How should the site be prepared for the use of fill in a DIS?

The correct approach to site preparation for the use of fill in a Drainage Improvement System (DIS) involves ensuring that there is sufficient fill beneath the tracks to provide stability and support for equipment. A minimum of 6 inches of fill is required beneath the tracks to prevent soil compaction and manage weight distribution effectively. This thickness helps maintain the integrity of the existing soil layers, preventing damage or alteration that could affect drainage capabilities.

Additionally, the site preparation stipulates that rototilling is not permitted. This restriction is in place to avoid disturbing the soil structure excessively, which could lead to drainage issues or soil compaction that negatively affects the performance of the DIS. Furthermore, the requirement for plowing the fill materials perpendicular to the slope is crucial for enhancing drainage patterns and optimizing the performance of the system. This technique aids in preventing water from running parallel to the slope, which can lead to erosion or water pooling in unwanted areas.

In contrast, some of the other options mention different fill thicknesses or allow practices like rototilling that could compromise site integrity and effective drainage, making them less suitable for proper DIS preparation.