Soil series profile

Tunbridge soil series

Tunbridge is a well drained soil with a sandy loam surface, mapped on 1,943,664 acres in 53 counties across 5 states. Hydrologic group C.

#37 by mapped area coarse-loamy Typic Haplorthods (Spodosols)

Drainage class: Well drained
Hydrologic group: C
Typical topsoil pH: 4.8
Mapped area: 1.9M

Typical Tunbridge profile

Texture and pH by depth

Depth to scale. More strongly shaded layers hold more clay. Horizon names are the soil survey's (A = topsoil, B = subsoil, C = parent material).

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Typical Tunbridge horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–1 in (Oi)	Slightly decomposed plant material	4.3	Not reported	25%	75%
1–3 in (Oa)	Highly decomposed plant material	4.3	Not reported	40%	60%
3–4 in (E)	Sandy loam	4.7	4%	67%	3%
4–7 in (Bhs1)	Fine sandy loam	4.7	4%	61%	9%
7–13 in (Bhs2)	Fine sandy loam	4.7	4%	61%	9%
13–18 in (Bs)	Fine sandy loam	4.7	4%	61%	6.5%
18–27 in (C)	Gravelly sandy loam	5.3	4%	67%	0.5%
27–79 in (R)	Bedrock	Not reported	Not reported	Not reported	Not reported

Representative values from the most extensive Tunbridge map unit (Becket-Tunbridge complex, 15 to 35 percent slopes, rocky, very bouldery, survey area NY041). Other map units of this series vary within the series range.

Stock photo for illustration, not a sample of this soil series. Credit on the Sources & method page.

What this means

What Tunbridge soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Tunbridge soils is very strongly acidic: pH 4.8 (most land between 4.7 and 4.8). 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 98% of mapped Tunbridge acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is fine sandy loam (65% of mapped Tunbridge acres).

>99% of mapped Tunbridge acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On 64% of mapped acres, 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.

For a septic system

For conventional septic absorption fields, NRCS rates 99% of the acres in mapped Tunbridge soils very limited, 0% somewhat limited and 0% not limited (1% 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.

Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.

Generated from the mapped numbers above using fixed rules, not a site visit. See how these notes are written.

Where Tunbridge soil is found

Mapped acres

Tunbridge is mapped in New York, Vermont, Maine, New Hampshire and Massachusetts.

Counties with the most mapped Tunbridge soil
County	Acres	Share of county land
Hamilton County, NY	150,368	13.7%
Essex County, NY	125,858	11.0%
St. Lawrence County, NY	117,699	6.9%
Coos County, NH	100,880	11.0%
Grafton County, NH	84,812	11.3%
Windsor County, VT	73,383	11.8%
Washington County, ME	68,240	4.3%
Berkshire County, MA	64,551	10.7%
Essex County, VT	61,153	14.4%
Franklin County, NY	61,080	5.9%
Oxford County, ME	60,841	4.8%
Herkimer County, NY	60,256	6.7%
Orange County, VT	60,156	13.7%
Hancock County, ME	56,331	5.7%
Cheshire County, NH	51,186	11.3%
Washington County, VT	50,995	11.6%
Lamoille County, VT	46,075	15.7%
Kennebec County, ME	44,061	8.0%
Merrimack County, NH	40,312	6.8%
Rutland County, VT	38,072	6.4%
Orleans County, VT	37,723	8.5%
Franklin County, ME	37,274	3.4%
Waldo County, ME	35,388	7.6%
Windham County, VT	34,516	6.9%
Lincoln County, ME	31,100	10.8%
Lewis County, NY	25,778	3.2%
Fulton County, NY	25,033	7.9%
Knox County, ME	24,816	10.5%
Saratoga County, NY	24,223	4.7%
Belknap County, NH	23,419	9.0%
Hillsborough County, NH	23,230	4.2%
Franklin County, VT	20,483	5.0%
Clinton County, NY	19,956	3.0%
Cumberland County, ME	16,983	3.0%
Caledonia County, VT	16,579	4.0%
Hampshire County, MA	16,136	4.6%
Penobscot County, ME	15,166	0.7%
Androscoggin County, ME	13,863	4.6%
Sagadahoc County, ME	11,826	7.4%
Bennington County, VT	11,699	2.7%
Hampden County, MA	11,328	2.9%
Worcester County, MA	9,399	1.0%
Piscataquis County, ME	8,903	0.4%
Sullivan County, NH	7,910	2.3%
Franklin County, MA	6,839	1.5%
York County, ME	6,766	1.1%
Chittenden County, VT	3,039	0.9%
Addison County, VT	2,632	0.5%
Somerset County, ME	2,087	0.1%
Carroll County, NH	1,954	0.4%
Oneida County, NY	951	0.1%
Aroostook County, ME	245	0.0%
Jefferson County, NY	111	0.0%

Septic absorption fields

NRCS rating, share of Tunbridge acres

Not limited 0%

Somewhat limited 0%

Very limited 99%

Not rated 1%

Septic tank absorption field rating across mapped Tunbridge acres. Scale 0 to 100% of mapped land.

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Septic tank absorption field rating across mapped Tunbridge acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	0.0%
Very limited	98.8%
Not rated	1.2%

Drainage, water table and flooding

Share of Tunbridge acres

Depth to seasonal high water table: About 5.9 feet (71 in) (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 9–45% (median 20%).
Topsoil organic matter: Median 3.2%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained >99%

Moderately well drained 0%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

Not rated <1%

Drainage class across mapped Tunbridge acres. Scale 0 to 100% of mapped land.

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Drainage class across mapped Tunbridge acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	99.8%
Moderately well drained	0.0%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%
Not rated	0.2%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%

B: moderate infiltration 35%

C: slow infiltration 64%

D: very slow infiltration (clayey, shallow or wet) 0%

A/D: D as is, A if drained 0%

B/D: D as is, B if drained 0%

C/D: D as is, C if drained 0%

Not rated 1%

Hydrologic soil group across mapped Tunbridge acres. Scale 0 to 100% of mapped land.

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Hydrologic soil group across mapped Tunbridge acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	35.0%
C: slow infiltration	63.9%
D: very slow infiltration (clayey, shallow or wet)	0.0%
A/D: D as is, A if drained	0.0%
B/D: D as is, B if drained	0.0%
C/D: D as is, C if drained	0.0%
Not rated	1.1%

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: All map unit components named Tunbridge (component kind "Series") in SSURGO: 1,943,664 acres.
Method: Shares are by mapped acres of Tunbridge components. The profile comes from the single largest Tunbridge component. Full methodology.

Independent reference site. No government affiliation or endorsement.

Full narrative description: USDA Official Soil Series Description for Tunbridge.