What does 'spoil' refer to in excavation?

• A. Material excavated that is unsuitable for reuse and is taken to a spoil area or disposal site
• B. Material suitable for reuse
• C. A type of backfill material
• D. A drainage layer

Answer: (A)

In earthwork, spoil means the waste portion of excavation—material that is not suitable for reuse. This material is removed from the excavation and placed in a designated spoil area or disposal site to keep the worksite organized and to meet project and environmental requirements. The idea is that not all excavated material can or should be reused as fill or backfill, so it’s set aside or disposed of rather than reused.

The other possibilities describe material intended for use in the project (material suitable for reuse as fill), a backfill material used around structures, or a drainage layer component. None of those describe waste excavated material, which is the essence of spoil.