TITLE 77: PUBLIC HEALTH
CHAPTER I: DEPARTMENT OF PUBLIC HEALTH
SUBCHAPTER r: WATER AND SEWAGE
PART 905 PRIVATE SEWAGE DISPOSAL CODE
SECTION 905.APPENDIX A ILLUSTRATIONS AND EXHIBITS

 

Section 905.APPENDIX A   Illustrations and Exhibits

 

Section 905.ILLUSTRATION M   Soil Suitability for On-Site Sewage Design

 

Section 905.EXHIBIT A   Loading Rates in Square Feet Per Bedroom and Gallons/Square Feet/Day

 

Design Group

Soil Group

(Most Limiting

Layer)

Minimum Separation To Limiting Layer1

Permeability Range

Size of System

Residential Reg. Absorption (ft2/bedroom)

Institutional/Commercial Allowable Application Rate (GPD/ft2)

 

 

 

 

 

 

I

1A

NR3

Very Rapid

NR3

NR3

II

2A; 2B; 2K

3 feet

Rapid

200

1.0

III

3B; 3K

3 feet

High Moderately Rapid

220

0.91

IV

3A; 3L; 4D; 4K

3 feet

Low Moderately Rapid

240

0.84

V

4A;; 4B; 4H; 4L; 5D

3 feet

Very High Moderate

265

0.75

VI

4F; 4M; 5B

3 feet

High Moderate

290

0.69

VII

4N; 5A; 5C; 5H; 5K; 6D

2 feet

Moderate

325

0.62

VIII

4O; 5E; 5I; 5L; 6A; 6B; 6E; 6H; 6K

2 feet

Low Moderate

385

0.52

IX2

5F; 5M; 6C; 6L; 7D; 7F

2 feet

High Moderately Slow

445

0.45

X2

5G; 6F; 6I; 7E; 7C; 7H

2 feet

Low Moderately Slow

500

0.40

XI2

5N; 6G; 6J; 6M; 7F; 7I

2 feet

Slow

740

0.27

XII2

7G; 7J; 7L; 8E; 8I

2 feet

Very Slow

1000

0.20

XII2

5O; 6N; 6O; 7M; 7N; 7O; 8J; 8M; 8O

NR3

NR3

NR3

0.00

XIII

9

SUBSURFACE DISPOSAL NOT RECOMMENDED

 

NOTES:

 

1     Limiting layers include fragipans; bedrock; compact glacial tills; seasonal high water table or other soil profile features that will materially affect the absorption of liquid from the disposal field.

 

2     Soils in this group are less than the minimum percolation rate established in Appendix A, Illustration H as suitable for subsurface seepage systems.

 

3     NR = Subsurface disposal system not recommended.

 

(Source:  Amended at 37 Ill. Reg. 14994, effective August 28, 2013)

Section 905.APPENDIX A   Illustrations and Exhibits

 

Section 905.ILLUSTRATION M   Soil Suitability for On-Site Sewage Design

 

Section 905.EXHIBIT B   Key for Determining Sewage Loading Rates (Gallons/Square Foot/Day)

 

Structure and

Parent Material

Single grain; Weak ;

Platy2

Granular, Angular and Subangular Blocky; Prismatic

 

 

Structureless or Massive

Loess: Outwash; Alluvium; Lacustrine8

Till3

Week

Moderate; Strong

Strong

Moderate; Strong

Loess; Outwash; Alluvium; Lacustrine8

Till3

Moist Consistence

lo vfr fr

vfr fr

fi

vfr

fi

vfr fr

fi

fr

fi

vfi

vfr

fr

fi

vfr fr

fi vfi

Texture

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

1.

Fragmental;  Ext. or Very gravelly sand

> 1.004

N/A5

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

2.

Sand; Loamy course sand; Loamy sand;  Gravelly sand; Coarse sand; Gravelly loamy sand

1.00

1.00

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

1.00

N/A

N/A

N/A

N/A

3.

Fine sand; Loamy fine sand; Coarse sandy loam

0.84

0.91

N/A

N/A

N/A

N/A

N/A

N/A

N/A

N/A

0.91

0.84

N/A

N/A

N/A

4.

Sandy loam; Fine sandy loam; Gravelly sandy loam; Gravelly loam; Gravelly silt loam

0.75

0.75

N.A

0.84

N/A

0.69

N/A

N/A

0.75

N/A

0.84

0.75

0.69

0.62

0.52

5.

Loam; Silt loam; Very fine sandy loam; Sandy clay loam; Silt; Very fine sand; Loamy very fine sand; Gravelly clay loam

0.62

0.69

0.62

0.75

0.52

0.456

0.406

0.62

0.52

N/A

0.62

0.52

0.456

0.276

N/R7

6.

Silty clay loam (<35% c); Clay loam (< 35% c)

.052

0.52

0.456

0.62

0.52

0.408

0.276

0.52

0.406

0.276

0.52

0.456

0.276

N/R

N/R

7.

Silty clay loam (>35% c); Clay loam (>35% c)

N/A

N/A

0.406

0.456

0.406

0.276

 

0.206

0.406

0.276

0.206

N/A

0.206

N/R

N/R

N/R

8.

Sandy clay; Clay

N/A

N/A

N/A

N/A

0.206,9

 

N/A

N/A

N/A

0.206,9

N/R

N/A

N/A

N/R

N/A

N/R

9.

Organics; Fragic; Lithic; Paralithic

–––SOIL PROPERTIES HAVE VERY SEVERE LIMITATIONS; SUBSURFACE DISPOSAL NOT RECOMMENDED–––––

 

FOOTNOTES:

 

1      Disturbed soils are highly variable and require special on-site investigations.

2      Moderate or strong platy structure for the soil textures in Groups 4, 5 and 6 have a loading rate of 0.40 g/sq.ft/d.  Platy structure having firm or very firm consistency or caused by mechanical compaction has a loading rate of 0.0 g/sq.ft/d.

3      Basal glacial tills structured by geogenic processes have the same loading rates as structureless glacial till.

4      This soil group is estimated to have very rapid permeability and exceeds the maximum established rate in Illustration H, Exhibit A.

5      N/A means not applicable.

6      These soil groups are estimated to have moderately slow to very slow permeability and are less than the minimum established rate in Illustration H, Exhibit A.

7     N/R means not recommended. These soils have loading rates considered too low for conventional subsurface disposal.

8      In some areas, lacustrine material may have physical properties similar to glacial till and should be placed in the glacial till columns.

9     Non-swelling (1:1 lattice) clays formed in bedrock residuum have a loading rate of 0.27 g/sq.ft/d. Swelling (2:1 lattice) clays are not recommended for subsurface disposal.

 

(Source:  Amended at 37 Ill. Reg. 14994, effective August 28, 2013)