The Ohio Household Sewage Rules require 4 feet of suitable soil for soil absorption systems. In this design example, the silt loam and sandy clay loam layers are considered suitable. The clay loam soil is not suitable due to its fine platy structure. The soil profile indicates 26 inches of suitable soil. The mound sand fill combined with the existing suitable soil must be at least 4 feet.
Mound Sand Fill Upslope Depth = (48 inches) - (Depth of Suitable Soil to Limiting Condition)
Mound Sand Fill Upslope Depth:
| Mound Sand Fill Upslope Depth | = (48 inches) - (Depth of Suitable Soil to Limiting Condition) |
| = (48 inches) - (26 inches) | |
| = 22 inches |