What is a key indicator of potential drainage issues in soil analysis?

A mottled soil appearance is indeed a key indicator of potential drainage issues during soil analysis. This appearance, characterized by the presence of different colors or patterns in the soil, usually indicates variations in moisture levels and soil saturation. Mottling typically occurs in soils that experience alternate cycles of saturation and drying, reflecting irregular drainage patterns. These patterns suggest that the soil may not drain effectively, which can lead to waterlogging or the inability to adequately absorb effluent from on-site sewage facilities.

Uniform soil texture, while suggesting a consistent type of soil, does not necessarily provide information about drainage capabilities. High organic content can contribute to soil health and nutrient retention but does not inherently indicate drainage problems. Sandy composition, on the other hand, typically suggests better drainage properties due to the larger particle size, allowing water to flow through more easily. However, if saturated conditions are present, sandy soils can also lead to rapid drainage without the necessary retention of moisture for wastewater treatment. Thus, mottled soil appearance serves as a more definitive signal of potential drainage issues, making it crucial for evaluating soil suitability for on-site sewage systems.