County soil summary
Soil types in Middlesex County, Massachusetts
The most widespread soils are Charlton, Hinckley and Freetown; the most common drainage class is well drained (30% of the land), and typical topsoil pH is 5.1.
- Well or moderately well drained
- 63% of land · state 72%
- Typical topsoil pH
- 5.1 strongly acidic · state 5.0
- Septic fields very limited
- 81% of land · state 88%
- Subject to flooding
- 11% of land, any frequency · state 8%
Most common soils in Middlesex County
Share of mapped land
A county is a patchwork of many soils. These 8 cover 51% of the mapped land; 48 named soil series are mapped here in all.
| Soil | Share of land | Drainage | Topsoil pH |
|---|---|---|---|
| Urban landLand type, not a soil series | 9.7% | — | — |
| Charlton | 6.8% | Well drained | 4.8 |
| Hinckley | 6.7% | Excessively drained | 4.6 |
| Freetown | 6.2% | Very poorly drained | Not reported |
| Canton | 6.1% | Well drained | 4.3 |
| Paxton | 5.6% | Well drained | 5.5 |
| Windsor | 5.3% | Excessively drained | 5.1 |
| Merrimac | 4.8% | Somewhat excessively drained | 5.1 |
What this means
What the soils in Middlesex County mean for gardens, lawns and septic systems
For your garden
Typical topsoil in Middlesex County is strongly acidic: pH 5.1 (most land between 4.6 and 5.5). 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 47% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is fine sandy loam (41% of the land).
63% of the land is moderately well to excessively drained, which suits most garden plants.
For your lawn and yard
31% of the land is in hydrologic group A, where water soaks in fast. Lawns there dry out quickly; deeper, less frequent watering and organic matter help.
A seasonal high water table comes within 18 inches of the surface on 22% 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 81% of the land in Middlesex County very limited, 2% somewhat limited and 3% not limited (14% not rated, such as urban land, pits or water).
Statewide, 88% of the land is very limited, so Middlesex County is less restrictive than typical.
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 11% of the land (<1% occasional, 2% 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 well drained (30%). 63% of the land is moderately well drained or better, compared with 72% across Massachusetts.
Show as a table
| Category | Middlesex County | Massachusetts |
|---|---|---|
| Excessively drained | 14.1% | 13.5% |
| Somewhat excessively drained | 6.1% | 10.4% |
| Well drained | 30.2% | 32.9% |
| Moderately well drained | 13.1% | 15.1% |
| Somewhat poorly drained | 0.0% | 0.0% |
| Poorly drained | 4.2% | 7.2% |
| Very poorly drained | 14.4% | 10.6% |
| Not rated | 18.0% | 10.2% |
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 | Middlesex County | Massachusetts |
|---|---|---|
| Not limited | 3.0% | 0.9% |
| Somewhat limited | 2.2% | 3.0% |
| Very limited | 80.6% | 87.7% |
| Not rated | 14.2% | 8.3% |
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 | Middlesex County | Massachusetts |
|---|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 30.9% | 24.5% |
| B: moderate infiltration | 8.1% | 13.1% |
| C: slow infiltration | 9.2% | 16.0% |
| D: very slow infiltration (clayey, shallow or wet) | 16.4% | 16.3% |
| A/D: D as is, A if drained | 4.2% | 3.4% |
| B/D: D as is, B if drained | 11.0% | 8.0% |
| C/D: D as is, C if drained | 6.0% | 10.2% |
| Not rated | 14.2% | 8.6% |
Flooding
Show as a table
| Category | Middlesex County | Massachusetts |
|---|---|---|
| No flooding | 85.7% | 87.7% |
| Rare or very rare | 8.4% | 4.5% |
| Occasional | 0.6% | 0.7% |
| Frequent or very frequent | 1.5% | 2.6% |
| Not reported | 3.8% | 4.4% |
Seasonal high water table
Show as a table
| Category | Middlesex County | Massachusetts |
|---|---|---|
| Within 18 inches at some time of year | 22.1% | 24.6% |
| 18 inches to 3.3 feet | 20.6% | 19.7% |
| Deeper than 3.3 feet or none reported | 55.5% | 54.8% |
| Not reported | 1.9% | 1.0% |
Topsoil pH and texture
First mineral layer of each soil
Typical topsoil pH is 5.1 (strongly acidic); 80% of rated land falls between 4.6 and 5.5. Median topsoil organic matter is 5.5%.
Show as a table
| Category | Middlesex County | Massachusetts |
|---|---|---|
| Strongly acidic (below 5.5) | 54.3% | 61.0% |
| Moderately to slightly acidic (5.5–6.4) | 15.2% | 17.6% |
| Near neutral (6.5–7.3) | 0.0% | 1.3% |
| Alkaline (7.4 and up) | 0.0% | 0.1% |
| Not reported | 30.5% | 20.0% |
Texture
Show as a table
| Category | Middlesex County | Massachusetts |
|---|---|---|
| Sandy | 22.3% | 20.2% |
| Loamy (loam, silt loam and similar) | 47.3% | 58.3% |
| Clayey (40%+ clay) | 0.0% | 0.0% |
| Organic (muck or peat) | 12.5% | 10.9% |
| Not reported (rock, urban land, etc.) | 18.0% | 10.6% |
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
- Middlesex County, Massachusetts (FIPS 25017): 524,802 acres of mapped land, 17,310 acres of open water excluded. State comparisons pool all mapped land in Massachusetts.
- 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.