St. Clair County, Michigan
The most common soil here is Parkhill, on about 11% of the land: a sandy clay loam, gritty but holds together. Blount and Latty come next.
About 6% of the land drains well, and 89% stays wet for long stretches; groundwater comes within two feet of the surface under 90% of it.
USDA rates 96% of the land very limited for a standard septic drain field, and 92% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 3% of the land floods occasionally or more.
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 St. Clair County, Michigan, 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 Somewhat 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 St. Clair County, Michigan. 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 |
|---|---|---|---|---|---|
| Parkhill loam, 0 to 1 percent slopes | 48K | Poorly drained | C/D | Very limited | Very limited |
| Blount loam, Erie-Huron Lake Plain, 0 to 2 percent slopes | 37K | Somewhat poorly drained | D | Very limited | Very limited |
| Allendale-Lenawee-Toledo complex, 0 to 3 percent slopes | 28K | Somewhat poorly drained | D | Very limited | Very limited |
| Wainola-Deford fine sands, 0 to 2 percent slopes | 25K | Somewhat poorly drained | A/D | Very limited | Very limited |
| Latty complex, 0 to 3 percent slopes | 24K | Somewhat poorly drained | D | Very limited | Very limited |
| Conover loam, 0 to 3 percent slopes | 24K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Bach very fine sandy loam | 20K | Very poorly drained | B/D | Very limited | Very limited |
| Allendale-Hoytville complex, 0 to 6 percent slopes | 19K | Somewhat poorly drained | D | Very limited | Very limited |
| Blount loam, 2 to 6 percent slopes | 16K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Allendale-Latty complex, 0 to 3 percent slopes | 16K | Somewhat poorly drained | D | Very limited | Very limited |
| Sloan, frequently flooded, and Ceresco, occasionally flooded, soils, 0 to 3 percent slopes | 13K | Very poorly drained | C/D | Very limited | Very limited |
| Conover-Parkhill loams, 0 to 2 percent slopes | 12K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Water | 12K | Not rated | Not rated | ||
| Londo loam, 0 to 3 percent slopes | 11K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Conover loam, 0 to 2 percent slopes | 10K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Nappanee-Hoytville complex, 0 to 3 percent slopes | 9K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Chelsea-Covert sands, 0 to 6 percent slopes | 9K | Well drained | A | Very limited | Very limited |
| Metamora-Parkhill complex, 0 to 2 percent slopes | 8K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Pert-Sims loams, 0 to 6 percent slopes | 8K | Somewhat poorly drained | C/D | Very limited | Very limited |
| Latty silty clay loam | 8K | Very poorly drained | 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 92% of soils are rated "very limited" for dwellings with basements. Specific challenges include poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 96% 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.