State soil summary
Soil types in Connecticut
The most widespread soil series in Connecticut are Charlton, Canton, Chatfield. Pick a county below, or enter a ZIP code for the county you live in.
- Well or moderately well drained
- 75% of mapped land
- Typical topsoil pH
- 5.3 strongly acidic · most land 4.3–5.6
- Septic fields very limited
- 87% <1% not limited
- Subject to flooding
- 6% of land, any frequency
Connecticut counties
7 county reports, by population
| County | Most common soil | Well drained | Topsoil pH | Septic very limited |
|---|---|---|---|---|
| Fairfield County | Charlton | 69% | 5.4 | 81% |
| Hartford County | Wethersfield | 72% | 5.3 | 92% |
| New Haven County | Charlton | 70% | 5.3 | 85% |
| New London County | Charlton | 76% | 5.2 | 86% |
| Litchfield County | Charlton | 81% | 5.3 | 85% |
| Middlesex County | Charlton | 77% | 5.3 | 86% |
| Tolland County | Charlton | 80% | 5.3 | 89% |
What this means
What Connecticut soils mean for gardens, lawns and septic systems
For gardens
Typical topsoil in Connecticut is strongly acidic: pH 5.3 (most land between 4.3 and 5.6). 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 82% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is fine sandy loam (57% of the land).
75% of the land is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 54% of the land, 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 23% of the land, often in spring. Basements, sump pumps and lawns in low spots feel it first.
For septic systems
For conventional septic absorption fields, NRCS rates 87% of the land in Connecticut very limited, 9% somewhat limited and <1% not limited (3% not rated, such as urban land, pits or water).
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.
Flooding is mapped on 6% of the land (<1% occasional, 3% frequent).
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Statewide mix
Share of all mapped land
Drainage
Show as a table
| Category | Share of land |
|---|---|
| Excessively drained | 6.1% |
| Somewhat excessively drained | 6.0% |
| Well drained | 47.8% |
| Moderately well drained | 15.4% |
| Somewhat poorly drained | 0.2% |
| Poorly drained | 10.3% |
| Very poorly drained | 5.9% |
| Not rated | 8.4% |
Septic absorption fields
Show as a table
| Category | Share of land |
|---|---|
| Not limited | 0.9% |
| Somewhat limited | 9.2% |
| Very limited | 86.5% |
| Not rated | 3.3% |
Topsoil pH
Show as a table
| Category | Share of land |
|---|---|
| Strongly acidic (below 5.5) | 54.0% |
| Moderately to slightly acidic (5.5–6.4) | 32.0% |
| Near neutral (6.5–7.3) | 1.1% |
| Alkaline (7.4 and up) | 0.2% |
| Not reported | 12.7% |
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
- Connecticut: 3,123,335 acres of mapped land in 8 counties, pooled (not an average of county figures).
- Method
- Shares are by mapped land area: each map unit’s acres in the county times each soil component’s percentage. Open water is excluded. Topsoil values use the first mineral horizon of each component. Full methodology.