Grafton County, New Hampshire
The most common soil here is Tunbridge, on about 11% of the land: a fine sandy loam, gritty and crumbly. Becket and Lyman come next.
About 76% of the land drains well, and 7% stays wet for long stretches; groundwater comes within two feet of the surface under 18% of it.
USDA rates 90% of the land very limited for a standard septic drain field, and 80% 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, and bedrock lies within 40 inches under 34% 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 Grafton County, New Hampshire, 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 Well drained and the dominant hydrologic group is C (slow infiltration, moderate runoff). The most common soil order is Spodosols — acidic forest soils with a distinctive leached layer, common under conifers. 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 Grafton County, New Hampshire. 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 |
|---|---|---|---|---|---|
| Tunbridge-Lyman-Rock outcrop complex, 25 to 60 percent slopes | 64K | Well drained | C | Very limited | Very limited |
| Tunbridge-Lyman-Rock outcrop complex, 15 to 25 percent slopes | 39K | Well drained | C | Very limited | Very limited |
| Water | 25K | Not rated | Not rated | ||
| Monadnock and Hermon soils, 15 to 25 percent slopes, very stony | 25K | Well drained | A | Very limited | Very limited |
| Becket fine sandy loam, 15 to 25 percent slopes, very stony | 19K | Well drained | C | Very limited | Very limited |
| Peru fine sandy loam, 8 to 15 percent slopes, very stony | 19K | Moderately well drained | C/D | Very limited | Very limited |
| Hermon and Monadnock soils, 8 to 15 percent slopes, very stony | 17K | Somewhat excessively drained | A | Somewhat limited | Very limited |
| Tunbridge-Lyman complex, 15 to 25 percent slopes, rocky | 17K | Well drained | C | Very limited | Very limited |
| Becket-Tunbridge association, 15 to 35 percent slopes, very stony | 16K | Well drained | C | Very limited | Very limited |
| Marlow fine sandy loam, 15 to 25 percent slopes, very stony | 15K | Well drained | C | Very limited | Very limited |
| Tunbridge-Lyman-Rock outcrop complex, 8 to 15 percent slopes | 15K | Well drained | C | Very limited | Very limited |
| Marlow-Tunbridge association, hilly, very stony | 13K | Well drained | C | Very limited | Very limited |
| Pillsbury fine sandy loam, 0 to 8 percent slopes, very stony | 13K | Poorly drained | D | Very limited | Very limited |
| Becket-Monadnock association, 15 to 35 percent slopes, very stony | 13K | Well drained | C | Very limited | Very limited |
| Adams loamy sand, 15 to 60 percent slopes | 12K | Excessively drained | A | Very limited | Very limited |
| Monadnock-Hermon association, 15 to 35 percent slopes, very stony | 11K | Well drained | B | Very limited | Very limited |
| Berkshire fine sandy loam, 15 to 25 percent slopes, very stony | 11K | Well drained | B | Very limited | Very limited |
| Tunbridge-Lyman complex, 8 to 15 percent slopes, rocky | 10K | Well drained | C | Very limited | Very limited |
| Monadnock and Hermon soils, 25 to 35 percent slopes, very stony | 10K | Well drained | A | Very limited | Very limited |
| Cardigan-Kearsarge-Rock outcrop complex, 15 to 25 percent slopes | 10K | Well drained | C | 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 80% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, poor drainage in some areas. A geotechnical assessment is recommended before building.
Septic Systems
About 90% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.