Appendix E: Load Rate Tables

The following tables divide the soils of Indiana by parent materials and horizons. Saturated hydraulic conductivities have been estimated for these soil horizons (updated from Franzmeier et al., 1991 and Franzmeier, 1991). Numbers in bold are the limiting load rate for the soil horizon at the saturated hydraulic conductivity, and at 4 and 7.5 times the load rate for septic tank effluent. Load rate for septic tank effluent has been determined from the following equation where load rate is in gpd/ft2 and Ksat is in cm/day:

Load rate = 0.22 * (Ksat)0.23

This equation is the basis for the load rate table currently used for sizing individual on-site systems.

Loess Parent Material (Miami, Fincastle, Toronto, Clermont, Zanesville, Stendal, Bartle)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
A

1.38

172

5.64

42.24

21.12

0.72

2.88

5.39

E,EB,BE

1.43

112

3.67

27.50

13.75

0.65

2.60

4.88

Bt (SiL)

1.47

89

2.92

21.86

10.93

0.62

2.47

4.63

Bt (SiCL)

1.46

27

0.89

6.63

3.32

0.47

1.88

3.52

Bx

1.53

16

0.52

3.93

1.96

0.42

1.67

3.12

C

1.43

56

1.84

13.75

6.88

0.56

2.22

4.16

 

Loam Till Parent Material (Crosby, Miami, Fincastle, Parr)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 *Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
2Bt or Bt

1.55

18

0.59

4.42

2.21

0.43

1.71

3.21

2 BC or BC

1.54

59

1.94

14.49

7.24

0.56

2.25

4.21

2C or C, non-compact

1.63

34

1.12

8.35

4.17

0.50

1.98

3.71

2C or C, compact

1.86

2

0.07

0.49

0.25

0.26

1.03

1.94

**Note that the limiting load rate as calculated based on saturated hydraulic conductivity will depend upon the level of compaction in the C horizon.

 

Silty Clay Loam or Clay Loam Till Parent Material (Blount, Morley, Glynwood)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
BT or 2BT

1.42

43

1.41

10.56

5.28

0.52

2.09

3.92

C or 2C

1.62

7

0.23

1.72

0.86

0.34

1.38

2.58

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Other Parent Materials

 

Sands (Plainfield, Brems, Morocco, Maumee)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
B

1.48

1970

64.62

483.78

241.89

1.26

5.04

9.45

C

1.56

1474

48.35

361.98

180.99

1.18

4.71

8.84

 

Loamy Sands (Maumee, Newton, Coloma)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
A

1.53

645

21.16

158.39

79.20

0.97

3.90

7.31

B

1.51

960

31.49

235.75

117.88

1.07

4.27

8.01

C

1.54

997

32.70

244.84

122.42

1.08

4.31

8.08

 

Sandy Loams (Gilford, Tracy, Hanna, Fox, Rensselaer)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
A

1.41

573

18.79

140.71

70.36

0.95

3.79

7.11

B

1.51

504

16.53

123.77

61.88

0.92

3.68

6.90

C

1.53

433

14.20

106.33

53.17

0.89

3.56

6.67

 

Sandy Clay Loam (Fox, Tracy, Door, Warsaw)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
A

1.27

375

12.30

92.09

46.05

0.86

3.44

6.45

B

1.52

174

5.71

42.73

21.36

0.72

2.88

5.41

 

Loam (Rensselaer, Door, Strawn, Fox)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
A

1.42

272

8.92

66.80

33.40

0.80

3.19

5.99

B

1.66

29

0.95

7.12

3.56

0.48

1.91

3.58

 

Silt Loam (Miami, Fox, Genesee, Pekin, Vincennes)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
A1

1.17

566

18.56

138.99

69.50

0.95

3.78

7.09

Ap

1.4

116

3.80

28.49

14.24

0.66

2.63

4.92

B

1.47

130

4.26

31.92

15.96

0.67

2.70

5.05

C

1.42

274

8.99

67.29

33.64

0.80

3.20

6.00

 

Silty Clay Loam (Brookston, Chalmers, Pewamo, Zipp)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
A

1.42

56

1.84

13.75

6.88

0.56

2.22

4.16

B

1.44

44

1.44

10.81

5.40

0.53

2.10

3.94

C

1.47

16

0.52

3.93

1.96

0.42

1.67

3.12

 

Clay Loam (Fox, Warsaw, Vincennes)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
B 1.45 46 1.51 11.30 5.65 0.53 2.12 3.98

 

Silty Clay or Clay (Switzerland, Carmel, Eden, Pate)

Kind of horizon Bulk density (g/cm3) Ksat (cm/day) Ksat in ft/day Load rate (from Ksat) gpd/ft2 Load rate/2 (from Ksat) (gpd/ft2) Load rate with mat 4* Load rate with matting 7.5 * load rate with matting
A 1.38 42 1.38 10.31 5.16 0.52 2.08 3.90
B 1.48 5 0.16 1.23 0.61 0.32 1.27 2.39

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An Evaluation of On-Site Technology in Indiana: Table of Contents