In which condition would soil wetness be considered unsuitable based on the depth criteria?

Soil wetness is a critical factor in the suitability of land for septic systems, particularly regarding the depth criteria. The condition where soil wetness is deemed unsuitable is when it is less than 36 inches and shows indications of lateral movement. This scenario suggests that the soil is saturated enough for water to move horizontally, which can lead to a higher risk of groundwater contamination and system failure.

Saturated soils can impede the proper functioning of septic systems because they restrict the natural percolation process necessary for treating effluent. When soil is too wet at a shallow depth, it may not provide an adequate environment for effluent to be effectively filtered and broken down by natural processes, thereby posing a significant risk to public health and the environment.

Conditions greater than 48 inches or between 40 and 48 inches typically indicate adequate depth for drainage, while a depth of exactly 36 inches does not necessarily indicate inadequate drainage. Therefore, the key factor here is the combination of both the shallow depth and the indication of lateral movement—together, they highlight a concerning wetness condition that renders the soil unsuitable for septic installation.