When shoveling from a stockpile, which layer should be sampled?

• A. Top
• B. Middle
• C. Inner
• D. Outer

Answer: (C)

Sampling from the inner layer of a stockpile is essential because it provides a more representative analysis of the material being stored. The outer and top layers can be affected by environmental factors, such as weather or surface contamination, which can skew test results. The middle layer might give some insight, but it still may not reflect the uniformity throughout the entire stockpile.

By selecting the inner layer, one minimizes the influence of external variables that can affect the outer and top layers, such as rain or wind, thereby ensuring that the sample reflects the true composition of the stockpile. This is crucial for accurate assessment and quality control, as it leads to better decision-making based on the actual material used in operations.