Which material can support backfill in a gravel system?

In a gravel system used for septic installation, geotextile fabric or biodegradable materials are appropriate for supporting backfill because they provide necessary drainage and filtration while preventing soil and other materials from entering the gravel layer, which could clog the system. Geotextile fabrics are specifically designed to allow water to pass through while retaining soil particles, thereby ensuring the gravel can function properly and maintain its structural integrity.

Biodegradable materials might also be beneficial as they can integrate into the natural environment without causing harm, promoting a more sustainable installation. This approach helps maintain the effectiveness and longevity of the drainage system, ensuring proper functionality over time.

Using materials like plastic, concrete slabs, or steel reinforcements generally do not provide the same level of permeability or support essential for a gravel system, which relies on the ability to let water flow freely while providing structural support. Therefore, geotextile fabric or biodegradable materials are the optimal choice for backfill in a gravel septic system.