County soil summary
Soil types in Chittenden County, Vermont
The most widespread soils are Lyman, Peru and Marlow; the most common drainage class is somewhat excessively drained (23% of the land), and typical topsoil pH is 5.2.
- Well or moderately well drained
- 73% of land · state 75%
- Typical topsoil pH
- 5.2 strongly acidic · state 5.1
- Septic fields very limited
- 92% of land · state 94%
- Subject to flooding
- 5% of land, any frequency · state 2%
Most common soils in Chittenden County
Share of mapped land
A county is a patchwork of many soils. These 8 cover 58% of the mapped land; 61 named soil series are mapped here in all.
| Soil | Share of land | Drainage | Topsoil pH |
|---|---|---|---|
| Lyman | 14.6% | Somewhat excessively drained | 4.0 |
| Peru | 12.2% | Moderately well drained | 4.8 |
| Marlow | 10.0% | Well drained | 4.8 |
| Cabot | 5.2% | Poorly drained | 5.2 |
| Vergennes | 4.7% | Moderately well drained | 5.9 |
| Farmington | 4.5% | Well drained | 6.2 |
| Adams | 3.7% | Somewhat excessively drained | 4.8 |
| Windsor | 3.5% | Excessively drained | 5.1 |
What this means
What the soils in Chittenden County mean for gardens, lawns and septic systems
For your garden
Typical topsoil in Chittenden County is strongly acidic: pH 5.2 (most land between 4.0 and 6.2). 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 73% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is fine sandy loam (29% of the land).
73% of the land is moderately well to excessively drained, which suits most garden plants.
For your lawn and yard
On 75% 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 33% of the land, 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 92% of the land in Chittenden County very limited, 3% somewhat limited and 0% not limited (5% not rated, such as urban land, pits or water).
That is close to the state as a whole (94% very 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.
Flooding is mapped on 5% of the land (2% occasional, 3% frequent).
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Drainage
How long the soil stays wet
The most common drainage class is somewhat excessively drained (23%). 73% of the land is moderately well drained or better, compared with 75% across Vermont.
Show as a table
| Category | Chittenden County | Vermont |
|---|---|---|
| Excessively drained | 5.6% | 3.5% |
| Somewhat excessively drained | 23.2% | 13.3% |
| Well drained | 21.4% | 38.3% |
| Moderately well drained | 22.4% | 20.3% |
| Somewhat poorly drained | 3.5% | 5.5% |
| Poorly drained | 14.6% | 12.7% |
| Very poorly drained | 2.9% | 3.3% |
| Not rated | 6.4% | 3.1% |
Septic absorption fields
NRCS rating for conventional drain fields
The rating looks at the soil from 24 to 60 inches deep: permeability, depth to a seasonal water table or bedrock, flooding and slope. “Very limited” means at least one feature is unfavorable enough that a conventional field is hard to make work.
Show as a table
| Category | Chittenden County | Vermont |
|---|---|---|
| Not limited | 0.0% | 0.0% |
| Somewhat limited | 2.8% | 4.1% |
| Very limited | 91.9% | 93.5% |
| Not rated | 5.3% | 2.4% |
Rain, runoff and water table
Hydrologic soil group, flooding, seasonal water table
Hydrologic soil group
How fast rain soaks in when the soil is already wet. Group A soaks in fastest, D slowest.
Show as a table
| Category | Chittenden County | Vermont |
|---|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 15.5% | 8.1% |
| B: moderate infiltration | 3.9% | 13.4% |
| C: slow infiltration | 15.3% | 24.7% |
| D: very slow infiltration (clayey, shallow or wet) | 33.8% | 33.9% |
| A/D: D as is, A if drained | 2.2% | 1.7% |
| B/D: D as is, B if drained | 3.8% | 3.0% |
| C/D: D as is, C if drained | 20.1% | 12.3% |
| Not rated | 5.4% | 2.9% |
Flooding
Show as a table
| Category | Chittenden County | Vermont |
|---|---|---|
| No flooding | 92.7% | 96.7% |
| Rare or very rare | 0.0% | 0.0% |
| Occasional | 1.8% | 0.7% |
| Frequent or very frequent | 3.4% | 1.7% |
| Not reported | 2.1% | 0.9% |
Seasonal high water table
Show as a table
| Category | Chittenden County | Vermont |
|---|---|---|
| Within 18 inches at some time of year | 33.4% | 32.5% |
| 18 inches to 3.3 feet | 11.0% | 10.4% |
| Deeper than 3.3 feet or none reported | 53.5% | 56.3% |
| Not reported | 2.1% | 0.9% |
Topsoil pH and texture
First mineral layer of each soil
Typical topsoil pH is 5.2 (strongly acidic); 80% of rated land falls between 4.0 and 6.2. Median topsoil organic matter is 6.5%.
Show as a table
| Category | Chittenden County | Vermont |
|---|---|---|
| Strongly acidic (below 5.5) | 52.6% | 62.8% |
| Moderately to slightly acidic (5.5–6.4) | 32.3% | 25.8% |
| Near neutral (6.5–7.3) | 8.5% | 6.9% |
| Alkaline (7.4 and up) | 0.1% | 0.0% |
| Not reported | 6.5% | 4.5% |
Texture
Show as a table
| Category | Chittenden County | Vermont |
|---|---|---|
| Sandy | 11.0% | 8.0% |
| Loamy (loam, silt loam and similar) | 73.1% | 82.1% |
| Clayey (40%+ clay) | 9.2% | 3.8% |
| Organic (muck or peat) | 1.5% | 3.2% |
| Not reported (rock, urban land, etc.) | 5.2% | 2.9% |
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
- Chittenden County, Vermont (FIPS 50007): 343,563 acres of mapped land, 53,737 acres of open water excluded. State comparisons pool all mapped land in Vermont.
- 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.