Soil survey area

Jefferson County, Illinois

Survey Area IL081• Illinois

The short version

The most common soil here is Bluford, on about 16% of the land: a silt loam, smooth, like flour. Ava and Belknap come next.

About 11% of the land drains well, and 56% stays wet for long stretches; groundwater comes within two feet of the surface under 56% of it.

USDA rates 94% of the land very limited for a standard septic drain field, and 77% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: 15% of the land floods occasionally or more, and bedrock lies within 40 inches under 6% 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 ground underfoot

The soils you're most likely standing on

The biggest named soils in Jefferson County, Illinois, each drawn five feet deep from its official USDA description, in its recorded colors.

Bluford

16% of the area

Silt loam topsoil · somewhat poorly drained

Smooth, like flour. Fertile and holds water well.

Alfisols

Ava

10% of the area

Silt loam topsoil · moderately well drained

Smooth, like flour. Fertile and holds water well.

Alfisols

Belknap

9% of the area

Silt loam topsoil · somewhat poorly drained

Smooth, like flour. Fertile and holds water well.

Inceptisols

Grantsburg

8% of the area

Silt loam topsoil · moderately well drained

Smooth, like flour. Fertile and holds water well.

Alfisols

Hoyleton

8% of the area

Silt loam topsoil · somewhat poorly drained

Smooth, like flour. Fertile and holds water well.

Alfisols

Wynoose

6% of the area

Silt loam topsoil · poorly drained

Smooth, like flour. Fertile and holds water well.

Alfisols

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 Somewhat poorly drained and the dominant hydrologic group is C/D (varies with drainage). The most common soil order is Alfisols — moderately leached forest soils with a clay-enriched subsoil. 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 Jefferson County, Illinois. 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
Bluford silt loam, 0 to 2 percent slopes	38K	Somewhat poorly drained	C/D	Very limited	Very limited
Belknap silt loam, 0 to 2 percent slopes, frequently flooded	35K	Somewhat poorly drained	B/D	Very limited	Very limited
Ava silt loam, 2 to 5 percent slopes	25K	Moderately well drained	C	Very limited	Very limited
Hoyleton silt loam, 0 to 2 percent slopes	22K	Somewhat poorly drained	C/D	Very limited	Very limited
Grantsburg silt loam, 2 to 5 percent slopes	21K	Moderately well drained	C	Somewhat limited	Very limited
Blair silty clay loam, 5 to 10 percent slopes, severely eroded	20K	Somewhat poorly drained	C/D	Very limited	Very limited
Hickory-Kell silt loams, 18 to 35 percent slopes	19K	Well drained	B	Very limited	Very limited
Bluford silt loam, 2 to 5 percent slopes, eroded	17K	Somewhat poorly drained	C/D	Very limited	Very limited
Cisne silt loam, 0 to 2 percent slopes	17K	Poorly drained	C/D	Very limited	Very limited
Wynoose silt loam, 0 to 2 percent slopes	14K	Poorly drained	C/D	Very limited	Very limited
Grantsburg silty clay loam, 5 to 10 percent slopes, severely eroded	14K	Moderately well drained	C	Somewhat limited	Very limited
Plumfield silty clay loam, 5 to 10 percent slopes	13K	Moderately well drained	D	Somewhat limited	Very limited
Bonnie silt loam, 0 to 2 percent slopes, frequently flooded	12K	Poorly drained	C/D	Very limited	Very limited
Water	11K			Not rated	Not rated
Hickory clay loam, 10 to 18 percent slopes, severely eroded	11K	Well drained	B	Somewhat limited	Somewhat limited
Ava silt loam, 5 to 10 percent slopes, eroded	8K	Moderately well drained	C	Very limited	Very limited
Wynoose silt loam, bench, 0 to 2 percent slopes	8K	Poorly drained	C/D	Very limited	Very limited
Ava silt loam, 2 to 5 percent slopes, eroded	8K	Moderately well drained	C	Very limited	Very limited
Hoyleton silt loam, 2 to 5 percent slopes, eroded	8K	Somewhat poorly drained	C/D	Very limited	Very limited
Sharon silt loam, 0 to 2 percent slopes, frequently flooded	5K	Moderately 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.

Alfisols

Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.

Entisols

Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.

What This Means

Building & Foundations

About 77% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.

Septic Systems

About 94% of soils are rated "very limited" for septic absorption fields. Poorly drained soils can't absorb septic effluent effectively. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.

Gardening & Agriculture

Many soils hold water for extended periods. Raised beds are highly recommended to improve drainage for vegetables. Well-adapted native plants and water-loving species will do best in natural conditions.

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