Soil series profile

Tokul soil series

Tokul is a moderately well drained soil with a gravelly medial loam surface, mapped on 187,058 acres in 5 counties in WA. Hydrologic group B.

#1960 by mapped area medial Aquic Vitrixerands (Andisols)

Drainage class: Moderately well drained
Hydrologic group: B
Typical topsoil pH: 5.8
Mapped area: 187k

Typical Tokul 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 Tokul horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–1 in (Oi)	Slightly decomposed plant material	4.5	Not reported	Not reported	75%
1–2 in (Oa)	Highly decomposed plant material	4.5	Not reported	Not reported	75%
2–6 in (A)	Gravelly medial loam	5.8	12%	45%	12.5%
6–9 in (Bs1)	Gravelly medial loam	6.2	8%	50%	3.5%
9–17 in (Bs2)	Gravelly medial loam	6.2	8%	50%	2%
17–24 in (Bs3)	Gravelly medial loam	6.2	8%	50%	1.5%
24–33 in (BC)	Gravelly medial fine sandy loam	6.0	4%	60%	0.5%
33–62 in (2Bsm)	Cemented material	6.0	2%	60%	0.5%

Representative values from the most extensive Tokul map unit (Tokul gravelly medial loam, 0 to 8 percent slopes, survey area WA661). 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 Tokul soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Tokul soils is moderately acidic: pH 5.8. Many vegetables grow well here, and some gardens benefit from a little lime. Test before adding any.

Loamy topsoil (loam, silt loam and similar) covers >99% of mapped Tokul acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is gravelly medial loam (97% of mapped Tokul acres).

100% of mapped Tokul acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

Most land is in hydrologic groups B and C, where rain soaks in at a moderate pace.

For a septic system

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

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 Tokul soil is found

Mapped acres

Tokul is mapped in Washington.

Counties with the most mapped Tokul soil
County	Acres	Share of county land
Snohomish County, WA	122,240	20.6%
King County, WA	50,186	4.1%
Skagit County, WA	13,791	1.8%
Whatcom County, WA	594	0.1%
Pierce County, WA	248	0.0%

Septic absorption fields

NRCS rating, share of Tokul acres

Not limited 0%

Somewhat limited 0%

Very limited >99%

Not rated <1%

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

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Septic tank absorption field rating across mapped Tokul acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	0.0%
Very limited	99.9%
Not rated	0.1%

Drainage, water table and flooding

Share of Tokul acres

Depth to seasonal high water table: About 2.2 feet (26 in) (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 2–45% (median 10%).
Topsoil organic matter: Median 12.5%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained 0%

Moderately well drained 100%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

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

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Drainage class across mapped Tokul acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	0.0%
Moderately well drained	100.0%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%

Hydrologic soil group

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

B: moderate infiltration 82%

C: slow infiltration 17%

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 Tokul acres. Scale 0 to 100% of mapped land.

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Hydrologic soil group across mapped Tokul acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	82.0%
C: slow infiltration	17.2%
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	0.8%

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 Tokul (component kind "Series") in SSURGO: 187,058 acres.
Method: Shares are by mapped acres of Tokul components. The profile comes from the single largest Tokul component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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