What occurs to the soil after waste is filled into trenches during the trench method?

When waste is filled into trenches during the trench method, the soil is typically compacted and used to cover the waste. This process serves several important functions. Covering the waste helps to minimize odors and prevent pests from accessing the waste material, as well as reducing the risk of leachate entering groundwater supplies. The compacted soil also aids in the stabilization of the waste, preventing subsidence and promoting controlled decomposition.

In contrast, leaving the soil uncovered for natural decomposition would not effectively manage odors or pests and could lead to environmental contamination. Removing soil completely from the site is impractical and would disrupt the ecosystem of the area, while treating the soil chemically before use is generally not necessary since the soil itself plays a critical role in the natural degradation process. Thus, the compaction and covering of waste with soil is a crucial step in the trench method to ensure effective waste management and environmental protection.