Why is it essential to ensure that backfill material is free of large rocks and debris?

Ensuring that backfill material is free of large rocks and debris is essential primarily because it supports proper drainage and prevents pipe shifting. If large rocks or debris are present in the backfill, they can create voids or uneven surfaces around pipes, which can disrupt the intended flow of water and wastewater. This improper drainage can lead to various issues, such as pipe displacement or stress, causing potential damage or failure of the systems.

Additionally, when the backfill is uniform and free from large objects, it allows for an even distribution of load and pressure around the buried utilities. This not only maintains structural integrity but also helps to avoid future complications related to soil erosion or pipe movement due to shifting ground conditions. Proper backfill practices are critical to maintaining the longevity and effectiveness of wastewater systems.