Which term describes the ease at which liquid can move through soil?

The term that accurately describes the ease at which liquid can move through soil is permeability. Permeability refers to the ability of soil or rock to allow water to flow through it. This property is crucial in the context of on-site sewage facilities as it affects how quickly effluent can infiltrate into the soil, which is essential for soil absorption and treatment of wastewater. Understanding permeability helps in selecting appropriate sites for on-site sewage systems and in designing systems that effectively manage effluent without causing saturation or contamination of groundwater.

In contrast, infiltration describes the process of water entering the soil surface, while absorption refers to the uptake of moisture by soil particles or plant roots. Retention, on the other hand, involves the ability of soil to hold water within its structure, which can affect the availability of water for plants but does not directly deal with how easily water can pass through the soil.