Which disposal option is suitable for clay soil?

The correct answer is drip or spray irrigation, particularly in clay soils, because of the unique properties of clay that affect water movement and drainage. Clay soil has a high compactness and a very small pore size, which leads to poor drainage and a slow percolation rate. As a result, traditional methods such as a conventional leach field may not be effective due to the inability of the soil to adequately absorb and process effluent.

Drip or spray irrigation systems are designed to deliver water directly to the soil in a controlled manner. This approach minimizes the risk of waterlogging and allows for better absorption in clay conditions, preventing surface runoff and ensuring that the effluent is efficiently utilized by plants or further treated in the soil. This option helps to leverage the characteristics of clay rather than struggle against them, making it an effective disposal method in these types of soils.

In contrast, options like septic tanks, conventional leach fields, and compost trenches may encounter significant challenges due to the slow infiltration rate of clay, leading to potential system failure or groundwater contamination. Therefore, drip or spray irrigation stands out as the most suitable choice for managing wastewater disposal in clay soil environments.