Very limited | Very limited |
| Andres silt loam, 0 to 2 percent slopes | 11K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Brenton silt loam, 0 to 2 percent slopes | 11K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Milford silty clay loam, 0 to 2 percent slopes | 9K | Poorly drained | C/D | Very limited | Very limited |
| Darroch silt loam, 0 to 2 percent slopes | 8K | Somewhat poorly drained | B/D | Very limited | Very limited |
| Water | 8K | Not rated | Not rated | ||
| Chenoa silty clay loam, 0 to 2 percent slopes | 6K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Martinton silt loam, 0 to 2 percent slopes | 5K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Bryce silty clay, 0 to 2 percent slopes | 5K | Poorly drained | C/D | Very limited | Very limited |
| Ridgeville fine sandy loam, 0 to 2 percent slopes | 5K | Somewhat poorly drained | A/D | Very limited | Very limited |
| Ade loamy fine sand, 1 to 6 percent slopes | 5K | Somewhat excessively drained | A | Not limited | Very limited |
| Gilford fine sandy loam, 0 to 2 percent slopes | 5K | Poorly drained | A/D | Very limited | Very limited |
| Braidwood loam, 20 to 70 percent slopes | 4K | Well drained | C | Very limited | Very limited |
| Bryce, shale substratum-Calamine silty clays, 0 to 2 percent slopes | 4K | Poorly drained | D | Very limited | Very limited |
| Swygert silty clay loam, 0 to 2 percent slopes | 4K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Shadeland silt loam, 0 to 2 percent slopes | 4K | Somewhat poorly drained | C/D | Very 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 86% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas. A geotechnical assessment is recommended before building.
Septic Systems
About 97% of soils are rated "very limited" for septic absorption fields. Poorly drained soils can't absorb septic effluent effectively. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Many soils hold water for extended periods. Raised beds are highly recommended to improve drainage for vegetables. Well-adapted native plants and water-loving species will do best in natural conditions.