What determines the backfill grade for a trench?

• A. By available backfill
• B. The specifications
• C. By guessing
• D. The type of soil

Answer: (B)

Backfill grade is set by the project specifications. Those specifications spell out how the trench must be filled, compacted, and finished to restore support and proper drainage, ensuring the trench remains stable after restoration. They specify the target compacted density (like a percentage of maximum dry density), allowable moisture content, and the lift thickness for each layer. The actual soil type influences how you achieve that grade (moisture adjustments, equipment, and compaction methods), but it doesn’t decide the grade itself. Relying on whatever material is available or guessing won’t meet the required criteria, and the grade must align with the documented specs to ensure long-term performance.