Site and Soil Evaluation and Soil Protection

Andy Kleinschmidt

OSU Extension, Van Wert County

419-238-1214 (office)

419-203-5967 (cell)

kleinschmidt.5@osu.edu or andykleinschmidt@gmail.com

Proposed septic field

Okay . . .

. . . Now for a little diversion

Sand Sandyloam

Siltloam

Clayloam

Clay

1

2

3

4

Inch

es w

ater

/ft s

oil

Plant Available Water

Rhoads and Yonts, 1984.

Available Water Holding CapacityAvailable Water Holding Capacity

Storage capacity

Silty clay loam 1.8Clay loam 1.8

Silty clay 1.6Silt loam 2.0

Sandy loam 1.4

Texture (in./ft.)

Comparison of Coarse Textured and Fine Textured Soils

Coarse Textured Soil

Less porespace but more macropores

Fine Textured Soil

More total porespace

Texture and Pore SpaceTexture and Pore Space

Granular

Small Polyhedrons or SpheroidsBounded by Curved or Irregular SurfacesSymbol for Structure (gr)

GRANULAR

BlockySubangular or Angular

Subangular Blocky – the three dimensions are about the same size, but polyhedrons are subrounded. Symbol (sbk)

Angular Blocky – the three dimensions are about the same size, but edges are shape and faces appear flattened. Symbol (abk)

BLOCKY

Bulk Density DeterminationBulk Density Determination

For our example, let’s assume we have 1 cubic centimeter of soil that weighs 1.33 grams

Soil is made of solids andpore spaces

1.33 grams

To calculate Bulk Density:Volume = 1 cm3

Weight = 1.33 grams

Bulk Density = Weight of Soil

Volume of Soil

Bulk Density = 1.33

1

Bulk Density = 1.33 grams/cm3

{ }

Bulk density (g/cm3)

Soil Cropped Uncropped

Hagerstown loam (PA) 1.25

Marshall silt loam (IA) 1.13

Nappanese silt loam (OH) 1.31

(50%)

(56%)

(51%)

(57%)

(63%)

(60%)

1.07

0.93

1.05

What impact does this have on pore space?

Bulk Density (con’t.)

Data from Lyon et al.

Some Common Bulk Densities

• Uncultivated/undisturbed woodlots – 1.0 to 1.2 g/cm3

• Cultivated clay and silt loams– 1.1 to 1.5 g/cm3

• Cultivated sandy loams– 1.3 to 1.7 g/cm3

• Compacted glacial till– 1.9 to 2.2 g/cm3

• Concrete– 2.4 g/cm3

What do you notice about this soil core?What do you notice about this soil core?

macropores

Preferential FlowPreferential Flow

Example of pesticide leaching through preferential flow.

Atrazine applied.

Initial storm of season.

Notice preferential flow.

A

B

Soil Horizon

Calculated from Kladivco, et al. (1999); models from Cornell

68% of leachable atrazine was lost to preferential flow during the first storm.

What are the implications from a treatment standpoint?

What ‘stands out’ about the landscape?

Soil Color, Soil Aeration or Drainage, and the Oxidation State of Iron

1. Iron is reduced1. Iron is reduced

2. Fe2. Fe++++

3. dull colors (grays, 3. dull colors (grays, blueblue))

4. poorly drained4. poorly drained

1. Iron is oxidized1. Iron is oxidized

2. 2. FeFe++++++

3. bright colors 3. bright colors ((yellowsyellows, browns), browns)

4. well drained4. well drained

POOR AERATION GOOD AERATION

Okay . . .

. . . Back to the site and soil evalution.

Not suitable . . .

• Wetland

• Poor soil structure

• Flood prone

• Extremely shallow to bedrock

• Recently disturbed

• Excessively gravelly

• What else makes a site not suitable?

Approx. 1.1 acre

Approx. 1.1 acre

Summary

• Surface view looked promising

• Standing corn stalks- looked good

• Did not visually see any ‘drowned’ out areas

• Mapped Pewamo

• Very weak and or no soil structure – high clay

• No system will work here (except for city services)

PIT

PIT

Approx. 20 acres

Ohio Rapid Assessment Method• Provides for a quantitative wetland assessment

of a parcel • Does not replace a formal wetland delineation• Allows for categorizing wetlands: Category 1, 2,

or 3.• Training and additional information online at:

http://www.epa.state.oh.us/dsw/wetlands/WetlandEcologySection.html#Training

Keep all traffic off the soil absorption fields (including construction traffic), especially when saturated or if there is snow cover.

• Do not discharge from basement footing drains or other clean water sources into the soil absorption fields.

• Divert downspouts and other rainwater drainage away from the soil absorption fields. The extra rainwater can overwhelm the system.

• Establish a grass cover over the soil absorption fields as soon as possible after installation to prevent erosion and promote plant uptake of water.

• Avoid planting trees on or adjacent to the soil absorption fields.

• Keep pavement, decks, above ground pools, and out buildings off of and away from the soil absorption fields. Construction activity can compact the soil and the structures limit access to the septic system or soil absorption fields for maintenance.

• Never put additional fill over the soil absorption fields.